Second generation transport biofuels – a mission to the ... second... · generation biofuels. A number of European countries are pioneering the development of next generation biofuels,

GLOBAL WATCH MISSION REPORT

Second generation transportbiofuels – a mission to theNetherlands, Germany andFinland

MARCH 2006

Global Watch Missions

DTI Global Watch Missions enable small groups ofUK experts to visit leading overseas technologyorganisations to learn vital lessons about innovationand its implementation, of benefit to entire industriesand individual organisations.

By stimulating debate and informing industrialthinking and action, missions offer uniqueopportunities for fast-tracking technology transfer,sharing deployment know-how, explaining newindustry infrastructures and policies, and developingrelationships and collaborations. Around 30 missionstake place annually, with the coordinatingorganisation receiving guidance and financial supportfrom the DTI Global Watch Missions team.

Disclaimer

This report represents the findings of a missionorganised by the National Non-Food Crops Centre(NNFCC) with the support of DTI. Views expressedreflect a consensus reached by the members of themission team and do not necessarily reflect those ofthe organisations to which the mission membersbelong, NNFCC or DTI.

Comments attributed to organisations visited duringthis mission were those expressed by personnelinterviewed and should not be taken as those of theorganisation as a whole.

Whilst every effort has been made to ensure that theinformation provided in this report is accurate and upto date, DTI accepts no responsibility whatsoever inrelation to this information. DTI shall not be liable forany loss of profits or contracts or any direct, indirect,special or consequential loss or damages whether incontract, tort or otherwise, arising out of or inconnection with your use of this information. Thisdisclaimer shall apply to the maximum extentpermissible by law.

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Second generation transport biofuels:

– a mission to the Netherlands, Germany and Finland

REPORT OF A DTI GLOBAL WATCH MISSION

MARCH 2006

CONTENTS

ACKNOWLEDGMENTS 4

EXECUTIVE SUMMARY 5

1 INTRODUCTION 10

1.1 Background 101.2 Limitations of first generation 10

biofuels1.3 Second generation biofuels 111.4 Biofuels in context 13

2 CURRENT STATUS OF 14UK BIOFUELS

2.1 Legislation and government policy 14 2.2 Biofuels 152.3 UK production facilities 152.4 Biofuel production 152.5 Limitations 16

2.5.1 Fuel standards 162.5.2 Available land 162.5.3 Cost 172.5.4 Environmental impact 182.5.5 Availability of technology 18

3 THERMAL BIOMASS 20CONVERSION TECHNOLOGIESFOR TRANSPORT FUELS

3.1 Pyrolysis 213.1.1 Fast pyrolysis 21

3.1.1.1 Principles 213.1.1.2 Reactors 223.1.1.3 Pyrolysis liquid – bio-oil 243.1.1.4 By-products 24

3.1.2 Bio-oil upgrading 253.1.3 Intermediate and slow pyrolysis 26

3.1.3.1 Screw pyrolysis 263.1.4 Torrefaction 263.1.5 Transport fuels from bio-oil 27

by upgrading

3.1.5.1 Hydrotreating using 27traditional hydro-desulphurisation catalysts

3.1.5.2 Hydrotreating of 28separated product

3.1.5.3 Zeolite cracking 283.1.5.4 Gasification of bio-oil 28

and synthesis of transport fuels

3.2 Liquefaction 283.3 Gasification 29

3.3.1 Status of biomass 29gasification technology

3.3.2 Synthesis gas quality 313.4 Synthesis of transport fuels 313.5 Bioenergy system 343.6 Bibliography of further reading 35

4 ENGINEERING, PLANT DESIGN 36AND TECHNICAL ISSUES

4.1 Towards commercial scale biofuel 36plants

4.2 BTL plant design 364.2.1 Biomass feedstocks 364.2.2 Biomass pretreatment 364.2.3 Conversion 37

4.3 BTL development considerations 384.4 Technical issues in BTL 424.5 Catalysts 42

4.5.1 Conditioning of the gas 434.5.2 Removal of trace impurities 434.5.3 Downstream synthesis 43

4.6 Risk sharing 444.7 Summary 45

5 IMPLICATIONS FOR ENGINE 46MANUFACTURERS

5.1 The internal combustion engine’s 46contribution to reducing CO2

emissions

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SECOND GENERATION TRANSPORT BIOFUELS: – A MISSION TO THE NETHERLANDS, GERMANY AND FINLAND

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5.2 First generation biofuels 465.3 Second generation biofuels 475.4 Impact on conventional 47

compression ignition (diesel) engines

5.5 Impact on compression ignition 48(diesel) strategies for future emission standards

5.6 Quantifying impact of new fuels 49

6 FEEDSTOCK AND A 50SUSTAINABLE SUPPLY CHAIN

6.1 Introduction 506.2 Feedstock potential 506.3 Available feedstocks 51

6.3.1 Industrial waste 516.3.2 Agricultural and forestry 51

residues6.3.2.1 Straw 526.3.2.2 Woodfuel 526.3.2.3 Wet agricultural 52

residues6.3.3 Dedicated energy crops 53

6.3.3.1 Perennial grasses 536.3.3.2 Short rotation coppice 53

(SRC)6.3.3.3 Oil palm co-products 546.3.3.4 Microalgae 55

6.4 Supply chains 566.4.1 Biomass sources 576.4.2 Logistics and storage 57

6.5 Summary 58

7 ENVIRONMENTAL IMPACTS 59

7.1 Background 597.2 CO2 emissions 597.3 Other air pollutants 617.4 Land 617.5 Water 627.6 General considerations 62

8 ECONOMICS, SOCIO- 64ECONOMIC BENEFITS ANDCOSTS

8.1 Overall economics 648.1.1 Comparison with GTL 64

and CTL8.1.2 ECN economic data 658.1.3 Synthetic diesel from BTL 65

8.2 Socio-economic benefits 658.3 Commercial concepts 65

8.3.1 Small scale production 668.3.2 Large scale centralised 66

conversion plant8.3.3 Biorefineries 67

8.4 Barriers and issues for second 68generation biofuels8.4.1 Feedstock availability and 68

costs8.4.2 Transport issues 688.4.3 Conversion costs 69

8.5 Summary 69

9 POLICY AND INCENTIVES 71

9.1 Scenarios 719.1.1 UK biomass for UK biofuel 71

production9.1.2 UK processing of imported 72

biomass9.1.3 UK import of synthetic 73

biofuels9.2 Potential deployment of second 74

generation technology9.3 Existing policy measures and 74

impact on encouraging secondgeneration technologies

9.4 Proposals to encourage second 75generation biofuels9.4.1 Linking support to GHG 75

benefits

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10 CONCLUSIONS 77

10.1 General 7710.2 Feedstock 7710.3 Process technologies 7810.4 Economics 7810.5 Policy 79

11 RECOMMENDATIONS 80

11.1 General 8011.2 Feedstock 8011.3 Process technologies 8011.4 Economics 8011.5 Policy 80

APPENDICES 82

A Visit reports 82B Mission team and ITP 103C Current UK biofuel support 106

instrumentsD Glossary 107E Some figures and conversion 112

factorsF List of exhibits 113

ACKNOWLEDGMENTS

The mission team would like to express itssincere thanks to the many individuals andbodies that made this mission possible:

• The UK Department of Trade and Industry(DTI) Global Watch Service that providedthe financial support

• The National Non-Food Crops Centre(NNFCC) that acted as the principalcoordinating body for this mission

• The DTI International TechnologyPromoters (ITP) network, and particularlythe ITP for Environmental and SustainableEnergy Technologies in Europe, NicolaSmoker

• Stephen Conlon, Deputy Head of Trade andInvestment and Kirsi-Mari Sykes of theBritish Embassy, Helsinki

• Hugh Ellis, Senior Trade Adviser of theBritish Embassy, The Hague

• Andie Killick of the Saxony State Ministryfor Economic Affairs and Labour

• Kerstin Rath of the British Embassy, Berlin

• All the individuals and companies the teamvisited, for an open and constructiveexchange of information and for the timethat they devoted

EXECUTIVE SUMMARY

Second generation transport biofuels offer anumber of key benefits over bothconventional fossil transport fuels and thecurrent generation of biofuels. These benefitsinclude the ability to achieve significant ‘well-to-wheel’ reductions in greenhouse gas(GHG) emissions, combined with dramaticallyreduced land requirements compared withfirst generation biofuels since most biomass,including many organic wastes, can be usedas feedstock. Additionally, second generationbiofuels are better internal combustion (IC)engine fuels than first generation fuels sincethey shouldn’t present any of the technicalproblems of degradation and materialincompatibility associated with firstgeneration biofuels. A number of Europeancountries are pioneering the development ofnext generation biofuels, and the firstdemonstration plants are now beginning toappear.

A DTI Global Watch Mission to Finland, theNetherlands and Germany in March 2006evaluated the status of research anddevelopment (R&D) and likely time scales tocommercialisation of next generationtechnologies, specifically thermal and relatedcatalytic technologies, and identified some ofthe main barriers to exploitation and how theymight be addressed.

Many of the underpinning technologies wereseen to be well understood, although inadjacent applications, and much R&D work isnow being undertaken to address their usefor the efficient production of biofuels. Ahistory of gasification of lignite in the formerGerman Democratic Republic (GDR) for theproduction of coal gas has left a valuablelegacy of expertise in this area. This know-how is now being developed for the

gasification of biomass and also severalclasses of organic and municipal waste inseveral institutes and companies. While muchof the basic technology is similar, and manytechnological barriers have been successfullyovercome, some issues such as adequategas clean up to remove the greater level oftar from the biomass derived syngas stillremain to be proved. One of the keytechnologies, Fischer-Tropsch (FT) synthesis,is well established in gas to liquid (GTL) andcoal to liquid (CTL) applications for theproduction of liquid fuels, but with fewcommercial plants. Following cleanup thereare negligible differences between syngasfrom different feedstocks.

The first steps towards commercial use ofthese technologies with biomass feedstockare now being taken, with Choren Industries'construction of its 13,000 tonnes per year(t/y) SunDiesel beta plant, and plans for200,000 t/y gamma plants. Even these,however, are still relatively small scale in thecontext of transport fuel requirements, andscaling to commercial sized plants remains tobe demonstrated.

Many of the technologies have beendemonstrated individually and the mostsignificant issues to be addressed appear tobe non-technical. Adequate, consistent,efficient feedstock supply for commercialscale plants will be a serious issue, and anumber of organisations are modelling thebiomass supply chain to optimise financial,carbon and energy costs. For countries withrelatively low levels of forestation, like the UK(and the Netherlands), the necessity ofefficient transportation of biomass, potentiallyfrom overseas, is prompting research intoprocesses for the densification of biomass.

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Torrefaction and flash pyrolysis are both beingdeveloped for this purpose, and theirefficiency modelled. Torrefaction yields a solidproduct, more readily ground than rawbiomass and then easily incorporated intoexisting coal handling systems, while flashpyrolysis yields a more energy dense bio-oilthat requires specialised handling andgasification.

For UK grown feedstock, for whichharvesting, handling and transport costs formthe major cost component, feedstock costsare expected to account for a significantproportion of the final costs of secondgeneration biofuels. The other majorcomponent, however, is the capital cost ofthe gasification and FT plant. Powerfuleconomies of scale for the technologies,together with the requirement for largevolume processing if biofuels are to form asignificant proportion of the road transportfuel supply, demand that plant be as large aspossible, with feedstock supply and logisticslikely to form the limiting constraints. Capitalinvestment of the scale of €2-3 billion (~£1.4-2.1 billion) will be required, not onlycontributing heavily to the product costs, butalso presenting a major investment risk. Thisis a significant barrier to exploitation of thesetechnologies, and until incentive mechanismsare in place that recognise the differentialGHG benefits over first generation biofuels,there is no incentive to commit to such amajor investment when smaller scale firstgeneration plant can be built for a fraction ofthe capital outlay.

One approach to the relatively high cost ofbiomass feedstock is to make use offeedstock that carries a negative market cost,for which there is the requirement fordisposal, such as organic waste and sewagesludge. Many of these have a high watercontent, making them unsuitable forgasification without (financially andenergetically) costly drying. To make use ofthese feedstocks, hydrothermal upgrading

(HTU) and supercritical gasification are in theearly stages of development and require thefeedstock in a pumpable, aqueous slurry.Other approaches to reduce cost includeadopting simplified refinery type processes(such as hydroprocessing/hydrocracking) ofbiomass derived liquids together with catalystdevelopment. The adoption of the biorefineryconcept, with co-production of high valuechemicals, might be another route toimproved financial viability.

The level of activity in the three countriesvisited was impressive, on a range of scalesfrom small and medium sized enterprises(SMEs) to large national research institutesand major multinationals. This was felt to bein sharp contrast to the situation in the UK.The UK is felt to be in the lead, though, inresearch into dedicated, high yield energycrops, a topic that appears to have attractedlittle interest elsewhere, especially in Finlandand Germany. As these countries have largeforestry resources this is not surprising.

In the Netherlands there has been researchon microalgae and seaweeds as potential,extremely high output biomass feedstockwith minimal land and fresh water demand;however, predicted costs are currently high. Asignificant difficulty with microalgae andseaweeds is the high water content. Thiscauses difficulties both for handling andtransport efficiency, and for conventionalgasification, which requires low moisturecontent. HTU or supercritical gasification mayagain be suitable processing technologies forthese materials.

The two key issues to be addressed ifwidespread second generation biofuelproduction is to be achieved in the UK arefinance and feedstock. With the presentmechanisms of both the Renewable TransportFuels Obligation (RTFO) and the EU BiofuelsDirective, which are based on a volume orenergy basis respectively, there is noincentive for the massive investment required

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for second generation technologies over firstgeneration ones, despite the significantlysuperior GHG (and other) benefits of theformer, and the feedstock limitations of thelatter. A mechanism that recognised thedifferential GHG benefits over first generationbiofuels could, however, potentially providethe necessary incentive for investment insecond generation technologies.

The development of an integrated biomasssupply chain in the UK is critical for both this,and other biomass applications. The firstround of the Bio-energy InfrastructureScheme is acknowledged and was welcome;however, the available funding (£3.5 million)was very limited, and the application windowrestrictive. It is hoped that the proposedsecond round can be more generous on bothcounts. Government support for biofuelsshould be considered alongside that for otherbiomass heat and power initiatives, and theoptimum use made of available biomassresources and infrastructure. However, thefeedstock requirements for significantbiofuels penetration into the transport fuelsmarket are considerable and, with the scaleof plant required for economic operation,bring unique issues. It must beacknowledged that international trade inbiomass for energy applications is already areality and must not be encumbered;importation of pretreated biomass couldprovide a way forward for the UK.

Three potential scenarios for UKimplementation of second generation biofuelstechnologies arise:

• It would be possible to build a UK industrybased on second generation biofuelsproduced in the UK from UK biomassfeedstocks. However, the scale ofproduction necessary both for significantbiofuel penetration into the transport fuel

market and for the economies of scalenecessary for economic production, meanthat the feedstock demand for a singleplant would be likely to be of the order of1-5 million t/y. This would represent asignificant proportion of the total availableUK biomass resource1, and to attempt togather all this to a single site would entail amassive logistical undertaking, andsignificant pressure on the transportinfrastructure. However, significantacreages of high yield energy crops mightmake this more feasible.

• A second scenario would see large scalesecond generation biofuel production plant,located on a sea port, and using importedbiomass feedstock. It is likely that asignificant proportion of this feedstockwould consist of low cost residue or wastematerial, and in order to improve bothfinancial and energetic economics, variousdensification strategies such as torrefactionor flash pyrolysis might be employed.

• The third strategy is the ultimate extensionof the second in that the biomass isimported in the most energy dense formpossible, namely as the finished biofuel,with large scale production plantconstructed in close proximity to regions ofhigh feedstock availability.

Second generation biofuels presentsignificant potential carbon reduction andsocio-economic benefits, and no insuperabletechnical hurdles. The scale of plant requiredfor economic operation, however, bringscertain practical issues if the potential is tobecome a reality in the UK. Overall, the focusin the UK should be on accelerating theimplementation of commercial, secondgeneration biofuels.

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1 Woodfuel Resource in Britain report, December 2003, The Forestry Commission

RECOMMENDATIONS

General

The nature of an integrated bioenergy chainfor production of renewable transport fuelsrequires close integration of biomassproduction, biomass conversion and fuelsynthesis. The relevant governmentdepartments, namely the Department forEnvironment, Food and Rural Affairs (Defra),DTI and the Department for Transport (DfT),should place a high priority on establishing aneffective cross-department task force tooversee this development and hence ensurethat the UK meets its aspirations for climatechange mitigation measures as well ascapturing wealth creation opportunities.

Feedstock

Biomass producers need to developfeedstock supply chains and optimisebiomass production to deliver maximum GHGbenefits. Coordination by government andlinking with the process technology andengine developers will be required.

International trade in biofuels and feedstocksis likely to be of great importance and shouldcontinue unhindered. Sustainability andenvironmental impact issues must becovered in accreditation criteria.

Process technologies

The UK should take a lead on implementingsecond generation technologies that offerhigh GHG reduction potential. One way toachieve this would be to establish aconsortium involving industry, biomassproducers and governments. The biorefinerymodel is one in which there remains thepotential for the UK to establish aninternational lead with appropriate fundingand prioritisation.

A comparative analysis of the alternativeprocessing routes would help identify themost promising technologies for transportfuels. The UK needs to build some capacity inunderstanding the science and technology(S&T) of transport fuel production frombiomass.

R&D into technologies for economically viabletransport fuel production at smaller scales tobetter match biomass resource availabilities inthe UK should be funded.

Economics

The very high capital expenditure required forbiomass to liquid (BTL) plant presents majorfinancial risk, making such major investmentsunlikely in the short to medium term withoutsignificant incentives. Government policies tomitigate such large investment risks shouldbe investigated. Mechanisms such as grantsor loans, with repayment schedules linked tosuccess, to assist in the development of suchtechnologies on a commercial scale, orenhanced capital allowances (ECAs), might beconsidered.

Policy

The UK has limited land resources that needto be optimised for food, materials andenergy production. All decision making shouldbe undertaken with consideration thatavailable limited land resources need to beused as effectively as possible.

Government policy for encouraging biofuelsneeds to change from a volume/energy basis toa GHG reduction basis. In this way, optimumchoices of feedstock and technologies will bepreferred by the market. The UK should attemptto use its influence in the EU to ensure policymechanisms focus on GHG reduction.

Policies to encourage the increased use ofbiofuels should be linked to environmentalsustainability standards.

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Government support for second generationbiofuels should be considered in conjunctionwith other UK biomass heat and powerinitiatives to ensure optimum integration ofinfrastructure, including the feedstock supplychain. Consideration of alternative uses for

the available biomass resource should alwaysbe included in any decision making process,and there should be meaningful discussionbetween UK government and industry on therole of second generation biofuels in the UKenergy mix.

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Exhibit S.1 Mission team outside the new Choren Beta plant (L-R): Tony Bridgwater, Geoff Hogan, Bob Saunders, David Bown, Anton Zimmermann, Warren Smith, Craig Jamieson, Nicola Yates, Nicki Smoker, Ian Barton

1 INTRODUCTION

1.1 Background1.2 Limitations of first generation

biofuels1.3 Second generation biofuels1.4 Biofuels in context

1.1 Background

Road transport represents 22% of UK carbondioxide (CO2) emissions2 and is the onesource that has been consistently rising since1990, despite significant efficiencyimprovements by vehicle and enginemanufacturers. In an interview with Reutersin May 2006, Richard Kinley, Officer-in-Chargeof the UNFCCC (UN Framework Conventionon Climate Change) said:

‘Transport is the worst offender for releasinggreenhouse gases into the atmosphere andgovernments must do more to cut emissionsfrom cars and trucks.’

However, personal transport is a politicallyhighly charged issue in the UK, as was seenby the September 2000 fuel protests, and ahigh energy density, portable power sourcewith low carbon emissions represents a vitalgoal, both for the UK and globally, if GHGemissions are to be constrained withoutmajor restrictions on personal mobility. Fuelcells and the hydrogen economy representone potential solution; however, they remainstubbornly the long term option and interimsolutions are required to reduce GHGemissions from road transport long beforethe fuel cell solution will be available.

A future shift to a hydrogen/fuel cell economywill require a concurrent replacement of both

vehicles and fuel supply infrastructure once allrelevant technologies are sufficiently mature.Such simultaneous introduction of bothtechnology and enabling fuel supplyinfrastructure is difficult to manage smoothly,typically leading to a transitional ‘chicken andegg’ situation with investment in eachattempting to wait for significant rollout in theother. This can significantly delay uptake of atechnology after it is technically ready foradoption. Interim solutions that do not requireextensive simultaneous upgrading ofinfrastructure are therefore vital, and thisstrongly suggests that the short to mediumterm focus should rest on conventionalhydrocarbon fuels such as diesel andgasoline.

For maximum ease of introduction, andminimal engine and infrastructure adaptation,therefore, low carbon liquid fuel, ie fuel thatoffers significantly reduced life cycle GHGemissions, that can be used by existing ICengines with the minimum of modification,and that can be readily handled anddistributed by the current transport fueldistribution infrastructure, is the preferableoption. In addition, such fuels should beobtainable on a renewable basis.

Renewable, liquid transport fuels that offercarbon reduction benefits in comparison withfossil fuels do already exist, in the forms ofbioethanol (and derivatives, such as ETBE –ethyl tertiary butyl ether) for gasoline engines,produced via fermentation of sugar or starch,and biodiesel for diesel engines produced bytransesterification of vegetable oils or animalfats. These are often referred to as firstgeneration biofuels.

1.2 Limitations of first generation

biofuels

First generation biofuels are derived fromrenewable, plant based feedstock and

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2 Defra, 2004

typically represent lower carbon fuels thantheir fossil equivalents, owing to the CO2

uptake of the growing plants. However, thebenefits they offer are limited. As bothconventional bioethanol and biodiesel areproduced from high level outputs of plants –sugar from beet or cane, starch from cereals,or vegetable oils – fuel output per hectare(ha) of land is relatively low. With total UKroad transport consuming 37.8 million tonnes(t) of petroleum products per year3, 12.3 million ha of land would be required forrape cultivation, plus 7.8 million ha of sugarbeet production to meet current usage levels.Since the total area of arable land in the UK is6.5 million ha, first generation biofuelsproduced from UK grown feedstock can dolittle more than scratch the surface of UKroad transport fuel requirements, purely onthe basis of land availability. GHG emissionreductions from first generation biofuels arealso variable and in many cases modest dueto the impacts of fertilisers, harvesting,transporting and processing large quantitiesof plant material to obtain relatively smallamounts of biofuel.

Sugar cane and oil palm can producesignificantly greater outputs per hectare, sointernational trade in feedstock and/ormanufactured biofuels might help to addressthis land availability issue to a small extent;however, the environmental impacts ofsufficiently widespread planting of dedicatedfuel feedstock crops globally, together withthe socio-economic impacts of turning overvast tracts of arable land from foodproduction to fuel production, would bequestionable on a number of counts.

Although used vegetable oil (UVO) can beused as a feedstock for the production ofbiodiesel there is a limited total volumepotential (a maximum of around 100,000tonnes per year (t/y) of diesel in the UK4), andvariability of this feedstock makes it more

difficult to ensure that the product meetsappropriate standards (EN14214 in the EU)than when using virgin vegetable oil. It is vitalthat public confidence in biofuels is notdamaged by a small proportion of poor qualityproduct; the impact of a small number ofnegative experiences will havedisproportionately greater impact than a farlarger number of good experiences.

First generation biofuels therefore cannotoffer a long term solution to growing GHGemissions from transport. However, bothethanol and FAME (fatty acid methyl ester)biodiesel processing technology is wellestablished and relatively simple. Firstgeneration biofuels can be seen asrepresenting a valuable first step in raisingpublic and industry awareness and exploringthe regulatory, fiscal, handling, blending anddistribution issues associated with theintroduction and promotion of a proportion ofbiofuels into the current distributioninfrastructure, while achieving valuablereductions in GHG emissions. Many firstgeneration biofuels also offer significantancillary benefits including no sulphurcontent, improved lubricity over ultra lowsulphur diesels, and significantly reducedparticulate, nitrogen oxide (NOx) and carbonmonoxide (CO) emissions.

The characteristics of, and issues associatedwith, first generation biofuels are discussedin greater detail in Chapter 2.

1.3 Second generation biofuels

The promise of second generation biofuels isto offer a transport fuel with lower land useimplications and improved GHG reductionperformance, preferably at lower cost.

The principal difference between secondgeneration biofuels and first generationbiofuels is the ability to make use of a wide

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3 DfT, 2004

4 British Association for Bio Fuels and Oils (BABFO)

range of biomass rather than just the oils,sugars and starch components. Thesesources include non-food biomass, dedicatedenergy crops, and biomass resourcescurrently viewed as residue such as strawand forestry thinnings. Second generationbiofuels may also be chemically different fromtheir first generation alternatives, offeringperformance or emissions benefits, or theymay be the same. Synthetic diesel can beboth superior to (eg cetane number, heatingvalue, stability, sulphur content etc) and,critically, a more consistent product than firstgeneration biodiesel or the productsobtainable from petrochemical refining;however, second generation (lignocellulosic)bioethanol is chemically identical to thatcurrently available. Environmentally, however,the principal differences between first andsecond generation biofuels are in thefeedstock, and consequently land useimplications, well-to-wheel GHG emissionsand in the required conversion processes.

Development of technologies for theproduction of second generation fuels isalready well advanced in some areas, thoughat an earlier stage in others, and significantadvances on first generation fuels in theimportant areas are potentially realisable.

Studies such as that performed by Woodsand Bauen5 at Imperial College, London, aspart of the DTI New and Renewable EnergyProgramme, review the technology status ofa range of renewable transport fuels andcompare the likely costs and GHG emissionreductions of each technology. The benefits ofsecond generation technologies may beclearly seen.

Technologies for the production of secondgeneration biofuels can broadly be dividedinto:

• Those employing biological and enzymaticprocesses, predominantly yieldingbioethanol from cellulosic feedstock, egusing enzyme or acid hydrolysis (notconsidered in this mission)

• Those making use of thermal andassociated catalytic technologies for arange of biofuels, including synthetic dieseland gasoline (the focus of this mission)

Thermal technologies have the advantage ofallowing the production of hydrocarbons thatare completely compatible with conventionalfuels for reasons of infrastructure and fuelmixing. In addition, thermal processes can beused to produce both diesel and gasolinesubstitutes.

Thermal technologies for the production ofsecond generation biofuels include:

• Gasification of biomass for the generationof synthesis gas

• Pyrolysis, particularly flash pyrolysis, for theproduction of pyrolysis oils or pyrolysisoil/char slurries as energy carriers

• Hydrothermal upgrading (HTU) of wetbiomass

• Fischer-Tropsch (FT) synthesis ofhydrocarbons from synthesis gas withassociated upgrading and refiningprocesses

• Synthesis of methanol followed bygasoline and/or diesel synthesis by MOGD(methanol to olefins, gasoline and diesel)or MTG (methanol to gasoline)

Ancillary topics such as choice of feedstock,novel feedstocks and supply chain issues, thebiorefinery concept, and work on analysis of

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5 Woods and Bauen, 2003; URN 03/982

environmental and financial impacts, and theiroptimisation, are all considered.

The term biomass to liquid (BTL) when usedin this report will specifically refer to thegasification of biomass followed by FTsynthesis of liquid biofuels.

In addition, the hydrogenation of vegetableoils may be considered as having some of thecharacteristics of these second generationprocesses in that it produces a product withsuperior properties to conventional biodieseland some environmental benefits (in reducednet carbon and other emissions) comparedwith transesterification. The product is alsototally compatible with conventional diesel inall proportions. However, as it uses vegetableoil feedstock, albeit potentially a wider rangethan is suitable for biodiesel, rather than moregeneral biomass, it cannot be regarded as agenuine second generation process by thecriteria employed here, but it maynevertheless have a useful role to play.

The thermal technologies for the productionof second generation biofuels of interest tothis mission are described in greater detail inChapter 3.

1.4 Biofuels in context

The primary purpose for introducing biofuelsis to reduce net global GHG emissions, notjust to reduce CO2 emissions from roadtransport, or even just to reduce UK carbonemissions. Technologies that may work in onecountry, therefore, may not be relevant to theUK if the net effect is an increase in GHGemissions (potentially elsewhere) because ofthe energetic inputs required for transport,processing or fertiliser requirements. It mayalso be appropriate to include considerationof other significant benefits of biofuels, suchas domestic energy security, local (especiallyurban) air quality, rural regeneration anddiversification, biodiversity, production of by-products, public education and motivation, or

as an intermediate step to developinfrastructure, methodology, expertise, fiscalor regulatory mechanisms. However, it isimportant to maintain a clear understandingof the motivations and ensure that theoptimum route is being chosen to achieve theintended goals. In particular it is vital toconsider whether technologies or strategieschosen represent the optimum use of theresources that will be required, whetherfinancial, land use, available biomass,research resources, social capital ormanpower and either nationally or globally.

In order to achieve this broad perspective onthe technologies the mission was to address,it was necessary to recruit a team with awide range of backgrounds and expertise. Aswell as the S&T of the processes, theengineering and catalysis aspects, feedstockand its supply chain and environmentalconsiderations, and the implications forengine development would all need to beaddressed. A team with the expertise toconsider all these aspects was thereforeselected, and the names of the teammembers and the organisations representedare listed in Appendix B.

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2.1 Legislation and government policy 2.2 Biofuels2.3 UK production facilities2.4 Biofuel production2.5 Limitations

2.5.1 Fuel standards2.5.2 Available land2.5.3 Cost2.5.4 Environmental impact2.5.5 Availability of technology

The UK Government has decided to put theUK on a path to reduce UK emissions of CO2

in 2050 to around 60% of the 1990 level.Road transport will have to contributetowards meeting this target. Governmentexpects to achieve this by a combination ofimproved vehicle efficiency and biofuels, as ablend in petrol and diesel, and possibly otherrenewable fuels.

2.1 Legislation and government policy

The EU Biofuels Directive 2003/30/EC setindicative goals for the adoption of biofuelsas:

• 2% of road fuel energy content by the endof 2005

• 5.75% by the end of 2010

A wide range of gaseous and liquid road fuelsderived from biomass can be used to meetthe indicative goals. Each member state hasto set its own targets within this framework.For 2005 the UK set a target of 0.3% (byenergy) of fuel sales, well below theindicative figure in the Biofuels Directive. TheUK has set a 5% by volume (3.8% by energycontent) target for 2010 as well as settinginterim targets for 2008 and 2009. Exhibit 2.1indicates the biofuel requirement to meet theBiofuels Directive indicative target.

The Government is taking concrete measuresto encourage the use of biofuels for roadtransport. Budget 2006 confirmed that the 20pence per litre (p/l) duty incentive in favour ofbiodiesel and bioethanol has been guaranteeduntil at least 2008. The Government willimplement the application of enhanced capitalallowances (ECAs) to support investment in themost environmentally beneficial biofuelprocessing plants. Further work on the detailsof an ECA scheme was announced in Budget2006. In addition, the 2004 Energy Act containsenabling legislation for the introduction of aRenewable Transport Fuels Obligation (RTFO)which will require companies to providebiofuels as a given percentage of their totalsales, or pay the buyout price. The basis and

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2 CURRENT STATUS OF UK BIOFUELS

Fuel Sales (Nov 03-Oct 04)(Mt/y)

Energy content(GJ/t)

Energy(PJ/y)

5.75% of energy(PJ/y)

Biofuelsrequired(Mt/y)

Petrol 19.165 43.99 843 48.5Diesel 18.570 42.82 795 45.7

Total 94.2Bioethanol 26.8 48.5 1.81Biodiesel 36.8 45.7 1.24

Total 94.2 3.05

Exhibit 2.1 Biofuels required in the UK to meet the 2010 indicative value of 5.75% by energy content of EUBiofuels Directive 2003/30/EC

feasibility of a RTFO has been examined by aGovernment interdepartmental committee;draft legislation is being developed with the aimof being in place from 2008.

The carbon saving and cost varies significantlybetween the various biofuel options. The netGHG emissions will vary with the crop orwaste chosen as the feedstock, the agriculturalsystem used to grow it, conversion technologyused to process it and how efficiently thebiofuel is used. While the RTFO is a valuabletool, both it and the EU Biofuels Directive arenon-specific about the biofuels to besubstituted and there is currently no incentiveto achieve the greater GHG savings associatedwith second generation biofuels in the face ofthe massive capital investment required.

2.2 Biofuels

Biofuels produced in the UK and across the EU are currently manufactured fromtraditional food crops, although their use inthe UK at present is limited. Their current useis more widespread in a number of othercountries, so experience to guide theirsuccessful introduction in the UK is available.

Conventional biodiesel (FAME) is relativelyeasy to incorporate into diesel blends.Ethanol requires special handling anddistribution due to its high blending vapour

pressure and affinity for water. ETBE, which ismade from bioethanol, eliminates theseproblems but raises concern over watercontamination, similar to that experiencedwith MTBE (methyl tertiary butyl ether) in theUSA. However, ETBE is safely used in manycountries, including France, and is likely to beused to replace current MTBE production.

2.3 UK production facilities

Current UK biofuels production is in afledgling status with two large scale biodieselplants in operation, plus a number of smalldemonstration projects. However, there areapproaching 300 micro scale producers andblenders. These are all biodiesel, largelyprocessing used cooking oil and blendingsmall volumes to supply a local market.

There have been a number ofannouncements to build conventional biofuelplants in the coming years and these arelisted in Exhibit 2.5.

2.4 Biofuel production

In the short to medium term, conventionalbiofuels (bioethanol and FAME) are likely toform the bulk of biofuels used in roadtransport. They will either be produced in theUK from conventional crops (grains, sugarbeet, oilseeds) and perhaps straw, or imported.Replacing 5.75% of the energy content ofcurrent UK petrol and diesel sales withbioethanol and FAME from conventional cropswould require around 1.3 million ha of land.6

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Biofuel Crop/feedstock Production processEthanol Sugar beet, sugar

cane, wheat,maize etc

Fermentation

ETBE Made frombioethanol

Reaction withisobutene

FAME(biodiesel)

Rape, soya, palm,used cooking oiletc

Transesterificationwith methanol

Diesel Rape, soya, palmetc

Refineryhydrotreater

Year Petrol Diesel Biofuels2001-2 28,229 19,110 02002-3 27,837 20,102 52003-4 27,407 21,230 222004-5 26,540 22,395 35

Exhibit 2.2 Examples of current biofuels and theirproduction processes

Exhibit 2.3 Total sales (millions of litres) of petrol,diesel and biofuels in the UK

6 See Exhibit 2.6. (1) This corresponds to an average biofuel yield of around 1.75 t/ha which is the middle of the 1.5 to 2.0 t/ha range quoted by BABFO; (2) Thedata used are from well-to-wheel studies published by Sheffield Hallam and Imperial College Centre for Energy Policy and Technology (ICCEPT) and DTI’sestimate of fuel sales; (3) This area could be reduced by utilising currently exported wheat and sugar for biofuels production; for example, the UK usuallyexports around 3 million t/y of wheat which could be used to produce about 1 million t of bioethanol

2.5 Limitations

2.5.1 Fuel standards

Conventional biofuel blending componentsare not ideal fuel molecules, and in Europeonly a maximum of 5% ethanol by volume or15% of ETBE (made from ethanol) may beblended into conventional petrol, or 5% ofFAME into diesel. Using fuels with higherlevels potentially invalidates vehiclewarranties. The limits for ethanol and ETBE

are also in the EU Fuels Directive 2003/17/EC.The limits are based on a variety of factorsincluding compatibility of materials, effect oftrace by-products from biofuel manufacture,and deposit formation. Other countriesoperate with higher blends, however, and theUSA utilises a 10% blend of ethanol whilst85% ethanol fuel vehicles are commonplacein Brazil and Sweden. Over time the limitsmay be changed by CEN (Comité Européende Normalisation – European Committee forStandardization).

The use of flexible fuel vehicles (FFVs), whichare specially designed to utilise a range ofbiofuel concentrations in either petrol or diesel,provide an alternative approach. Ford sells anethanol FFV Focus in Sweden. Saab haslaunched an ethanol FFV in the UK, and Volvohas plans to introduce one into the UK market.

2.5.2 Available land

The UK can only devote a limited area of landto the cultivation of crops for biofuels. Thetotal land area of the UK is around 24 millionha. In 2002 Defra estimated that about 6.5million ha was arable land made up of around:

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Company Location Capacity Product FeedstocksArgent Motherwell 45 kt Biodiesel Tallow and UVOBiofuels Corp Teesside 250 kt Biodiesel Rape, soya and palmD1 Oils Preston 7.7 kt Biodiesel UVO, rapeEbony Solutions Northwich 2.5 kt Biodiesel UVOGlobal Commodities Norfolk, Hull 300 kt Biodiesel RapeGreenergy Oldbury 12 kt Biodiesel RapeRix Hull 50 kt Biodiesel RapeVarious Widespread about

UKSmall scale (eg 1 t/mo)

Biodiesel UVO

Company Location Capacity Product FeedstocksBritish Sugar Wissington 55 kt Ethanol Sugar beetGreenergy Immingham 100 kt Biodiesel Rape, used cooking oilGreen Spirit Somerset 100 kt Ethanol WheatRix Hull 50 kt Biodiesel RapeRoquette Corby 100 kt Ethanol Wheat

Exhibit 2.4 Current biofuel plants in the UK

Exhibit 2.5 Proposed biofuel plants in the UK

Fuel Crop Biofuelsrequired(Mt/y)

Biofuelsyield(t/ha)

Landrequired(millionha)

Bioethanol 50%fromwheat

0.91 2.5 0.36

Bioethanol 50%fromsugarbeet

0.90 4 0.23

FAME Rapeseed 1.24 1.75 0.71Total 3.05 1.3

Exhibit 2.6 UK land area to produce the 5.75% byenergy content of biofuels required to meet the 2010indicative value in EU Directive 2003/30/EC

• 4.5 million ha under arable cultivation • 0.7 million ha ‘set-aside’ (reduced in

subsequent years)• 1.2 million ha under grass less than five

years old so could theoretically be broughtback into use for growing crops, althoughthere may be major cultural andenvironmental constraints including asignificant reduction in animal husbandry

A further 11 million ha is specified to begrazing land for livestock including roughgrazing. Around half of this is improvedgrazing which is intensively managed and lowin biodiversity. This is theoretically suitable forarable or perennial energy crops, but inpractice it is very unlikely that farmers wouldplough up grassland to plant an arable crop asthis would be a reversal of current trends ofagricultural specialisation.

Forest or woodlands cover 2.8 million ha. Theremainder of the UK’s land area is taken upby towns, roads, recreation and semi-naturalenvironments, eg sand dunes, grouse moorsand non-agricultural grasslands and inlandwaters.

Hence there are about 2 million ha of arableland available in the UK to grow biofuels,without affecting current food production. Inpractice, environmental constraints will reducethe area available to 1-2 million ha, limiting theamount of conventional biofuels that can beproduced from UK grown biomass to around5-10% of the UK's road fuel use. This wouldenable the maximum currently permitted byUK and European fuels standards, 5% byvolume of bioethanol and FAME, to be addedto petrol and diesel respectively. This wouldrequire 0.9 million ha of arable farmland.Meeting the Biofuels Directive indicative targetfor 2010 is also within reach for UK productionof bioethanol and FAME. This would requirearound 1.3 million ha of arable farmland.

As UK FAME production requires more landthan bioethanol production, the area required

for biofuel production will increase if thedemand for diesel continues to rise and thedemand for petrol continues to fall. The arearequired for the UK production of bioethanoland FAME could be reduced by using thewheat and sugar currently exported for theproduction of bioethanol and, in the future,the conversion of straw to bioethanol.

Furthermore, energy crops for electricitygeneration will compete with land for fuelcrops. It may be possible to alleviate this tosome extent by developing ‘biorefineries’ toextract a range of products, includingtransport fuels, from the woody plant materialwith the residue being burnt for heat and/orpower. Further work is required to explorethis possibility.

In its study for DfT (Liquid biofuels andhydrogen from renewable resources in theUK to 2050: a technical analysis, December2003), E4Tech estimated that around a thirdof UK road fuels could be replaced bybiofuels provided these were from secondgeneration production processes which give ahigher yield of road fuels per ha, more land (4million ha) allocated and waste streamsconverted. Imported biofuels would thereforebe needed if the UK wanted to move to veryhigh usage of biofuels.

2.5.3 Cost

In general, the cost of most domestic andoverseas produced biofuels is around twice thatof conventional road fuels, though Brazilianbioethanol is now very close, so someintervention in the market is required tostimulate the widespread introduction of biofuelsin the competitive UK road fuels market. Thiscould be a duty differential, the current policy,and/or a Renewable Transport Fuels Obligation(RTFO) under the 2004 Energy Act. Both theseoptions have advantages and disadvantages.

Like many other ways of reducing CO2

emissions from road transport, the cost per

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tonne of carbon saved with biofuels is high.No precise figures are available but publishedstudies give a range of costs. For example,Sheffield Hallam’s January 2003 study forDefra quotes £600-1200/tC for FAME fromoilseed rape, British Sugar (privatecommunication) estimate £450-500/tC andthe December 2003 JRC/Concawe/Eucarwell-to-wheel study quotes £570-900/tC forFAME and £660-1,500/tC for bioethanol.These figures are much higher than options inother sectors including the EU EmissionsTrading Scheme where the current price ofcarbon is around £20/tC and the UKTreasury’s illustrative cost of saving carbon of£70/tC in 2000 rising to £100/tC in 2030.

2.5.4 Environmental impact

The Low Carbon Vehicle Partnership (LCVP) isdeveloping a biofuels accreditation scheme toensure that biofuels are produced in asustainable way and that the GHG savingsfrom the various options are identified. Thescheme will be non-bureaucratic andinternationally accepted so that imported anddomestically produced biofuels are covered.The objective is the global reduction of GHGemissions so it is important that biofuel ‘farmto tank’ emissions are fully established andoptions assessed on a global basis.

2.5.5 Availability of technology

The technology for producing biofuels frombiomass could become available in thefollowing timeframe. The timeframe could bealtered by government support fordevelopment of the new processes or byadvancement in the technology ofconventional biofuel production:

2000-2010: Conventional biofuels, biogas,FAME from vegetable oil and bioethanol fromwheat, sugar beet etc are available now.Other processes are at the demonstration orpilot plant phase. The first commercial plantconverting straw to bioethanol will becommissioned towards the end of thisperiod. Refinery conversion of vegetable oil todiesel will be proven. Combining liquid biofueland electricity production will be used toimprove the carbon efficiency of utilisingbiomass.

2010-2025: Fuels, electricity and chemicalsare available from a range of energy crops,waste and biomass. Processes to convertlignocellulose to bioethanol are available,initially with straw as the feedstock. BTL (FT diesel) technology should also becomeavailable post 2015, along with improvedpower generation from gasification ofbiomass. The biofuel content of petrol anddiesel may be increased from the current 5%by volume.

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Exhibit 2.7 Future fuels pathway

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3.1 Pyrolysis3.1.1 Fast pyrolysis

3.1.1.1 Principles3.1.1.2 Reactors3.1.1.3 Pyrolysis liquid – bio-oil 3.1.1.4 By-products

3.1.2 Bio-oil upgrading3.1.3 Intermediate and slow

pyrolysis3.1.3.1 Screw pyrolysis

3.1.4 Torrefaction3.1.5 Transport fuels from bio-oil by

upgrading3.1.5.1 Hydrotreating using

traditional hydro-desulphurisationcatalysts

3.1.5.2 Hydrotreating ofseparated product

3.1.5.3 Zeolite cracking3.1.5.4 Gasification of bio-oil

and synthesis oftransport fuels

3.2 Liquefaction3.3 Gasification

3.3.1 Status of biomass gasificationtechnology

3.3.2 Synthesis gas quality3.4 Synthesis of transport fuels3.5 Bioenergy system3.6 Bibliography of further reading

There are three main thermal processesavailable for converting biomass toconventional hydrocarbon transport fuels:pyrolysis, pressure liquefaction andgasification. Exhibit 3.1 summarises theprimary processes, primary products,secondary and refining processes and marketapplications.

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3 THERMAL BIOMASS CONVERSION TECHNOLOGIES FOR TRANSPORT FUELS

Exhibit 3.1 Thermal biomass conversion processes for transport fuels and chemicals

Fast pyrolysis andliquefaction

Refining

Synthesis

Upgrading

Gasification

Gasification Gas

Bio-oil

Gas

Chemicals

Transportfuels

By-productelectricity

Conversion ConversionPrimaryproduct

Conversion Market

Fast pyrolysis and liquefaction are still at arelatively early stage of development but offerthe benefits of producing a liquid fuel withconcomitant advantages of easy storage andtransport. Gasification utilising coal and oilfeedstocks has been practised for manyyears, with the notable current example ofSasol in South Africa (Shell also has a smallFT plant in Bintulu, Malaysia), and in thebiomass area gasification has benefited frommore R&D, with the result that there aremore demonstration and commercialactivities than for pyrolysis and liquefaction.

3.1 Pyrolysis

Pyrolysis is thermal decomposition occurringin the absence of oxygen. It is always alsothe first step in combustion and gasification,but in these processes it is followed by totalor partial oxidation of the primary products.Lower process temperatures and longervapour residence times favour the productionof charcoal. High temperatures and longerresidence times increase biomass conversionto gas, and moderate temperatures and shortvapour residence times are optimum forproducing liquids. Exhibit 3.2 indicates theproduct distribution obtained from differentmodes of pyrolysis.

Fast pyrolysis for liquids production iscurrently of particular interest as high yieldsof liquids are produced that are easy to storeand transport from decentralised plants to a

large central processing facility that offerseconomies of scale in conversion tomarketable products.

3.1.1 Fast pyrolysis

Fast pyrolysis occurs in a time of a fewseconds or less. Therefore heat and masstransfer processes and phase transitionphenomena, as well as chemical reactionkinetics, play important roles. The criticalissue is to bring the reacting biomassparticles to the optimum processtemperature as quickly as possible to releasethe volatile vapours, then cool these vapoursas quickly as possible to minimise secondaryreactions. The usual way of achieving the highheating rates necessary is by using smallparticles, for example in the fluidised bedprocesses that are described later. Thealternative is to transfer heat very quickly onlyto the particle surface that contacts the heatsource, as applied in ablative pyrolysis. Acritical technical challenge is heat transfer tothe reactor in commercial systems.

3.1.1.1 Principles

In fast pyrolysis, biomass decomposes togenerate mostly vapours and aerosols andsome charcoal. After cooling andcondensation, a dark brown mobile liquid isformed which has a heating value about halfthat of conventional fuel oil. While it is relatedto the traditional pyrolysis processes for

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Mode Conditions Liquid Char Gas Examples visitedFast Moderate temperature, around 500ºC,

short hot vapour residence time ~1 s75% 12% 13% BTG, TNO, VTT

Intermediate Moderate temperature, around 500ºC,moderate hot vapour residence time~10-20 s

50% 20% 30% FZK

Slow(carbonisation)

Low temperature, around 400ºC, verylong residence time

30% 35% 35%

Gasification High temperature, around 800ºC, longresidence time

5% 10% 85% FZK, Future Energy,SVZ

Exhibit 3.2 Typical product yields (dry wood basis) obtained by different modes of pyrolysis of wood

making charcoal, fast pyrolysis is an advancedprocess, with carefully controlled parametersto give high yields of liquid. The essentialfeatures of a fast pyrolysis process forproducing liquids are:

• Very high heating and heat transfer rates atthe reaction interface, which usuallyrequires a finely ground biomass feed

• Carefully controlled pyrolysis reactiontemperature of around 500ºC and vapourphase temperature of 400-450ºC

• Short hot vapour residence times oftypically less than 2 s

• Minimum exposure to char and alkalimetals as these are effective crackingcatalysts

• Rapid cooling of the pyrolysis vapours togive the bio-oil product

The main product, bio-oil, is obtained in yieldsof up to 75% wt on a dry-feed basis, togetherwith by-product char and gas, which can beused within the process to provide theprocess heat requirements so there are nowaste streams other than flue gas and ash.The char can be sold as a valuable by-productif there is a market.

A complete fast pyrolysis process includesdrying the feed to typically less than 10%water in order to minimise the water in theproduct liquid oil, grinding the feed to around2 mm particle size in the case of fluidised bed(FB) reactors to give sufficiently smallparticles to ensure rapid reaction, pyrolysisreaction, separation of solids (char), andquenching and collection of the liquid product(bio-oil).

Virtually any form of biomass can beconsidered for fast pyrolysis. While mostwork has been carried out on wood becauseof its consistency and comparability between

tests, nearly 100 different biomass types havebeen tested by many laboratories, rangingfrom agricultural wastes such as straw, olivepits and nut shells to energy crops such asmiscanthus and sorghum, forestry wastessuch as bark, and solid wastes such assewage sludge and leather wastes. High ashcontent feedstocks of above around 3% cangive a phase separated product from thecatalytic effect of the alkali metals, particularlypotassium.

In its 20 kg/h circulating FB pilot plant, VTThas focused on forest residues owing to thelarge resource available in Finland. BTG in theNetherlands has focused on woody biomassand energy crops, but it processes oil palmwastes as empty fruit bunches in its mostrecent 50 t/d demonstration or prototypecommercial plant in Malaysia based on itsrotating cone technology.

3.1.1.2 Reactors

At the heart of a fast pyrolysis process is thereactor. Although it probably represents atmost only about 10-15% of the total capitalcost of an integrated system, most R&D hasfocused on the reactor, although increasingattention is now being paid to control andimprovement of liquid quality andimprovement of collection systems. The restof the pyrolysis process system consists ofbiomass reception, storage and handling,biomass drying and grinding, productcollection, storage and, when relevant,upgrading. The key aspects of theseperipheral steps are described later.

A key technical barrier is heat transfer to thereactor, as pyrolysis is an endothermicprocess. This is addressed in various ways indifferent reaction systems including recyclingof hot sand from a separate char combustoras in the BTG prototype commercial plant,the VTT pilot plant and the FZK screw reactor;and indirect heat transfer as in the TNO andFZK rotary kiln system. In all cases there are

22


unresolved concerns about scale-up to thelarge scale plants needed to maximiseeconomies of scale.

Bubbling fluidised beds

Bubbling fluidised beds (usually referred to asjust fluidised beds – FBs – as opposed tocirculating fluidised beds – CFBs) have theadvantages of a well understood technologythat is simple in construction and operation,good temperature control and very efficientheat transfer to biomass particles arising fromthe high solids density. FB pyrolysers givegood and consistent performance with highliquid yields of typically 70-75% wt fromwood on a dry-feed basis. Small biomassparticle sizes of less than 2-3 mm are neededto achieve high biomass heating rates and therate of particle heating is usually the rate-limiting step.

Residence time of solids and vapours iscontrolled by the fluidising gas flow rate andis higher for char than for vapours. As characts as an effective vapour cracking catalystat fast pyrolysis reaction temperatures, rapidand effective char separation/elutriation isimportant. This is usually achieved by ejectionand entrainment followed by separation inone or more cyclones so careful design ofsand and biomass/char hydrodynamics isimportant. There is some experience of hotvapour filters for reducing solids.

Circulating fluidised beds and transported bed

Circulating fluidised beds (CFBs) have manyof the features of bubbling beds describedabove, except that the residence time of thechar is almost the same as for vapours andgas and there is greater attrition of the charowing to the higher gas velocities, which canlead to higher char contents in the collectedbio-oil. An added advantage is that CFBs aresuitable for very large throughputs eventhough the hydrodynamics are more complex.This technology is widely used at very high

throughputs in the petroleum andpetrochemical industry. Heat supply is usuallyfrom recirculation of heated sand from asecondary char combustor, which can beeither a bubbling or circulating fluidised bed.In this respect the process is similar to a twinFB gasifier except that the reactor (pyrolyser)temperature is much lower and the closelyintegrated char combustion in a secondreactor requires careful control to ensure thatthe temperature and heat flux match theprocess and feed requirements. A variationon the transported bed is the rotating conereactor.

The BTG rotating cone concept is effectivelya transported bed process. Sand is heated bycombustion of by-product char and fed to thepyrolyser where it is mixed with biomass. Thechar and sand are recirculated to an FBcombustor to reheat the sand. This iscurrently operating successfully in Malaysiaon a prototype commercial plant of 50 t/d dryoil palm waste. The VTT process employs aCFB or transported bed for pyrolysis with aclose coupled char combustor to reheat thesand which is then recirculated to thepyrolyser.

Ablative pyrolysis

Ablative pyrolysis is substantially different inconcept from other methods of fast pyrolysis.In all the other methods the rate of reaction islimited by the rate of heat transfer throughthe biomass particles, which is why smallparticles are required. The mode of reaction inablative pyrolysis is like melting butter in afrying pan – the rate of melting can besignificantly enhanced by pressing the butterdown and moving it over the heated pansurface. In ablative pyrolysis, heat istransferred from the hot reactor wall to ‘melt’wood that is in contact with it underpressure. The pyrolysis front thus movesunidirectionally through the biomass particle.As the wood is mechanically moved away,the residual oil film both provides lubrication

23


for successive biomass particles and alsorapidly evaporates to give pyrolysis vapoursfor collection in the same way as otherprocesses. The rate of reaction is stronglyinfluenced by pressure, the relative velocity ofthe wood and the heat exchange surface andthe reactor surface temperature. The keyfeatures of ablative pyrolysis are therefore asfollows:

• High pressure of particle on hot reactorwall, achieved due to centrifugal force

• High relative motion between particle andreactor wall

• Reactor wall temperature <600ºC

As reaction rates are not limited by heattransfer through the biomass particles, largeparticles can be used and in principle there isno upper limit to the size that can beprocessed. The process in fact is limited bythe rate of heat supply to the reactor ratherthan the rate of heat absorption by thepyrolysing biomass as in other reactors. Thereis no requirement for inert gas, so theprocessing equipment is smaller and thereaction system is thus more intensive.However, the process is surface areacontrolled so scaling is more costly and thereactor is mechanically driven, and is thusmore complex.

Cyclone and other reactors

A wide range of other reactor configurationshave been developed such as the cyclonereactor of TNO. This also uses sand as a heatcarrier but relies on the centrifugal motion ofbiomass and hot sand processing for goodmixing and heat transfer. In all other respectsthe pyrolysis system behaves and performslike other fast pyrolysis systems. A rotaryparticle separator is also available to improvechar separation. The work at TNO issupported by a novel cyclonic TGA(thermogravimetric analyser).

3.1.1.3 Pyrolysis liquid – bio-oil

Fast pyrolysis liquid typically is a dark brown,free-flowing liquid and approximates tobiomass in elemental composition. It iscomposed of a very complex mixture ofoxygenated hydrocarbons with an appreciableproportion of water from both the originalmoisture and reaction product. Solid char mayalso be present. It has a higher heating valueof about 16-17 MJ/kg as produced with about25% wt water that cannot readily beseparated. The complex mixture ofoxygenated compounds provides both thepotential and challenge for utilisation.Pyrolysis liquid will not mix with anyconventional hydrocarbon based fuels. Itcannot be completely vaporised once it hasbeen recovered from the vapour phase. If theliquid is heated to 100ºC or more to try toremove water or distil off lighter fractions, itrapidly reacts and eventually produces a solidresidue of around 50% wt of the originalliquid and some distillate containing volatileorganic compounds (VOCs) and water, muchof which results from cracking of the liquidrather than evaporation. The importantcharacteristics of the liquid are summarised inExhibit 3.3. Different feedstocks, differentfeed characteristics and different reactorconfigurations will affect the characteristics ofthe bio-oil, but there are no clearrelationships.

Bio-oil contains about 70% of the energycontent of the initial biomass, while the charcontains about 25% and the gas about 5%. Aslurry of the bio-oil and char will containnearly 90% of the energy content of thebiomass, as long as additional energy is inputto the process to provide the process heat,the requirement for which is about 15% ofthe energy content of the biomass.

3.1.1.4 By-products

Charcoal and gas are by-products, typicallycontaining about 25% and 5% of the energy in

24


the feed material respectively. The pyrolysisprocess itself requires about 15% of theenergy in the feed, and of the by-products, onlythe char has sufficient energy to provide thisheat. The heat can be derived by burning thegas and/or the charcoal by-product. The onlywaste arising from the process is the ash fromchar combustion if this is used in-process.

Char separation is a critical step in theprocess as char is both catalytically active andalso causes a physical handling problem inutilisation. TNO has developed a rotaryparticle separator to enhance char separation.BTG recycles all the char and sand forcombustion to reheat the sand which is usedas the heat transfer medium. VTT also burnsthe char in a separate FB combustor forreheating the sand which is recirculated, andhas also tested a hot vapour filter to minimisethe char content of the product bio-oil. Thehigher turbulence of CFBs can lead to greaterchar attrition, leading to problems in charseparation.

The combination of bio-oil and char into apumpable slurry has been tested tomaximise its energy content by FZK. Thisacts as an energy carrier to transport asmuch of the energy in the biomass aspossible in a liquid form to optimise handling,storage and transport.

3.1.2 Bio-oil upgrading

The main concerns in utilisation of bio-oilrelate to phase separation, ageing (a tendencyfor viscosity to increase over time), and solidscontent, mostly char. Phase separation is aresult of high water content of the feedmaterial and/or secondary cracking reactionsfrom high ash, high char and/or long hotvapour residence time. A well designed andoperated fast system operating on a low ashfeed will consistently deliver a homogeneous,single phase bio-oil. Char separation remains achallenge and several devices have beentested such as hot vapour filtration at VTT andthe rotary particle separator at TNO.

25


Physical property Typical valueMoisture content 25%pH 2.5Specific gravity 1.20

HHV as produced 17 MJ/kgViscosity (40ºC and 25% water) 40–100 cPSolids (char) 0.2%Vacuum distillation residue up to 50%Characteristics• Liquid fuel• Ready substitution for conventional fuels in many

stationary applications such as boilers, engines,turbines

• Heating value of 17 MJ/kg at 25% wt water isabout 40% that of fuel oil/diesel

• Does not mix with hydrocarbon fuels• Not as stable as fossil fuels• Quality needs definition for each application

Elemental analysis: CHONAsh

55–58%5.5–7.0%35–40%0–0.2%0–0.2%

Exhibit 3.3 Typical properties of wood-derived crudebio-oil

Exhibit 3.4 Fast pyrolysis bio-oil

3.1.3 Intermediate and slow pyrolysis

If the residence time in fast pyrolysis extendsto more than around 10 s, secondaryreactions become more important and resultin an increased effect of cracking reactionsthat reduce the liquid organic yield, increasethe water yield and increase the char yield asshown in Exhibit 3.2 earlier. This invariablyresults in a phase separated liquid with awatery aqueous phase and a high viscosityliquid phase that is more tar-like than fastpyrolysis liquid.

Production of a bio-oil/char slurry will containabout 80-90% of the initial energy content ofthe biomass depending on the extent ofsecondary cracking reactions. It is not clearwhether a phase separated liquid will producea slurry with char that remains phaseseparated, or whether two slurries will beproduced from each of the aqueous phaseand the organic phase.

3.1.3.1 Screw pyrolysis

Screw pyrolysis is what is referred to asintermediate pyrolysis in Exhibit 3.2. It is notas fast as fast pyrolysis due to the mechanicalnature of the system which intimatelycontacts biomass with a moving bed of sand.The hot vapour residence time is around 10 srather than 1 or 2 s in the systems describedabove, and secondary cracking thus reducesthe liquid yield to around 50% and the liquidis phase separated. The pilot plant at FZK hasa capacity of around 20 kg/h and plans are inhand to install a 0.5 t/h demonstration plantutilising a displaced Lurgi LR test reactor. Thisis a part of a €22 million (~£15 million)bioenergy test centre under construction atFZK. The sand is heated with by-product gas,supplemented when necessary.

The two phase liquid is mixed with the charby-product to form a slurry that contains up to90% of the energy in the biomass. Twoslurries can be produced based on the

aqueous phase and on the separated organicphase. This would complicate the handling ofslurry.

Future Energy has carried out tests onpressure oxygen gasification of the slurry inits pilot plant in Freiberg.

3.1.4 Torrefaction

Torrefaction can be considered as a pre-pyrolysis process for substantially changingmany of the characteristics of biomass thatmake it relatively difficult to handle, transportand prepare for thermal conversion. Torrefiedbiomass can be processed much like coal andthus existing coal gasification processes canbe readily adapted to biomass feeding.

Torrefaction, as developed by ECN, is a lowtemperature pyrolysis process that is typicallycarried out at 200-250ºC before there isappreciable decomposition of cellulose andlignin, thus retaining a large proportion of theenergy content of the original biomass.Torrefied biomass can be transported andprocessed more efficiently than raw biomass,particularly in size reduction for feeding to anentrained flow gasifier. However there is asignificant energy and capital cost in thetorrefaction process, and a waste waterdisposal problem, none of which are knownto have been thoroughly explored.

Exhibit 3.5 Torrefied pellets at ECN

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3.1.5 Transport fuels from bio-oil byupgrading

Bio-oil from fast pyrolysis or liquefactionprocesses can be catalytically upgraded toproduce hydrocarbon fuels that can beconventionally processed for example inrefineries. Full deoxygenation to high-gradeproducts such as transportation fuels can beaccomplished by two main routes:hydrotreating and catalytic vapour crackingover zeolites. The range of options is shownin Exhibit 3.6. VTT is planning to develop anintegrated approach to upgrading and refiningfor transport fuels and chemicals, but nodetails are yet available.

There is considerable interest in the conceptof decentralised fast pyrolysis and transportof bio-oil or bio-oil/char slurry to a centralprocessing plant for upgrading. The bio-oil orslurry collected from several or many smallerplants can then be more economically andefficiently processed in much larger plants,for example for large scale gasification forsynthesis of FT diesel or methanol. This isproposed by FZK and Future Energy for FT,and by Technische Universität BergakademieFreiberg (TUB-F) for methanol.

3.1.5.1 Hydrotreating using traditional hydro-desulphurisation catalysts

Hydrotreating gives a naphtha-like productthat requires orthodox refining to deriveconventional transport fuels. The process isseparate from fast pyrolysis and processes aliquid feed in a high pressure two stageprocess over conventional hydro-desulphurisation catalysts in the presence ofhydrogen. The catalyst supports have beenfound to be unstable in the high watercontent environment of bio-oil and someprogress has been made on the use ofcarbon catalyst supports. There is asubstantial hydrogen requirement to bothhydrogenate the organic constituents of bio-oil and remove the oxygen content as water.The hydrogen requirement can berepresented by a requirement to process anadditional amount of biomass equal to about80% of that required to produce the bio-oil.The process is thus very inefficient and alsovery high cost from the high-pressurerequirements and cost of hydrogen.

This technology can be applied to liquefactionproducts (see Section 3.2) and to vegetableoils, both of which have much lower oxygencontents than bio-oil and thus have a muchlower hydrogen requirement. Neste isbuilding a 170,000 t/y plant for hydrotreatingvegetable oils in Finland and has recently

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Exhibit 3.6 Transport fuels and chemicals from fast pyrolysis

Fast pyrolysis

RefiningSynthesisGasification

Hydrogenseparation

Zeolitecracking

Hydro-treating

Char Slurry

Liquid

H2

Chemicals

Transportfuels

Electricity

announced plans for a similar plant in Austria.The advantage is that a synthetic diesel isproduced that is completely compatible withexisting diesel in all proportions.

3.1.5.2 Hydrotreating of separated product

A more recent development is to separatethe bio-oil into organic and aqueous fractions.The aqueous fraction is steam reformed tohydrogen which is used to hydro-process theorganic fraction. A crude product is obtainedfor refining in a conventional oil refinery. Nodetails are available but it is claimed to bemore promising economically and technicallythan the traditional approach discussedabove.

3.1.5.3 Zeolite cracking

Zeolite cracking can be carried out on theprimary vapours from fast pyrolysis and canthus be integrated into the fast pyrolysisprocess, thereby obviating the need for aseparate upgrading process and need for highpressure. Close-coupled operation in aseparate reactor is preferred to give betterprocess control and more effective contactwith the catalyst. In this process the oxygenis rejected as CO2 rather than water, thusreducing carbon efficiency but avoiding theneed for hydrogen. A further complication ofzeolite cracking catalysts is the propensity forrapid coking, and thus a more complex rapidcatalyst regeneration system is required.Hydrocarbon products from this process havea high octane number but have been found tocontain high levels of aromatic hydrocarbonswhich are undesirable. Catalyst and processdevelopment may reduce this problem.

3.1.5.4 Gasification of bio-oil and synthesis oftransport fuels

Pressurised oxygen gasification of bio-oil hasonly recently been tested to a limited extent.A variety of proprietary pressurised oxygenblown gasifiers are available from applications

in coal and heavy oils. Substantial scales ofoperation are necessary to justify theexpense of an oxygen plant and highpressure operation. This militates againstsmall scale biomass gasification, hence theincreasing interest in using bio-oil and bio-oil/char slurries as energy carriers to feed astate-of-the-art gasification and liquid fuelsynthesis plant. Typical commercial size islikely to be between 15,000 and 20,000barrels per day (bbl/d) fuel product. Thisequates to between 10,000 and 15,000 t/dbiomass or between 3 and 4 million t/ybiomass. Section 3.4 describes the optionsfor synthesis of transport fuels.

Future Energy is engaged in a testprogramme for pressurised oxygengasification of bio-oil/char slurry. It hasconcerns over the variability of feed qualitythat might result from a phase separatedproduct. The aqueous fraction has a muchlower heating value than the organic fractionand a sudden change in feed to the gasifiercould result in oxygen overload in the gasifierwith potentially serious consequences.

TUB-F is also developing a partial oxidationprocess for bio-oil prior to synthesis ofmethanol for conversion to gasoline.

The relative merits of the different processroutes have not recently been evaluated andit would be valuable to establish the relativeperformance of the processes in terms oftechnology, economics and environment,including consideration of the refining neededto produce a transport fuel product that istotally compatible with current fossil fuelderived products.

3.2 Liquefaction

Pressure liquefaction is analogous to pyrolysisin that there is no oxidation of the reactingbiomass. Biomass is fed to a pressurisedsystem at up to 200 bar and is heated toaround 300-400ºC in a liquid environment. The

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biomass decomposes and reacts to give aproduct with a much lower oxygen contentthan bio-oil (10-15% wt compared to 35-40%wt), that is more stable than bio-oil, but whichhas much higher viscosity, often requiringtemperatures above 60-80ºC to give apumpable liquid. The earliest significant workin the USA around 1980 developed twoprocesses, one based on recycled productliquid from which the light ends had beenremoved and the other based on a water oraqueous medium. This later approach iscurrently being researched in Europe. A waterbased system enables wet biomass to beprocessed without drying.

The 100 kg/h hydrothermal upgrading (HTU)pilot plant located at TNO operates at 330ºCand 175 bar with an aqueous feed. The liquidproduct is separated and the water fraction isrecycled. A continuous run of 500 h has beensuccessfully achieved. The liquid yield isaround 40% wt with an oxygen content ofaround 15% which is substantially lower thanbio-oil. There are plans for demonstration at25,000 t/y.

3.3 Gasification

Fuel gas and syngas can be produced frombiomass either by partial oxidation to give amixture of CO, CO2, hydrogen and methanewith nitrogen if air is used as the oxidant, orby steam or pyrolytic gasification. Exhibit 3.7summarises the main products in each case.The term syngas is often used in the contextof a nitrogen free gas with high concentrationof CO and hydrogen in proportions that aresuitable for synthesis of hydrocarbons,alcohols and ethers etc.

The process of gasification is a sequence ofinterconnected reactions: the first step,drying, is a relatively fast process. The secondstep, pyrolysis, is also relatively fast but it is acomplex process that gives rise to the tarsthat cause so many problems in gasificationprocesses. Pyrolysis occurs when a solid fuel

is heated to 300-600ºC in the absence of anoxidising agent, giving a solid char,condensable hydrocarbons or tar and gases.The relative yields of char, liquid and gasmainly depend on the rate of heating and thefinal temperature and this has beendiscussed in Section 3.1.1. In gasification bypartial oxidation the gas, liquid and solidproducts of pyrolysis then react with theoxidising agent (air, oxygen or steam) to givethe permanent gases CO, CO2, H2 and lesserquantities of hydrocarbon gases. In steam orpyrolytic gasification, the by-product char isburned in a secondary reactor to reheat thehot sand which is recycled to the gasificationreactor to provide the heat for gasification.

3.3.1 Status of biomass gasificationtechnology

Biomass gasifiers for production of transportfuels need to be very large by currentbiomass gasification standards, which limitstechnologies to CFBs and entrained flowsystems. Similarly, oxygen blown pressurisedsystems are probably essential. There islimited experience of oxygen blown orpressurised biomass gasification in Europegenerally, although VTT has considerableexperience with pilot plant design andoperation of both oxygen and pressurisedsystems.

However, extrapolation of experiences withcoal and other materials is not unreasonable.There are significant differences that mostlyrelate to the high level of volatiles in biomasscompared to coal (70-75% vs 20-25%) andthe physical and structural characteristics ofbiomass vs coal, in that biomass is muchmore difficult to grind and much moreresistant to compressive forces. Entrainedflow biomass gasifiers will thus have a higherfeed preparation requirement. Cold gasefficiencies of up to 75-80% are potentiallyachievable in a well integrated plant.

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30


Gasification mode Details Examples seenon visits

Partial oxidationwith air

The main products are CO, CO2, H2, CH4, N2 and tar, giving a lowheating value gas of ~5 MJ/m3. The high nitrogen content is a majordiluent. Fixed beds, FBs, CFBs and entrained flow reactors are used.

ECN, TUB-F, VTT

Partial oxidationwith oxygen

The main products are CO, CO2, H2, CH4 and tar (no N2), giving amedium heating value gas of ~10-12 MJ/m3. There is a significanteconomic and energetic cost of using oxygen, but the product gas isessentially nitrogen free. While fixed beds have been used, CFBs andentrained flow reactors are more widely promoted.

Choren, FutureEnergy, TUB-F,VTT

Steam (pyrolytic)gasification

The main products are CO, CO2, H2, CH4 and tar giving a mediumheating value gas of ~15-20 MJ/m3. The process has two stages: theprimary reactor produces gas and char, and the fluidising sand andchar is passed to a second reactor where the char is burned with air toreheat the sand, which is then recirculated to the first reactor toprovide the heat for reaction. The gas heating value is maximised dueto a higher methane and higher hydrocarbon gas content, but at theexpense of lower overall efficiency due to loss of carbon in the secondoxidising reactor. FBs, CFBs and entrained flow reactors are used andpromoted.

FZK

Pressure operation Pressurised gasifiers operate under pressures of typically 15-50 bar,with the hot gas being cooled to around 500ºC to aid precipitation ofalkali metals on the particulates prior to hot gas filtration to remove theparticulates. As a tar free gas is needed for liquid fuel synthesis, aneffective tar cracking and/or removal system is essential.Pressurised feeders need significant quantities of inert gas for flushingthe lock hoppers during the feeding cycle, unless alternatives are usedsuch as plug feeders. Both capital and operating costs are significantlyhigher for pressurised operation, although these are to some extentbalanced by savings from reduced vessel and piping sizes, theavoidance of a gas compressor for the gas turbine and higherefficiencies. Examples include the CFB demonstration plant atVärnamo and Carbona.There is a trade-off between the high cost of a pressurised feedingsystem and compression of a product gas from an atmosphericgasifier. Currently, a pressurised gasifier is believed to have economicadvantages.Liquid feeding as bio-oil or slurry has significant operational andeconomic advantages over solid biomass feeding.

Choren, FutureEnergy, SVZ, TUB-F, VTT

Oxygen gasification The advantages of using oxygen include:• Higher reaction temperatures, which can lead to lower tar levels and

smaller gasifiers• Lower gas volumes from the reduction or absence of nitrogen,

leading to smaller vessel and piping sizes and hence lower costs• The absence of nitrogen leads to more efficient use of gas for

synthesis of liquid fuelsThere is, however, a significant energy and financial cost associatedwith the use and supply of oxygen, from both its procurement and theadditional measures needed to mitigate hazards in handling and use.

Choren, FutureEnergy, SVZ, TUB-F, VTT

Supercritical High pressure and high temperature gasification in supercritical water. ECN, FZK

Exhibit 3.7 Modes of thermal biomass gasification

3.3.2 Synthesis gas quality

The synthesis gas (syngas) qualityrequirement for liquid fuel production is veryhigh. Tar is a particular problem in biomassderived gas and probably remains the mostsignificant technical barrier. Exhibit 3.9 givestypical product gas compositions for the morecommon gasifiers.

Exhibit 3.10 lists the more significantcontaminants. The level of contamination willvary depending on the gasification processand the feedstock. Extensive gas cleaning isneeded to deliver a sufficiently clean gas tothe synthesis train. Trace contaminants

containing sulphur (eg H2S), chlorine (eg HCl,COCl) and nitrogen (eg ammonia) in a rangeof compounds will usually require reductionto a few parts per million (ppm) for mostcatalyst systems used in synthesisingalcohols and hydrocarbons, and each catalysthas its own limitations and tolerances. All thetechnology is available for gas purification, butoptimisation is necessary to maximiseperformance and minimise cost. Othercomponents include CO2, methane, higherhydrocarbons such as ethylene and ethane,propane and propylene, and nitrogen.Generally these act as diluents, but differentgeneric and specific processes have differentlevels of tolerance for each component. ECN,FZK and VTT are carrying out extensiveresearch on all aspects of contaminantcontrol and management.

3.4 Synthesis of transport fuels

Fischer-Tropsch (FT) is a process forconverting a mixture of carbon monoxide(CO) and hydrogen (H2), known as synthesisgas or syngas, into hydrocarbon liquids.Hydrocarbon product distribution is definedby a single parameter, the alpha number,which is dependent upon the ratio of CO toH2, the catalyst, and the reaction temperatureand pressure employed. The process is bestknown for its application by Sasol in SouthAfrica where coal is gasified in fixed bedgasifiers and the resultant, cleaned syngas isconverted over an iron based catalyst to arange of transport fuels and chemicals.

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Gasifier type Examples visitedFB and CFB – air VTT, ECNFB and CFB – oxygen, pressure VTTCFB – air VTT, ECNCFB – oxygen, pressure VTTUpdraft – air VTTUpdraft – oxygen, pressure SVZEntrained flow – airEntrained flow – oxygen,pressure

ECN, FutureEnergy, FZK, SVZ

Downdraft air ECNDowndraft oxygen Indirect, pyrolytic or steamgasification; typically in a twinFB

ECN

Bio-oil gasification BTG, FutureEnergy, FZK,TUB-F

Gas composition, dry, vol% HHV Gas quality

H2 CO CO2 CH4 N2 MJ/Nm3 Tars Dust

FB air-blown 9 14 20 7 50 5.4 Fair Poor

Updraft air-blown 11 24 9 3 53 5.5 Poor Good

Downdraft air-blown 17 21 13 1 48 5.7 Good Fair

Downdraft oxygen 32 48 15 2 3 10.4 Good Good

Twin FB 31 48 0 21 0 17.4 Fair Poor

Pyrolysis (for comparison) 40 20 18 21 1 13.3 Poor Good

Exhibit 3.9 Typical product gas characteristics from different gasifiers

Exhibit 3.8 Gasifers and examples visited duringmission

Modern FT, based on high performance cobaltcatalysts, has achieved further prominence inrecent years as it is the core technology forconverting natural gas into transport fuelsboth in Asia and more recently in the MiddleEast.

The basic process is reaction of CO and H2 inthe following conceptual process:

(2n+1)H2 + nCO CnH2n+2 + nH2O

The hydrocarbons produced range frommethane to very heavy hydrocarbons, such aswaxes that are solid at room temperature,depending upon the alpha value. An FTprocess therefore usually includes upgradingof the waxy liquids (such as by hydrotreatingor hydrocracking), refining (such as distillation)and recycling of unwanted products toincrease desired product yields. Very largeplants are necessary to give acceptableeconomies of scale. The minimum sizecurrently considered economically viable fromnatural gas is around 25,000-34,000 bbl/d orabout 1.0-1.3 million t/y.

This process has been commercially operatedby Sasol in South Africa since around 1955,where over 1 million t/y of coal are processed

into a full range of marketable hydrocarbonfuels and chemicals, and is referred to as coalto liquid (CTL) technology. Since the oilshocks of the 1970s and 1980s all of the oilmajors have have been active in developinggas to liquid (GTL) processes to convertnatural gas and natural gas liquids to transportfuels. Although Shell has been operating arelatively small GTL plant in Malaysia forsome years, it is only now that substantialGTL plants are being constructed in theMiddle East and Asia. There are therefore anumber of potentially suitable technologiesfor synthesis of transport fuels from syngasderived from biomass. Biomass to liquid(BTL) is currently attracting considerableinterest in Europe for both environmental andsecurity of supply reasons, but there is littleactivity in the UK. The biggest barrier is thelimited availability of biomass at any onelocation that makes the economies of scalenecessary for commercially viable FT difficultto achieve. There is potential for catalyst andprocess development to allow downscaling toaddress this barrier.

Both Choren and Future Energy are workingin this area, Choren via biomass gasificationfollowed by SMDS (Shell Middle DistillateSynthesis) and Future Energy via bio-oil (from

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Contaminant Examples Problems SolutionTars Refractive aromatics Clogs filters, difficult to

burn, deposits internallyTar cracking thermally orcatalytically, or tar removalby scrubbing

Particulates Ash, char, FB material Erosion Filtration, scrubbingAlkali metals Sodium, potassium

compoundsHot corrosion Cooling, condensation,

filtration, adsorptionFuel-bound nitrogen Mainly NH3 and HCN NOx formation Scrubbing, SCR (selective

catalytic reduction)Sulphur H2S Catalyst poison, corrosion,

emissions Lime or dolomitescrubbing, absorption

Chlorine HCl, COCl Catalyst poison, corrosion,emissions

Lime or dolomitescrubbing, absorption

Carbon dioxide Diluent Scrubbing – manyproprietary processes areavailable

Methane and higherhydrocarbons

CH4, C2H6, C3H8 etc Diluent and loss of energyif not processed

Reforming

Exhibit 3.10 Synthesis gas contaminants and their problems

fast pyrolysis such as by BTG or intermediatepyrolysis such as by FZK) gasification in anentrained flow gasifier. Liquid feeding to apressurised gasifier is easier than with solidbiomass. In particular it is lower cost as aliquid or slurry can be fed under pressurewith simpler and lower cost equipment thansolid biomass with lock hoppers or screwfeeders. The product gas is also likely to becleaner with lower tar content. A potentialproblem with liquid or slurry feeds is phaseseparation since a lower heating value/higherwater content feed will require less oxygenand, if suitable controls are not in place, canlead to oxygen overload in the reactor withpotentially serious consequences.

Methanol production from synthesis gas iswell established, and this chemical can beconverted to gasoline at high efficiency by theMobil MTG (methanol to gasoline) processusing zeolite ZSM–5 catalyst (see Exhibit3.11). This process has been technicallyproven at full scale in New Zealand, wherenatural gas is converted to methanol and thento gasoline, although the plant no longeroperates as the process is not commerciallyviable. The gasoline product is too aromaticbut the potential exists for processdevelopment. An analogous process knownas MOGD (methanol to olefins, gasoline anddiesel) has been developed for diesel fuel.

There are similar concerns over economies ofscale as for FT technology. TUB-F is focusingon this route to gasoline via methanolthrough system studies initially, although agasification system is under development. Itis also working on bio-oil gasification in asystem that seems likely to be comparable tothat of Future Energy.

Once-through systems have been proposed(see Exhibit 3.11) in which the syngas is notrecycled, but passes to an integratedgasification combined cycle (IGCC) gasturbine after a single pass through thesynthesis reactor. This reduces thecomplexity and hence cost of the synthesisprocesses and is claimed to offer theadvantages of higher efficiency, lower costand increased flexibility.

Methane or synthetic natural gas (SNG) isanother fuel of interest because it can readilybe distributed via gas grids in most Europeancountries. ECN has a particular interest in thisproduct.

A detailed, comparative analysis of thetechnologies for producing alternativetransport fuels is not known to have beencompleted recently and this would helpidentify the most promising technologies andtransport fuel synthesis routes.

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Exhibit 3.11 Biomass or bio-oil to transport fuels

Biomass

Bio-oil Refining

Hydrocarbonsynthesis

Methanolsynthesis

MTG orMOGD

Gasification,cleanup,

conditioning

Bio-oil-charslurry

Chemicals

Transportfuels

Electricity

3.5 Bioenergy system

A more global perspective of theopportunities for meeting the transport fuelrequirements in the UK is shown in Exhibit3.13. This includes the potential forproduction of:

• Biomass in the UK and/or overseas

• An intermediate such as bio-oil in the UKor overseas

• A finished transport fuel product in the UKand/or overseas

Included is consideration of integratedproduction of both transport fuels andchemicals to optimise energetically,economically and technically the use ofbiomass; this is commonly referred to as abiorefinery.

System analyses have been carried out bymost of the organisations visited. The Öko-Institut in particular has carried out extensiveand thorough analyses of a wide range ofsystems under different scenarios. VTT hasexplored the potential of integrating transportfuels production into pulp and paper mills byoptimising the use of its existing resourceswith additional imports of supplementarybiomass. This results in much higher overallenergy efficiencies to transport fuels. ECN

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Liquid fuel Studies ExperimentationMethanol ECN, SVZ,

TUB-F, VTTFZK (planned),SVZ

FT diesel Choren, ECN,Future Energy,VTT

Choren, ECN

Vegetable oildiesel

Neste Neste

Gasoline via MTG

TUB-F

Fuel alcoholSNG ormethane

ECN, VTT ECN

DME (dimethylether)

VTT

Hydrogen ECN, VTT

Exhibit 3.12 Activities on synthetic transport fuels atorganisations visited

Exhibit 3.13 Opportunities for meeting the UK renewable transport fuel demand

Gasification Markets

Feed productionin UK

Feed preparation in UK, eg pyrolysis

Feed productionoverseas – imported

Feed preparationoverseas, eg pyrolysis

Upgrading

Transportfuel synthesis



Biorefinery

Overseas

UK

has also carried out extensive studies ondifferent bioenergy chain configurations fortransport fuels.

3.6 Bibliography of further reading

Recent journals and articles

Bridgwater AV, The production of biofuels andrenewable chemicals by fast pyrolysis ofbiomass, International Journal of GlobalEnergy Issues (2006 in print)

Brammer JG, Lauer M and Bridgwater AV,Opportunities for biomass-derived ‘bio-oil’ inEuropean heat and power markets, EnergyPolicy (2005)

Czernik S and Bridgwater AV, Applications ofbiomass fast pyrolysis oil, Energy and Fuel18:590-598 (2004)

Bridgwater AV and Maniatis K, The productionof biofuels by the thermochemical processingof biomass, pp 521-612 in Molecular to globalphotosynthesis, Ed Archer MD and Barber J(IC Press, 2004)

Bridgwater AV, Biomass fast pyrolysis,Thermal Science 8(2):17-45 (2004)

Recent books

Bridgwater AV and Boocock DGB (Eds),Science in thermal and chemical biomassconversion, 1946 pp (CPL Scientific Press,2006)

Bridgwater AV (Ed), Pyrolysis handbook,volume 3 (CPL Press 2005)

Bridgwater AV (Ed), Pyrolysis and gasificationof biomass and waste, Strasbourg,September 2002 (CPL Scientific Press, 2003)

Bridgwater AV (Ed), Fast pyrolysis of biomass– a handbook, volume 2, ISBN 1-872691-47-1(CPL Press, 2002)

Bridgwater AV (Ed), Progress inthermochemical biomass conversion, ISBN 0-632-055533-2, 1759 pp (Blackwell, Oxford,UK, 2001)

Recent reports

Bioenergy – a scoping mission to the USAand Canada, February/October 2005, DTIGlobal Watch Mission Report, URN 06/829,56 pp, published February 2006:www.globalwatchservice.com/missions

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4.1 Towards commercial scale biofuelplants

4.2 BTL plant design4.2.1 Biomass feedstocks4.2.2 Biomass pretreatment4.2.3 Conversion

4.3 BTL development considerations4.4 Technical issues in BTL4.5 Catalysts

4.5.1 Conditioning of the gas4.5.2 Removal of trace impurities4.5.3 Downstream synthesis

4.6 Risk sharing4.7 Summary

This chapter deals with issues relating to theimplementation of the second generationtechnologies outlined in Chapter 3.

4.1 Towards commercial scale biofuel

plants

What will commercial scale biomass to liquid(BTL) plants look like? For thermal biomassconversion routes based on gasification andsynthesis, the basic steps are similar toemerging coal to liquid (CTL) conversionprocesses, as described in Chapter 3. A bigadvantage for BTL is that it makes use of thesame intermediate (syngas), and producesthe same product (synthetic diesel) from FTsynthesis. Also, solids handling systems arelikely to be similar for solid biomass feed tothe gasifier. With high oil prices and securityof supply as key drivers, there is considerableactivity today in demonstration plants anddeveloping commercial scale CTL plants.Hence such developments should makemodern gasification and synthesis plantdesigns proven and commercially available forany future BTL plant. In addition, gasificationis relatively feedstock insensitive and so the

same process and engineering designsshould be capable of converting a widediversity of biomass. Various concepts forcommercial BTL plant presented to themission team are discussed in Chapter 8.

4.2 BTL plant design

Basic routes for thermal biomass conversionto liquid fuels are covered in Chapter 3 andsummarised in Exhibit 4.1. Engineering anddesign for thermal conversion routes tosynthetic diesel will need to consider thefollowing aspects:

4.2.1 Biomass feedstocks

Potential biomass sources are from forestryand agriculture. Such sources range fromwood (residues and energy crops), grasses(eg miscanthus), and various agro-residues,such as straw, rice husks, sugar caneresidues (bagasse) and palm oil residues.Industrial waste (MSW) can also beconsidered a potential biomass source.Feedstock considerations are discussed inChapter 6.

4.2.2 Biomass pretreatment

Biomass has a very different nature fromconventional fossil fuel feedstocks. Suchsources represent a very wide range ofpotential feed type and characteristics to theconversion plant and a significant engineeringchallenge in preparing biomass forprocessing, compared to fossil fuels.Pretreatment is essential to allow stablefeeding and operation into conversion unitsand to reduce transportation costs. A numberof different steps under development werepresented to the mission team, as follows:

36


4 ENGINEERING, PLANT DESIGN AND TECHNICAL ISSUES

• Size reduction and drying of very diversematerial. High water content (can be up to65% wt) and a fibrous nature aresignificant issues; the water content needsto be reduced to below 15% wt forefficient transportation and/or as gasifierfeed. BTG discussed recent pretreatmentdifficulties in their demonstration plant, dueto the fibrous nature of palm oil residues(empty fruit bunches)

• Pelletisation of the dried solids, inparticular for long distance transportation

• Torrefaction (roasting), which upgradesbiomass to dry coal powder properties, aspresented by ECN (see Section 3.1.4)

• Pyrolysis to bio-oil. Several companiespresented current designs, as outlined inChapter 3. This technology is mostlydevelopmental with a number of newreactor designs being developed andrequiring scale-up

Very little large scale demonstration, scale-upor process integration has been done to date.Improved pretreatment is one of the targetsfor future demonstration plants beingprogressed by organisations such as ChorenIndustries and FZK.

Transportation of biomass, in particular overlong distances, is an important considerationin pretreatment from both a cost perspectiveand energy use, ie well-to-wheel CO2

emissions. Potential benefits from feedstockdensification, such as using bio-oil as anenergy carrier, need to be explored. Chorenprefers not to use bio-oil as an energy carrieron efficiency reduction grounds and becauseof handling and stability concerns, whilstFuture Energy is focusing on this route due tothe attractions of large scale fuel synthesisand the ease of feeding liquids into apressurised gasifier.

4.2.3 Conversion

There are three main considerations in theconversion section:

• Gasification to syngas. Biomassgasification technology is covered inSection 3.3. Biomass applications aresimilar to coal conversion to syngas, suchas CTL processes, and the significantimprovements in modern commercial scalegasifier designs can be applied to BTL

• Syngas quality issues are outlined inSection 3.3. Overall, with the exception oftar removal, clean-up requirements aresimilar to a raw syngas derived from coal,where the syngas is to be used forconversion to liquids. Contaminantremoval, CO to H2 ratio and pressureadjustment are needed. Hence processand plant design considerations are similarto those required for CTL processes. ForMSW processing, however, syngas clean-up to remove contaminants may wellrequire special consideration

• FT synthesis and product upgrading ofthe FT waxy liquids to diesel. As describedin Section 3.4, there is growing interest innatural gas and coal based processescombined with FT synthesis technology.Process and plant designs for conversionof syngas from oxygen-blown gasificationprocesses are being established by recentworld-scale GTL project developments.Designs for modern commercial scale CTLplants, based on modern gasificationtechnology and modern FT synthesiscatalysts, are under development. Anumber of world-scale CTL projects shouldbe under way within the next few years,making gasification and synthesis designsproven and commercially available forfuture large scale BTL plants

As described in Chapter 3, and shown inExhibit 4.1, there are also non-syngas routes

37


to transport fuels under consideration, suchas hydroprocessing. These technologies usemore conventional refining and petrochemicalengineering and plant design than thegasification route but require significantcatalyst development. If successful, suchschemes may offer lower capital cost andhigher overall efficiency compared to syngas-based routes.

4.3 BTL development considerations

How commercially ready are the thermalbiomass conversion routes? Overall thetechnologies in question are not mature;there is no commercial BTL (gasification andsynthesis) biomass plant in operation.However, a number are in demonstrationphase that will allow scale-up to commercialplant, as presented to the mission team. Forexample, Choren plans to link all of the BTLprocess steps together in a continuous plant.In addition, the syngas conditioning step islikely to benefit from future developments incoal conversion, which also produces a dirtyraw syngas that needs significant clean-upbefore synthesis, in particular if a cobaltcatalyst is used for the FT synthesis.

Access to FT technology may be an issue.Already Choren is linked with Shell, within itsstrategy of providing a whole technologypackage rather than individual technologyblocks. Others may well follow a similarroute.

Demonstration

Germany, in particular, has an impressiveamount of demonstration work in progress,mainly based on modernising old Germancoal gasification technology and know-how. A summary of technologies at thedemonstration stage presented to themission team is shown in Exhibit 4.2.

Developmental

Other processes reviewed during the missionare at an earlier stage of commercialisationand have to be considered developmental.These have been tested on small scale units,sometimes in batch operation, but needproving on larger scale equipment in order tomove towards commercialisation, in particularwhere novel reactor designs are involved.Developmental technologies presented to themission team are summarised in Exhibit 4.3.

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Biomass feedstocksupply

Biomass pre-treatment Conversion Product

Wood (residues andenergy crops)

Grasses (egmiscanthus)

Agro-residues• Straw• Rice husks• Bagasse (sugar

cane)• Palm oil residues

Size reduction

Drying

Pelletisation

Torrefaction(roasting)

Pyrolysis to bio-oil

Gasification (ofpellets or bio-oil)and syngastreatment

FT synthesisand productupgrading

Methanolsynthesis (also DMEproduction)

(Shift reactionandmethanation)

Synthetic diesel

Methanol/(DME)

(Hydrogen)

‘Secondgenerationbiodiesel’

Gasolineblendstock

Bio-oil hydroprocessing and deeprefining

Zeolite cracking

Exhibit 4.1 Process options in second generation biofuels

More novel technology such as hydrothermalupgrading (HTU) will need larger scaledemonstration to establish process and plantdesign. Hydrothermal deoxygenation (HDO)uses more conventional ‘refinery based’process plant but needs significant catalystdevelopment. Neste Oil technology is also amore refinery based process.

Overall, from the companies visited, there isan impressive amount of technologydevelopment under way in Europe, in particularbased on modernising the old German coaltechnology. Development highlights presentedto the mission team on various technologiesand proposed commercial designs aresummarised in Exhibit 4.4.

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Technology Company Application CommentGSP entrained flow gasifier(Future Energy)(Note: GSP technology nowowned by Siemens)

Sustec Coal, wastes and biomassfeed to syngas

Coal and biomass operation atSchwarze-Pumpe

Fast pyrolysis (rotating conereactor)

BTG Bio-oil production 2 t/h demonstration plant inMalaysia on palm oil residues;target market is powerproduction due to low quality bio-oil; multiple small units planned

BTL (Carbo-V® gasificationand Shell FT synthesis)

Choren BTL process demonstration Beta demonstration plant 13,000t/y (~350 bbl/d) due to start 2007

Gasification and methanolsynthesis (Lurgi fastpyrolysis/GSPgasification/Lurgi methanol)

FZK Full chain testing, includingbio-oil slurry feed to gasifier,and methanol production

2 MW demonstration plant(~4,000 t/y capacity) underconstruction; slurry feed togasifier

NExBTL Neste Vegetable oil hydrogenation Development unit underconstruction at Porvoo refinery;joint venture with Total in planning

Exhibit 4.2 Process demonstration plants

Exhibit 4.3 Process plants under development

Technology Company Application CommentHTU and HDO (on biocrudefrom HTU)

TNO Wet biomass (typical feed25% wt biomass in water)

Pilot plant testing; potentiallycheaper and more efficient thanFT; based on old Shell technology

PyRos fast pyrolysis (cyclonicreactor

TNO Bio-oil from biomass orwastes

Looking at FCC system for largerscale and adding zeolite to sandto help deoxygenation

Fast pyrolysis VTT Bio-oil production for powergeneration and refineryupgrading

20 kg/h pilot unit for biomasstesting

Pressurised FB gasification(biosyngas)

VTT Fuel flexible gasifier forbiosyngas production

Pilot unit operated up to 20 barpressure

VERENA (gasification of wetbiomass)

FZK Focus on lignocellulose(wood and grasses)

Pilot plant using supercriticalwater at very high pressure; highcost materials of construction

Methanol to gasoline (HTWgasifier + Lurgi MtSynfuel)

TUB-F Biomass to gasoline Looking to pilot at Total Leunarefinery

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Company Technology/topicscovered

Process developmenthighlights

Commercial-scale concept

VTT Fast pyrolysis process toconvert low value residuefeedstocks

First phase: integrated thermalprocessing (ITP) for heat andpower

Second phase: biorefineryconcept

10-20 MWth biomasspyrolysis unit with bio-oilupgraded at biorefinery;claimed integrated efficiencyof 80-90% may be optimistic

Pressurised FBgasification (biosyngas)for a variety ofapplications

500 kW pilot unit operated up to20 bar; new 30 bar unit underconstruction

200-300 MWth FB gasifier(10 bar); fuel-flexible oxygen-based syngas plus FTsynthesis for BTL, possiblyintegrated withmanufacturing site, eg papermills

Neste NExBTL process(hydrogenation ofvegetable oils and animalfats)

Building 170,000 t/y product unitat Porvoo Refinery; a jointventure (JV) with Total is inplanning

Hydrocracked products similar toFT diesel

Not raw biomass feed, butproduces higher quality oilthan first generation; Nesteclaims value where there isexisting excess hydrogenproduction

ECN BTL Process design and economicsfor BTL plants

Supply chain comparisons

Range of commercial plantsizes evaluated

Biorefineries Studies to meet ~150 million t/y(Europe 30% target by 2030)

Thermal biorefinery concept

Microalgae, seaweed Microalgae biomass productionand concepts for onshore andoffshore

Large scale seaweedproduction integrated withoffshore wind farms andaquaculture in the North Sea

WUR Biomass supply chain System modelling for biomasssupply chain (Biologics andBioloco)

Supply chain options andoptimisation

Biorefineries Chemicals production (addsmore value) from biomass; smallscale local preprocessing toretain functionality

Biomass for bulk chemicalsproduction

Microalgae Biomass reactor developmentfor increased algae production

Green cell factories – fattyacids and agriculturalproducts

TNO HTU (hydrothermalupgrading); technologydeveloped and abandonedby Shell in early 1990s)

Wet feed (typical 25% wtbiomass in water) to yieldbiocrude; pilot plant tests at 120-180 bar in multitubular reactor

Commercial plant size130,000 t/y dry biomassfeed; several HTU units willfeed a central HDO plant

HDO (Hydrothermaldeoxygenation)

Some trials with Shell and Total;conventional hydroprocessingand hydrocracking

Fast pyrolysis PyRos 70% pyrolysis oil yield incyclonic reactor design

Looking at FCC system forlarger scale and addingzeolite to sand to helpdeoxygenation

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Company Technology/topicscovered

Process developmenthighlights

Commercial-scale concept

BTG Fast pyrolysis 70% pyrolysis oil yield inrotating cone reactor design

Demonstration project inMalaysia on palm oil residues(50 t/d); multiple small unitsplanned

Choren BTL process (Carbo-V®

gasification and Shell FTtechnology)

Beta demonstration plant13,000 t/y (~350 bbl/d) productfrom 75,000 t/y biomass due tostart mid 2007; oxygengasification at 4 bar, FT at 30 bar

Gamma semi-commercialplant: 200,000 t/y FT diesel(~5,000 bbl/d); may begreenfield or brownfield site

Future Energy GSP entrained flowgasifier (technology nowowned by Siemens)

Pilot scale gasifier test facilitiesfor feedstock testing andoptimisation; bio-oil/char feed

Demonstration unit at SVZ

GSP and MEGA-GSP;minimum 1,000 MWth

biomass feed

TUB-F Methanol to gasoline(HTW gasifier + LurgiMtSynfuel)

Looking to pilot at Total Leunarefinery

Commercial plant ~15,000t/d methanol as energycarrier; fuel synthesis inrefinery

HP-POX (methanol basedroute)

With Lurgi, pilot plant (100 bar)to produce methanol directly;operated intermittently

SVZ Operating site for anumber of gasifiertechnologies

Operating site withdemonstration GSP entrainedflow gasifiers (150 MW), a BGLslagging gasifier and seven Lurgigasifiers processing a widerange of industrial wastes andbiomass as pellets or briquettes;receives gate fee for wastefeeds

Methanol (100,000 t/y) andpower production since1995; looking to add newconversion plant; gasificationcapacity is 85,000-175,000t/y

FZK TAMARA Test facility for wastecombustion system

Thermal waste treatment

THERESA Rotary kiln pyrolysis test unit,designed for MSW treatment,including flue gas cleaning

Thermal waste treatment

Haloclean lowtemperature pyrolysisreactor

Rotary drum pyrolysis test unit;electrical waste (WEEE) initially;now biomass, mainly straw

Thermochemical conversionof straw

Gasification and methanolsynthesis

Tests using GSP pilot plantgasifier at Future Energy withslurry feed (biochar in bio-oil)from straw

Lurgi (LR) fast pyrolysis, GSPgasifier, Lurgi methanoldemonstration plant planned(wood, straw biomass)

VERENA pilot plant Uses supercritical water at veryhigh pressure

Gasification of wet biomass

Öko-Institut Biomass energystrategies

Model and GEMIS model anddatabase now integrates nearlyall biomass flows in Germanyand in the EU

Supply chain modelling

Exhibit 4.4 Development highlights from mission

4.4 Technical issues in BTL

Process efficiency is a key technical issue indeveloping BTL routes. In particular, thermalefficiency will determine overall net CO2

emission reductions and a ‘well-to-wheel’analysis is essential. In general, syngas-basedroutes to liquids are energy intensive and sohave relatively low overall efficiencies. Sometypical figures are shown in Exhibit 4.5.

Choren claims an overall 45-55% efficiencyfor manufacture of diesel product will bepossible in its Beta plant, depending on theoperating method used. Maximum dieselmode requires some power input. Also,Choren avoids the reduction in efficiency thatresults from a local pyrolysis step followed byprocessing in a central plant. Data presentedby ECN showed an overall 55% efficiency toFT liquids (note that a typical FT liquid (C5+)product yield is 80%:20% diesel to naphthaby volume). Future Energy indicated an overallefficiency of ~20% biomass to fuel.

Biomass is a ‘low density carbon’ source, dueto water and oxygen content in the feedstock,and also has a relatively low hydrogencontent. By pretreating the biomass feed,carbon density is increased but carbon tohydrogen ratio is not improved. Pretreatmentremains an area for further improvement.

As in CTL, the hydrogen to CO ratio in thesyngas needs significant adjustment usingthe water gas shift reaction:

CO + H2O CO2 + H2

Choren appears to be adopting a different

approach, in particular for its Beta plant,which is to add hydrogen from a separateplant. This is usually a very expensive optionbut may be justified for a small scale plant inorder to reduce capital costs.

More developmental non-syngas routesshould not be ignored as a potential means ofimproving overall process efficiency.

4.5 Catalysts

Successful implementation of a secondgeneration biofuels project will rely heavily onthe use of catalytic stages to accomplishseveral tasks. As has already been described,there are several different process routesbeing considered for production of secondgeneration biofuels and these lead to differentcatalyst requirements.

If a fast pyrolysis process is used to producea bio-oil then significant upgrading will berequired to convert it to useful transport fuels.This may involve catalytic hydrotreating withreasonably conventional refineryhydroprocessing catalysts, or zeolite cracking(see Section 3.1.5). Or it may involve first agasification stage to produce syngas.

If the biomass is converted to a synthesis gasstream, either by high temperaturegasification with oxygen or conversion undermilder conditions, the catalytic requirementsare likely to be in three areas:

• Conditioning of the gas• Removal of trace impurities• Synthesis of products suitable for use as

fuels

The exact combination of catalyst duties willdepend on the chosen biomass feed, thethermal upgrading process employed and thechosen product.

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Route Typical efficiency (%)Thermal Carbon

GTL-FT 60-65 77-82Methanol-DME 70 82CTL 24 35

Exhibit 4.5 Typical process efficiencies for syngasroutes

4.5.1 Conditioning of the gas

The two most likely requirements for catalyticgas conditioning downstream of a biomassgasifier will be conversion of unreacted tarsand adjustment of the CO:CO2 ratio using thewater gas shift reaction to achieve a suitablestoichiometry in the gas.

The process route recommended by VTT forbiomass conversion involves relatively lowtemperature gasification and henceproduction of a gas with some unreactedtars. These tars can either be removed byfiltering, scrubbing or by reaction over acatalyst to produce increased yield ofsynthesis gas. Although VTT has beeninvestigating different catalyst options, thesehave met with some difficulties and acommercially viable solution may not yet havebeen realised.

Water gas shift catalysts are well provencommercially for driving the conversion of COwith water to produce hydrogen and CO2.There are two types of water gas shiftcatalyst. The first of these is sour shift that isbased on cobalt and molybdenum andoperates in sour gas containing at least 300ppm of H2S. The sulphur is necessary to keepthe catalyst in a sulphided form for maximumactivity. The second type is so-called sweetshift that is widely used in synthesis gasplants based on steam reforming of sulphur-free hydrocarbons. Sweet shift catalysts aregenerally sensitive to sulphur and so carefulsulphur removal is needed for these systemsto operate effectively.

Most gasification applications that use shiftreaction systems use sour shift catalystbecause of the relatively high level of sulphurin the feedstock, which is normally coal,petroleum coke or asphalt. However, the levelof sulphur in the syngas resulting from thegasification of most biomass feeds would notcontain a high enough concentration ofsulphur. Hence there is a choice to remove

the residual sulphur (which is likely to beexpensive) or to dope the gas with H2S orsome other sulphur compound.

4.5.2 Removal of trace impurities

Most synthesis catalysts, whether for FT ormethanol synthesis, are relatively sensitive totrace impurities and so these must beremoved from the gas:

• Sulphur removal – this can normally bedone with simple fixed bed absorbentswhich effectively remove H2S at a widerange of temperatures

• COS conversion – if the gas containsappreciable levels of carbonyl sulphide(COS) it may be necessary to convert thisto H2S using a hydrolysis catalyst prior to abed of H2S absorbent

• Carbonyl removal – some carbonyls maybe formed in high temperature gasifiersand these can be removed on many highsurface area absorbents

• Halogen removal – some biomass feedsmay contain halogens which need to beremoved; this can normally be done at awide range of temperatures usingactivated alumina or mixed metalabsorbents

4.5.3 Downstream synthesis

For most process schemes for BTL theexpected synthesis technology is FTsynthesis. The largest commercial operationproducing FT liquids from gas derived viagasification is currently by Sasol in SouthAfrica. This technology is well proven and, inthe Sasol case, takes place overpredominantly iron catalysts. In addition tothe Sasol experience, several large GTLprojects are currently under development orimplementation, predominantly in the MiddleEast where gas is readily available at modest

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cost. These projects are generally beingbased around cobalt catalysis for the FTsynthesis. The cobalt catalyst generallyproduces a narrower range of hydrocarbonproducts, but is considered to be moresusceptible to poisoning than the older ironcatalysts, and therefore more stringentupstream gas purification is required.

Both iron and cobalt catalyst systems for FTsynthesis are considered to be commerciallyviable and hence no significant developmentsare needed to overcome issues that may behindering the introduction of secondgeneration biofuels.

As an alternative option, synthesis ofmethanol may be considered and themethanol either used as a chemical product orfor further conversion to gasoline. Conversionof synthesis gas to methanol is well proventechnology and developments are not neededto enhance implementation of biofuels.

The only plant operating at commercial scalethat was visited as part of the mission wasSVZ at Schwarze Pumpe. This plant isrelatively complex as it uses three differenttypes of gasification technology and its mainproduct is methanol, although a significantproportion of the synthesis gas is used togenerate power in a gas turbine. Thefeedstocks at SVZ are a mix of coal, sewagesludge and waste plastic. The catalystsystems used at SVZ are as follows:

• Gas conditioning – a single bed of sourshift catalyst is used to adjust thestoichiometry of the gas so it has the rightbalance of CO and CO2 for methanolproduction. As the feedstock is rich incarbon there is an excess of CO2 which isremoved in a conventional wash system.The activity of the sour shift catalyst ishigh, and this would lead to excessconversion of CO to CO2 and so a bypassis used to conveniently control the gascomposition

• Gas purification – the wide mix of feedsleads to several different impurities in thefinal synthesis gas that would otherwisepoison the downstream methanol catalyst,contaminate the final product or causecorrosion issues in the plant equipment.The purification system is operateddownstream of the acid gas removalsystem which removes most of the CO2

and H2S from the synthesis gas. There arefour purification catalysts and absorbents:

– Carbon trap to remove carbonyls– Activated alumina to remove halogens

(mainly HCl)– Precious metal hydrogenation and

combustion catalyst to removeunsaturated hydrocarbons and someoxygen

– Mixed metal sulphur guard to removeresidual sulphur

• Methanol synthesis – after the gasconditioning and purification systems thesynthesis gas is suitable for production ofmethanol and therefore there is aconventional methanol reactor using astandard copper/zinc catalyst

4.6 Risk sharing

The cost of developing second generationtechnologies is very high and extremely risky.One option, therefore, might be to form aconsortium of stakeholders which would behelpful in reducing the individual cost and riskand might potentially accelerate developmentand give access to a greater spread oftechnologies. This should result in a higherprobability that development of secondgeneration biofuel technology will take place.However, it should be noted that traditionallythis has not been the approach in developingprocess technology. New processes givecommercial advantage and intellectualproperty rights (IPR), giving the inventors theability to license the process and earnroyalties.

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4.7 Summary

Commercial BTL plants are some years away.Syngas from biomass and biomasspretreatment are areas that require largerscale process development. Biomasspretreatment for very diverse feed sources isa significant process challenge and thereneeds to be large scale demonstration andprocess integration for a wide range ofpotential feedstocks. Such developments arehappening in Europe, in particular technologydevelopments planned in Germany. FTsynthesis designs should benefit fromcommercial developments in natural gas andcoal based conversion to liquids. However,access to technology may be an issue for FTsynthesis in future BTL projects. Other non-syngas routes should not be neglected andmay provide overall improvements in processefficiency and cost if catalyst developmentsare successful. Risk sharing should beconsidered for biofuel implementation in theUK in order to accelerate development andgive access to a greater spread oftechnologies.

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5.1 The internal combustion engine’scontribution to reducing CO2

emissions5.2 First generation biofuels5.3 Second generation biofuels5.4 Impact on conventional

compression ignition (diesel) engines

5.5 Impact on compression ignitionstrategies for future emission standards

5.6 Quantifying impact of new fuels

The internal combustion (IC) engine isprobably most commonly associated with thecars and trucks seen on the roads every day,but its impact goes far beyond that. Diesel ICengines provide reliable power to theconstruction equipment used to build andmaintain the UK’s infrastructure, to thenation’s farm machines and to many of thecountry’s trains. Diesel engines also powerstationary generators for stand-by and remoteelectrical supply. As well as providing reliablesources of power, the improvements inemissions both historically and as a result ofupcoming legislation over the next decademean that diesel and gasoline engines areincreasingly low emission power providers.

5.1 The internal combustion engine’s

contribution to reducing CO2

emissions

As work progresses on driving down NOx andparticulate emissions to 90% lower thantoday, attention is turning to reducing CO2

emissions in response to concerns aboutGHGs. The CONCAWE/EUCAR/EC JRC well-to-wheel study (January 2004) showed thatBTL diesel produced from plant matter yieldswell-to-wheel reductions in CO2 emissions of

up to 90%, which is comparable with thebest possible hydrogen scenarios.

5.2 First generation biofuels

The existing, first generation, biofuels can bebroadly divided into three groups:

• Biodiesel (fatty acid methyl ester (FAME))from plant oils or animal fats– for diesel engines

• Bioethanol from starch or sugars– for petrol (gasoline) engines

• Biogas – for natural gas engines

Additionally there are those who advocate theuse of unprocessed plant oils in dieselengines, although the available data showsthat engine reliability is greatly diminished.There is as yet no standard for plant oil (egrapeseed oil) as a transport fuel although theGerman Institute for Standardization(Deutsches Institut für Normung – DIN) is inthe process of developing a standard forthese oils.

FAME biodiesel (or first generation biodiesel),conforming to the relevant European Norm(EN) and American Society for Testing andMaterials (ASTM) standards, can be burned ina standard diesel engine. Some materialchanges are required since biodiesel is knownto impact negatively on natural and nitrilerubber polymers and some metals. Somediesel fuel system manufacturers usebiodiesel compatible materials or provideoption kits to make the fuel systemcompatible. However, the common positionstatement of the diesel fuel injection system

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5 IMPLICATIONS FOR ENGINE MANUFACTURERS

manufacturers is still that they will onlyprovide warranty for use with up to 5%biodiesel blends.

Apart from this need to change materials, thekey engine related drawbacks that may beassociated with FAME biodiesel use are:

• Power loss due to reduced calorific value(~8%-10% typically)

• Increased NOx emissions (~10% butdependent on the specific engine)

• Biodiesel has an increased tendency tooxidise compared to mineral oil diesel andcan also biodegrade in storage; both ofthese degradation mechanisms ofbiodiesel in storage can result in enginefailures

Another significant potential drawback withfirst generation biodiesel (FAME) is thepotential for variability in product supplied tothe market. The European standard for FAMEbiodiesel (EN14214) has done a lot to ensurethat only good quality biodiesel is sold, butconsistency remains an issue. Furthermore,because the exact properties of the end fuelcan be affected by the choice of plant oil usedas feedstock, this also contributes tovariability in emissions, and performanceremains an issue.

5.3 Second generation biofuels

By contrast, second generation biofuelsrelying on the BTL process should avoid thepotential for variability due to feedstockchoice and large numbers of small producers.This is because, as reported elsewhere in thisdocument, the properties of the liquid fuelproduced by FT synthesis are not affected bythe biomass which is gasified at thebeginning of the process. Furthermore, theneed for large scale FT production facilities toensure that BTL fuels can be producedeconomically means that, when full scale

production commences, consistency ofsupply should be enhanced by virtue ofproduction being located at a few large scalefacilities.

BTL diesel also has similar stability topetroleum diesel and as a result will not besubject to the same problems of degradationin storage which afflicts FAME biodieselcurrently. This means that no special handlingrequirements are needed, particularly forthose customers who store their own fuel inbulk, or agricultural customers who may parka machine for several months at a time. Thedegradation to which FAME biodiesel issusceptible, if stored inadequately, may resultin engine failures, particularly of fuel systemcomponents.

A benefit of the FT process is that it ispossible to adjust the properties of the fuelproduced and tailor it for particularcharacteristics. For example, diesel with aparticular cetane number and/or evaporationcurve could be produced. From the point ofview of combustion in IC engines, the abilityto produce fuels with properties tailored todifferent advanced combustion strategies isparticularly beneficial.

5.4 Impact on conventional

compression ignition (diesel)

engines

A higher cetane number can be desirablefor conventional diesel combustion since, ingeneral, increasing cetane number results inimproved autoignition and therefore reducesignition delay with a consequent reductionin cylinder pressure rise rates and thereforereduction in NOx formation. The samereduction in ignition delay has the effect ofadvancing ignition which results inincreased NOx and so these two effectsmay cancel each other out or tend towardsone or the other depending on the engine inquestion.

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Neste reported tests carried out by Scania ona heavy duty diesel truck engine showing thathydrotreated vegetable oil fuel (NExBTL inthis case) resulted in decreased regulatedemissions. Exhibit 5.1 shows the resultsreported compared to sulphur free EN590petroleum diesel.

Exhibit 5.1 Decreased regulated emissions forhydrotreated vegetable oil fuel (NExBTL) compared tosulphur free EN590 petroleum diesel in a heavy dutydiesel truck engine

Choren, which produces BTL diesel at its pilotplant in Germany, report NOx reductions ofbetween 30% and 50% in light duty dieselengine tests by Volkswagen andDaimlerChrysler. Tests conducted at ArgonneNational Laboratory (ANL) on a Mercedespassenger car diesel engine and a Caterpillarsingle cylinder heavy duty diesel researchengine showed NOx reductions of up to 20%and particulate emission reductions of up to50% for both engines.7

According to the analysis published in SAEpaper 2005-01-3776 the BTL fuel produced byChoren (SunDiesel) has a cetane number of80 and a lower boiling range thanconventional US diesel (D2, ASTM D86). Thecylinder pressure and heat release datapresented in SAE 2005-01-3776 for theCaterpillar engine showed that there was nochange in the ignition delay despite thedifference in cetane number of the two fuels.SunDiesel’s cetane number is 80 while D2diesel has a cetane number of 47. The rate ofheat release does change, with the peak heatrelease rate for SunDiesel being lower thanfor conventional diesel.

A final point worth noting about the BTLdiesels described here is that the FT BTLdiesel from Choren has a 3% higher energycontent (lower heating value) than regulardiesel while the NExBTL diesel wasapproximately the same. This is a distinctadvantage for second generation dieselbiofuels over FAME biodiesel which has about10% lower energy content than conventionaldiesel. The fact that there should be no loss inpower associated with switching to secondgeneration diesel biofuels will be of benefit toend users.

5.5 Impact on compression ignition

strategies for future emission

standards

As mentioned above, researchers areinvestigating a number of strategies formeeting future heavy duty diesel NOx

emission standards. These bodies of researchcan be broadly divided into two categories:

• Conventional diesel combustion with after-treatment strategies such as Urea SCR(selective catalytic reduction), NOx trapsetc

• Advanced combustion strategies, such ashomogeneous charge compression ignition(HCCI) with minimum after-treatment

By using an after-treatment device such as aurea SCR system it is possible to reduce theNOx emitted at the exhaust exit. As withmost real world situations, no after-treatmentdevice will be 100% efficient. This means thatadvances are still required in combustionstrategies to reduce engine-out emissions toa suitable level so that the particular after-treatment system chosen is able to reducethe NOx emissions to the required level. TheBTL fuels currently available have beendemonstrated to reduce regulated emissionsfrom conventional diesel combustion engines.

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Emission Measured reduction

NOx ~18%

Particulates ~28%

Hydrocarbons ~22%

CO ~6%

7 Ng et al, SAE 2005-01-3776

There may be further benefits to be gainedfrom using the FT process to tailor the fuelstill further.

By comparison, the principle behind advancedcombustion strategies such as HCCI is toreduce engine-out emissions and avoid theneed for NOx removal after-treatment devices.HCCI combustion keeps in-cylinder NOx

formation to a minimum by avoiding the hightemperature flame which is normally found indiesel combustion. This ‘cool’ combustionavoids the high temperature flame whereNOx is formed in conventional dieselcombustion. The evidence published so far ismixed. Some research indicates that for HCCIcombustion, fuel with lower cetane thanconventional diesel is desirable in order tocontrol the combustion. Other research hasindicated that a higher cetane helps certainregimes of HCCI combustion.

5.6 Quantifying impact of new fuels

It is important for engine producers that BTLfuels are made available for testing in theirengines at an early stage so that the impactof these new fuels can be quantified as soonas possible. The exact changes in emissionsand performance with a new fuel may differfrom one model of engine to another and soit may be necessary to assess BTL fuelperformance on a wide range of engineplatforms.

The fuel injection equipment such as pumpsand injectors will be particularly susceptible tochanges in fuel properties. From this point ofview, the ideal scenario would be that anynew fuel would not necessitate changes tofuel system components.

Based on the experience of first generationbiofuels it is likely that the proportion of newfuels in the market as a percentage of thetotal fuel used will increase gradually over aperiod of time. If the second generationbiofuels are uniformly blended into the

national supply then the proportion of fuelentering a given engine will not be significantinitially. In some instances though, locallegislation or tax structures might make fuelblends with significant proportions of biofuel(>20%) desirable. Such legislation is alreadyin place in some countries. Examples of thisare:

• USA – diesel with 20% biodiesel (FAME)blended in (B20) qualifies as an alternativefuel for federal, state and public utilityfleets that have targets for alternative fuelusage

• Germany – where tax incentives havemeant that the pump price of biodiesel islower than petroleum diesel, commercialoperators were quick to demand biodieselcompatibility from the engines they use

With BTL fuels, the closer their similarity toconventional diesel from the point of view ofchemical structure and energy content, anydemand for high proportion secondgeneration biofuel blends should pose fewerof the kind of problems outlined for FAMEbiodiesel previously.

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6.1 Introduction6.2 Feedstock potential6.3 Available feedstocks

6.3.1 Industrial waste6.3.2 Agricultural and forestry

residues6.3.2.1 Straw6.3.2.2 Woodfuel6.3.2.3 Wet agricultural

residues6.3.3 Dedicated energy crops

6.3.3.1 Perennial grasses6.3.3.2 Short rotation coppice

(SRC)6.3.3.3 Oil palm co-products6.3.3.4 Microalgae

6.4 Supply chains6.4.1 Biomass sources6.4.2 Logistics and storage

6.5 Summary

6.1 Introduction

Feedstock supply and logistics for theproduction of second generation transportbiofuels is a vital component in the successof achieving the EU Biofuel Directive'sguideline of 5.75% by 2010. The technologiesseen in this mission have focused on thedevelopment of wastes and residues as themain feedstock, with some use of importedoils and indigenous forestry. Initially thesetechnologies have been implemented using afeedstock that is readily available in sufficientquantities, such as industrial wastes andagricultural by-products. Future developmentwill allow the supply to be refined andimproved and to include dedicated, highyielding energy crops when demandincreases.

6.2 Feedstock potential

The Biomass Task Force reported that 20 million t of biomass produced in the UKcould be available to the energy sector. Thisbiomass will come from wastes and cropsnot necessarily suitable for second generationtransport fuel production, and selection of themost economic and suitable feedstock mustbe considered.

The Öko-Institut highlights a number ofconstraints in place which will affectfeedstock production in Germany. Itenvisages that environmental restrictions willlimit feedstock quantities. Biomass productionwill become a sustainable farming system,less intensive than food production, and moreland will be taken for nature protection(biodiversity, and soil protection). Thirty percent of organic farming will remain until 2030and there will be no conversion of wetlandsor extensive grassland into arable land.However, land will become available after thereforms of the EU sugar market have beenimplemented.

Land in the Netherlands is currentlyconsidered too valuable to produceindigenous energy crops and the governmentforesees that any dedicated crop feedstockwill be imported.

Estimates of the quantities of feedstockavailable for renewable transport fuels (RTFs)are varied but it is considered that the EU willneed all of the available biomass to make asignificant difference in CO2 reductionsthrough the use of biofuel.

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6 FEEDSTOCK AND A SUSTAINABLE SUPPLY CHAIN

6.3 Available feedstocks

Selection of feedstock varied greatly betweenthe countries visited by the mission, althoughchoice within countries was more defined.Woodfuels were the preferred feedstock inFinland owing to the high level of forestrycover across the country. However, importedand indigenous oils were used for theproduction of NExBTL.

In the Netherlands, feedstocks were derivedfrom imported wood products and waste,with some work being carried out on themore novel crops such as marine algae. It isconsidered that Germany envisages that themajority of the feedstock used for RTFproduction will be ‘home grown’, thereforethe greatest variety of material selected forconversion processes was seen here. Therewas some development of dedicated energycrops such as short rotation coppice (SRC)and miscanthus in Germany but this wasseen as the future rather than the currentposition.

6.3.1 Industrial waste

Industrial waste represents a vast, mostlyuntapped, resource of biomass feedstock forbiofuels production. A wide range of biomassresidues and waste materials are producedfrom a diverse spectrum of industriesincluding the construction, food, medical,brewing and paper sectors.

In the UK this resource (municipal solid waste(MSW) and industrial wood waste) has beenestimated by the Waste and ResourcesAction Programme (WRAP) to be of the orderof 10 million t/y, and alternative outlets forthese streams are needed to divert materialaway from landfill sites.

The combustion of refuse derived fuel (RDF),the high calorific element separated fromMSW, is an established strategy for waste toenergy in some EU member states. The use

of RDF in the UK is limited due to concernsover flue emissions, public perception and theconstraints of the waste incineration directive(WID).

The use of industrial wastes as feedstocks forsecond generation biofuels technologypresents an alternative and valuable marketfor these feedstocks. Indeed, the use ofMSW as a fermentation feedstock for theproduction of ethanol is close to beingcommercial; Loso Noco has recentlyannounced its intention to build a largeethanol facility in the UK utilising thisfeedstock.

Improved pyrolysis and gasificationtechnologies for the production of secondgeneration biofuels being developed by thegroups visited during this mission offer robustand flexible routes to process a wide varietyof industrial wastes. The facility at SchwarzePumpe in Germany gasifies industrial wastefeedstocks to produce methanol, a potentialfeedstock for gasoline or diesel (MOGDprocess). Industrial waste streams consideredfor gasification and pyrolysis processesinclude MSW, debarking waste, sawdust,waste wood chips, paper mill residue, blackliquor and spent grains from brewing. In theUSA and Sweden considerable activity isbeing directed towards the pulp millbiorefinery concept whereby black liquorgasification technology and subsequentbiofuels production is integrated withinexisting pulp mill operations.

6.3.2 Agricultural and forestry residues

The agricultural and forestry industriesproduce high levels of residue that can beused for RTF production. These feedstockscould be made available in the quantitiesrequired and, in some cases, already have awell developed supply chain. Agriculturally theamount of energy available from biomass by-products and dedicated crops is currentlyvery similar, with the exception of oil-based

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feedstocks. This allows for the developmentof new technologies to first utilise thesereadily available residue products and then tointroduce more refined dedicated crops whenthe industry becomes more established. Thiscould reduce the problem of the ‘chicken andegg’ situation that has been currently holdingup the biomass energy industry. However,some residues are currently being utilised foranimal production and nature protection, anduse of these ‘wastes’ will create a gap withinthe agricultural sector and environment.

6.3.2.1 Straw

Straw is a by-product of the production ofarable crops such as wheat, barley, oats andrape. The UK currently produces 16 Mt/y ofstraw, 40% of which is chopped and returnedto the soil. These crops require high fertiliserand pesticide inputs and need annualharvesting and establishment. However, theyhave a well developed market andestablished infrastructure which will allow thesupply of an energy feedstock to runalongside an existing food market.

Most arable crops will yield up to 8 t/ha ofstraw which will require little drying for any ofthe technologies seen on the mission(moisture content <15%). However, it doescontain a high level of corrosive elementssuch as potassium, chloride and silica.Gasification technologies using straw arehighly likely to suffer expensive maintenancecosts, and the waste materials such as ashwill be heavily contaminated.

6.3.2.2 Woodfuel

The UK has the potential to supply 10 Mt ofwoodfuel from forestry waste.8 The majorityof the feedstock would come from forestryand woodland with 10% coming fromprocessing products. This figure does not

include use of recycled wood (solid recoveredfuel – SRF), and WRAP estimates that thereis up to another 10 Mt of wood wasteavailable in the UK annually. Suitability of thiswaste relies heavy on the end product, andnot all of the material would be used for RTFproduction. In some of the technologies seenon this mission, selection of wood has beenan important influence on the quality andyield of desired product. Bio-oil yields at VTTwere significantly reduced when the type offorest residue feedstock was altered.

Choren has selected woodfuel as the primaryfeedstock used in its Beta plant. Theseresidues alongside SRF and straw will providethe plant with 75,000 t/y and will produce18.5 million litres of Sunfuel. At its proposedGamma plants, Choren envisages that thewood feedstock will come from a 30 kmradius around the plants, and that each will beusing 1 million t/y of biomass.

VTT has calculated that 6-10 Mtoe/y ofbiofuels could be produced from Europeanforest residues, and considers wood residuesto be the primary feedstock for energyproduction in Finland.

6.3.2.3 Wet agricultural residues

Disposal of agricultural wet residues hasalways presented problems. The costs oftransportation to disposal sites are high dueto increased weight of the biomass from highmoisture content (MC). Any technology thatcould use these feedstocks as an energyresource must be highlighted. However,these technologies need to be relatively smallto limit the need for feedstock transportation.These wet wastes can amount to 4,000 Mt/y(dry basis) globally and 200 Mt/y (dry basis)within the EU.9 However, these figuresinclude peat as a feedstock which may not beconsidered as a renewable fuel.

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8 www.woodfuelresource.org.uk

9 TNO

At TNO, the development of hydrothermalupgrading (HTU) has enabled wet agriculturalresidues such as sugar beet pulp and onionpulp to be introduced as a feasible feedstock.These problematic feedstocks are also beingaddressed at FZK in Germany, where the useof supercritical water on wet agriculturalwastes is being developed. At its pilot plantVERENA, silaged corn (maize) residues arebeing used with 70% MC.

In the UK, 3 Mt of animal slurries andmanures are generated annually and thesetechnologies could help utilise this waste.Also in the UK, one of the problems currentlybeing addressed is the removal of the wetpulp produced during sugar beet ethanolconversion. The wet feedstock basedtechnologies could not only utilise this wetresidue but could increase the proportion ofthe crop used for energy production. This inturn would increase the carbon efficiency ofthe crop and improve the profitability.

6.3.3 Dedicated energy crops

The competition for land for energyproduction, including transport fuels, is strongand will increase in future years. The use ofavailable land for feedstock production mustutilise high biomass yielding crops.

6.3.3.1 Perennial grasses

Maximising the biomass production of theland area in the UK will require high yieldingcrops with minimal inputs. Miscanthus(Miscanthus giganteus) and switchgrass(Panicum virgatum) are the C-4 perennialgrasses being considered in the UK aspotential energy crops. By utilising the C-4metabolic pathway, the crop requires verylittle fertiliser input and uses water moreefficiently. This in turn means that the cropcan produce high yields of biomass moreeconomically and with lower carbon inputsthan arable crops.

Miscanthus and switchgrass are perennialgrasses that once established can beharvested annually and have a lifetime inexcess of 20 years. Research has shown thatmiscanthus can reach yields of over 15 t/ha inthe UK without the need for nitrogen fertiliserand can maintain these yields consistently forover 13 years. In the UK, miscanthus is acommercially available option for feedstocksupply and has been successfully establishedon 10,000 ha across the UK.

6.3.3.2 Short rotation coppice (SRC)

SRC in the UK mainly consists of willow (Salixspp), with production of poplar SRC (Populusspp) currently being developed. These nativetree species are relatively high yielding andrequire low levels of fertiliser. The agronomicknowledge of the crop is well established andan extensive breeding programme has beendeveloped for willow. Current published willowSRC commercial yields are 7 t/ha (dry basis);however, these original plantations were grownon poor soils and a more realistic mean yieldwould be around 9-10 t/ha (dry basis). SRC hasa high MC (50%) at harvest, and the crop willrequire drying during the preprocessing stage.

Willow SRC is commercially available, withwell developed production chains. Currently~5,000 ha of SRC willow has been planted inthe UK, with a further 50,000 ha of plantingcontracts for miscanthus and SRC beingoffered in the next five years.

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Exhibit 6.1 Miscanthus

In 2000, the UK Government had theforesight to see the need to developdedicated biomass production in the UK torun alongside developing renewabletechnologies, and implemented anestablishment grant for miscanthus and SRC.Four years later this development aid wasincreased further with the implementation ofthe Bioenergy Infrastructure Scheme thatenabled the development of biomass cropsupply chains. These schemes, together withthe CAP reform payment (€45/ha ≈ £31/ha),have allowed the UK to become a marketleader in the production of dedicated ‘woody’biomass crops in Europe.

In Germany these crops are viewed as animportant contributor of biomass in the futureyears. Choren has set up a company –Choren Biomass GmbH – dedicated to thedevelopment of energy crops such asmiscanthus, SRC and switchgrass. The Öko-Institut will be proposing incentives for SRCdevelopment to the German Government in2007, and foresees that the production of dedicated crops will be a vital component ofthe biomass supply chain.

6.3.3.3 Oil palm co-products

Unfortunately, conflicting pressures on landuse in countries such as Indonesia have ledto the association of palm oil with tropicalrainforest destruction. Recently, theRoundtable on Sustainable Palm Oil (RSPO)was formed to draw together keystakeholders globally and agreeenvironmental standards of production.Millions of hectares of land are available forexpansion without the need for deforestation,and hardier varieties of oil palm are now alsoavailable, enabling production in areas wherethere is no competition with rain forest.

Within these parameters, the oil palm holdsgood potential for use as a multipurposeenergy crop, spanning first and secondgeneration biofuel production. Originatingfrom tropical West Africa, it is mostsuccessful in areas within 10 degrees of theequator. Mature oil palms produce 20 t/ha/yof fruit bunches, 4 t of which is vegetable oil.This is four times the yield of oilseed rapegrown in the EU. Oil palm is the highestyielding conventional crop in the world, in

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Parameter SRC poplar(Populus spp)

SRC willow(Salix spp)

Miscanthus(Miscanthusgiganteus)

Switchgrass(Panicumvirgatum)

Reed canarygrass(Phalarisarundinacea)

Current typical yield (t/ha dry matter)

7a 7a 12 10 8

Establishment time (y) 3+ 3+ 3+ 2-3+ 1-2Pesticide requirements Low Low Low Low Very lowFertiliser requirements Low/medium Low/medium Low Very low MediumAgronomic knowledge Good Good Reasonable Low LowEstablishment costs High High Very high Very low Very lowPest/disease problems ? Beetle

RustNone serious None serious Possible insect

pest problemsPlantation longevity (y) 20+ 20+ 20+ ? 20+ ?? 10+ ??Other issues Resistant to

lodgingResistant tolodging

Resistant tolodging

a SRC poplar and willow yields are estimates from farmers' willow fields and represent the fact that manycrops are grown on low grade land; plot yields are greater (~10 t/ha dry matter)

Ref: Powlson DS, Riche AB and Shield I, Biofuels and other approaches for decreasing fossil fuel emissionsfrom agriculture, Annals of Applied Biology 146(2):193-201 (2005): www.blackwell-synergy.com/links/doi/10.1111/j.1744-7348.2005.040056.x/abs

Exhibit 6.2 Summary of information currently available on biomass crops in use or being researched in the UK

addition to which it produces palm kernel oilfor oleochemicals and significant biomass thatcan be used for fuel production via secondgeneration technologies.

BTG is working with a palm oil company inMalaysia to produce pyrolysis oil from theempty fruit bunches after the oil bearing fruithave been extracted. Their fibrous nature hascaused some technical difficulties which thegroup is working to overcome. BTG is hopingin future to use discarded palm leaves in thesame process, although other studies haveshown these to be suitable for animal feed asan alternative.

In general, empty fruit bunches are currentlystacked and composted to form a soilimproving mulch around the base of oilpalms, especially in parts of the plantationthat have poorer soils. It is thereforeimportant that alternative uses take intoconsideration the need for recycling ofnutrients and organic matter in the productionsystems.

Because oil palm is a tree crop, it does notrequire the same intensity of cultivation asannual oilseed crops such as oilseed rape orsoya beans. It is thus less energy and CO2

intensive. According to Neste, its productionresults in less than half the CO2 emissions ofsoya oil and less than a fifth of those ofoilseed rape (see Exhibit 6.3), and it is aviable feedstock for its hydrogenationprocess. Palm oil sells at the equivalent ofaround $30-40/bbl (~£17-23/bbl), making it

cheaper than crude oil at current worldmarket prices.

6.3.3.4 Microalgae

Microalgae are tiny, sometimes single celled,aquatic plants that can often be found inseas, rivers, lakes and waterways. They thrivein water that is rich in nutrients, especiallynitrogen, and can multiply rapidly, turning thewater green.

In warm regions of the world they arecultivated commercially, often in racewayponds with CO2 injection to enable rapid,intensive growth. They are mostly used fornutraceuticals. For example, Spirulina is raisedin this way and processed to make healthtablets as dietary supplements.

Microalgae are potentially the mostproductive plants on earth, with very highphotosynthetic efficiencies. Research hasbeen undertaken, notably in the USA andJapan, to try to harness this for bioenergyproduction. Environmentally, this would haveseveral distinct advantages over conventionalbiofuel feedstocks:

• They have productivities an order ofmagnitude higher than many conventionalcrops, enabling large amounts of fuel to beproduced from a small area

• They do not require soil, which means thatthey can be grown in areas unsuitable forconventional agriculture

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Fossil diesel NExBTL RMERaw material Crude oil Rapeseed oil Palm oil Soya oil Animal fat Rapeseed oilProduction 1.3 0.25 0.54 0.28 1.3Transport 0.005 0.18 0.09 0.033Processing/refining

0.2 0.2 0.2 0.2

End use 3.2 0 0 0 0 0TOTAL 3.8 1.51 0.45 0.83 0.51 1.6-2.3

Exhibit 6.3 NExBTL CO2 emission comparisons in kg CO2 equiv/kgoe

• There are varieties that can grow inseawater, which avoids conflicts withagriculture for precious freshwaterresources; growth ponds could beconstructed in coastal desert regions,using their abundant land, sunshine andseawater to produce clean, renewablebiofuels

Production of methane, hydrogen, biodieseland second generation biofuels frommicroalgae have all been considered.However, challenges remain with making iteconomical. ECN and WUR both estimatedcosts of around €2,000/t (~£1,400/t) dryweight, which is based on a simple, butstandard production system. This is an orderof magnitude too high for economical, stand-alone fuel production, which would requiremuch cheaper production systems combinedwith consistently high productivities. Suchsystems have been designed, but furtherresearch and demonstration projects areneeded in this area.

In the meantime, production of microalgaecan be made more economical by using themto treat waste water. This is already beingdone commercially in warmer regions, suchas California, where the algae convert thesunlight into bioenergy whilst absorbing thenutrients and oxygenating the waste water.By combining bioenergy production withwater treatment and reuse, the economicsare improved considerably. Fewer inputs arerequired (nutrients, CO2) and the value of theoutputs is increased. As the ‘bio-economy’expands, there could be increasingopportunities for microalgae in waste watertreatment as part of an integrated solution tobiofuel production.

6.4 Supply chains

During this mission there was very littleopportunity to investigate supply chains indepth. Demand for feedstock is currentlyquite low and feedstock is sourced eitherlocally or imported using the establishedanimal feed market. As demand increases,

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Exhibit 6.4 Screenshot of the Bioloco program (courtesy of WUR)

supply chains and biomass markets must bedeveloped globally and within the EU.

Analysis of future potential supply chains hasbeen carried out at WUR. Dr Bert Annevelinkhas developed an integrated framework toassess spatial and related implications ofbiomass delivery chains. The problem heidentified was how the large global supply ofbiomass can be made available for biofuelconversion. He has broken down the biomassdelivery chain into three links: biomasssources, logistics and storage, and biofuelproduction. He has identified the spatialimpacts of each aspect of the delivery chainand has identified the technical and socialinteractions that are affected by the chain.Using the information collected concerningthese three stages he has developed abiomass chain model, Bioloco. This model willsuggest an optimum biomass chain based ona chosen optimisation criterion, financial orenergetic, or to meet preset goals for each.

6.4.1 Biomass sources

Current feedstock selection is based onfeedstock supply and availability. Futurerefinement and competition for individualfeedstocks will mean that each technologywill begin to select for different quality traits.Identification of these traits is beinginvestigated by most of the institutes visited.

Information on the quality traits identifiedmust be made available to feedstockproducers. This link can benefit producers aswell as the biofuel technologies. During thismission there were no visible links betweenfeedstock producers and conversiontechnologies. The producers may be able tomanipulate the feedstock to enhance adesirable characteristic or to reduce negativetraits. This link must be established toincrease the efficiency of a supply chain. Inthe UK, this knowledge transfer gap is beingbrought together with the SUPERGENBiomass and Bioenergy Consortium. Funded

by the Engineering and Physical SciencesResearch Council (EPSRC), this consortiumprovides not only academic links between thetwo research areas but is aided and advisedby industrial partners from both ends of thechain.

Physical properties of the feedstock arebecoming an important characteristic insupply selection. Feed intake systems inmost technologies are a major considerationwhen choosing a material. Feed blockagesaccount for the majority of down time formost commercial plants.

Selection of feedstock on compositionalquality has been made easier by thedevelopment of a feedstock biomass andwaste composition database, Phyllis, hostedby ECN. This database contains informationon ultimate and proximate analysis of over 60 different feedstock materials. This can beused as an important screening service toselect feedstock suitable for conversiontechnologies.

6.4.2 Logistics and storage

The widespread implementation of secondgeneration biofuels production technology willrequire the development of highly integratedand efficient biomass supply infrastructure toensure secure delivery of competitivelypriced feedstocks to large pyrolysis andgasification facilities. In addition, this biomasssupply chain must function at minimumenergy inputs and environmental impacts.Feedstock supply chains are well establishedfor both fossil transport fuel and firstgeneration biofuel production, the latterexploiting established infrastructure for foodsupply. However, the development of efficientbiomass supply chains presents a number ofunique challenges:

• Low bulk and energy density of solidbiomass

• High moisture content of biomass

57


• Physical and compositional heterogeniety• Antiquated and innefficient harvesting

techniques• Seasonal variations in biomass supply• Constraints on transportation distances for

indigenous biomass feedstocks

To address these barriers, more R&D work isnecessary to develop improved harvesting,drying and densification (baling, chipping,pelleting etc) technologies. The unoptimisednature of current biomass supply chains mayconstrain the scale of biofuel productionplants such that they are economicallydisadvantaged against larger facilities thatenjoy greater economies of scale. Choren hasstated that its first full scale BTL biodieselplant (200,000 t/y of diesel), planned for2009/10, will require 1 million t/y of biomassfeedstock, which will be sourced within a 30 km radius of the plant. The majority of thefeedstock is likely to be based on forestry andagricultural residues. The output of this plantis relatively small compared to GTL plants inconstruction utilising natural gas feedstock.

A number of technologies in development,observed during this mission, are addressingthese key barriers described above. ECN isdeveloping torrefaction biomass pretreatmentmethodologies for densifying biomass andwood pellets prior to feeding into gasificationprocesses. This torrefaction process, a mildthermal treatment, not only increasesbiomass pellet energy density, but alsoreduces the tendency of the material toabsorb moisture from the atmosphere andimproves its grindability and its fluidisationproperties.

The various pyrolysis technologies observedduring the mission could ultimately help toaddress existing biomass logistics issues bytransforming solid material into pumpable,energy dense and easily transportable liquid.Such conversion technologies could beoperated at satellite centres close tofeedstock sources, eg forestry operations, for

distribution of bio-oil to large centralisedgasification facilities.

6.5 Summary

The use of residues as a feedstock forsecond generation transport fuels has beenidentified and exploited throughout thecountries visited during this mission.Dedicated biomass crops are not currentlywidely being investigated. Development ofthese crops will be a vital issue in futureyears when feedstock composition andrefinement is established. New technologiesthat utilise wet feedstock will beadvantageous to enable the disposal of wetresidues; however, it must be stressed thatthese technologies are in the developmentstage and may take some time to reachcommercial status.

Global markets must be introduced fordedicated biomass crops to allow us toexploit more suitable climates and soils forincreased biomass production. Exploitation ofavailable land in the UK will require dedicatedenergy crops to increase in their land areaand research into the development of thesecrops must continue.

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7 ENVIRONMENTAL IMPACTS

7.1 Background7.2 CO2 emissions7.3 Other air pollutants7.4 Land7.5 Water7.6 General considerations

7.1 Background

Amongst renewable energy sources, biofuelshave a unique role to play, being the onlydirect substitute for fossil oil based fuels.Their popularity is growing rapidly due tofactors such as increasing oil prices andconcerns over future security of supplies.However, in the EU it is the environmentalbenefits that are most often cited as the keydriver. Therefore, this chapter will examine theenvironmental implications of increasedbiofuel production as they relate to CO2

emissions and the key resources of air, land

and water. This is a complex subject, withlimited scope in this report to do little morethan raise general issues and make broadcontrasts between first and secondgeneration biofuel production.

7.2 CO2 emissions

Modern agricultural methods have beendeveloped for maximum food productionrather than overall energy efficiency. Largeamounts of energy are required for poweringmachinery and for artificial fertiliserproduction; less is required for perennialcrops or trees that can be used as feedstocksfor second generation biofuels and so theCO2 benefits are generally better. If residuesare used as feedstocks, the carbon andenergy balances are even more favourable.This is made clear in Exhibit 7.1, whichcompares well-to-wheel CO2 emissions from

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Exhibit 7.1 Well-to-wheel energy content and GHG emission analysis

Gasoline2002 (PISI)

EU EtOH:Wheat, conv

NG boiler,DDGS as

animal feed

EU EtOH: LCW. wood

BrazilianEtOH: Sugar

cane

Diesel 2002(PISI)

EU FAME:Rape, gly.as animal

feed

EU: Syn-diesel:W. wood

300

250

200

150

100

50

0

Total fossil energy use MJ/100 km GHG emissions g CO2 eq/km

32% 79% 87%

47% 93%

various fuels with synthetic diesel from wastewood shown on the right hand side.

Since artificial nitrogen fertilisers are generallyproduced from natural gas, with the release ofthe substituted carbon, it is important toconsider how nitrogen may be recycled inorder to minimise CO2 emissions. In thermalprocesses such as synthetic diesel production,most nutrients can be recycled by returningthe ash to the soil, but nitrogen is often lost asgas. Avoiding this through nitrogen recoverywould improve the energy balance and help toreduce overall GHG emissions.

Transportation of feedstocks and fuels isanother important consideration and in thisarea there is an environmental trade-offbetween biodiversity and transport distances.For gasification and FT plants, economies ofscale are significant so they require largeamounts of biomass. For example, Choren isproposing plants that require 1 million t/y ofbiomass. It expects to derive all necessary

feedstock from within 30 km of the plantusing forestry residues. This would require anaverage biomass yield of around 3.5 t/ha/yfrom the whole area. High output energy cropscan give significantly higher biomass outputper ha and this could be used to reducetransportation distances. There is the potentialfor this to lead to loss of biodiversity, however.

Transportation by ship is much more energyefficient than by land, but the fundamental problemremains: woody plant matter is bulky and not veryenergy dense. Therefore, intermediate processeswere considered that would increase the energydensity prior to shipping. Pelletising wood is onecurrently used method for doing this. Torrefaction,developed by ECN, has a similar effect, creating adried, smokeless fuel with similar mechanicalproperties to coal, making grinding far easier. Thetwo processes can be combined to create torrefiedpellets. Another potential technology is pyrolysis,which produces bio-oil, and methanol was alsosuggested as a suitable intermediate step. Thesemore concentrated fuels have a lower

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Exhibit 7.2 Typical outputs from Öko-Institut model (DE = Germany; PL = Poland; BR = Brazil; SRF = shortrotation forestry) (courtesy of Öko-Institut)

Person transport

Costs 2010 2020 Jobs CO2-equiv SO2-equiv

€cent/kWhinput person/TWhinput g/kWhinput

Fossil diesel with tax 9.9 10.88.8 325.9 0.5

Fossil diesel without tax 3.5 4.0Rapeseed oil – DE, with credit 4.1 4.9 306 150.8 1.1RME – DE, no credit 8.0 8.5 342 174.9 1.2RME – DE, with credit 7.7 8.2 314 65.4 1.0RME – PL, no credit 7.6 8.2 537 188.8 1.2RME – PL, with credit 7.3 7.9 508 78.7 1.0BTL-wood-residue – DE 5.3 5.1 153 -131.2 0.6BTL-wood-SRF – DE 8.8 8.9 1757 -99.7 0.8BTL-wood-SRF – PL 4.1 5.2 – -222.4 -0.6Fossil gasoline with tax 13.0 14.2

9.1 342.8 0.5Fossil gasoline without tax 5.2 5.7BioEtOH wheat – DE 7.2 7.8 217 197.3 0.7BioEtOH wheat – DE organic 9.5 10.2 518 130.4 0.2BioEtOH sugarbeet – DE 11.9 12.7 253 229.6 0.9BioEtOH wheat – PL 3.3 3.4 – 219.4 0.8BioEtOH sugar cane – BR 3.4 3.4 67 107.9 1.0Biogas (maize) 6.9 6.7 220 87.1 0.6Biogas (maize-organic) 8.8 8.7 360 71.1 0.4Biogas (double-cropping) 4.0 3.8 1870 88.8 0.5

Die

sel c

arPe

tro

l car

environmental impact from transportation andwould then be taken to a centralised gasifier and FTplant for synthetic biofuel production.

Research is being undertaken internationallyinto the use of pyrolysis to extract energy fromwoody matter, whilst leaving behind a carbonrich biochar which can be safely stored in soilfor hundreds of years.10 Many of the world’ssoils have lost carbon and this replenishmentactually improves their fertility, increasingbiomass production and yields. Thus, secondgeneration biofuels can theoretically beproduced with additional carbon storage,making them ‘carbon negative’.

Research undertaken at the Öko-Institutexamined the carbon and employment benefitsthat could arise from different biofuel options inboth diesel and gasoline substitution. Thesynthetic diesel option gave the greatest CO2

savings, producing a negative figure due tocarbon savings from electricity co-generation.

Thus second generation biofuel technologieshave considerable potential for reducinggreenhouse gas emissions fromtransportation. Since this is an importantreason for adopting biofuel usage, it shouldbe taken into consideration when taxincentives are set, rewarding lower carbonemissions rather than just giving a standardbiofuel rebate per litre (see Chapter 9).

7.3 Other air pollutants

In addition to greater CO2 reductions, secondgeneration biofuels can offer solutions forimproving local air quality owing to theircleaner burning properties. This topic iscovered in greater detail in Chapter 5.

7.4 Land

To replace oil with first generation biofuelswould require vast areas of land – roughly all

of the world’s crop land – to be dedicated tothe task. There is disagreement over theamount of land remaining that could beconverted for crop production, but even iflarge areas were available, the impacts ofdoing so would be considerable for theenvironment and biodiversity. Existingproductive land is being lost internationally asa result of degradation and desertification andthis encroachment is increasing rapidly. Forexample, the UN predicts that in 19 years’time, two thirds of Africa’s crop lands willhave become desert. Furthermore, as a resultof population growth and increasingaffluence, worldwide consumption of food isexpected to have doubled from today’s levelsby 2050, and energy demand is expected todouble or triple over the same period.

Clearly there are major challenges and, usingfirst generation technologies alone, the scopefor large scale biofuel production will be limitedin the long term by land availability. There isjustifiable concern that future biofuel productionshould be achieved with minimal impacts onfood production and the environment.

As a result there is already interest in firstgeneration crops that can be grown onunproductive land unsuitable for food crops.For example, Jatropha is a tough shrub beingplanted extensively in arid areas as a defenceagainst spreading deserts. Its roots helpprevent soil erosion and the fruit seedscontain vegetable oils with potential as abiodiesel feedstock.

Second generation technologies open upfurther possibilities in the UK and abroad:

• Inedible agricultural residues, such aswheat straw, can be converted to fuel,whilst the edible part is still used for humanconsumption. However, consideration mustbe given to the current uses of theseresidues (eg for animal feed or soil

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10 Lehmann J, Gaunt J and Rondon M (2005), Bio-char sequestration in terrestrial ecosystems – a review: mitigation and adaptation strategies for global change

improvement) and the environmentalimplications of diverting them for bioenergy

• Whole trees can be used as feedstock,irrespective of variety. Trees can be grownon land too steep for cultivation or otherwiseunsuitable for arable crops; because thewhole biomass can be used, greater fueloutputs are possible per ha compared withpurely first generation technologies, whichonly use a portion of the plant

The production of second generation biofuelsand the impacts on the landscape and theenvironment is the subject of ongoingresearch. In the European context, perennialgrasses such as miscanthus or short rotationcoppice (SRC) willow are popular optionsalready being developed for heat and powergeneration. Studies have shown them to beuseful wildlife habitats, although they mayimpact the visual appearance of a landscapedue to their height. Vast tracts of tall growingmonocultures planted to feed large dedicatedbiofuel plants may cause controversy insensitive rural areas, and additional trafficvolumes resulting from the transportation ofthe biomass to the processing plants wouldalso need to be considered.

Although there are high potential, carbon andenergy efficient species selected for theirsuitability as energy crops there may also beexciting scope for multipurpose, sustainableforestry to be practised on a large scale withsignificant environmental benefits. Becausesecond generation technologies are notexacting with respect to feedstockrequirements, a wide variety of trees may begrown as mixed, multifunctional woodland,thus improving its biodiversity andenvironmental value. This could simultaneouslyachieve the twin goals of environmental gainand clean, renewable fuel production.

7.5 Water

Almost 70% of the freshwater resourcesused by human beings are for agriculturalproduction.11 In a world where demands forthis precious resource are increasing, it isimportant that it is considered whencontemplating future strategies. Ideally,where dedicated feedstocks are selected,they would be under rain fed agriculturalsystems, with minimal additional inputs.Applications of pesticides and fertilisersincrease the risks of water pollution, and soilsare especially vulnerable to leaching whenthey are left bare. Perennial crops and treeshave the advantage of generally requiringfewer inputs and of maintaining soil cover,thus reducing the potential for watercontamination compared with annual crops.

Therefore, long term feedstocks for secondgeneration biofuel production can havesignificantly less impact on water resourcesthan intensive annual crop production,provided that the right plant or tree isselected for the right situation.

7.6 General considerations

According to the European EnvironmentAgency12, there is sufficient biomass potentialin the EU-25 to support ambitious renewableenergy targets in an environmentallyresponsible way. In addition to this there arevery significant opportunities for developingcountries to become major producers, usingbiofuel production as a lever for economicand environmental development. Puttingfigures on the amount of biomass that couldbe produced worldwide is very complex, andstudies vary in their estimations by a factor ofnine.13 However, second generation biofueltechnologies could enable significantincreases in biofuel production with minimal

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11 FAO (2003) World agriculture: towards 2015/2030

12 EEA briefing, number 2/2005

13 Berndes G, Hoogwijk M and van den Broek, The contribution of biomass in the future global energy supply: a review of 17 studies, Biomass and Bioenergy

25:1-28 (2003): http://grove.ufl.edu/~bests/Net%20Energy/Berndes%20et%20al.%202003.pdf

environmental impacts. Indeed, there couldeven be environmental benefits achieved bymaking better use of residues andencouraging reforestation in areas where theenvironment has become degraded.

If environmental objectives are a prime driver,it is important that systems are put in place toensure that feedstocks are producedsustainably. Well-to-wheel CO2 emissionsmake up an important part of this. Usingenvironmental economics, it is possible tofactor positive and negative externalities intothe costs of biofuels, with greater incentivesfor customers to buy fuels that are producedin the most environmentally responsible ways.

A complete life cycle analysis ofenvironmental impacts associated withsecond generation biofuel production andconsumption is beyond the scope of thisreport, but considerable work has been donein this area by the Öko-Institut. The GEMIS(Global Emission Model for IntegratedSystems) model and other work it has done isfreely available on line.14

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14 www.oeko.de/projects_engl.htm, www.gemis.de

8.1 Overall economics8.1.1 Comparison with GTL and CTL8.1.2 ECN economic data8.1.3 Synthetic diesel from BTL

8.2 Socio-economic benefits8.3 Commercial concepts

8.3.1 Small scale production8.3.2 Large scale centralised

conversion plant8.3.3 Biorefineries

8.4 Barriers and issues for second generation biofuels8.4.1 Feedstock availability and

costs8.4.2 Transport issues8.4.3 Conversion costs

8.5 Summary

The current cost of most domestic andoverseas produced biofuels is around twicethat of conventional road fuels, as discussedin Chapter 2. As with first generation biofuels,the estimated cost of producing secondgeneration biofuels from biomass feedstocksis high compared to conventional fuels.Consequently, the cost of avoided CO2 is alsoestimated to be high (see Chapter 2).

In general, second generation technology forthese biofuels is either still at thedemonstration stage or developmental stage,as described in Chapter 4. Currently, there areno commercial plants in operation, nor

integrated demonstration plants. Also, thereis considerable uncertainty relating tofeedstock supply and pretreatment costs. In fact, in view of this lack of maturity ofeconomics, data for commercial scalebiofuels production should be taken asindicative only.

8.1 Overall economics

Only very limited economic data werepresented to the mission team. A summaryof economic data on the larger scale plantsand costs for various processes is given inExhibit 8.1. Only ECN presented a breakdownof production costs and some indication ofthe potential benefits from economies ofscale for the BTL route. ECN presented itscosts on an energy basis, which is morecommon to the power industry, rather thanon a weight or volume basis.

8.1.1 Comparison with GTL and CTL

In general, processes that produce asynthetic diesel (from gas, coal or biomassfeedstocks via syngas and FT synthesis) havemuch better economics at high crude oilprices, ie higher product values. However,these syngas based process routes are veryenergy and capital intensive technologiescompared to refining and petrochemicalprocesses. For example, typical GTL and CTL

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8 ECONOMICS, SOCIO-ECONOMIC BENEFITS AND COSTS

GTL Typical current capital costs for a GTL plant producing 4 million t/y (~100,000 bbl/d) FT liquidsare in the range €2.5–3 billion (~£1.7-2.1 billion), depending on location

CTL A CTL plant producing a nominal 2 million t/y (~50,000 bbl/d) FT liquids is estimated to cost inexcess of €2.5 billion (~£1.7 billion), excluding any carbon capture and storage (CCS) costs

BTL Based on current views, a BTL plant with a nominal production capacity of 0.6 million t/y(~15,000 bbl/d) FT liquids is expected to cost around €1.5 billion (~£1.0 billion); a larger scaleplant will give economies of scale, eg a BTL plant producing a nominal 3 million t/y (~75,000bbl/d) FT liquids is expected to cost in the range €3–3.5 billion (~£2.1-2.4 billion)

Exhibit 8.1 Typical capital costs of GTL, CTL and BTL plant

plant costs are compared with a current viewon biomass BTL capital costs in Exhibit 8.1.

For transport fuels, crude oil price is a goodindicator of overall economics. With lowfeedstock costs and world scale productioncapacity (>4 million t/y FT liquids), GTLrequires a minimum crude price in the range$25-30/bbl (~£14-17/bbl). With higherprocessing costs and typical productioncapacities in the range 2-4 million t/y, CTL isestimated to need crude oil prices in therange $45-60/bbl (~£25-34/bbl). Futurerequirements for carbon capture and storage(CCS) to minimise CO2 emissions will add tothe cost of CTL.

8.1.2 ECN economic data

For BTL, ECN presented estimatedproduction costs for a range of plantcapacities. At low production capacity,conversion plant production costs are high,but significant economies of scale arepossible. Feedstock costs, includingpretreatment, are high throughout andrepresent a high proportion of the productioncosts for the larger scale plant. ECN biomasscosts at €4/GJ (~£2.8/GJ) appear to becomparable with UK estimates of £40/t (drybasis) for energy crops (RothamstedResearch), including fixed costs. However, the ECN claim that large scale BTL fuelproduction can be competitive with fossilfuels, at the current oil price, seems to beextremely optimistic.

8.1.3 Synthetic diesel from BTL

Overall, synthetic diesel from BTL is expectedto be significantly more costly to producecompared to either GTL or CTL processes.Biomass BTL plants not only have high capitalcosts but also have relatively high feedstockcosts. In addition, biomass feedstockavailability and cost can limit the size of BTLconversion plant to much smaller productioncapacity than for either GTL or CTL. Therefore

BTL production costs presented to themission team are significantly higher thantypical equivalent costs for either GTL or CTLprocesses.

8.2 Socio-economic benefits

Biomass production for use in bioenergy canbring socio-economic benefits, as presentedby the Öko-Institut. Jobs from biomass canhelp to foster economic renewal in rural areasand encourage regional development. Mostsignificant to job creation is energy cropcultivation, but production of power frombiomass can also bring significant benefits.Öko-Institut estimates that, by 2030, inGermany over 200,000 jobs could be created,both direct and indirect (construction andinfrastructure). However, jobs related totransport fuels from biomass play only a smallpart in this projection. Nonetheless, Öko-Institut is including job creation benefits aspart of its overall supply chain modelling.

Also Choren is including job creation benefitsin order to improve overall economics from itsproposed commercial BTL plant. The Chorenapproach is a regional one, where its GammaBTL plant (~200,000 t/y product) will requirean intake of ~1 million t/y biomass. It ispossible that the small BTL plant is also partof a regional green energy infrastructure, iepower and heat production, in order tomaximise local biomass supply and socio-economic benefits. Recently, for eachGamma BTL plant, Choren has suggestedthat 150 direct and 700 indirect jobs could becreated.

8.3 Commercial concepts

A number of concepts under considerationfor commercial scale production of biofuelsfrom biomass were presented to the missionteam. These concepts basically fell into thefollowing categories:

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8.3.1 Small scale production

This concept is based on using stand-aloneproduction plants, close to local biomasssupply (see Exhibit 8.2).

The capacity of the conversion plant is limitedby local biomass supply. Dedicated biomassfeedstocks are used, within a specified limiteddistance from plant to minimise feedstockcosts and transportation. The use of an energycarrier is not required. There may be somelocal heat and power integration as part of alocal bioenergy infrastructure.

A typical example of this approach is Choren’sproposed Gamma plant. The planned capacityis 200,000 t/y product requiring a biomassintake of ~1 million t/y. Choren indicated thatthe biomass would come from within a 30 km radius. There are significant productioncosts associated with such a small capacity

commercial BTL plant, in particular oxygencosts for the gasification step. In view of this,Choren is now considering two possibleoptions:

• Greenfield site – located near Baltic Seafor regional biomass and imports

• Brownfield site – located in existingchemical park, with access to existingoxygen supply and possible utilitiesintegration; it is also possible that arapeseed oil plant will be built alongside,so that Choren could use the by-products

8.3.2 Large scale centralisedconversion plant

This concept is based on using a large scale,centralised conversion plant with biomassfeedstock supplied from distributed smallscale local biomass sources (see Exhibit 8.3).

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Exhibit 8.2 Small scale stand-alone conversion plant for BTL

Exhibit 8.3 Large scale centralised conversion plant for BTL

Local supply of biomass

Gasification and syngasconditioning

FT synthesis and productupgrading

Synthetic diesel

Biomass pretreatment(size reduction

and drying)


Heat and power

Local biomass pretreatment• Size reduction and drying• Pelletisation of dried solids or

pyrolysis to bio-oil



Transportation to central

conversion plant

Central gasification and syngasconditioning

Imports to centralconversion plant

FT synthesis andproduct upgrading

Heat and power




Heat and powerSynthetic

diesel



Biomass pretreatment is done locally andmay have heat and power integration.Transportation to the central conversion plantis by means of solid biomass pellets or byusing an energy carrier such as bio-oil. Localand imported biomass feeds are envisaged,with probably a coastal location for theconversion plant in order to reduce importedbiomass costs.

This is a typical approach being considered inthe Netherlands. ECN sees dedicatedbiomass FT plants of several GW capacitywith no polygeneration. A centralised BTLplant producing 0.6 million t/y liquids willrequire a biomass intake of ~3 million t/y. A very large centralised BTL plant, say

producing ~3 million t/y liquids, will require abiomass intake of ~15 million t/y.

8.3.3 Biorefineries

Biorefinery concepts are not new but arecreating renewed interest as a means ofimproving biomass economics. This approachinvolves a bioenergy system, as outlined inSection 3.5. A generic model is shown inExhibit 8.4.

A large centralised facility with a number ofintegrated process routes is envisagedinvolving a wide range of potential biomasssources, with local and imported supply.Several different process routes are employed

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BIOREFINERY

Exhibit 8.4 Biorefinery concept for second generation biofuels

Methanol,DME

Synthetichydrocarbon

biofuels

Specialitychemicals

Power andheat (CHP)

Municipal solidwaste (MSW)

Importedbiomass


Biomasspretreatment

Transportation to biorefinery

Methanolsynthesis and

DME production

Gasification and syngasconditioning

FastPyrolysis

FT synthesis and productupgrading

Wet biomassresidues

Microalgae

HTUHydro-deoxygenation

(HDO)

to give a wide range of products, egchemicals, power and transport fuels. Theobjective is to:

• Maximise feedstock availability• Optimise process integration for optimum

efficiency and cost• Maximise revenues from products

No economics or overall costs werepresented to the mission team but ECN,WUR and VTT are developing concepts.Simple biorefineries could be just BTL plantintegration into an existing site. In addition toa BTL plant, more complex biorefineries couldalso include:

• CHP from residues• Methanol/DME • Bioethanol, ie fermentation process route • HTU and HDO processing wet feeds• Industrial waste (MSW), possibly with

separate gasification and syngasconditioning to the other biomass, but acommon synthesis unit

8.4 Barriers and issues for second

generation biofuels

Second generation biofuels are at an earlystage of development, and estimatedproduction costs for synthetic diesel frombiomass are extremely high. Two factors, inparticular, have a large influence on cost andhence future deployment:

• Biomass feedstock costs• Small capacity BTL plant, limited by

biomass supply

Although it is expected that commercial planteconomics will become more definedthrough development of some of thecommercial concepts presented to themission team and supply chain development,

significant barriers to commercialdevelopment are likely to exist from:

• Feedstock availability and cost• Transport issues• Conversion costs

8.4.1 Feedstock availability and costs

Fundamental issues include:

• Feedstock (growing and gathering) – thereis a wide variety of types, availability andcost; what is the optimum combination ofbiomass feedstock and conversion?

• Availability of biomass feedstocks atcompetitive prices

• Lack of development of energy crops – arethese too expensive?

• Pretreatment – what pretreatments andwhere? Biomass type and characteristicsvary considerably and present a significantprocessing challenge

Both Neste and ECN saw barriers frominsufficient biomass and the ‘wrong type’ ofbiomass for ambitious growth. Öko-Institutindicated that Germany is planning significantfuture R&D investment in the biomass supplyside.

8.4.2 Transport issues

The low energy density of biomass and thelow production rate from a given area presenta fundamental challenge to biomassconversion. Energy carriers such as pyrolysisoil may help to concentrate supply andincrease transportation distances, but howmuch will this be supported by cost and theoverall CO2 balance? How does this comparewith converting to synthetic diesel closer tofeedstock source, as in GTL, and transportingthe finished product?

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8.4.3 Conversion costs

Conversion through gasification and FTsynthesis is a very capital intensivetechnology. Although significant developmentwork is in progress, fundamental questionsfor commercial scale BTL application include:

• Can small capacity conversion plant becommercially viable, and how?

• Significant reduction in production coststhrough economies of scale are possible –what size of BTL plant can be supported?Will a wide variety of biomass feedstockssignificantly improve viability?

• Will future improvements in developmentaltechnologies offer alternative routes andlower costs?

Can BTL grow from a fledgling industry todayto be commercially viable in the $40-70/bbl(~£23-40/bbl) crude oil price range, as for GTLand CTL processes? This currently appearsextremely unlikely, and incentives and policychanges are needed if much larger scale BTLdeployment is to become a reality. Asoutlined in Section 4.6, risk sharing should beconsidered for biofuel implementation in theUK in order to accelerate development andgive access to a greater spread oftechnologies. Suggested policy measuresrelating to the UK are covered in Chapter 9.

8.5 Summary

Compared to commercial GTL and emergingCTL processes, BTL has significant barriers tocommercial development in view of highfeedstock costs, transport issues and smallcapacity conversion plant. These combine tomake synthetic diesel by BTL very expensiveto produce.

Significant improvements in commercialviability are likely as BTL developers, such asChoren, look for better commercial solutions

on biomass availability and cost, as well aslower processing costs. Within Europe, suchsolutions are likely to include socio-economicbenefits from job creation and ruraldevelopment. Germany is likely to putsignificant future R&D investment into thesupply side.

It appears unlikely that synthetic diesel fromBTL will ever be directly competitivecommercially with fossil fuels, and thechallenge is to find policies and incentivesthat will encourage large scale BTLdeployment from a renewables standpoint.Risk sharing should be considered for biofuelimplementation in the UK in order toaccelerate development and give access to agreater spread of technologies.

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70


Company Process Capacity Capital cost Comments

VTT BTL 300 MWth

biomass feed to plant

€210-235million(~£145-162million)

FB syngas production plus FT, possiblyintegrated with paper mill

Neste NExBTL 170,000 t/ybiomass product

€100 million(~£69 million)

Similar production costs to RME butsuperior product; oil hydrogenation ratherthan transesterification process

ECN BTL 250 MWbiomass feed to plant

– Typical biomass scale:~80,000 t/y FT liquids; production cost~€27/GJ (~£19/GJ)

1,750 MWbiomass feed to plant

– Central conversion plant: ~0.6 million t/y FTliquids; production cost ~€17/GJ (~£12/GJ)

10,000 MWbiomass feed to plant

– Very large central conversion plant: ~3 million t/y FT liquids; production cost~€15/GJ (~£10/GJ)

1.3 million t/y FT liquids

€1.2 billion(~£0.83billion)

Capital costs seem low for this scale

Microalgae 25 million t/y dry biomass

Integrated production in North Sea? €50/t(~£34/t) (dry) onshore; €300/t (~£210/t) (dry)offshore

TNO HTU and HDO Commercialdesign for130,000 t/ybiomass

~€50 millionfor HTU plant(~£34 million)

Production costs ~€11-12/GJ (~£7.6-8.3/GJ)(including HDO); future plant ~€6-7/GJ(~£4.1-4.8/GJ); feedstock cost ~€1/GJ(~£0.69/GJ)

HTU 25,000 t/y €17 million(~£12 million)

BTG Fast pyrolysis 50 t/d €7 million(~£5 million)

Installed and running

Choren BTL Beta plant~13,000 t/y FT diesel

Ready 2007; Gamma plant target 2009/10

FZK Gasificationand methanol

2 MW demoplant (~4,000 t/ycapacity) underconstruction

€22 million(~£15 million)

Lurgi (LR) fast pyrolysis, GSP gasifier, Lurgimethanol demonstration plant

Exhibit 8.5 Economic data for second generation biofuels

9 POLICY AND INCENTIVES

9.1 Scenarios9.1.1 UK biomass for UK biofuel

production9.1.2 UK processing of imported

biomass9.1.3 UK import of synthetic biofuels

9.2 Potential deployment of secondgeneration technology

9.3 Existing policy measures andimpact on encouraging secondgeneration technologies

9.4 Proposals to encourage secondgeneration biofuels9.4.1 Linking support to GHG

benefits

9.1 Scenarios

Biomass is an unusual renewable energy (RE)resource in that it can be used for a range ofapplications, including both heat and electricityon a non-intermittent, firm basis, as well as forproduction of a range of biofuels – solid, liquidand gaseous. It is, however, a resource limitedby land use considerations, geographicaldistribution and resultant transport emissions,and consequently its use must be prioritised.

One of the primary benefits of secondgeneration biofuels is the ability to make useof a far wider range of biomass than the firstgeneration alternatives; however, the use ofeven biomass currently classified as residueor waste for transport fuel manufacturedepletes the resource available for heat orpower generation. The manufacture ofbiofuels, and therefore the steps taken topromote their uptake, must be undertaken inthe context of all alternative uses for thebiomass, and even the land required. This isdiscussed in greater detail in Chapter 7.

The potentially huge demand for biofuelsnationally, in the EU and globally, if evenrelatively modest proportions of the currentdemand for transport fuels are replaced,coupled with the high capital cost ofgasification and FT plant, mean that arelatively small number of centralised, verylarge scale facilities bring significanteconomies of scale and are the most realisticoption. Such large plants, however, requirehigh throughput of biomass feedstock tomaintain economic operation. Owing to thetypically low energy density of raw biomass,and the significant potential environmentaldamage associated with long distancetransport of feedstock, especially over land,siting of biomass gasification and FT plantsmust be undertaken with great care andconsideration of the feedstock supply chain.To take simply the UK demand for diesel, a5% penetration by FT diesel would requirearound 1 million t/y, requiring about 5 milliont/y of biomass feedstock. This is the scale ofjust five of the Gamma plants proposed byChoren.

It is therefore appropriate to consider variousscenarios for the use of biomass for biofuels:

9.1.1 UK biomass for UK biofuelproduction

Under this scenario a small number ofgasification and associated FT plants are setup in the UK using UK sourced biomass forfeedstock. In order to make use of existinglogistics infrastructure, the most likely sitingfor such plants would be associated withexisting oil refineries. There are nine major UKoil refineries, each sited in close proximity toa major seaport and good rail access. If five200 kt/y plants were constructed, co-located

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with existing refineries, they would eachrequire 1 million t/y of feedstock, or over 100 t/h to be delivered 24 hours a day, 365days a year. The total would represent overhalf of the total UK available wood resourcefrom forest and woodland, arboriculturalarisings, SRC and primary processingproducts, or, alternatively, around half theavailable recycled wood.

While it might be technically possible totransport such a large proportion of the UK'stotal wood resource to a small number ofsites, even if maximum use were made ofthe railway, waterway and coastal shippinginfrastructure there would also be aconsiderable requirement for road transport,and the pressure on the UK’s transportinfrastructure would be considerable. Thetransport costs would also dominate thefeedstock costs, and the embedded energyand associated GHG emissions of the finalfuel would escalate.

In addition, the impact on other industriescurrently making use of this resource, orintending to do so, would also beconsiderable. In particular it would be likely tohave a significant negative impact on thedeployment of biomass heat and powerprojects in the UK. At present a largeproportion of the potentially available woodresource from UK woodlands and forestry notowned by the Forestry Commission is notharvested as the price available for thinnings,brash and small round wood does not makethe process economically attractive for smallscale private owners. It would be necessaryeither for the price of biomass to rise, or forthe supply chain to become significantly moreefficient (such as by making greater use ofgreen wood, chipped in the forest directlyinto trucks, for transporting directly to point ofuse with no intermediate handling steps), ifthis potential resource is to become available.Without this resource it would be likely thatthe massive buying power and capitalinvestment of biomass gasification and FT

plants would dominate the domesticwoodfuel market, leaving the less accessibleresource for the local heat and powerprojects, pushing up the woodfuel price anddissuading future investment withoutsignificant further incentives.

Significant plantings of high yield energycrops could affect this position considerably,however. 1 million t of biomass could beobtained from within a 10 mile (16 km) radiusif the average yield were 12 t/ha, within thecapabilities of energy crops such asmiscanthus under good, UK conditions.Although an average yield of this level wouldbe unlikely to be achievable in the UK oversuch an extensive area, with the influence offactors such as road penetration, habitationand biodiversity concerns, it serves toillustrate how energy crops could play avaluable role.

Of course this scenario would be unlikely toevolve in this way in a free market as boththe cost and embedded energy of lowdensity biomass transported large distancesover land in relatively small quantities wouldrapidly become less attractive than feedstockimported by the shipload. This becomesespecially true for biomass residues that havevery low, or even negative costs wheredisposal is a valuable service. In general,biomass is not time sensitive and issusceptible to large scale bulk handling andshipping, a relatively cost-effective andenvironmentally low impact transportationoption. These options are already exploited bythe biomass co-firing industry (whosecombined demand is already on the scale ofa million t/y) in the UK, and leads to thesecond scenario.

9.1.2 UK processing of importedbiomass

An alternative to the scenario above is that agasification and FT plant associated with a UKoil refinery would obtain its feedstock from a

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range of biomass sources overseas. It is likelythat a proportion of this would be organicprocessing residues such as olive cake fromthe rim of the Mediterranean from the oliveoil industry. Buying biomass on a global openmarket enables optimum prices to be paid;however, despite the relatively low CO2

intensity of sea freight travel, it is desirable tominimise transport as much as possible.

Sea freight contributes about 14 grams ofCO2 per tonne kilometre (g CO2/t km), whilerail contributes 23 g CO2/t km, road freight123 g CO2/t km and air freight 900 g CO2/t km.15 However, ships are fast becoming thebiggest source of (non-CO2) air pollution inthe EU. By 2020 they are expected to emitmore than all land sources combined.16 It istherefore vital that if biomass is to betransported in bulk around the world it bedone as efficiently as possible.

The various biomass densificationtechnologies discussed during the missionoffer the potential to reduce GHG emissionsfrom feedstock transport in this way, andvarious organisations visited have developedsophisticated models to allow the analysis andoptimisation of different options againstenvironmental and financial criteria. ECN, FZK,WUR and the Öko-Institut have all done workdeveloping models to help optimise thesupply chain and choose the bestcombinations of plant siting and densificationprocesses. Such processes range fromchipping the biomass, through drying,pelletising and torrefaction to flash pyrolysis,each with different financial and energy costsand with the feedstock transported at differentdegrees of densification.

There is of course no universal solution.Different densification processes bringdifferent processing costs, both financial andin terms of embedded energy. Different

densified products too, such as pyrolysis bio-oil or torrefied pellets, bring different degreesof ease of handling and subsequentprocessing. Which is the most suitable for aparticular combination of conditions willdepend on the amount and type of biomassavailable, and its geographical distribution anddistance from a potential processing plantand distance and nature of local transportinfrastructure; the distance which it needs tobe transported to a centralised gasificationand FT plant; how many, and the geographicaldistribution of such feedstock densificationplants; etc. For instance, if the majority offeedstock will be delivered from relativelylocal sources as either raw biomass ortorrefied pellets, it may not be justified tobuild a dedicated facility at the gasificationplant to handle pyrolysis oil from a single site.

Where there is sufficient availability ofbiomass remote enough from the gasificationand FT plant to warrant a high degree ofdensification, flash pyrolysis can offer this;however, handling it and processing it at thegasifier will be different from that for solidbiomass feedstock.

The option of establishing a pyrolysis bio-oilplant at the site of an available resource ofcheap biomass, for densification for transport,is the one that BTG has been developing inMalaysia to make use of oil palm seed podresidues. At present this is not intended forsubsequent gasification and conversion tobiofuel, and the current plans are for co-firingin the Netherlands.

The ultimate extension of the process ofbiomass densification is:

9.1.3 UK import of synthetic biofuels

Instead of importing the biomass feedstock,the most energy dense form for shipping is

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15 European Environment Agency indicator fact sheet TERM 2003 27 EEA 31

16 Clean Air for Europe impact assessment, p31 (2005)

the finished biofuel. Where there is sufficientsupply of feedstock within a small enoughdistance to warrant a full scale gasificationand FT plant, this is certainly the mostefficient option in transport terms, and avoidsthe need for a pyrolysis stage. A gasifier andFT plant is, however, a complex and majorinstallation, requiring significant infrastructure,in addition to transport links and access tofeedstock. A (relatively large) skilledworkforce, fire and security services andconstruction, engineering, consumablesupplies etc, will all be required. While it ispossible for all these to be brought in, it addsconsiderably to the complexity and expenseof such a project.

Imports of second generation biofuels atscale are likely only to come from developingcountries since developed countries such asthe EU or the USA will preferentiallyconsume the fuel at home. For developingcountries to create the infrastructure andoperate the processing plant will be asignificant challenge, and the environmentaland socio-economic impacts must bethoroughly assessed at the outset. However,the implementation of second generationtechnologies in these countries could offersubstantial socio-economic gains.

9.2 Potential deployment of second

generation technology

When considering the scenarios for thedeployment of high temperature processesfor second generation biofuels, thetechnology options are limited. However, thekey advantage is the wide variety offeedstocks which potentially can be fed intothese processes. As has been discussed inprevious chapters, they can range from wastebiomass and energy crops to sewage sludge.

The options are to convert the biomass intopyrolysis oil, or other densified form, insmaller satellite plants for feeding to a centralgasifier, or preparing the feedstock for direct

feeding to the gasifier. As is described in thetechnology sections, syngas is producedwhich will almost certainly need treatment toremove impurities. The syngas is then usedto feed an FT process to convert the gas intodiesel and other liquid fuels.

These technologies have existed for manyyears but they have not necessarily beenconnected together to produce diesel fuelfrom renewable biomass. However, Choren isbuilding a small-scale version of this processto demonstrate its viability. This small plantwill produce around 13 kt/y of diesel. It isestimated that a full-scale plant to reduce the unit cost of diesel, to produce 200 kt/y FT diesel, will cost around €0.5 billion(~£0.35 billion). Alternatively, this amount ofcapital could build around 10 conventionalbiodiesel plants of 250 kt throughput, in otherwords over 12 times the total productioncapacity. Of course there would be issues ofvegetable oil availability but in a policy worldonly looking at volume of biofuels included intransport fuels clearly conventional biofuelswin. However, the real aim of reducing GHGis not fully achieved.

We take the Choren model as our scenariofor consideration as it is the most advancedand closest to market of all the secondgeneration technology options available today.

9.3 Existing policy measures and

impact on encouraging second

generation technologies

There are a small number of policy options toencourage these technologies into the market.Typically, in the EU, biofuels are encouraged bytax incentives and the largest currently is in theGerman market at €0.47/litre (~£0.32/litre). The Choren plant visited in Germany usinggasification and FT technology is onlydemonstration size although its annualproduction rate will be 13 kt. Even with thissize of plant the very large tax incentive inGermany will still not cover the additional cost

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of production. The unit cost of production willinevitably reduce when the plant size isincreased to 1 million t/y but the capital costincreases to around €2 billion (~£1.4 billion).Even with this size of plant it is unlikely thatthe current levels of tax incentives across theEU would sufficiently encourage investment ofthis scale.

Alternative mechanisms will therefore needto be considered to encourage thesetechnologies into the market. However, dueto the extremely high capital costs it may bethat these technologies are never cost-effective for widespread use and are onlyused to dispose of specific waste or energycrops – in other words, niche applications atspecific locations – and their throughput maybe limited.

Due to the increasing cost of tax incentivesto Finance Ministries across the EU, manymember states are now implementing orconsidering biofuel obligations, sometimescalled a flexible mandate. These set a volumerequirement on fuel suppliers to include apercentage of biofuels blended with fossilfuels. In the UK the Renewable TransportFuels Obligation (RTFO) is being introduced inApril 2008. The detailed design and legislationnecessary to implement the scheme iscurrently under development. This is almostcertainly the most sophisticated scheme inthe EU, but even this mechanism on its owndoes not have the potential to drive secondgeneration biofuels into the market, since ona litre basis conventional biodiesel will alwaysbe cheaper than second generation biofuels.Therefore, if there are insufficient supplies tomeet the obligation the fuel supplier pays anadditional tax (buy-out price) and this will bepassed on to the motorist. Therefore,potentially there may not be a driver toencourage second generation biofuels intothe market. Therefore, an additional oralternative mechanism needs to bedeveloped.

9.4 Proposals to encourage second

generation biofuels

When investigating which mechanism couldbe used to encourage second generationtechnology, the best route appears to beunderstanding why second generationtechnology is necessary. Biofuels offer manyadvantages to society above fossil fuels butthe key issue which drives the expansion ofbiofuels beyond the nominal target of 5.75%is climate change. If one only considersconventional crops then the current targetprobably meets the requirements of theagricultural sector in boosting the ruraleconomy. If the aims of sustainable mobilityand reducing GHG emissions from thetransport sector are to be achieved then atool needs to be used which creditstechnologies which are most efficient atreducing GHG emissions. Additionally thisshould not stop at the conversiontechnologies but should also include thefeedstocks, ie the crops used to feed theseprocesses.

This tool will need to be extremelysophisticated to model the energy inputsthrough the supply chain and the productionprocess. Choren claims that its process routeand feedstock give a 90% GHG savingcompared with fossil diesel. This is very closeto the savings achieved by burning woodybiomass to produce electricity. It is alsoconsiderably more efficient than theproduction of FAME from vegetable oilswhich typically only reduce GHG by 55%.Therefore the dilemmas on where best touse the biomass created in the scenariosdescribed above are no longer of suchconcern, since the GHG benefits of burningthe biomass in a power station are similar toproducing FT diesel from the same biomass.This is of particular significance as the optionsfor reducing GHG emissions from thetransport sector are extremely limitedcompared with other energy sectors.

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9.4.1 Linking support to GHG benefits

A number of studies have produced well-to-tank and well-to-wheel analyses of GHGemissions from biofuels, but these studiesdiffer in calculation methodologies andassumptions. They also do not offer aninterface to allow the stakeholder to performtheir own calculations for their particularsupply chain. So the data on GHG benefitstend to be generic, rather than specific to theparticular biomass, processing plants andtransport logistics used. The generic dataoften reflect favourable options which arerarely employed in practice. Therefore there isa need to use a common methodology forquantifying the GHG benefits for varioussupply chain options.

The Low Carbon Vehicle Partnership (LCVP) isdeveloping a methodology which could beused to calculate the GHG emissions fromspecific biofuel chains, as well as identify andpromote chains with lower emissions. Thistool could also be used for reporting on thecarbon intensity of biofuel chains, andeventually for the precise certification of thecarbon intensity of biofuels. Once developedand operational, this tool could be used toreward the lowest GHG emitting biofuels.Provided this tool is practical, user friendlyand accepted by policy makers as the mostappropriate and accurate mechanism forcarbon certification then it could easily belinked to the policy mechanism.

Linking carbon certification to the policyobjective of encouraging second generationbiofuels with higher GHG benefits gives afew alternatives. However, the simplest policycould be converting the current BiofuelsDirective targets from an energy basis to aGHG reduction basis. Therefore, the EUBiofuels Directive could set targets onmember states of reducing the GHGemissions from road transport by say 4% by2010. This would be a significant policy andconceptual change on behalf of the EC and

member state governments. Such a changewould need to specify the common tool toquantify the benefits from each alternativerenewable transport fuel.

The probability of changing the EU Parliamentand Commission’s current policy during thecurrent review period is extremely slim, but itis possible to influence UK Governmentpolicy, particularly in the second phase of theRTFO. This would involve the RTFO changingfrom a volume target to a GHG target forobligated parties. This sounds a very simpleamendment, but the effort required by manystakeholders to achieve this policy changeshould not be underestimated. It is also likelyto require the consensus of many conflictingstakeholders. As an example, some lowefficiency conventional biofuel producers maysee it as a threat to their process orfeedstock.

This single policy change would immediatelyencourage R&D and eventually investment infull scale second generation technologies.Additionally, it would have the double effectof encouraging GHG efficiency improvementsin existing conventional technologies.

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10 CONCLUSIONS

10.1 General10.2 Feedstock10.3 Process technologies10.4 Economics10.5 Policy

10.1 General

Second generation transport biofuels offer anumber of significant advantages over firstgeneration products:

• Significantly greater GHG emissionreductions are possible

• Potentially considerably reduced landrequirements/increased yield

• Better diesel engine fuel than FAME withnone of the negative material impactsassociated with FAME biodiesel

FT based fuel synthesis also offers othermajor benefits:

• A cleaner fuel, with no sulphur or nitrogen

• Ideally suited to modern diesel engineswithout modification

• Totally compatible with existing diesel inany proportion and can be readilyassimilated into existing fuel supplyinfrastructure

Biomass uniquely has the potential to providea low carbon liquid transport fuel that iscompatible with the existing user base andfuel supply infrastructure.

There are clear logistical and economicadvantages in producing transport fuels that

are completely compatible with existingtransport fuels in any proportion.

10.2 Feedstock

Consideration of the feedstock supply chainand optimisation of biomass production arecritical.

There are potential difficulties with obtainingsufficient feedstock for significant penetrationof the transport fuel market from within theUK. Import of feedstock is one potentialoption.

A range of techniques for densification ofbiomass feedstock for transport are beingdeveloped which would be important in futureproduction of these fuels in the UK. Pyrolysisand bio-oil stabilisation have some technicalhurdles to overcome. Torrefaction seems aninteresting process that may also offerprocessing and handling benefits.

Biomass feedstock supply logistics may limitthe realistic scale of BTL plants in the UK andhence their cost competitiveness.

The majority of biomass feedstocks beingevaluated in Europe are wood based oragricultural residues. There appears to be littlefocus on miscanthus or other dedicatedenergy crops. This may in part be a result ofhigher levels of forestry in many Europeancountries.

If agricultural and forestry residues are to beconsidered as feedstock, existing uses mustbe considered to avoid double countingavailable volumes. Unintended impacts such asreductions in soil fertility and broaderenvironmental issues must also be considered.

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Germany is likely to put significant futureR&D investment into biomass supply.

10.3 Process technologies

Gasification of biomass is very feedstockinsensitive, allowing the use of a wide rangeof biomass. Viable feedstocks range fromwoody biomass to sewage sludge.

A wide range of bioenergy systems are beingconsidered that include:

• European biomass and imported biomass

• Solid biomass gasification for synthesisgas

• Biomass pyrolysis to produce an energycarrier followed by centralised pyrolysisliquid (bio-oil) gasification for synthesis gas

• Synthesis of hydrocarbon fuels fromsynthesis gas via FT and via methanol

• Synthesis of other fuels that have transportapplications

• Biorefineries for optimisation of products

The technology to produce second generationdiesel from a clean syngas using hightemperature processes has been available formany decades. Some demonstration work isrequired, however, to link all the elementstogether to build a full scale plant.

Large scale biomass gasification has not yetbeen demonstrated on a scale appropriate forFT technology. While there are no foreseenproblems in cleaning up syngas for FTsynthesis, this also has yet to be proven.Access to FT technology is currentlyrestricted to a small number of providers andtherefore could become a commercial issue.

A wide range of different renewable transportfuels are being considered in all the countries

visited, of which high quality synthetic dieseland gasoline are the main focus. Other fuelsbeing considered include methanol, DME andhydrogen.

There is no clear choice of process ortechnology for production of transport fuelsfrom biomass. Some technologies are closeto commercialisation whereas others are atearly stages of development.

The biorefinery model is one in which there issignificant interest; however, there has beenvery little development to date. It offers thepotential to help the financial position ofsecond generation biofuels and is a field inwhich the potential remains for the UK toestablish a leading position.

The UK has no research facilities in secondgeneration biofuel processing technologies;however, it has significant capability inunderpinning technologies.

10.4 Economics

The very high capital cost of biomassgasification and FT plants is almost certainlythe primary reason for their current extremelylow level of deployment.

High delivered feedstock costs in comparisonwith coal and natural gas, of which harvestingand transport form significant components,also present a significant barrier.

Significant improvements in commercialviability are likely as BTL developers, such asChoren, look for better commercial solutionson biomass availability and cost, as well aslower processing costs. Within Europe, suchsolutions are likely to include socio-economicbenefits from job creation and ruraldevelopment.

There was significantly more medium sizedand small entrepreneurial business activity insecond generation biofuels technologies in

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the countries visited than in the UK (egChoren, BTG).

10.5 Policy

There is no publicly funded activity in the UKto develop second generation biofuels,although individual companies in the UK areactively supporting activities in this areaelsewhere in Europe and the world.

The current policy mechanisms operating inthe EU are unlikely to be sufficient toencourage implementation of thesetechnologies at any level of obligation.Alternative policy mechanisms are thereforerequired if these technologies are to beencouraged. If support mechanisms wereadopted in which the net GHG reductionpotential of products and processes wererecognised, this would effectively differentiatebetween first and second generationproducts, allowing the environmental,performance and diversity aspects of thelatter to be realised. It would also assist inmaking comparisons between alternativetechnologies.

The mission team saw no national incentivemechanisms to support either secondgeneration biofuels specifically or to promotethe production of energy crops.

The alternative uses of biomass need to beaddressed in the UK and EU to ensure thatthese valuable resources are used in themost appropriate way to reduce GHGemissions.

There is a high level of interest and activity insecond generation transport fuels in Europewith significant public funding. There is anappreciable level of industry support inFinland and Germany.

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11 RECOMMENDATIONS

11.1 General11.2 Feedstock11.3 Process technologies11.4 Economics11.5 Policy

11.1 General

The nature of an integrated bioenergy chainfor production of renewable transport fuelsrequires close integration of biomassproduction, biomass conversion and fuelsynthesis. The relevant governmentdepartments – Defra, DTI and DfT – shouldplace a high priority on establishing aneffective cross-department task force tooversee this development and hence ensurethat the UK meets its aspirations for climatechange mitigation measures as well ascapturing wealth creation opportunities.

11.2 Feedstock

Biomass producers need to developfeedstock supply chains and optimisebiomass production to deliver maximum GHGbenefits. Coordination by government andlinking with the process technology andengine developers will be required.

International trade in biofuels and feedstocksis likely to be of great importance and shouldcontinue unhindered. Sustainability andenvironmental impact issues must becovered in accreditation criteria.

11.3 Process technologies

The UK should take a lead in implementingsecond generation technologies that offerhigh GHG reduction potential. One way toachieve this would be to establish a

consortium involving industry, biomassproducers and governments. The biorefinerymodel is one in which there remains thepotential for the UK to establish aninternational lead with appropriate fundingand prioritisation.

A comparative analysis of the alternativeprocessing routes would help to identify themost promising technologies for transportfuels. The UK needs to build some capacity inunderstanding the S&T of transport fuelproduction from biomass.

R&D into technologies for economically viabletransport fuel production at smaller scales tobetter match biomass resource availabilities inthe UK should be funded.

11.4 Economics

The very high capital expenditure required forBTL plant presents major financial risk,making such major investments unlikely inthe short to medium term without significantincentives. Government policies to mitigatesuch large investment risks should beinvestigated. Mechanisms such as grants orloans, with repayment schedules linked tosuccess, to assist in the development of suchtechnologies on a commercial scale, orenhanced capital allowances (ECAs), might beconsidered.

11.5 Policy

The UK has limited land resources that needto be optimised for food, materials andenergy production. All decision making shouldbe undertaken with consideration thatavailable limited land resources need to beused as effectively as possible.

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Government policy for encouraging biofuelsneeds to change from a volume/energy basisto a GHG reduction basis. In this way,optimum choices of feedstock andtechnologies will be preferred by the market.The UK should attempt to use its influence inthe EU to ensure policy mechanisms focuson GHG reduction.

Policies to encourage the increased use ofbiofuels should be linked to environmentalsustainability standards.

Government support for second generationbiofuels should be considered in conjunctionwith other UK biomass heat and powerinitiatives to ensure optimum integration ofinfrastructure, including the feedstock supplychain. Consideration of alternative uses forthe available biomass resource should alwaysbe included in any decision making process,and there should be meaningful discussionbetween UK government and industry on therole of second generation biofuels in the UKenergy mix.

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Appendix AVISIT REPORTS

A.1 VTT (Valtion Teknillinen Tutkimuskeskus – Technical ResearchCentre of Finland)

A.2 Neste Oil Oyj

A.3 ECN (Energieonderzoek Centrum Nederland – Energy Research Centre of the Netherlands)

A.4 WUR (Wageningen Universiteit en Researchcentrum – Wageningen University and Research Centre)

A.5 TNO (Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek – Netherlands Organisation for Applied Scientific Research)

A.6 BTG (Biomass Technology Group BV)

A.7 Choren Industries GmbH

A.8 Future Energy GmbH

A.9 TUB-F (Technische Universität Bergakademie Freiberg – Technical University Bergakademie Freiberg)

A.10 SVZ (Sekundärrohstoff-Verwertungszentrum Schwarze Pumpe) GmbH

A.11 FZK (Forschungszentrum Karlsruhe)

A.12 Öko-Institut eV

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A.1 VTT (Valtion Teknillinen

Tutkimuskeskus – Technical

Research Centre of Finland)

Biologinkuja 3-5EspooPO Box 1000FI-02044 VTTFINLAND

T +358 20 722 111F +358 20 722 7001www.vtt.fi/?lang=en

Contacts

Dr Yrjö SolantaustaChief Research Scientist, Liquid [email protected]

Tuula MäkinenSenior Research Scientist, Energy [email protected]

Esa KurkelaDevelopment Manager, [email protected]

Paterson McKeoughChief Research Scientist, Liquid [email protected]

Including meeting with

Dr Jukka LeppälahtiSenior Technical Advisor, [email protected]

VTT is the largest contract research organisationin Northern Europe, with a turnover of €218million (~£150 million), of which 70% is fromexternal income. It has a staff of 2,661 andoperates within a number of research themesincluding digital and communicationstechnologies and environmental technologies.

Also present was Dr Jukka Leppälahti of Tekes(Teknologian Kehittämiskeskus – FinnishFunding Agency for Technology andInnovation). Tekes is the main public fundingorganisation for R&D, and is therefore highlyattuned to Finnish Government policyobjectives. It has a close relationship with VTT.

A presentation was given by Tuula Mäkinenon biofuels in Finland, based on the reportpresented by VTT to the Ministry Committeeon Biofuels for Transport the previous week.The current situation for biofuels in Finlandwas reviewed, and a number of questionsposed. The potential timescale andmechanisms by which a 5% target could beachieved, the optimum choice of vehicles anddistribution channel and how much could bemet based on indigenous raw materials wereall addressed. It was concluded that 3% wasa realistic target by 2010, but 5% could beachieved with an additional tax reduction of2%. Current vehicles and distributionchannels were felt to be the mostappropriate. It was concluded that aproportion of 2-3% in 2010, and 7-8% in2020, could be met from indigenous rawmaterials. Little benefit was seen for currentgeneration biofuels; however, a developmentprogramme to introduce second generationbiofuels, based largely on thermal processes,to markets by 2015 was suggested, toachieve a biofuel share of 8% by 2020.Lignocellulosic ethanol was not predicted tobe competitive by the time thermalprocesses became available.

A presentation on pressurised FB gasificationdesigned to be fuel flexible was given by EsaKurkela, to handle woody biomass, straw,MSW and other wastes. The currentdevelopment unit was 500 kW scale.Commercial scale of 200-300 MWfeed wasenvisaged, preferably integrated with energyconsuming manufacturing plants, such aspaper mills. In addition, work was being doneon catalytic gas treatment. Lower heatingvalue (LHV) efficiencies of different biosyngas

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conversion processes, including the use ofoff-gas and steam, and costings had beenmodelled. They consider the minimumeconomic scale to be about 150 MWfeed andcalculate the front end as about 66% of theinvestment costs.

A presentation on pyrolysis of biomass to bio-oil was given by Dr Yrjö Solantausta. Inthe first phase, bio-oil was to be used inunmodified boilers for heat and power, in aprocess integrated with current installations(integrated thermal processing – ITP). In thesecond phase it would also be upgraded forbiorefinery feedstock. Integration of the frontend with current biomass users, and the backend with current conventional petrochemicalrefiners was felt to be important, with astand-alone efficiency of 70% and anintegrated efficiency of 80-90%.

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A.2 Neste Oil Oyj

Porvoo RefineryKilpilahti Industrial Area06101 PorvooFINLAND

T +358 10 458 11F +358 10 458 2117www.nesteoil.com

Contacts

Jyrki IgnatiusVice President, [email protected]

Sami OjaManager, Marketing & Sales, [email protected]

Raimo LinnailaBusiness Development Manager, [email protected]

Neste Oil is a major (conventional) oilcompany, the market leader in Finland, whosecore business is oil refining, but with divisionsin shipping, oil retail and components. Thecomponents division examines potential nichemarkets and includes biofuels work. It isowned 50.1% by the Finnish State.

A presentation was given by Jyrki Ignatius,giving an introduction to Neste Oil and itswork in biofuels, and its view of biofuels. Thecompany considers first generation biofuelsto represent high cost of avoided CO2;second generation offers better fuel qualityand lower cost CO2. It is building a €100million (~£69 million), 170,000 t/y (product)plant to produce its next generation NExBTLbiofuel at the Porvoo refinery and expects tostart production from Q2 2007 as a JV withTotal. Neste’s vision for 2030 is that liquidfuels will still dominate, of which 20-50% willbe liquid biofuels, the majority secondgeneration biofuels. Gaseous fuels will be

mainly used in dedicated fleets. It sees thebiggest barriers to biofuels in the EU as thelack of mandatory, harmonised legislation, theavailability of sufficient biomass feedstocks atcompetitive prices, lack of development ofenergy crops, current fuel quality issues andcustomer perception.

A presentation on the Neste NExBTL biofuelwas given by Raimo Linnaila. The NExBTLprocess is one of hydrogenation of vegetableoils (or animal fats) to give pure CnH2n+2

paraffins. It is a colourless, clear product thatcan be used directly in the current car poolwithout modification. It offers cetanenumbers in the range 84-99, well aboveconventional EN590 diesel, and has LHVmarginally higher than EN590 (significantlyabove RME). It also has zero oxygen, sulphurand polyaromatic content and physicalproperties (cloud point, viscosity etc) as good,or better than EN590 or RME. Nestecalculates life-cycle emissions for NExBTL of0.5-1.5 kg CO2/kgoe fuel (depending uponfeedstock) against 1.6-2.3 kg CO2/kgoe forRME and 3.8 kg CO2/kgoe for fossil diesel. Itis working with multiple EU authorities fortests and approvals. Tests with Scania inheavy engines, and with VTT for passengercars, show significant reductions in manyemissions, particularly particulates, comparedwith EN590 diesel. By-products include waterand a propane rich biofuel gas. It considersthat it is a valid process where there isexisting excess hydrogen production plant, asthe cost of the hydrogen plant is not includedin the €100 million (~£69 million) cost of theplant. 200,000 t of feedstock yields 170,000 tof product, which is close to the theoreticalmaximum. It sees no technical limits to thescaling potential, but currently all plants areintegrated to existing sites. Current costs arecomparable to RME but depend on feedstockprices as the plant investment is not a majorcomponent.

Finally, a presentation on NExBTL in the UKwas given by Sami Oja. Neste is working with

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DTI, DfT and HM Revenue & Customs(HMRC) to get NExBTL included in UK biofuellegislation and is a member of the steeringgroup of a UK sustainability standard forbiofuels.

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A.3 ECN (Energieonderzoek Centrum

Nederland – Energy Research

Centre of the Netherlands)

Westerduinweg 31755 LE PettenNETHERLANDS

T +31 224 564 729F +31 224 568 487www.ecn.nl/en/bkm

Contacts

Dr Harold BoerrigterProgramme Coordinator, Gasification & [email protected]

Dr Hans ReithBiomass Transport Fuels & [email protected]

Bram van der DriftBiomass Heat & [email protected]

Dr Jan-Willem Erisman Unit [email protected]

ECN has an annual turnover of around €105million (~£72 million), employs about 900people and is involved in many areas ofresearch in energy and energy efficiency. Itsees itself as bridging the gap between pureresearch and applications. Within theBiomass, Coal and Environmental ResearchUnit it includes clusters on Gasification andGas Conditioning and Biofuels and RefineryProcesses, as well as Heat and PowerProduction and its Environmental Researchprogramme. Facilities include a range ofgasifiers, gas cleaning and filters, a thermalcracker and an FT reactor.

A presentation on the technology options forsynthetic biofuel production via syngas and

product gas was given by Harold Boerrigter.The distinction between product gas, formedfrom low temperature gasification andcontaining CH4 and other hydrocarbons anduseful as a fuel, and (bio)syngas, obtainedfrom high temperature gasification andcontaining only CO and H2 and suitable forsynthesis, was drawn. ECN's view is thatSNG will supplement natural gas as aspecialist, fleet transport fuel, for heatproduction and energy carrier over the next40 years, with particular application forreduced local emissions. An indirect biomassgasifier using steam, optimised for nitrogenfree product gas for SNG production waspresented. Only 48% of product gas issuitable for FT synthesis, against 100% ofsynthesis gas. ECN therefore recommendsthe use of high temperature (entrained flow –EF) gasification and a high temperature tarcracker for FT. Although biomass is relativelylow ash, it is not sufficiently low to use non-slagging gasifiers, so ECN uses a dry feedslagging design proven for coal, that canoperate 1,200-1,600ºC, 20-40 bar. Althoughoptimum operating temperature is lower forbiomass (1,200-1,300ºC) than for coal (1,400-1,600ºC), ECN believes co-gasification is theoptimal choice, and has experimented up to30% biomass with coal. The gasifier is fuel-flexible, suitable for solid woody biomass,bioslurry as well as coal. ECN sees dedicatedbiomass gasification FT plants, of severalgigawatt capacity, with no polygeneration.

A presentation on optimum biosyngasproduction was given by Brem van der Drift.The observation was made that there isinsufficient biomass, of the ‘wrong’ kind, forthe ambitious goals. ECN therefore seesinternational shipping as significant. Scales forbiosyngas processes it sees as 100 MW forthe chemical sector, >100 MW for the gasand electricity sector, and >1,000 MW fortransport fuels. Fifty per cent of worldwidebiomass technical potential is woody, 20-40%grassy, so it sees these as key feedstocks.With the ECN slagging EF gasifier, remaining

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issues include ash melting, biomass feeding,gas properties, efficiency and economy.Experiments with a lab scalecombustion/gasification simulator haveshown the optimum flux/fuel mix(silica/alumina/fuel: 0.5/0.45 kg/kg) to keep>80% of the fuel ash in molten phase toallow flow. Optimum particle size for coal is<100 µm, for biomass <1 mm. Biomass canbe fed with coal, requiring <100 µm particles,as a slurry, or in a dedicated feed. To grindfibrous biomass to fine dust as coal, ECN hasdeveloped the torrefaction process. This is alow temperature (200-270ºC) roasting processthat results in a hydrophobic, zero moisturecontent (MC), high energy density fuel thatcan be ground very fine. Torrefied wood canalso be pelletised while still hot at relativelygood overall energy and economic efficiency.ECN sees torrefaction as preferable to flashpyrolysis for energy densification of biomass

resources for shipping to centralised FT plantunder many conditions. Finally, aconsideration of the economics of a range ofscenarios for the conversion of overseasbiomass to FT products in Europe waspresented from which it emerged thattransport is crucial to final syngas costs,demanding high energy density for shipping.

Presentations on ECN work on biorefineryand microalgae were given by Hans Reith.Biorefineries are seen as assisting theeconomics of biofuel production and assistingthe establishment of the supply chain,combined with CHP of residues. Processesinclude bioethanol and lactic acid productionfrom lignocellulose and production of phenolsfrom lignin using a modified organosolvpretreatment with high pressure CO2. The fullbiorefinery cycle also includes the productionof fine chemicals, solvents, fertilisers,

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Exhibit A.1 Dr Harold Boerrigter explaining the CFB biomass gasifier at ECN

elemental sulphur, base chemicals, gaseousand liquid fuels, electricity and heat. Workwith microalgae suggests 30-60 t/ha/y (dryweight) biomass would be achievable in theNetherlands. With >30,000 species, differentcharacteristics can be achieved. Up to 50%dry weight of oil accumulation, 50-80% wtpolysaccharide, up to 80% wt hydrocarbons,or 200-350 Nm3/t dry weight biogasproduction. In the Netherlands, 40% oilaccumulation could be achievable, giving apotential of 8,200 litre/ha biodiesel, comparedwith 1,400 litre/ha for RME. Biomassproduction costs are predicted as >€2,000/t(>£1,400/t) dry weight, because ofinvestment and harvesting costs, against afuel value of €300-500/t (~£200-350/t),therefore co-products/processes (such ascarotenoids, omega fatty acids, waterpurification) are necessary for economicproduction. The Bio-Offshore project proposeslarge scale seaweed production integratedwith offshore wind farms and aquaculture inthe North Sea. 5,000 km2 (10% of theNetherlands' waters) is proposed. Costs of€50/t (~£34/t) dry weight are predicted nearshore, and €300/t (~£210/t) offshore, with apotential of 350 PJth (25 million t dry biomassat >50 t/ha/y dry weight); however,dewatering at sea would be required.

A presentation on the economics of largescale biofuel production was given by HaroldBoerrigter based on ECN’s slagging EFgasifier, and FT synthesis based on the ShellSMDS plant. ECN sees the requirement for arelatively small number of large scale plants,associated with harbours and integrated withthe existing chemical infrastructure, and usingcurrent, commercially available technologies.A breakdown of investment costs for a 200MWth (1,700 bbl/d FT products) scale plantshows the highest proportions for the airseparation unit (ASU) oxygen plant (28%) andthe Rectisol gas cleaning (22%), with thegasifier at 19%, the FT synthesis 16%,product upgrading 9% and H2 manufacturingand syngas conditioning 6%. Scaling costs for

a number of plants suggest a scale-up factorof 0.7. At 10 MWth the FT fuel product cost isestimated as €40/GJ (~£28/GJ), of which€30 (~£21) is conversion costs. At 10,000MWth these figures fall to €15/GJ (~£10/GJ)(or €0.55/litre (~£0.38/litre)) and €4 (~£2.80)respectively, for the same biomass andpretreatment costs, though higher transportcosts. ECN believes this would becompetitive at current ($60/bbl (~£34/bbl)) oilprices.

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A.4 WUR (Wageningen Universiteit en

Researchcentrum – Wageningen

University and Research Centre)

Agrotechnology and Food Sciences GroupBornsesteeg 59Building 1186708 PD WageningenNETHERLANDS

T +31 317 475 029F +31 317 475 347www.wur.nl/UK

Contacts

Prof Johan SandersValorisation of Plant [email protected]

Prof René WijffelsMarine [email protected]

Bert [email protected]

Richard [email protected]

WUR is a collaboration between WageningenUniversity, which specialises in the lifesciences, Van Hall Larenstein School ofHigher Professional Education and a numberof research institutes of the Dutch Ministry ofAgriculture. WUR has 5,600 staff, 8,500students and specialises in food and foodproduction, plants and animals, environmentand climate and economics and society.Bioenergy, biorefinery, and biobased productsare key research areas within theAgrotechnology and Food Sciences Group.

A presentation on WUR's work on microalgaewas given by Professor René Wijffels. Thetheoretical maximum photosyntheticefficiency is 21%, while 16% has been

achieved using flat panel reactors. Differentreactor designs were described by ProfWijffels, including flat panels whichincorporate dilution of light, tubular reactorswhich offer large surface area to volume ratio,hybrid flat panel/tubular with stacked array oftubes, and flat panels with high biomassdensity in which the cells are constantlymoved instead of diluting the light, giving aflashing illumination effect on a 0.2 stimescale. The work was motivated tomanufacture omega-3 fatty acids andantioxidants for the aquaculture industry,which is limited by the catch of fish for feedfor these nutrients.

A presentation was given by Bert Annevelinkon work to asses the biomass supply chainand its implications, covering biomasssources, logistics and storage and biofuelproduction for electricity, heat and transport.Spatial impacts including water demands(quantity and quality), biodiversity, soil(nutrients, erosion, carbon), landscape,climate change, alternative land uses etc areall included. The project has led to a biomasslogistics computer simulation (Biologics) anda biomass logistics computer optimisation(Bioloco). Bioloco can optimise on a financialor energetic basis, or work within goals forboth. It includes combinations of drying,comminution and transport alternatives, andconsiders seasonal fluctuations of bothsupply and demand. It is currently onlyavailable for WUR’s own use and is intendedfor strategic planning, rather than day-to-dayoperations. It is intended to address suchquestions as optimum choice of biomassfeedstock and source, what pretreatmentsand where they should be performed,optimum scale and location of conversionplants, and the resultant financial andenergetic costs of the whole chain. The IEABioenergy Assessment Model (BEAM)includes similar elements.

A presentation on the valorisation of lignumfor chemicals and products was given by

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Richard Gosselink. Lignin (typically 20-30% ofbiomass) is currently viewed as a wasteproduct and burned; however, it can beconverted to phenols. Lignindepolymerisation under supercriticalconditions was described.

A presentation on biorefinery processes wasgiven by Professor Sanders. The relativevalues of heat (€4/GJ ≈ £2.80/GJ), electricity(€22/GJ ≈ £15/GJ), transport fuel (€10/GJ ≈£6.90/GJ) and bulk chemicals (€75/GJ ≈£52/GJ), and their fossil raw materials costs –€3 (~£2), €6 (~£4), €8 (~£6) and €30(~£21)/GJ respectively – were given, showingthe justification for integrated chemicalproduction. A processing model in whichinitial preprocessing is local and small scale(eg farm based, especially removing water tominimise shipping costs) was proposed. Thisalso allows the return of nutrients to the soil.Processing to retain the functionality offunctional chemicals, rather than ground upsynthesis were felt to be key.

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A.5 TNO (Nederlandse Organisatie voor

Toegepast-Natuurwetenschappelijk

Onderzoek – Netherlands

Organisation for Applied Scientific

Research)

Laan van Westenk 5017334 DT ApeldoornNETHERLANDS

T +31 55 549 34 93F +31 55 549 32 01www.tno.nl

Contacts

Dr Jan ZeevalkinkThermal [email protected]

Prof Gerrit BremThermal [email protected]

TNO is a contract research and consultancyorganisation operating in five core areas:quality of life; defence, security and safety;science and industry; built environment andgeosciences; and information andcommunication technology. TNO wasestablished in 1930 to support companies andgovernment, has around 5,000 employeesand annual turnover of €550 million (~£380million) and receives approximately 25%government funding. It also undertakestesting and certification and generates its ownIPR which it licenses. In the 1980s it startedlooking at coal combustion technologies, andin the 1990s oil.

A presentation on hydrothermal processing,including supercritical water gasification(SWG) and hydrothermal upgrading (HTU) ofbiomass was given by Dr Jan Zeevalkink.SWG uses water at high temperature andpressure (above its critical point) to yield an H2

rich (60%) product gas from aqueous biomassslurry at typical levels of 10-20% biomass.

Use of supercritical ethanol or methanol canallow transesterification of vegetable oilswithout using water or lye to yield cleanbiodiesel. HTU typically uses 25% biomass inliquid water at 300-350ºC and 120-180 bar,with a reaction time of 5-20 minutes to yield45% biocrude, 25% gas (>90% CO2), 20%water and 10% dissolved organics with athermal efficiency of 70-90%. The biocrudecan be separated into light (50-70%) andheavy fractions by flashing or extraction. Thelight biocrude contains no minerals, is solublein organic solvents such as acetone and canbe upgraded by hydrothermal deoxygenation(HDO). The heavy fraction solidifies below80ºC. Shell and Delft University have donesome work on upgrading biocrude. Theyregard it as a cheaper alternative, at higherenergetic efficiency than FT, which can beoptimised at small scale (though larger thanpyrolysis plant). HTU allows the use of highMC organic waste material like sugar beetpulp and onion pulp or domestic waste at low,zero or negative cost. Production costs of thepilot plant (including HDO) are €11-12/GJ(~£8/GJ), though a future (2015) plant wouldbe about €6-7/GJ (~£4-5/GJ), which would becompetitive with fossil diesel without subsidy.The capital cost of an HTU plant would bearound €50 million (~£34 million), and itwould be envisaged that several HTU plantswould feed a central HDO plant.

A presentation on flash pyrolysis of biomassand the TNO PyRos technology was given byProfessor Gerrit Brem (a part-time professorat the University of Twente). TNO views flashpyrolysis as a simple method for increasingthe energy density of biomass by a factor of4-5 times, decoupling the production andapplication of pyrolysis oil. Reactionparameters of 500ºC, 1 bar, no added oxygenand a reaction time of around 1 s to avoidcracking give around 70% oil (‘liquid wood’containing 20-30% water), 15% gas and 15%char. TNO has looked at a wide range ofdifferent reactor designs. The PyRos design isbased on a commercial cyclone dust filter

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operating at 500ºC. Sand is used as avolumetric heat carrier (in combination with aheated wall) and is injected at the top withthe biomass in proportion 10:1 sand tobiomass. The sand and char drops out of thebottom of the cyclone for reuse. Wasteelectronics or sewage sludge could also beused as feedstock with modifications to thedesign. The cyclone reactor allows compactdesign and quick quenching. It is also veryefficient at catching oil aerosols. TNO islooking at replacing some of the sand withzeolite catalyst. Further research will includeupgrading the oil and controlling the oil qualityand composition within the reactor.

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A.6 BTG (Biomass Technology

Group BV)

Pantheon 127521 PR EnschedeNETHERLANDS

T +31 53 486 11 86F +31 53 486 11 80www.btgworld.com

Contacts

Prof Wolter PrinsHead Research & Development [email protected]

Dr Bert van de [email protected]

Daan AssinkProcess [email protected]

BTG is an independent private research andconsultancy company formed in 1979 thatworks on technology and projectdevelopment to increase bioenergy in primaryenergy supply.

A presentation was given by Dr Wolter Prinson BTG and its biomass pyrolysis process.The pyrolysis technology is based on arotating cone reactor design with a sand heatcarrier developed in the early 1990s at theUniversity of Twente, and further developedsubsequently by BTG to give 70% pyrolysisoil, 15% gas (that has been used to run a gasengine) and 15% char. BTG built at 1 MWpilot plant then delivered a 10 MW plant toMalaysia for pyrolysis of oil palm residues. Itwas installed in April 2005. In this design thefeedstock is fed in near the bottom of the unitand carried up by the rotation of the cone.The Malaysian plant is currently operating athalf capacity owing to the difficult (‘fluffy’)nature of the feedstock. It also has problemswith sand circulation owing to sticky ash, with

oil filtering and with the ash content of theoil. BTG intends to use excess heat for dryingfeedstock and ash for the soil. Current costsare €6-7/GJ (~£4-5/GJ). There has been anapplication from Electrabel for co-firing the oilin Holland. Investment in the plant was €3 million (~£2 million), including feedingunit; maximum output is 30 t/d. It has norefractory lining so start-up time is around 4-5 h, allowing 5 d/wk operation. Seasonallyrunning out of feedstock is a current problem.

BTG is also working on an FB gasifier and areverse flow tar cracking unit for gas cleanup toallow gasification of bio-oil for operation of a gasengine. Successfully injecting bio-oil into an FBcan be difficult, and efficiency is relatively low.Incorporation of a catalyst into the FB gasifierallows the temperature to be reduced. BTG isalso working on upgrading the bio-oil(decarboxylation and dewatering) to reducetransport costs, and also hydrotreating andpartial deoxygenation. It has tried running astandard diesel engine on pure bio-oil (havingstarted on ethanol); however, the standardinjectors corroded within 10-15 minutes.Stainless steel replacements work well, though.

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Exhibit A.2 Rotating cone pyrolysis reactor at BTG

A.7 Choren Industries GmbH

Frauensteiner Strasse 5909599 FreibergGERMANY

T +49 3731 26 62 0F +49 3731 26 62 25www.choren.com/en

Contacts

Dr Carlhans UhleChief Financial [email protected]

Choren is a private company set up in theearly 1990s (initially in 1990 as UET GmbH),since 1992 for the gasification and refining oforganic raw materials for energy. The name isderived from Carbon Hydrogen OxygenRENewable.

An introduction to the company and itstechnology was given by Dr Carlhans Uhle.The three phase gasification technologyoriginally came from the old GDR, and yields35% CO, 35% H2, 25% CO2. The yield of FTliquid fuel corresponds to about 4,000 litre/ha,about 3-6 times as much as first generationbiodiesel.

Choren currently has an Alpha plant inoperation and is working on a Beta plant at 45 MWth, 75,000 t/y biomass (18.5 millionlitre/y) at 85% capacity and using FTtechnology from Shell. The Beta plant isexpected to be in production by mid 2007;however, this is also only an intermediatestage, and a Gamma plant is planned for2009/10, and four more by 2015, each yielding200,000 t/y of fuel, from 1 Mt biomass,sourced from within a 30 km radius of eachplant, by which sites will be selected.

At present, Choren is using forestry residues.It can use agricultural residues but cannot atpresent use 100% straw without

modification. Energy crops are not yet seenas necessary.

There is currently a total tax exemption on allbiofuels until 2009; however, the newgovernment prefers to stop exemptions andmove to an obligation. Until this has beenfinalised, Choren will not make a decision onfuture investment, which will be sited wherethe economic conditions, as well as thefeedstock availability, are optimal; however,they require sufficient industrial infrastructure.

Choren buys in oxygen, and currently buys inhydrogen, but does not intend to do this inthe long term.

To achieve 20% biofuels in Europe, only 300Gamma scale plants would be required in theEU.

Choren has tried running a gas engine on theproduct gas, and is considering CHP to assistcash flow.

Choren buys biomass directly from farmersrather than through brokers, and defines theMC it wants. Very little waste is produced;the ash is used for road building.

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Exhibit A.3 Beta plant under construction at Choren

A.8 Future Energy GmbH

Halsbrücker Strasse 3409599 FreibergGERMANY

T +49 3731 785 300F +49 3731 785 352www.future-energy.de

Contacts

Friedmann MelhoseSenior Process [email protected]

Future Energy has been involved in entrainedflow gasification for more than 30 years,developing technology from the DeutschesBrennstoffinstitut Freiberg (Freiberg FuelResearch Institute) in the 1970s forgasification of brown coal. The first pilot plant(3 MWth) was commissioned in 1978/9 andhas been used with a wide range offeedstocks including coals, sewage andindustrial sludges, oils, slurries, chemicalwastes and biomass. The technology wascommercialised in 1984 (200 MW scale) atGaskombinat Schwarze Pumpe (GSP – nowSVZ Schwarze Pumpe). Future Energy, alongwith SVZ Schwarze Pumpe, was a member ofthe Sustec Group; however, the coalgasification business of the Sustec Group(including Future Energy) has since (May2006) been acquired by Siemens.

A presentation was given by FriedmannMelhose on Future Energy and its GSP andMEGA-GSP entrained flow gasifier technology.The entrained flow gasifier range, with apressurised water cooling screen, can handlea wide range of feedstocks withoutpretreatment for coals, heavy oil, chemicalresidues, or with pretreatment forheterogeneous wastes and biomass. It gives>99% conversion of carbon, the raw syngasis 100% tar free and there is no dioxin orfuran formation. It features 2.5-3.5 s reaction

time and has low thermal mass so needs onlyabout 1 h start-up time. Operating pressure is24-40 bar and temperature 1,100-1,600ºC forcoal, or 40-60 bar and 1,400ºC for biomass.

A key feature is the pressurised water coolingscreen which runs at 250ºC, which isprotected by a (13 mm) silicon carbide (SiC)‘ramming mass’ layer and a (5.5 mm) layer ofsolid slag, over which liquid slag at 1,400ºCflows. A stable thermal gradient is maintainedby monitoring the water temperature andadjusting flow. The cooling screens showoperating lifetimes >10 y. The liquid slag flowsdown into a water quench at the bottom ofthe reactor where it granulates.

Modifications to the design are necessary forfeedstocks with different characteristics, asash free (<1%) feedstock requires arefractory lining as there is insufficient slag toprotect the cooling screen. High (>20%) saltcontent feedstock also requires modifieddesign. The reactor design allows goodmixing from back flow, and the cooling screendesign makes incorporation of additionalapertures much easier than with a refractorylining.

Biomass gasification yields 27% H2, 50% CO,14% CO2, 6.3% N2 (from the carrier gas), soa 350ºC CO shift stage, as well as separationof the sour gases from the syngas, arerequired. Using recycled CO2 as carrier gas,purging etc, allows the N2 level to bereduced; also a high density feedstock flow tominimise carrier gas. The granulated slagproduced is of very similar chemicalconstituency to the local native rock. Biomasshas to be fed as a bio-char/oil slurry; fastpyrolysis bio-oil is ideal, although some initialwork on torrefaction and pulverisation ofbiomass has been done with ECN.

Large scale operation is required for biomass(eg 1,000 MWth), suggesting a centralisedgasifier, sited at a refinery, with a fewdistributed, fast pyrolysis units for local

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feedstock processing. Biomass could besupplemented seasonally with fossilfeedstock.

The total efficiency of the whole processfrom biomass to fuel is 15-20%.

Future Energy has an in-house test facility toperform experiments on feedstockpreparation, optimisation of gasificationconditions and reactor design.

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Exhibit A.4 Top of entrained flow gasifier at FutureEnergy

A.9 TUB-F (Technische Universität

Bergakademie Freiberg – Technical

University Bergakademie Freiberg)

IEC (Institut für Energieverfahrenstechnik undChemieingenieurwesen – Institute of EnergyProcess Engineering and ChemicalEngineering)Reiche Zeche/Fuchsmühlenweg09596 Freiberg (Sachsen)GERMANY

T +49 3731 39 45 11 F +49 3731 39 45 55www.iec.tu-freiberg.de

Contacts

Prof Bernd MeyerDirector of [email protected]

Dr Steffen [email protected]

Mathias [email protected]

TUB-F is the University of Mining andTechnology. It was formed as the SaxonyState Lignite Research Foundation in 1918and has 4,616 students. The IEC is the largestInstitute. It was originally involved in studyingthe gasification of brown coal, but has beenlooking at gasification of biomass in the lastfew years.

A presentation on a number of activities wasgiven by Professor Bernd Meyer. TUB-F is thecoordinator of the DeZeV (DeutschesZentrum für Vergasungstechnik – GermanCentre for Gasification Technology), of whichChoren, Future Energy and Sustec SchwarzePumpe are also members. IEC is working ona commercial, HTW, 10 bar FB gasifiercombined with a Lurgi MtSynfuel processmethanol synthesis plant for the productionof 15,000 t/d of methanol as an intermediary

for 5,438 t/d diesel, 685 t/d gasoline (plus 579 t/d light products) using a zeolite catalyst.It sees this as a decentralised biomasspreconditioning step with methanol as energystore/vector, with fuel synthesis in a large,central refinery.

IEC is also working on a 1,000 MWe IGCC(integrated gasification combined cycle)generating demonstration plant with E.ON,featuring polygeneration of power, basicchemicals and fuels, based on (extremelycheap) brown coal. It sees centralisedgasification, with decentralised powergeneration, as optimum and is also workingon biomass gasification.

Another project is HP-POX (high pressurepartial oxidation), initially of oil and gasresidues, and also biomass pyrolysis oil andchar slurries, with FZK supplying the bio-oilslurries. This operates at 100 bar, 1,200-1,500ºC, 5 MWth, 500 litre/h oil and producesmethanol directly. Formic acid and acetic acidare also formed, and IEC is looking atslagging, fouling corrosion, and the paths ofheavy metals and impurities.

Work is being done on partial oxidation ofaromatic hydrocarbons, thermal and catalyticcracking of crude oil and FT products, andhydrogenation of vegetable oils by Dr MathiasOlschar. IEC believes the economics of themethanol route to diesel fuels is comparablewith FT, and offers some advantages andsome disadvantages. About 10-20% of IEC’sresearch effort is biomass related, with about80% still on coal.

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A.10 SVZ (Sekundärrohstoff-

Verertungszentrum Schwarze

Pumpe) GmbH

Südstraße02979 Spreetal/SpreewitzGERMANY

T +49 3564 69 37 70F +49 3564 69 37 34www.svz-gmbh.de/GB/indexgb.html

Contacts

Lutz [email protected]

Frank [email protected]

SVZ, formed on the site of a brown coalgasification plant, was part of the (Swiss)Sustec Group. However, in May 2006 it wasbought by (German) Siemens. It has been anindependent company since 1995, has 260employees, and gasifies 400,000 t/y solid and50,000 t/y liquid waste in 10 gasifiers to run a44.5 MWe gas turbine, a 30 MWe steamturbine and a 100,000 t/y methanol plant.

A presentation on SVZ was given by Dr LutzPicard. SVZ was established on the site ofthe Schwarze Pumpe gasification plant thatproduced town gas from lignite briquettesfrom 1964. There are now three types ofgasifiers on site: two GSP entrained flowgasifiers, seven rotating grate FDV (Lurgi)gasifiers, and one BGL slagging gasifier.These handle used plastics, including WEEE,sewage sludge, contaminated wood, treateddomestic waste, pellets from tar and sewagesludge, shredder residue, contaminated oilsand oil/water mixtures, and solvents. Highlevels of impurities can be accepted becauseof the high operating temperatures.

After gas cleaning, the output of the BGLgasifier is 64% H2, 19.6% CO, 6.3% CO2,

8.4% CH4 and 1.4% N2. The syngasconstituents can be adjusted by incorporationof a coal component. All wastes are pelletedor briquettes.

The methanol plant was added in 1995 andoperates at 45 bar and 250ºC with a coppercatalyst. The methanol is sent out for a widerange of applications, including toDaimlerChrysler for its fuel cell cardevelopment.

Synthetic biofuels are of increasing interest,and SVZ expects FT fuel production to start inthe next 2-3 years, though probably derivedfrom coal. SVZ is retaining the samegasification capacity but gradually replacingold plant as part of a €30 million (~£21million) investment. It receives a gate fee ofup to €150/t (~£100/t) for waste handling.

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Exhibit A.5 Part of SVZ site

A.11 FZK (Forschungszentrum

Karlsruhe)

Hermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGERMANY

T +49 7247 82 0F +49 7247 82 5070www.fzk.de

Contacts

Dr Jürgen VehlowThermal Waste Treatment Division (TAB)[email protected]

Prof Helmut SeifertDirector Institute for Technical Chemistry, [email protected]

Prof Edmund HenrichHead of Applied Physical [email protected]

Dr Nikolaos BoukisHigh Pressure Process [email protected]

FZK undertakes precommercial R&D in areasof public interest. It is a part of the HelmholtzAssociation of National Research Centres andundertakes research in five areas – structureof matter; earth and environment; health;energy; and key technologies – and runs 11programmes. FZK has more than 3,800employees, with 1,420 scientists, and it hasan annual budget of €406 million (~£280million), of which €75 million (~£52 million) isself generated. State ownership is 90%Federal and 10% the State of Baden-Württenberg.

FZK collaborates with universities andindustry in Germany and internationally, andwith other Helmholtz Centres. It includes anumber of institutes, including the Institutefor Technical Chemistry (ITC), which includes

the Thermal Waste Treatment Division (ITC-TAB) and the Chemical-Physical ProcessingDivision (ITC-CPV).

An introduction was given by Dr HelmutSeifert to the Thermal Waste TreatmentDivision (ITC-TAB). This handles differentwastes, with a range of thermal processesincluding combustion (including the TAMARAcombustion system), pyrolysis (including theTHERESA rotary kiln and Haloclean pyrolysisunits) and gasification, and covers a range ofaspects including thermal processes, materialflows, aerosols and particles, and pyrolysisand gas treatment.

A presentation was given by Dr AndreasHornung of ITC-TAB on the Halocleanenhanced low temperature pyrolysis process.It uses a screw drive and relatively longtimescale pyrolysis with chopped, milled orpelletised feedstock with steel balls for heattransfer. The temperature is chosen tooptimise solid, oil or gas proportions, asrequired. One application is for the productionof activated carbon (eg for water purification)combined with electricity generation wherethere is abundant waste biomass, such as inareas of olive production around theMediterranean. Gas treatment followinggasification is a major topic. The intention isto install a three stage line at FZK with a fastpyrolysis unit, gasifier and gas treatment.Because of the long residence time, tars arebroken down and do not leave the system;however, the phenol and water levels are toohigh for the product gas to be used directly ina gas engine without gas cleaning and acondenser. There are currently problems withusing food crops as feedstock in Germany asit is illegal to burn them, though rape is feed,not food. A new building is currently underconstruction to house a new fast pyrolysisunit which will use sand for heat transfer. Itwill cost €22 million (~£15 million) including a gasifier and synthesis unit (probablymethanol).

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A presentation on BTL work was given byProfessor Edmund Henrich of the Chemical-Physical Processing Division (ITC-CPV). Theyare working with a GSP entrained flowgasifier, oxygen blown to minimise nitrogendilution, operating at 50-100 bar, 1,200ºC inslagging mode and with a residence time of afew seconds. They are considering feedstocksupply strategies for a 5 GW scale centralsyngas plant with local pyrolysis plants,comparing use of road and rail. They concludethat a combination of tractor (up to 30 km)and rail is far more energetically efficient thantruck haulage. Different pyrolysis reactortypes have been studied and the wellestablished twin screw design (LR Lurgi-Ruhrgas) chosen. The FZK system works witha biomass throughput of 5-10 kg/h; the onlyheating is through the sand heat carrier,though other heat carriers are being studied,including steel shot and SiC as some sandcan be carried out with gas. In experimentswith gasifying slurries at Future Energy withtheir 3-5 MW EF gasifier operating at 26 barand 1,200-1,600ºC, they have achieved about45% CO and 25% H2 with a suitable slurry

and atomisation. They need a 2:1 liquid tochar ratio because of 50-80% porosity of thechar. Anything that can be pumped and with aheating value >10 MJ/kg can be used. Theyare also working with the 130 MWth GSPgasifier at Schwarze Pumpe and with Lurgi ona 20-25 t/h pyrolysis plant on the FZK sitelooking at methanol or DME output. They arealso looking at methods for estimating capitalinvestment and simplified estimation of totalproduction costs.

A presentation on gasification of wet biomasswas given by Dr Nikolaos Boukis of ITC-CPV.The technique employs biomass insupercritical water at above 250 bar at 600ºC(much higher temperature than HTU process)with a residence time of around 1 minute forthe treatment of sewage sludge, ‘wine trash’and other wet organic wastes. The pilot plantVERENA employs a 100 kg/h high pressurepump at 350 bar, a preheater fired with fluegas, and a main heat exchanger for heatingprior to the 35 litre reactor to 700ºC. Thefeedstock must be ground to <1 mm. Productgas from corn silage with 9.2% dry matter byweight consists of 45% H2, 37.6% CH4, 9.3%C2H6 with low levels of other hydrocarbons,CO, CO2 and N2, with a total carbon yield of90% and thermal efficiency of 80%. Sulphur,nitrogen and chlorine leave the process withthe aqueous effluent. The product gas isproduced, and maintained, at high pressure.Work is continuing to address plugging fromsalt deposits, corrosion and yield and tooptimise reaction temperature, H2:CH4 ratio,reliability and economics. Work to operate ata lower temperature (~350ºC) using a zirconiacatalyst has led to their CATLIQ process,which is being commercialised by a Danishcompany.

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Exhibit A.6 Dr Andreas Hornung explaining theHaloclean screw pyrolysis reactor at FZK

A.12 Öko-Institut eV

Rheinstraße 95D-64295 DarmstadtGERMANY

T +49 6151 8191 0F +49 6151 8191 33www.oeko.de/index_engl.htm

Contacts

Dr Uwe FritscheCoordinator Energy & Climate [email protected]

Öko-Institut (Institut für Angewandte Ökologie– Institute for Applied Ecology) was foundedin 1977 as a non-profit environmentalresearch institute with income from projectbased funding. It is sponsored by the GermanEnvironment Ministry, has a turnover around€7 million (~£5 million) and strives to makeits findings as widely disseminated aspossible. It has more than 100 staff from arange of disciplines at three locations.

A presentation on their work on sustainablebiomass energy strategies for Germany waspresented by Dr Uwe Fritsche. The Öko-Institut has developed GEMIS (GlobalEmission Model for Integrated Systems) toanalyse the needs of the biomass energysector. This model incorporates an integratedanalysis of 99.5% of all biomass flows inGermany and 95% of biomass flows in theEU, current technology options, together withtechnology learning curves, analysis of landuse implications, human labour flows (directand indirect employment) and considerationof the demands of all sectors andenvironmental constraints. It makes use oftransparent, reviewed, freely available data.

GEMIS starts with energy use scenarios andworks back to the resource (feedstock) useimplications. The model and database of dataused in the model is freely available on the

web via www.gemis.de. The model includesboth economic and carbon benefits ofscenarios, and interlinkages between marketsare factored in, though carbon trading is not.Wage costs are assumed to be equilibratedacross the EU-25 after 2010, though notbefore, while land use cost differentialsremain. Financial (and carbon) implications ofgeographical siting of parts of a project (fromGermany's perspective) can be assessedusing the model.

At present, publicly available ‘typical’technology performances are used, thoughthere is work to incorporate data from theRENEW Project on specific technologies.Options such as ‘double cropping’ areavailable. Lignocellulose derived ethanol is notincluded in the model. Life cycle comparisonsof biomass technologies for electricity, heatand transport can be compared.

Assumptions for land availability includefigures for nature protection, organic farmingand set-aside. Demand side efficiency gainsare also included, and considered a veryimportant component. Cogeneration is seenas key, requiring heat users, and co-firingseen as cost effective with CO2 trading.

The project can be used to analyse trade-offsbetween scenarios, effects over time andinform policy recommendations.

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Appendix BMISSION TEAM AND ITP

Ian Barton

Commercial Manager, Catalysts DivisionJohnson Matthey [email protected] www.matthey.com/about/catalysts.htm

Johnson Matthey Catalysts Division has threebusiness units, of which Process Catalystsand Technologies provides catalysts andrefining technologies to many market sectors,including GTL processing. It offers a portfolioof products, services and manufacturingcapability for syngas generation, gastreatment, FT synthesis, hydroprocessing andhydrogen production.

Dr David Bown

Technology Manager, Oil & GasAMEC [email protected] www.amec.com

A major international project management,services and process engineering company,AMEC Oil & Gas is involved in theimplementation of new technologies, such asGTL and CTL. AMEC has a long-standingrelationship with Syntroleum, and hasexperience with the design and engineeringof licensed Syntroleum GTL technology on anumber of projects for the production ofsynthetic liquid fuels from natural gas andcoal.

Professor Tony Bridgwater

Bio-Energy Research GroupAston University, [email protected]

Professor Tony Bridgwater is founder of theBio-Energy Research Group (BERG) at AstonUniversity which carries out research intothermal biomass conversion including fastpyrolysis of biomass and solid waste andadvanced gasification and bio-energy systemsanalysis, design and evaluation.

BERG is a member of the EPSRC SuperGenBiomass and Bioenergy project, the EuropeanBioenergy Network of Excellence and theEuropean ThermalNet which includes thePyNe Biomass Pyrolysis Network, GasNet forgasification technologies and CombNet forcombustion.

Craig Jamieson

Next [email protected]

Next Generation is a start-up companyformed as spin-out from research into massproduction of microalgae for fuels andchemicals etc. The company was invited to bethe UK’s first and only representative on theIEA International Biofixation Network, whichbrings together researchers of microalgae forCO2 mitigation.

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Robert Saunders

Business Advisor, Future Fuels BP International [email protected] www.bp.com

BP International is one of the world's largestenergy companies. As well as its traditionalpetrochemical businesses, it invests heavily ina wide range of alternative and REtechnologies.

Bob Saunders is part of the BP InternationalFuture Fuels Group looking at next generationfuels. He is Chair of the BSI Committee onLiquid Fuel Specification, a member of theLow Carbon Vehicle Partnership (LCVP) FuelsWorking Group and a member of theRenewable Energy Association (REA)Renewable Transport Fuels Group. He is apast secondee to DTI during initialdiscussions on the Renewable Transport FuelsObligation (RTFO).

Dr Warren Smith

Technology Transfer ManagerNational Non-Food Crops [email protected] www.nnfcc.co.uk

The National Non-Food Crops Centre(NNFCC) provides an independent source ofinformation on the use and implementation ofnon-food crop products and technologies inthe UK. It disseminates scientific andtechnical information as widely as possible tohelp facilitate technology uptake. NNFCCcovers all aspects of the use of plant derivedmaterials, derivatives and by-products for non-food purposes, including for energy.

Nicola Yates

Energy Crop ResearchRothamsted [email protected] www.rothamsted.ac.uk

Rothamsted Research offers scientific R&D ofagricultural crops for enhanced quality andproduction, more sustainable production,increased environmental benefits, protectionand remediation of soil quality, enhancementof biodiversity and new, sustainable productsand applications for crops. The developmentof improved strains of energy crops forcombustion and other energy applications isone key area of research.

Dr Anton Zimmermann

Engine Research EuropeCaterpillar [email protected] www.cat.com

For 80 years, Caterpillar Inc has been buildingthe world's infrastructure and, in partnershipwith Caterpillar dealers, is driving positive andsustainable change on every continent. A Fortune 100 company, Caterpillar is atechnology leader and the world's leadingmanufacturer of construction and miningequipment, diesel and natural gas enginesand industrial gas turbines. In 1998 Caterpillaracquired the British based Perkins EngineCompany. Caterpillar Engine Research Europeis located at Perkins's Peterborough site.

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Dr Geoff Hogan

Managing DirectorERIN Research [email protected]

ERIN Research Ltd is a small, specialisedcompany that undertakes informationgathering and activities to promotetechnology transfer in fields of low carbonand RE technologies and sustainablematerials and technologies. It aims to assistUK organisations in both the industrial andacademic sectors to learn about thedevelopment and use of sustainable, lowcarbon and RE technologies, and to sharebest practice between experts around theworld.

Nicola Smoker

International Technology PromoterDTI Global Watch [email protected] www.globalwatchservice.com/itp

The DTI Global Watch International TechnologyPromoter (ITP) network assists UK companiesto identify overseas technology partners,develop or transfer technologies, products,processes or management practices.

Nicola Smoker is ITP for Europe specialisingin environmental, sustainable energy andprocess technologies.

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Renewable Transport Fuels Obligation

(RTFO)

The RTFO was announced in November 2005as a mechanism that will require that 5% (byvolume) of all UK transport fuels sold on UKforecourts must come from renewablesources by 2010. This would be a 20 fold riseon current sales. The RTFO will be introducedin early 2008. It will work by a system ofcertification by which oil companies willreceive certificates from the schemeadministrator for biofuel sold. Thesecertificates will be tradable, and work in asimilar way to the current system of ROCs(Renewables Obligation Certificates) forelectricity generation, by which companiesthat exceed their statutory obligation may selladditional certificates to companies that havenot met their obligation.

The UK RTFO reflects the EU BiofuelsDirective 2003/30/EC of May 2003 that setsindicative targets for the sale of biofuels at2% by energy content for 2005 and 5.75% by2010. The UK figure of 5% by volume isequivalent to about 3.8% by energy content.

The RTFO is predicted by the Government tolead to 1 million t of CO2 emission saving in2010.

Reduced duty rate for biodiesel

The UK Budget 2001 announced a new dutyrate for biodiesel set at 20 pence per litrebelow that for ULSD, and this was introducedin the 2002 Budget. In Budget 2003 a dutyrate for bioethanol of 20 pence per litre belowthat of unleaded petrol was announced andintroduced in January 2005. These dutydifferentials are guaranteed to stay in placeuntil 2007-8.

This measure has resulted in current sales ofbiofuels of about 10 million litres per month,about 0.25% of all road fuel sales.

Enhanced Capital Allowance (ECA) for

biofuels production plant

In the 2005 Pre-Budget Report theGovernment announced that, subject to stateaids approval, it would go ahead with a 100%first year allowance for biofuels plant thatmeet certain qualifying criteria and whichmake a good carbon balance inherent in thedesign, to help support innovation. This wouldallow companies investing in such qualifyingbiofuel production plant to write off 100% ofthe capital cost of the investment againsttheir taxable profits for the period duringwhich they make the investment, assistingcash flow and shortening the payback period.

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Appendix CCURRENT UK BIOFUEL SUPPORT INSTRUMENTS

Appendix DGLOSSARY

~ approximately≈ approximately equal to< less than> greater than% per cent€ euro (€1 ≈ £0.69 ≈ $1.2)£ pound sterling (£1 ≈ €1.45 ≈ $1.75)$ US dollar ($1 ≈ £0.57 ≈ €0.83)µm micrometre = 10-6 mANL Argonne National Laboratory (DOE, USA)are = 100 m2

ASTM American Society for Testing and Materials (USA)ASU air separation unit atm atmosphere ≈ 1.013 bar = 1.013 x 105 PaBABFO British Association for Bio Fuels and Oils (now part of REA)bar = 105 Pabbl barrelBEAM BioEnergy Assessment Model (IEA)BERG Bio-Energy Research Group (Aston University, UK)BGL British Gas LurgiBR BrazilBSI British Standards InstitutionBTG Biomass Technology Group BV (Netherlands)BTL biomass to liquidºC degrees CelsiusC carbonC2H6 ethaneC3H8 propaneCAP Common Agricultural Policy (EU)CCS carbon capture and storage CEN Comité Européen de Normalisation – European Committee for

Standardization (HQ Belgium)CFB circulating fluidised bedCFPP cold filter plugging pointCH4 methaneCHP combined heat and powerCNG compressed natural gasCO carbon monoxideCO2 carbon dioxideCONCAWE Conservation of Clean Air and Water in Europe (association, HQ Belgium)COS carbonyl sulphideCPV Chemical-Physical Processing Division (ITC, FZK)

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cP centipoise = 0.01 P = 0.001 N s/m2 (Pa s)CTL coal to liquidd day = 86,400 sDDGS distillers dried grains with solublesDE GermanyDefra Department for Environment, Food and Rural Affairs (UK)DeZeV Deutsches Zentrum für Vergasungstechnik – German Centre for Gasification

Technology (TUB-F)DfT Department for Transport (UK)DIN Deutsches Institut für Normung – German Institute for Standardization DME dimethyl etherDOE Department of Energy (USA)DTI Department of Trade and Industry (UK)d/w dry weightEC European CommissionECA enhanced capital allowance ECN Energieonderzoek Centrum Nederland – Energy Research Centre of the

NetherlandsEd editorEEA European Environment Agency (HQ Denmark)EF entrained flowEN European Norm (standard)EPSRC Engineering and Physical Sciences Research Council (UK)ETBE ethyl tertiary butyl etherEtOH ethanolEU European UnionEU-25 the 25 member countries of the EU EUCAR European Council for Automotive R&D (HQ Belgium)F faxFAME fatty acid methyl esterFB fluidised bedFCC fluid catalytic crackingFDV festbettdruckvergasung – fixed bed high-pressure gasificationFFV flexible fuel vehicleFT Fischer-Tropsch (process)FZK Forschungszentrum Karlsruhe (Germany)g gram = 0.001 kgGDR (former) German Democratic Republic/East GermanyGEMIS Global Emission Model for Integrated Systems (developed by Öko-Institut)GHG greenhouse gasGJ gigajoule = 109 JGSP Gaskombinat Schwarze PumpeGTL gas to liquidh hour = 3,600 sH hydrogen (atomic)H2 hydrogen (molecular/gas)H2S hydrogen sulphideha hectare = 100 are = 10,000 m2

108


HCCI homogeneous charge compression ignitionHCl hydrogen chlorideHCN hydrogen cyanide/hydrocyanic acidHDO hydrothermal deoxygenationHGCA Home-Grown Cereals Authority (UK)HHV higher heating valueHMRC HM Revenue & Customs (UK)HP POX high pressure partial oxidationHQ headquartersHTU hydrothermal upgradingHTW High Temperature Winkler (process)IC internal combustionICE internal combustion engineICCEPT Imperial College Centre for Energy Policy and Technology (UK)IEA International Energy Agency (HQ France)IEC Institut für Energieverfahrenstechnik und Chemieingenieurwesen – Institute of

Energy Process Engineering and Chemical Engineering (TUB-F)IGCC integrated gasification combined cycle (gas turbine)IPCC Intergovernmental Panel on Climate Change (UNFCCC)IPR intellectual property right(s)ISBN International Standard Book NumberITC Institute for Technical Chemistry (FZK)ITP (1) integrated thermal processing; (2) International Technology Promoter

(network, DTI)J joule = 1 N m = 1 W sJRC Joint Research Centre (EC)JV joint venturekg kilogramkgoe kg of oil equivalent = 42 x 106 J = 42 MJkm kilometre = 1,000 mkt kilotonne = 1,000 t = 106 kgkW kilowatt = 1,000 WkWh kilowatt-hour = 1,000 Wh = 3.6 x 106 J = 3.6 MJL leftLCA life cycle assessmentLCVP Low Carbon Vehicle Partnership (UK)LHV lower heating valueLPG liquified petroleum gasm metrem2 square metrem3 cubic metreMC moisture contentMJ megajoule = 106 Jmm millimetre = 0.001 mMOGD methanol to olefins, gasoline and dieselMSW municipal solid wasteMt megatonne = 106 t = 109 kgMTBE methyl tertiary butyl ether

109


MTG methanol to gasolineMtoe million tonne (megatonne = Mt = 106 t) of oil equivalent = 42 x 1015 J = 42 PJMW megawatt = 106 WMWe megawatt (electrical output)MWth megawatt (thermal output)NNFCC National Non-Food Crops Centre (UK)N (1) nitrogen; (2) newton = 1 kg m/s2

N2 nitrogenNH3 ammoniaNm3 normal (0ºC, 1 atm) cubic metreNOx nitrogen oxide(s)odt oven dried tonnep penceP poise = 0.1 N s/m2 (Pa s)Pa pascal = 1 N/m2

PAH polycyclic aromatic hydrocarbonpH potential of hydrogen (measure of acidity or alkalinity)PISI port injection spark ignitionPJ petajoule = 1015 JPJth petajoule (thermal output)PL PolandPO Post Officepp pagesppm parts per millionQ1, Q2… first quarter, second quarter… (of year)R rightR&D research and developmentRCEP Royal Commission on Environmental Pollution (UK)RDF refuse derived fuelRE renewable energyREA Renewable Energy Association (UK)RME rape methyl esterROC Renewables Obligation Certificate (UK)RSPO Roundtable on Sustainable Palm Oil (Secretariat: Malaysia)RTF renewable transport fuelRTFO Renewable Transport Fuels Obligation (UK)s secondS&T science and technologySAE Society of Automotive Engineers (USA)SCR selective catalytic reductionSiC silicon carbideSMDS Shell Middle Distillate Synthesis (process, Shell)SME small and medium sized enterpriseSNG synthetic natural gasspp speciesSO2 sulphur dioxideSRC short rotation coppiceSRF (1) solid recovered fuel; (2) short rotation forestry

110


SVZ Sekundärrohstoff-Verwertungszentrum Schwarze Pumpe (Germany)SWG supercritical water gasificationsyngas synthesis gast tonne (metric ton) = 1,000 kgT telephoneTAB Thermal Waste Treatment Division (ITC, FZK)tC tonne of carbonTGA thermogravimetric analyserTekes Teknologian Kehittämiskeskus – Finnish Funding Agency for Technology and

InnovationTNO Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek

– Netherlands Organisation for Applied Scientific Researchtoe tonne of oil equivalent = 42 x 109 J = 42 GJTUB-F Technische Universität Bergakademie Freiberg – Technical University

Bergakademie Freiberg (Germany)TWh terawatt-hour = 1012 WhUK United KingdomULSD ultra low sulphur dieselUN United NationsUNFCCC United Nations Framework Convention on Climate ChangeUS(A) United States (of America)UVO used vegetable oilVOC volatile organic compoundvol volumeVTT Valtion Teknillinen Tutkimuskeskus – Technical Research Centre of Finlandvs versusW watt = 1 J/sWBCSD World Business Council for Sustainable Development (HQ Switzerland)WEEE waste electrical and electronic equipmentWh watt-hour = 3,600 JWID Waste Incineration Directive (EC)wk weekWRAP Waste and Resources Action Programme (UK)wt weightWUR Wageningen Universiteit en Researchcentrum – Wageningen University and

Research Centre (Netherlands)y year

111


Appendix ESOME FIGURES AND CONVERSION FACTORS

Exhibit E.1 Properties of selected fossil fuels and biofuels

Exhibit E.2 Conversion factors for selected units of energy

112


Fuel Lower heatingvalue (MJ/kg)

Cetane number Density at 15ºC(kg/m3)

bbl/t

Fossil gasoline (EN228) 44 – 730 8.6

Fossil diesel (EN590) 42.8 >49 820-845 7.6-7.3

Synthetic diesel 40 73-81 740 8.5

Ethanol 27.0 – 789 7.9

FAME (EN14214) 37 >51 860-900 7.3-7.0

Woody biomass (dry) 19-22 – 500-700 –

MJ GJ kWh toe

MJ 1 10-3 0.278 24 x 10-6

GJ 1,000 1 278 0.024

kWh 3.6 0.0036 1 86 x 10-6

toe 42,000 42 11,700 1

Appendix FLIST OF EXHIBITS

Exhibit Page Caption

S.1 9 Mission team outside the new Choren Beta plant (L-R): Tony Bridgwater, Geoff Hogan, Bob Saunders, David Bown, Anton Zimmermann, Warren Smith, Craig Jamieson, Nicola Yates, Nicki Smoker, Ian Barton

2.1 14 Biofuels required in the UK to meet the 2010 indicative value of 5.75% by energy content of EU Biofuels Directive 2003/30/EC

2.2 15 Examples of current biofuels and their production processes

2.3 15 Total sales (millions of litres) of petrol, diesel and biofuels in the UK

2.4 16 Current biofuel plants in the UK

2.5 16 Proposed biofuel plants in the UK

2.6 16 UK land area to produce the 5.75% by energy content of biofuels required to meet the 2010 indicative value in EU Directive 2003/30/EC

2.7 19 Future fuels pathway

3.1 20 Thermal biomass conversion processes for transport fuels and chemicals

3.2 21 Typical product yields (dry wood basis) obtained by different modes of pyrolysis of wood

3.3 25 Typical properties of wood-derived crude bio-oil

3.4 25 Fast pyrolysis bio-oil

3.5 26 Torrefied pellets at ECN

3.6 27 Transport fuels and chemicals from fast pyrolysis

3.7 30 Modes of thermal biomass gasification

3.8 31 Gasifers and examples visited during mission

3.9 31 Typical product gas characteristics from different gasifiers

3.10 32 Synthesis gas contaminants and their problems

113


3.11 33 Biomass or bio-oil to transport fuels

3.12 34 Activities on synthetic transport fuels at organisations visited

3.13 34 Opportunities for meeting the UK renewable transport fuel demand

4.1 38 Process options in second generation biofuels

4.2 39 Process demonstration plants

4.3 39 Process plants under development

4.4 40-41 Development highlights from mission

4.5 42 Typical process efficiencies for syngas routes

5.1 48 Decreased regulated emissions for hydrotreated vegetable oil fuel (NExBTL) compared to sulphur free EN590 petroleum diesel in a heavy duty diesel truck engine

6.1 53 Miscanthus

6.2 54 Summary of information currently available on biomass crops in use or being researched in the UK

6.3 55 NExBTL CO2 emission comparisons in kg CO2 equiv/kgoe

6.4 56 Screenshot of the Bioloco program (WUR)

7.1 59 Well-to-wheel energy content and GHG emission analysis

7.2 60 Typical outputs from Öko-Institut model (DE = Germany; PL = Poland; BR = Brazil; SRF = short rotation forestry)

8.1 64 Typical capital costs of GTL, CTL and BTL plant

8.2 66 Small scale stand-alone conversion plant for BTL

8.3 66 Large scale centralised conversion plant for BTL

8.4 67 Biorefinery concept for second generation biofuels

8.5 70 Economic data for second generation biofuels

A.1 88 Dr Harold Boerrigter explaining the CFB biomass gasifier at ECN

A.2 94 Rotating cone pyrolysis reactor at BTG

114


A.3 95 Beta plant under construction at Choren

A.4 97 Top of entrained flow gasifier at Future Energy

A.5 99 Part of SVZ site

A.6 101 Dr Andreas Hornung explaining the Haloclean screw pyrolysis reactor at FZK

E.1 112 Properties of selected fossil fuels and biofuels

E.2 112 Conversion factors for selected units of energy

115


116

Grant for Research and Development – is available through the nine English RegionalDevelopment Agencies. The Grant for Researchand Development provides funds for individualsand SMEs to research and develop technologicallyinnovative products and processes. The grant isonly available in England (the DevolvedAdministrations have their own initiatives).www.dti.gov.uk/r-d/

The Small Firms Loan Guarantee – is a UK-wide, Government-backed scheme that providesguarantees on loans for start-ups and youngbusinesses with viable business propositions.www.dti.gov.uk/sflg/pdfs/sflg_booklet.pdf

Knowledge Transfer Partnerships – enableprivate and public sector research organisations to apply their research knowledge to importantbusiness problems. Specific technology transferprojects are managed, over a period of one tothree years, in partnership with a university,college or research organisation that has expertise relevant to your business.www.ktponline.org.uk/

Knowledge Transfer Networks – aim to improvethe UK’s innovation performance through a singlenational over-arching network in a specific field oftechnology or business application. A KTN aims to encourage active participation of all networkscurrently operating in the field and to establishconnections with networks in other fields thathave common interest. www.dti.gov.uk/ktn/

Collaborative Research and Development –helps industry and research communities worktogether on R&D projects in strategicallyimportant areas of science, engineering andtechnology, from which successful new products,processes and services can emerge.www.dti.gov.uk/crd/

Access to Best Business Practice – is availablethrough the Business Link network. This initiativeaims to ensure UK business has access to bestbusiness practice information for improvedperformance.www.dti.gov.uk/bestpractice/

Support to Implement Best Business Practice

– offers practical, tailored support for small andmedium-sized businesses to implement bestpractice business improvements.www.dti.gov.uk/implementbestpractice/

Finance to Encourage Investment in Selected

Areas of England – is designed to supportbusinesses looking at the possibility of investingin a designated Assisted Area but needingfinancial help to realise their plans, normally in the form of a grant or occasionally a loan.www.dti.gov.uk/regionalinvestment/

Other DTI products that help UK businesses acquire andexploit new technologies

Global Watch Information

Global Watch Online – a unique internet-enabled service delivering immediate andinnovative support to UK companies in theform of fast-breaking worldwide business andtechnology information. The website providesunique coverage of UK, European andinternational research plus businessinitiatives, collaborative programmes andfunding sources.Visit: www.globalwatchservice.com

Global Watch magazine – distributed freewith a circulation of over 50,000, this monthlymagazine features news of overseasgroundbreaking technology, innovation andmanagement best practice to UK companiesand business intermediaries.Contact:[email protected]

UKWatch magazine – a quarterly magazine,published jointly by science and technologygroups of the UK Government. HighlightingUK innovation and promoting inwardinvestment opportunities into the UK, thepublication is available free of charge to UKand overseas subscribers.Contact:[email protected]

Global Watch Missions – enabling teams ofUK experts to investigate innovation and itsimplementation at first hand. The technologyfocused missions allow UK sectors andindividual organisations to gain internationalinsights to guide their own strategies forsuccess.Contact:[email protected]

Global Watch Technology Partnering –providing free, flexible and direct assistancefrom international technology specialists toraise awareness of, and provide access to,technology and collaborative opportunitiesoverseas. Delivered to UK companies by anetwork of 23 International TechnologyPromoters, with some 8,000 currentcontacts, providing support ranging frominformation and referrals to more in-depthassistance with licensing arrangements andtechnology transfer.Contact: [email protected]

For further information on the Global WatchService please visitwww.globalwatchservice.com

The DTI Global Watch Service provides support dedicatedto helping UK businesses improve their competitivenessby identifying and accessing innovative technologies andpractices from overseas.

Printed in the UK on recycled paper with 75% de-inked post-consumer waste content

First published in July 2006 by Pera on behalf of the Department of Trade and Industry

© Crown copyright 2006

URN 06/1162

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