NOVEL BIO-BASED PRODUCTS FROM SIDE STREAMS OF PAPER AND

BOARD PRODUCTION

The research leading to these results has received

funding from the European Community's 7th

Framework Programme under grant agreement

no 604187

Contents PART 1: The Reffibre Project

Summary ................................................................................................................................ 3

1. Introduction ....................................................................................................................... 4

2. Paper and board industry side streams ............................................................................. 5

3. Inventory of side stream valorisation opportunities ............................................................ 6

4. Discussion ...................................................................................................................... 11

5. Conclusions .................................................................................................................... 12

Appendices .......................................................................................................................... 13

PART 2: Maximum value from paper for recycling .........................................................………….49

Summary

The paper and board production process, especially when carried out with paper for recycling as the raw material, leads to the generation of large amounts of side streams, mainly sludges, rejects and process water. The main two outlets for the European paper and board industry’s (PBI) solid side streams have historically been landfilling and incineration. Both of them entail significant costs for the sector, while landfilling has been recently facing also regulatory limitations in several countries. Reducing these costs, and even turning them into profits, depends on the ability of the sector to utilise the valuable components in the side streams by reusing them internally or converting them to intermediates or products for other parties.

This report identifies and describes a number of side stream valorisation opportunities, either already on the market or in various stages of development, and aims to inform stakeholders in the sector of ways to utilise the full potential of their raw materials. The valorisation routes presented are organised in four categories, namely application of the side stream in its current form without further processing, application by conversion into a material product, application by conversion into energy, and application by conversion into an energy carrier and include the following options:

Land management

Absorbent materials production

Building materials production

Wood-plastic composites production

Fractionation

Hydrolysis to fermentation feedstock

Nanocellulose production

PHAs production

Alginates production

Incineration

Gasification

Pyrolysis

Anaerobic digestion

Secondary fuels production

The report demonstrates the significant potential for the valorisation of the large amounts of side streams of the paper and board industry, with several of the options described having the additional benefit of being able to produce high-value materials that could be reused within the sector’s own production processes.

1. Introduction

The Confederation of European Paper Industries (CEPI), in cooperation with Kenniscentrum Papier en Karton (KCPK), published in 2011 the report “Maximum value from paper for recycling – Towards a multi-product paper mill”. The basis for that document was the idea that obtaining maximum value per unit of paper for recycling (PfR) –a key raw material for a large part of the European paper and board industry (PBI)- is an important aspect of papermaking. Given that increased demand for biomass has been expected within traditionally non-biobased sectors, such as energy generation and chemicals production, as they are trying to move towards the realisation of Biobased Economy visions, it was suggested that extracting the maximum economic value out of PfR would sooner or later become a decisive factor with regard to the profitability of a paper or board producer. Taking into account that a significant amount of the PfR that is fed into the papermaking process does not leave it in the form of an end product but rather in that of side streams, efforts to find useful and profitable applications for it have been of great interest to the PBI as a means of improving its economic performance. The 2011 report attempted to bring into perspective a representative selection of side stream valorisation opportunities, which were either being implemented or under development at the time of publication, so as to inform stakeholders in the sector of ways to utilise the full potential of their raw materials.

The REFFIBRE FP7 project, running between 2013 and 2016, aims to help the PBI decrease waste generation, improve resource efficiency and strengthen its competitiveness through the production of novel products with a lower environmental impact and a high added value out of side streams. Methodologies, tools and models needed in order to determine the technical and economic feasibility of Multiple Output mill concepts, as well as to assess their environmental impacts, are developed within the project. Operational data is required so as to test and validate these models. The implementation of innovative technologies for the production of novel products on a demonstration scale is necessary in order to generate and collect real data from the chosen REFFIBRE cases. Based on the need for a pilot scale demonstration of novel valorisation technologies we have carried out within the project a new review of the opportunities either already available to and implemented by the PBI or currently in various stages of development. This review is now being made available as an update of the 2011 CEPI/KCPK report, enabling decision makers within the sector to remain up to speed with regard to the developments that have taken place in the past five years.

2. Paper and board industry side streams

The side streams generated by paper and board mills that are considered for the purposes of this report are defined as follows:

Rejects (ragger, heavy, coarse, fine); produced during the utilisation of PfR, they can contain fibre lumps, plastics, metals, sand and glass. The most important types of rejects in terms of their valorisation potential are:

o coarse rejects, produced during early filtration steps in which large non-fibre objects such as plastics are removed, and

o fine rejects, produced during filtration steps with screens with very small slots so as to remove possible sticky content that may disturb the production process and diminish the quality of the end product; fine rejects contain a considerable amount of fibres

Deinking sludge; produced during the flotation deinking of PfR, it contains mostly short fibres/fines, inorganic fillers, as well as ink particles

Primary wastewater treatment sludge; produced during process water clarification by mechanical means, it contains mostly short fibres/fines and fillers

Secondary wastewater treatment sludge; produced during process water clarification by biological means

Process water (often referred to as wastewater when treated before its discharge); a key component of papermaking, it is usually treated on-site for the removal of contaminants

Reliable statistics regarding side stream generation by the PBI are difficult to come by; in 2005 around 11 million tonnes of solid waste were generated in Europe (including from pulp production) and roughly 70% (7.7 million tonnes) thereof originated from using PfR as a raw material1. According to the same source, the utilisation of PfR results in 50-100 kg of dry solid waste per tonne of packaging paper production, 170-190 kg per tonne of newsprint production, 450-550 kg per tonne of graphic paper production and 500-600 kg per tonne of tissue production. Different paper mills, however, produce different amounts of side streams of varying compositions. Information about process water is even more scarce; as an indication, more than 70,000 dry tonnes of COD were contained in the process water of the Dutch PBI in 2008, when the sector’s production volume was around 3 million tonnes, 80% of which was based on the use of PfR as a raw material.

The main two outlets for PBI solid side streams have historically been landfilling and incineration, although the significance of the former has greatly decreased owing to bans imposed in several European countries. In any case, both options have entailed significant costs for the sector, with recent information from Germany and the Netherlands indicating that disposing of rejects and sludges could cost up to 100 € per tonne. Reducing these costs, and even turning them into profits, depends on the ability of the sector to utilise the valuable components in the side streams by reusing them internally or converting them to intermediates or products for other parties.

1 Monte MC, Fuente E, Blanco A, Negro C. Waste management from pulp and paper production in the European Union, Waste Management, 29, pp. 293-308, 2009

3. Inventory of side stream valorisation opportunities

The opportunities identified for the purposes of this report are summarised in the table below. They are organised in four categories, namely application of the side stream in its current form without further processing, application by conversion into a material product, application by conversion into energy, and application by conversion into an energy carrier.

Table 1. PBI side stream valorisation opportunities discussed in this report.

Use as such On-site or external

processing

Applied in the PBI

Applicable for

Deinking sludge

Primary sludge

Secondary sludge

Coarse rejects

Fine rejects

Process water

Land management

(land spreading,

land remediation, landfill cover)

n/a Yes, in some

forms

Absorbent materials

production (animal

bedding)

n/a Yes

Conversion to product

Land management (composting)

n/a No

Absorbent materials

production

Both possible

Yes, limited

Building materials

production External

Yes, in some forms

Wood-plastic composites production

External Yes, limited

Fractionation On-site Yes, limited

Hydrolysis to fermentation

feedstock

Both possible

No

Nanocellulose production

Both possible

No

PHAs production

Both possible

No

Alginates production

On-site No

Conversion to energy

Incineration Both

possible Yes

Conversion to energy carriers

Gasification On-site Yes, limited

Pyrolysis On-site Yes, limited

Anaerobic digestion

On-site Yes

Secondary fuels

production On-site Yes

A brief description of each valorisation possibility included in this report will be provided in this chapter. More extensive factsheets are provided in Annex I.

Land management

PBI deinking and primary wastewater treatment sludges can be used for a number of land management applications. Two practices are widely applied: land spreading, where sludges are spread on agricultural land for nourishing and conditioning purposes, and application as landfill cover, where sludges are used as a barrier cover in landfills, using their favourable permeability characteristics. Other land management options that have been suggested -but do not appear to have been applied yet in practice- are the use of sludge for land remediation, where the side stream is contributing to the revegetation of degraded soils (e.g. old surface mines), and the composting of sludge, which can offer a better product for use in agriculture and horticulture compared to the spreading of untreated sludge. Drawbacks common to some or all of these options include regulatory limitations, often negative public perceptions, limited potential for absorbing large side stream volumes and the necessity to pay gate fees for disposing of the side stream.

Production of absorbent materials

PBI deinking and primary wastewater treatment sludges can be used in the production of absorbent materials. This may take two forms, namely the production of animal bedding and the production of absorbent materials for liquids with applications in, for example, the cleaning of chemical and fuel spills. The production of animal bedding may require minimal to no processing of the side stream, while industrial absorbents can be produced by means of simple mechanical processing. Although this route offers some valorisation of the side streams, animal bedding production is not a high-value application, while the market prospects of large amounts of industrial absorbents from PBI side streams are uncertain. For both of these options, known examples of application in practice within the PBI already exist.

Production of building materials

The production of various materials used by the construction sector out of PBI side streams has been implemented for some time in some cases or is in various stages of development in others. The possibilities include application of PBI side streams in the production of cement, concrete, bricks, and various types of board materials (e.g. gypsum fibreboard, MDF, hardboard, etc.). PBI sludges have been applied for some time in brick and cement production, where they act as a fuel for generating part of the heat required by the process and as a partial replacement for virgin raw materials. Use of various types of PBI side streams, both sludges and rejects, has been suggested, but not widely applied yet, including in the production of panel materials for the construction sector, where their use is intended to partially substitute other fibre sources (e.g. PfR and wood). Current experiences with valorisation via the production of building materials (e.g. use in cement kilns) indicate that at least some of these possibilities involve a gate fee charged to the paper mill for disposal of their side streams.

Production of wood-plastic composites

Various types of PBI side streams, both sludges and rejects, could be used in the production of wood-plastic composites (WPCs). These are, as the name denotes, composite materials made of wood fibre, usually in the form of wood flour, and thermoplastic materials, such as PE, PP, PVC, etc. Depending on the characteristics of a given side stream, it could be applied either as a low-cost substitute for more expensive raw materials without leading to a deterioration of the end product quality, or as an additive that could improve the characteristics of the end product, for example by reinforcing it. WPCs have a growing market and various existing and potential applications. Each one of these applications sets its own requirements with regard to the characteristics and quality of the end product, which may pose higher, lower or no obstacles for the use of PBI side streams in the production process.

Fractionation

Although fractionation is included here among the identified side stream valorisation opportunities, it is in practice an intermediate step that, when undertaken, makes the pursuit of other valorisation routes possible or, at least, simpler and more efficient. The term “fractionation” denotes in this report the separation of one or more fractions from a side stream, although it can also be applied in the pulp stream, based on the specific characteristics of each fraction’s components. When applied on side streams of the PBI, fractionation can produce fractions that are either suitable for reuse within the same sector or attractive for applications outside the paper industry; the characteristics of the new fractions make them better suited for the proposed application than the untreated side stream would be, which improves the chances of profitable side stream valorisation instead of simply less costly disposal. The extent of side stream fractionation can be determined by the paper mill, depending on its wishes. Fractionation could be as simple as separating the organic (fibres, fines) from the inorganic (fillers) material in a sludge stream or as complex as producing various organic fractions of fibres and fines with different characteristics. Currently applied or proposed examples of side stream fractionation involve technologies that are already widely used within the sector, with their optimal combination appearing to be the key factor for success.

Hydrolysis to fermentation feedstock

Hydrolysis of PBI sludges for the production of sugars could become a major step towards the further integration of the sector within the emerging Biobased Economy. Cellulose in the side streams can be enzymatically broken down into glucose molecules, with the sugars being metabolically converted to chemicals (e.g. lactic acid) or energy carriers (e.g. ethanol). The fact that PBI sludges are cheap and geographically concentrated sources of cellulose, with the fibres having been extensively treated and thus more amenable to enzymatic treatment, makes them an interesting possibility for the production of sugars. Fractionation for the removal of ash could help improve the efficiency and economics of this route. No industrial references exist at this point in time but literature suggests that research in this topic has gained considerable momentum.

Production of nanocellulose

Nanocellulose is seen as a high-performance material that will start playing an increasingly important role in the future, with applications across many different sectors, including the paper industry. The production of one type of nanocellulose (nanocrystalline cellulose) from PBI sludges is being developed by an Israeli company on the basis of the acid hydrolysis of the sludge. The same company is also working on an array of this product’s applications, among which ideas of interest to the PBI, such as use in paper sizing and as gas barrier coating. The first demonstration plant for this production technology, initially with bleached pulp as raw material, will become operational by the end of 2016.

Production of polyhydroxyalkanoates (PHAs)

PHAs are a family of polyesters that serve as carbon and energy storage units within certain microorganisms and have significant potential as biodegradable bioplastic materials. Their competitiveness against conventional plastics is currently limited due to their high production costs, but efforts made for their production out of side streams are promising to address this issue. PBI wastewater could be one of these side streams, utilised within a process that acts as a wastewater treatment process, resulting in the production of a valuable biobased product. Applying such a concept in practice could also help paper mills close their water loops without the usual accompanying problems. Production of PHAs out of industrial wastewaters, including those of the PBI, has reached pilot scale and the development of functioning PHAs value chains and markets should be the next step towards realising the concept in practice.

Production of alginates

A new aerobic wastewater treatment technology developed in the Netherlands is promising great process-related benefits, such as energy savings and reduced space requirements, when applied for the treatment of municipal and industrial wastewaters, either in new treatment plants or in retrofitted older installations. As well as being a treatment technology, this could be a valorisation possibility for the organic content of wastewater, as it can deliver a by-product in the form of alginate-like exopolysaccharides. These resemble alginates produced from seaweed and research is currently underway regarding possible applications of this by-product. One of the most interesting ideas is its potential use in paper sizing, a function that seaweed-based alginates also perform. The water treatment technology is already operational, primarily within municipal treatment plants, and the first installation focusing on the extraction of the alginate by-product is planned for 2017.

Incineration

One of the most widely applied options for dealing with PBI side streams, incineration has greatly benefited from the utilisation of fluidised bed technology which is more apt for feedstocks that are high in ash and moisture content. The production of steam and electricity can help a paper mill reduce its dependence on fossil fuels, lower its energy costs and add a new source of income, especially in countries where generous state incentives are available for the generation of green energy.

Gasification

Another technology available for the thermal treatment of PBI side streams, gasification leads to the production of synthesis gas, a mixture of CO, CO2, CH4, H2O and N2. Synthesis gas can either be used directly as fuel (e.g. co-combustion in a steam boiler) or converted to other fuels or chemicals. The high investment costs for the application of this technology may, in certain countries, be partially covered by state subsidies for the generation of green energy, as was the case with the first commercial reject gasifier that will become operational in 2016 in the Netherlands.

Pyrolysis

Another form of thermal treatment, in the total absence of oxygen, pyrolysis produces a mixture of solid, gaseous and liquid products, depending on the composition of the feedstock and process conditions. Pyrolysis oil and gas can be directly used as fuels, providing the pyrolysis process itself with the energy necessary, and the oil could potentially also be converted into other fuels or chemicals. When PBI sludges are pyrolysed the mineral fraction returns as a clean secondary product, which could be applicable again as a filler for papermaking if its quality is sufficiently high, while when mixed rejects are pyrolysed the metal fraction returns as a clean secondary product. Reject pyrolysis has already been commercially applied, while sludge pyrolysis is in the phase of pilot scale development.

Anaerobic digestion

The breaking down of organic matter by microorganisms in the absence of oxygen has already been widely applied within the PBI as a wastewater treatment technology but could be equally interesting for the treatment of secondary sludge from aerobic wastewater treatment. The latter requires, however, some form of pre-treatment in order to improve the digestibility of complex organic matter; several options have been suggested or are already on the market. The biogas

produced by anaerobic digestion of water and sludge can be internally utilised by a paper mill so as to cover part of its energy needs, while sludge digestion can reduce the volumes that need to be disposed of and offer an array of other process benefits within the wastewater treatment plant.

Production of secondary fuels

Rejects from the stock preparation in paper mills utilising PfR as their raw material can be converted into various forms of secondary fuels (e.g. fluff or pellets) to be co-fired at energy generation plants or by other industrial users. This option has already been in practice for several years.

4. Discussion

The list of valorisation opportunities found above is far from exhaustive, with more options being developed worldwide by industrial parties or researchers; information about all of them is difficult to gather, due among other things to the secrecy that often surrounds new technologies. It provides, however, a good indication about the technologies that are already applied within the sector, as well as those whose development has gained significant recent momentum.

Conversion to energy and energy carriers has a strong presence in this report, with all five options described for sludges, rejects and process water having been applied in practice in at least one known case within the PBI. Although they make good use of the energy content of side streams, a development that is already a step forward compared to the era of landfilling, they are still not optimal solutions for a future in which the principles of the Biobased Economy and the Circular Economy will increasingly guide business decisions. In order to adapt to such a new reality more needs to be done with regard to extracting value out of side streams in another way, by utilising their potential as raw materials and not as energy sources. On the other hand, the current economic reality in certain counties, with subsidies and other incentives available for the generation of green energy, makes these valorisation options much more attractive and diminishes the risks of undertaking the significant investments needed for e.g. a new incineration or gasification facility. In our experience, removing this direct and/or indirect state support from the equation would quite possibly lead decision makers to reconsider their commitment to such energy generation-focused projects.

An important step towards optimally valorising the content of PBI side streams should be managing to reclaim as much high-quality material from them as possible for the sector’s own operations. It can be said with some certainty that the maximum value of a tonne of reclaimed fibres will be obtained when they are applied in papermaking compared to any other valorisation possibility. Developments in the field of side stream fractionation could prove to be very important in this context, allowing the sector to keep the materials that can best serve its own production process, while seeking the optimal valorisation route for the fractions that have less to offer to the PBI. Some papermakers are already trying to implement side stream valorisation by means of recirculating the materials back to their production process without fractionation; this option has shortcomings however. Reintroducing all components of a side stream to papermaking can have a negative influence in terms of process parametres such as dewatering, drying, machine speed etc., or product characteristics such as strength; these adverse effects of side stream reuse can be avoided by means of fractionation.

Besides reclaiming fibres, this report showcases in a number of examples the potential of extracting other valuable materials for the PBI from the sector’s side streams. The examples of PHAs, alginates and nanocellulose are characteristic of these possibilities. The PBI needs to pay more attention to producing its own additives in the years to come in order to improve process efficiency or product performance.

A factor that is often not adequately discussed, despite its importance, is the need to create partnerships in the field of side stream valorisation. Such partnerships must sometimes involve parties from within the PBI sector, e.g. when more paper mills pool together their side streams in order to gather sufficient quantities for attracting the interest of a third party that may have a use for them, or when one paper mill separates fractions from their side streams that could be best utilised by the producer of another paper or board grade. In other cases the potential partnerships may involve parties that belong to different sectors; a paper mill and a chemical producer, for example, could be brought together by their geographical proximity and the availability of mutually useful materials. Such local partnerships between a small number of parties could actually be easier to realise in the short term than national networks bringing together many stakeholders with often diverse priorities and needs.

5. Conclusions

Significant potential exists for the valorisation of the large amounts of side streams that are generated during the paper and board production process, especially when PfR is utilised as the raw material. A far from exhaustive list of such technologies and techniques has been compiled for the purposes of this report. These can be organised in four categories, namely application of the side stream in its current form without further processing, application by conversion into a material product, application by conversion into energy, and application by conversion into an energy carrier. Several of the proposed concepts have the added benefit that they could potentially lead to the reclamation of high-quality materials from PBI side streams to be reused within the sector’s operations. It should be mentioned that local conditions, e.g. the composition of a mill’s side streams, regional/national subsidy schemes, distance from necessary partners, etc., can play a major role in determining the attractiveness of any of the aforementioned options for any individual paper or board mill.

Appendices

Appendix 1. Factsheets of side stream valorisation options

Title: Application in land management

Raw material type: PBI sludges.

Short description: A number of land management options are available as an outlet for sludge generated by the PBI. The following options can make use of favourable sludge characteristics:

Land spreading

Land remediation

Landfill cover

Composting

Intermediate and end products: All land management options entail the direct application of sludge in the area selected.

Process: There are no complicated processes involved in the application of PBI side streams for land management. In the case of land spreading, for example, the practice consists of simply spreading the sludge on agricultural land or ploughing it into soil. Dewatering of the sludge (e.g. by screw pressing) can take place in advance so as to facilitate its storage and transportation. In the case of land remediation, the sludge can be applied in contaminated sites, such as old surface mines, in order to restore their ecosystem function by addressing nutrient deficiencies and toxicities that impede the re-establishment of self-sustaining plant cover. In landfills PBI sludges can be used for substituting other materials (e.g. clay, bentonite) in the hydraulic barrier layer or they can be used in the landfill’s liner and its daily cover layers. Finally, composting of PBI sludge involves the solid phase decomposition of the organic matter by microorganisms under controlled conditions, leading to the production of a marketable product (compost) for application in agriculture and horticulture.

Benefits and Drawbacks: The land spreading of sludge can nourish and condition soil and assist in breaking down pesticides, and can be beneficial for water retention in fast-draining soils. On the other hand, large areas are required for this application, given that there are limitations regarding the maximum amounts applied, and the practice is restricted to certain periods throughout the year, which means that storage capacity for sludge is required. Some odour problems may also exist, especially during the first days after application. The heavy metals content of certain sludges could also be a point of concern, as well as the possibility of groundwater contamination via the leaching of salts, nitrates or heavy metals. The greatest drawback of this route, however, is that land spreading is not allowed in several

countries.

When applied to land remediation PBI sludges can be a valuable tool for the revegetation of degraded soils that face limitations with regard to water retention, acidity, nutrient availability and bulk density. The application of sludge can also chemically stabilise metals in polluted soils and convert them to forms that are not available for uptake by plants. A question with regard to this route is whether remediation activities could generate sufficient demand and absorb significant sludge quantities.

In landfill cover application PBI sludges demonstrate good permeability characteristics, no odour problems and can support vegetative growth. When incineration ash is added to them, geomechanical, chemical and stability characteristics can be further improved. In a world, however, in which landfilling is set to assume an increasingly peripheral role as a waste management option this outlet has no long-term potential.

Composting reduces sludge volumes and transportation costs, improves storage and handling, removes odours, degrades phytotoxic compounds and provides a better overall soil amendment than untreated sludge. Co-composting of sludge with nitrogen-rich organic waste (e.g. kitchen and catering waste) can be beneficial for both materials. The need for a large space is, however, one disadvantage of traditional composting processes.

Land management options, where legally allowed, do not appear to have a very attractive economic potential, limited either by the need to pay gate fees for the disposal of the sludge and/or by an insufficiently large demand.

Technology Readiness Level: Land spreading and use of sludge in landfill covers have been applied for many years. Composting of organic materials is also well developed, although no references were found in the case of PBI side streams, while the use of sludge in land remediation has been described in several studies but has not been, to the best of our knowledge, applied in practice.

Experiences in the Paper and Board industry: Land spreading of PBI sludge has been a popular outlet in some countries (e.g. United Kingdom), while reports of sludge use as landfill cover, especially in the United States of America (USA), also exist.

Literature/websites: http://www.paper.org.uk/information/guidance/landspreadingcode_Nov2015.pdf

http://www.flagstaff.az.gov/DocumentCenter/Home/View/11013

www.uws.ac.uk/workarea/downloadasset.aspx?id=2147493392

Title: Absorbent materials production

Raw material type: Suitable for deinking and primary wastewater treatment sludges.

Short description: There are two main options with regard to the production of absorbent materials from PBI side streams: animal bedding and absorbents for oil and other hydrophobic and hydrophilic liquids from water or hard surfaces.

Intermediate and end products: The end product of this valorisation route is the absorbent material, which can have various forms (e.g. loose or pelletised) depending on the application.

Process: Depending on the intended product, the production process for an absorbent material may include steps such as drying, some form of mechanical treatment and mixing with other materials. As an example, the production from deinking sludge of the CAPSorb absorbent material for hydrophobic liquids is described in the following steps:

Drying the deinking sludge to the point where releasing the cellulose fibres from the inorganic matrix can be efficiently performed by means of mechanical processing. This requires the sludge to be dried by up to 70-80% and waste heat from a paper mill can be used

Mechanical processing (fluffing) of the dried sludge, which increases its surface area and absorbency and also makes it possible for the material to float, e.g. for cleaning oil spills on water surfaces

Further chemical treatment (e.g. esterification) can be an optional step, when even better absorbency or buoyancy are required

Production of animal bedding for cow sheds in the USA by Syracuse Fiber Recycling, on the other hand, is described as involving simply mixing PBI sludge with cement dust so as to increase its dry matter content.

Benefits and Drawbacks: The benefit for paper mills when offering their side streams for the production of absorbent materials is to avoid sludge disposal costs. This valorisation route involves simple processes that require low investments, relative to other possibilities, and which can utilise already available unused resources, such as waste heat for sludge drying. It should be mentioned that experiences with PBI sludge as animal bedding indicate that its use can result in healthier and more productive animals compared to other alternatives.

The main drawback of this route is, in the case of animal bedding, the absence of a high-value end product or, in the case of absorbents for liquids, the uncertainty regarding the existence of a sufficiently large market, as all kinds of absorbents are competing not only among themselves but also against other options such as solidifiers and detergents.

Figure 1. Demonstration of the CAPSorb absorbing material’s capacity to remove oil from the surface of water (Source: TEC)

Technology Readiness Level: Both types of absorbent products mentioned here are already available on the market.

Experiences in the Paper and Board industry: Examples of animal bedding production from PBI sludges include Sappi Maastricht (the Netherlands) and Syracuse Fiber Recycling (USA), which collects sludge from various paper mills in the state of New York (e.g. SCA Tissue South Glenn Falls). Kadant GranTek (USA), on the other hand, is using PBI sludge for the production of its Gran-sorb absorbent for oil and other liquids.

Literature/websites: http://www.gran-sorb.net/

http://www.toc.si/caps/

http://www.saratogian.com/article/ST/20131014/NEWS/131019773

http://www.sappi.com/group/Sustainability/2013%20Sappi%20Fine%20Paper%20Europe%20Sustainability%20Report.pdf

Title: Building materials production

Raw material type: Depending on the specific application, it can be a route suitable for the valorisation of PBI sludges, but also of fine rejects or even fly ash from sludge incineration installations.

Short description: Side streams of the PBI can be used for the production of materials with applications within the construction sector. Specific materials that have been explored, or where PBI side streams are already applied, include cement, concrete, bricks, as well as various types of panels.

Intermediate and end products: The end product varies depending on the specific application within the building materials’ route, while no intermediate products are generated.

Process: For the production of bricks PBI sludge can simply be mixed with the clay that serves as the main raw material. Sludge addition of about 15% has been found to be acceptable for industrial production. It has been suggested that sludge could serve as a pore-forming agent in the production of insulating firebricks. These pores drastically reduce a brick’s thermal conductivity, making it useful for both industrial applications and the realisation of energy savings in buildings.

In cement production PBI sludge is utilised for both its caloric value and as a raw material. The sludge can be dried with the use of waste heat available in the cement mill and subsequently added to the cement kiln; fibres are incinerated, acting as an additional fuel in the process, while the inorganic ash is a compound of the cement clinker produced. Some more potential applications have been proposed besides this already applied option. PBI sludge could be converted by means of calcination, a form of thermal treatment, into highly reactive metakaolin to be used as an additive in cement. Another possibility could be the production of sludge-cement composites for lightweight board applications (e.g. roofs, ceilings, etc.).

An interesting potential application of paper sludge ash that has been recently described in literature focuses on the side stream’s conversion to a super-hydrophobic powder by means of simple, low-cost, surface functionalisation. A partial substitution of cement in concrete by this new material could improve overall concrete durability by increasing its resistance to water-induced deterioration processes.

An example of the possible applications of PBI side streams in the production of various types of panels for the construction sector is the case of gypsum fibreboard. Cellulose fibres from PfR (unused newsprint) are mixed with gypsum and water for the formation of a “mat”. After dewatering by means of vacuum and pressing the board is cut to size and the moisture content is further reduced using dryers. PBI side streams (sludge and fine rejects) could serve here as sources of fibre to substitute PfR. Recent research has also focused on the use of PBI side streams for the partial (up to 20%) replacement of wood fibre in the production of MDF and hardboard.

Benefits and Drawbacks: The valorisation of PBI side streams via the production of materials for the construction sector entails a useful application of these streams, as well as the potential to induce virgin raw material and/or energy savings, depending on the application, in the production of the aforementioned products. Current experiences with such valorisation routes, however, indicate that the economic potential for the PBI is limited, as the side stream owner still needs to pay a gate fee to, for example, the cement mill for accepting material.

Technology Readiness Level: Depending on the specific application within the broader construction materials theme, technology readiness levels can vary. Some options, such as the production of cement and bricks, have been commercial for a long time, others, such as various types of panels, have been successfully demonstrated on pilot scale trials, while possibilities such as the super-hydrophobic powder from incineration ash are still at a research phase.

Experiences in the Paper and Board industry: The production of cement and bricks using PBI side streams has been widely applied for several years. In the field of panel production, the German company Fermacell has recently been evaluating samples of PBI side streams to identify the right materials to substitute PfR in gypsum fibreboard production.

Literature/websites: http://www.boosteff.com/PageFiles/8988/The%20Fututre%20Manufacturing%20Concept%20for%20hardboard%20and%20MDF.pdf

https://www.scribd.com/doc/212641040/PaperResiduesConst1-efb26766-393

Vegas I, Urreta J, Frías M, García R. Freeze–thaw resistance of blended cements containing calcined paper sludge, Construction and Building Materials, 23, pp. 2862-2868, 2009

Yadollahi R, Hamzeh Y, Ashori A, Pourmousa S, Jafari M, Rashedi K. Reuse of waste sludge from papermaking process in cement composites, Polymer Engineering and Science, 53, pp. 183-188, 2013

Cusidó JA, Cremades LV, Soriano C, Devant M. Incorporation of paper sludge in clay brick formulation: Ten years of industrial experience, Applied Clay Science, 108, pp.191-198, 2015

Wong HS, Barakat R, Alhilali A, Saleh M, Cheeseman CR. Hydrophobic concrete using waste paper sludge ash, Cement and Concrete Research, 70, pp. 9-20, 2015

Title: Wood-plastic composites production

Raw material type: Potentially suitable for most types of PBI side streams (deinking and primary wastewater treatment sludges, fine rejects, fly ash from sludge incineration facilities). The characteristics of the side stream used, however, will have a strong influence on the composite’s quality and, therefore, its potential applications.

Short description: Side streams of the PBI can be used in the production of Wood-Plastic Composites (WPCs). As the name denotes, WPCs are composites made of wood fibres, usually in the form of wood flour, and thermoplastic materials such as PE, PP, PVC, etc. Depending on the nature of the side stream to be valorised via this route, it can either constitute a cheap filler that partially substitutes more expensive raw materials or it can improve the composite’s properties, e.g. by having a reinforcing effect.

Intermediate and end products: The intermediate product of side stream valorisation via WPCs production is granules of the composite material, which can be subsequently used for the production of the selected end products by means of injection moulding, profile extrusion etc. A wide array of end products is possible, depending on the characteristics of the composite.

Process: The first step in the production of WPCs from PBI side streams is the drying of the side streams, as the dry matter content of the input material needs to be high (around 90%). Given the need to remove most of the moisture, evaporation drying is likely to be necessary. The dried side stream is subsequently compounded at a given ratio with the selected thermoplastic material, and possibly also some chemical additives, such as colourants and coupling agents, for the production of the WPC granules.

Benefits and Drawbacks: The WPCs market has been showing strong growth lately, with the European market having been forecast to grow from 220,000 tonnes in 2010 to 350,000 tonnes at the end of 2015. Many applications of these materials are found within the building sector, ranging from door and window frames to decking and tiles, and from wall siding to fences. Other applications can be found, as an indication, in furniture and the automotive sector. It should be mentioned that each of these products may need to adhere to a certain set of regulations, which will need to be scrutinised in order to determine the compliance of the proposed side stream-incorporating new product.

Given that many of the applications of WPCs are found in items that need to be also aesthetically pleasing, a potential drawback of side stream use may be the possibility of altering the appearance of the end product. This needs to be investigated for each proposed combination of a side stream with an intended end product. A path with lower barriers may be found in the form of products in which only practical characteristics are of concern. An example thereof is transportation pallets, which, if made with the use of side stream-incorporating WPCs, could help paper producers apply within their own supply chains items produced via the valorisation of their own side streams.

The need to dry the side streams in order to be usable in WPCs production is a drawback but, depending on the local situation, some paper mills may be able to apply waste heat

already available on their sites.

Technology Readiness Level: WPCs production is already commercial and utilises long-established processes. The incorporation of PBI side streams will not require the development of new technologies but rather extensive testing in order to determine whether a specific side stream is applicable for the production of a specific product.

Experiences in the Paper and Board industry: The only existing application of the WPCs route for the valorisation of PBI side streams so far has been the use of waste from adhesive label production by UPM for the production of the UPM ProFi WPCs.

Figure 2. Outdoor decking constructed with UPM ProFi WPC material (Source: UPM)

Literature/websites: http://www.upmprofi.com/About/Environment/Pages/Default.aspx

Huang HB, Du HH, Wang WH, Shi JY. Characteristics of paper mill sludge-wood fiber-High-Density Polyethylene composites, Polymer Composites, 33, pp. 1628-1634, 2012

Soucy J, Koubaa A, Migneault S, Riedl B. The potential of paper mill sludge for wood–plastic composites, Industrial Crops and Products, 54, pp. 248-256, 2014

Title: Fractionation

Raw material type: Suitable for deinking and primary wastewater treatment sludges; application to the main pulp stream during the paper and board production process can also be considered.

Short description: The concept of fractionation can be defined for the purposes of this report as the separation of one or more fractions from a specific stream, either of “waste” material or pulp, based on the specific characteristics of each fraction’s components. When fractionation is applied at side stream level it could provide fractions that are reusable within the paper and board production process, as well as fractions that are more attractive than the original material for external applications. Pulp fractionation, on the other hand, can produce pulp streams that will be subjected to different forms or varying degrees of processing (e.g. selective refining) based on their fibre characteristics, as well as fractions that are unusable by the paper mill (e.g. ash).

Intermediate and end products: The products of a fractionation process may depend on the wishes of the party implementing it. In the case of side stream fractionation one could opt for an organic (fibres, fines) and an inorganic (mineral fillers) fraction, or could move beyond this level by also producing separate fibre and fines fractions.

Process: The specifics of a fractionation process can vary depending on what the intended outcome is. A filler reclamation system (ECO plant) from effluent treatment sludge operating at Stora Enso Oulu can be used here as an example. A wire washer is used for separating the recoverable inorganic material from fibres and other rejects; this material is subsequently subjected to centrifugal cleaning for the removal of impurities (e.g. dirt). The reclaimed fillers are chemically treated for a slight brightness increase and dosed to the paper machines, while the rejects of the process are thickened and, after being mixed with bark, combusted in a solid fuel boiler. Another example is the concept proposed by Kadant for sludge fractionation into fibres, bonding fines, non-bonding fines and ash. Here a fibre fraction is generated first from a sludge stream by means of screening. In the next step flotation is applied for separating ash from fines. The fines are then split into a bonding fines and a non-bonding fines fraction by means of hydrocyclones.

Figure 3. Wire washer used for filler reclamation at the ECO plant (source: Jortama, 2003)

Benefits and Drawbacks: Applying fractionation concepts in practice can entail several benefits for the PBI. First of all, a fuller utilisation of the purchased raw material can be achieved by reclaiming perfectly good fibres that were lost during their first pass through the production process. An indicative example of the potential in this area is offered by the application on a laboratory scale of the Kadant fractionation concept on deinking sludge from tissue production; it was found that about 20% of the feed consisted of recoverable long fibres. A further 10-15% of the feed consisted of recoverable fines with good bonding potential that are considered able to improve strength properties of the paper product when returned to the production process. Such reclaimed fractions can either be utilised by the same paper mill that produced the original side stream or offered to neighbouring paper producers. Besides this possible internal utilisation of reclaimed fractions fractionation could also be a step towards the realisation of more extended circular economy cases with the participation of parties from other sectors. Being able to separate the organic and inorganic fractions of a side stream could make both of them much more attractive for actors interested in having one fraction without the other (e.g. for green chemicals production from cellulosic side streams or for the neutralisation of acid side streams by means of affordable calcium carbonate). It is therefore possible that fractionation could play an important role in moving from a situation where a paper mill is paying high gate fees so as to have its sludge incinerated by a third party to a situation where fractions of this sludge can find their own best possible applications (within and outside the PBI), while reducing the operating costs of the mill or even constituting new sources of income.

Figure 4. Fractions (produced on laboratory scale) of deinking sludge from a tissue producer (source: Kadant)

If fractionation is applied as part of the stock preparation for treating all or part of the pulp stream, instead of as an end-of-pipe solution, it could, as well as having the aforementioned benefits, make the targeted treatment of specific fractions possible (e.g. refining of only one raw material fraction), thus improving both overall pulp quality and the energy and/or resource efficiency of the production process. Given that this report is focused on side stream valorisation opportunities, these possibilities will not be further analysed here.

Technology Readiness Level: Known fractionation concepts, such as the aforementioned Kadant system or the ECO plant, make use of equipment whose utilisation is widespread within the PBI (e.g. wire washers, hydrocyclones, flotation cells, etc.). The critical step here is not, therefore, developing new equipment but combining existing tools in the right way for the task at hand.

Experiences in the Paper and Board industry: It has already been mentioned that Stora Enso Oulu has applied in practice the ECO plant for filler reclamation and reuse. Another filler recovery system (Trenntechnik) has also been operated at a former Stora Enso mill (Uetersen, now Feldmuehle Uetersen).

Literature/websites: http://www.kcpk.nl/algemeen/bijeenkomsten/presentaties/20160203-vg-middag-sessie (sheets 50-86)

Jortama, P. Implementation of a novel pigment recovery process for a paper mill, Department of Process and Environmental Engineering, University of Oulu, 2003 (available at: http://jultika.oulu.fi/files/isbn9514272226.pdf)

Title: Hydrolysis to fermentation feedstock

Raw material type: Deinking sludge, primary wastewater treatment sludge.

Short description: Cellulose-containing side streams of the PBI have been receiving attention as a potential feedstock for enzymatic hydrolysis in order to produce fermentation sugars, to be subsequently converted into green fuels or energy.

Intermediate and end products: Depending on the type of process applied (see Process below), cellulose can be converted into sugars as an intermediate product, or directly converted into the end product. The potential end products from the conversion of PBI side streams that have received the most attention are ethanol and lactic acid, but a much wider range of chemicals can be produced via fermentation processes, including propionic acid, 1,3-propanediol, 3-hydroxypropionic acid, succinic acid, 2,3-butanediol, butyric acid, butanol, etc.

Process: The enzymatic hydrolysis of cellulose refers to the breaking down of cellulose chains into glucose molecules by cellulase enzymes, while fermentation is a metabolic process that converts sugars into acids, alcohols or gases. Two options are available with regard to carrying these out, namely Separate Hydrolysis and Fermentation (SHF), where the two processes occur sequentially in separate reactors, and Simultaneous Saccharification and Fermentation (SSF), where the two processes take place simultaneously within one reactor. In general, SSF is considered to be beneficial in terms of process integration, as only one tank is required, and of shorter residence times, while SHF offers the optimal process conditions for each step.

Figure 5. Schematic representation of an SSF process

Sludge fractionation could offer certain advantages when implemented as a pre-treatment method before an enzymatic hydrolysis process. Calcium carbonate in PBI sludges adsorbs enzymes with a higher affinity than cellulosic fibres, thus limiting saccharification efficiency,

while the removal of inorganics can also help reduce the reactor sizes required, thus lowering the investment costs. Besides fractionation, other proposed additional steps are aimed at reducing enzyme dosages, and thus overall process costs, and include the addition of cationic polyelectrolytes in order to promote enzyme binding to cellulose, as well as pre-treatment of the sludge with hydrogen peroxide in order to increase enzymatic digestibility by dissolving lignin and exposing (hemi)cellulose to enzyme attack.

Benefits and Drawbacks: The conversion of PBI side streams to fermentation feedstock by means of enzymatic hydrolysis has the potential of being a major step towards the closer integration of the sector into the emerging Biobased Economy. Many of these fermentation products already have well established markets or are expected to become increasingly important in the future, especially when the currently used petrochemical-based raw materials can be replaced by biomass.

PBI side streams are considered to have several upsides as sources of cellulose for hydrolysis. They are concentrated in significant volumes and at low cost in permanent sites, which already have utilities and infrastructure that could be used for the proposed processes. Cellulose fibres in PBI side streams have already been extensively treated (mechanically, chemically) and thus are much more accessible to enzymes than “raw” lignocellulose sources; this has the potential to reduce enzyme use during hydrolysis, with the cost of enzymes being a very significant factor in overall hydrolysis economics. SSF can also be focused on the most easily accessible polysaccharides, with the residue of the process being anaerobically digested into biogas, thus allowing the production of both chemicals and energy with reduced residence times for the hydrolysis process.

Technology Readiness Level: Known research on the production of fermentation feedstock from PBI side streams is still on a laboratory scale. To the best of our knowledge no further upscaling has taken place so far.

Experiences in the Paper and Board industry: None yet.

Literature/websites: Marques S, Santos JAL, GÍrio FM, Roseiro JC. Lactic acid production from recycled paper sludge by simultaneous saccharification and fermentation, Biochemical Engineering Journal, 41, pp. 210-216, 2008

Kemppainen K, Ranta L, Sipilä E, Östman A, Vehmaanperä J, Puranen T, Langfelder K, Hannula J, Kallioinen A, Siika-aho M, Sipilä K, von Weymarn N. Ethanol and biogas production from waste fibre and fibre sludge-The FibreEtOH concept, Biomass and Bioenergy, 46, pp. 60-69, 2012

Chen H, Han Q, Daniel K, Venditti R, Jameel H. Conversion of industrial paper sludge to ethanol: Fractionation of sludge and its impact, Applied Biochemistry and Biotechnology, 174, pp. 2096-2113, 2014

Gurram RN, Al-Shannag M, Lecher NJ, Duncan SM, Singsaas EL, Alkasrawi M. Bioconversion of paper mill sludge to bioethanol in the presence of accelerants or hydrogen peroxide pretreatment, Bioresource Technology, 192, pp. 529-539, 2015

Title: Nanocellulose production

Raw material type: Suitable for deinking and primary wastewater treatment sludges; a low lignin content is required.

Short description: The Israeli company Melodea has been working on the production of nanocrystalline cellulose (NCC), with PBI side streams serving as the feedstock for an acid hydrolysis process. Besides the potential of this route as a side stream valorisation option, NCC could become an additive in paper production to improve certain product properties.

Intermediate and end products: NCC is the end product of the acid hydrolysis production process, without any intermediate products.

Process: Nanocrystalline cellulose, also known as cellulose nanocrystals or nanowhiskers, is produced by means of acid hydrolysis of cellulose fibres, usually with sulfuric acid. The amorphous regions of cellulose are preferentially hydrolysed, while the crystalline regions are more resistant to acid attack. Washing and centrifugation steps are part of the production process, separating cellulose sediment from the liquid phase, while mechanical treatment (e.g. sonication) is applied in order to disperse the obtained nanocrystals as a uniform stable suspension. Melodea has also developed technology that allows it to recover most of the acid used for the hydrolysis in order to repeatedly reuse it.

Figure 6. Main steps of the NCC production process (source: Melodea)

Benefits and Drawbacks: This route offers the possibility to valorise current side streams by converting them into high-value products. The produced NCC is a material with a multitude of potential applications within various sectors and could therefore become a significant source of income for the side stream-generating paper mill. Some of the examined NCC applications include the following:

Transparent gas barrier coating for packaging materials, e.g. substituting aluminium in food packaging

Anti-friction coating

Foams for sandwich composites

Foams for insulation materials

Additive in various materials and products (e.g. cement, acrylic glues, paints, thermoplastics, etc.) to improve properties such as adhesiveness, scratch resistance, tensile strength, erosion resistance, bonding, etc.

Figure 7. NCC foam panels (source: Melodea)

Of additional interest to the paper sector is the potential of NCC’s use as an additive in paper and board production. Paper sizing with the use of starch/NCC mixtures is an example of such an application currently under evaluation so as to determine whether this could result in reduced starch use and/or the production of paper products with improved performance. Although still some way from realisation in practice, it is conceivable that in the future it may be possible for the paper industry to convert its side streams into additives of value for its own production processes and products.

One drawback of this valorisation route is its requirements with regard to the properties of the side streams that can be considered promising feedstocks for the economically viable production of NCC. These requirements may cover parametres such as the fibre and lignin contents of the input material. The absence of a sufficiently developed nanocellulose market is also an issue for now, but nanocellulose is seen as a material with a huge potential for the coming years.

Technology Readiness Level: The first demonstration plant making use of Melodea’s process for the production of NCC from bleached pulp will become operational within 2016. The plant is located in Sweden and has a capacity of 100 kg NCC per day.

Experiences in the Paper and Board industry: So far there are no cases of commercial production of NCC from PBI side streams or of commercial use of NCC in paper production. It should, however, be mentioned that Holmen is an investor in Melodea.

Literature/websites: http://www.melodea.eu/

Brinchi L, Cotana F, Fortunati E, Kenny JM. Production of nanocrystalline cellulose from lignocellulosic biomass: Technology and applications, Carbohydrate Polymers, 94, pp. 154-169, 2013

Title: Polyhydroxyalkanoates production

Raw material type: Process water and secondary wastewater treatment sludge.

Short description: An alternative to traditional wastewater treatment technology is offered in the form of utilising the organic content of the water as food for polyhydroxyalkanoates (PHAs)-accumulating microorganisms. The term PHAs refers to a family of polyesters that serve as carbon and energy storage units within certain microorganisms and which also have considerable potential as a bioplastic material.

Intermediate and end products: The intermediate product of a wastewater treatment plant that aims at producing PHAs will be PHAs-enriched biomass; the PHAs must be extracted from the biomass at a subsequent step and constitute the end product in the case of this route. The discarded biomass after the extraction of the PHAs can be seen as a secondary product, e.g. as a source of nutrients.

Process: A wastewater treatment plant geared towards the production of PHAs will need to perform two functions:

Cultivation, which refers to selecting PHAs-producing microorganisms from the bacterial flora present, and

Accumulation, where the previously selected microorganisms are fed until maximising the PHAs content in their cells

Both of these functions, which can be performed in two separate steps or combined into one, simultaneously serve to treat the wastewater treatment plant’s influent. If the process is carried out in separate phases, then in the first phase selective pressure is applied on the microbial culture in the form of alternating periods of short presence of a carbon substrate (feast) and long absence of the carbon substrate (famine) under fully aerobic conditions; PHAs-storing bacteria generally outcompete other bacteria in such a feast-famine regime. The cultures that are enriched with PHAs-accumulating microorganisms in the first step are used in the second step in order to produce PHAs. For this purpose they are supplied with an excess of substrate while simultaneously withholding other nutrients so as to inhibit growth and direct as much carbon as possible towards PHAs storage. It must be noted that these two steps may in some cases be preceded by a pre-treatment of the raw material by means of acidogenic fermentation. As Volatile Fatty Acids (VFAs) are readily utilised by many species of bacteria as a substrate for the synthesis of PHAs, the fermentation degree of an influent is an important parametre to be evaluated in order to determine whether this pre-treatment step is necessary in any given case. When carried out, this fermentation pre-treatment can have an additional function by influencing the ratios between the different VFAs types that will form the substrate; this “engineering” of the substrate can in turn offer some degree of control over the composition of the produced PHAs co-polymers and thus some control over the material properties of the end product itself.

Figure 8. Two-step PHAs production from wastewater (Source: AnoxKaldnes)

The same principles can also be applied when the secondary sludge of a wastewater treatment plant is valorised via the production of PHAs. In this case the sludge is hydrolysed for the production of VFAs, which are subsequently fed as substrate to the selected PHAs-accumulating microorganisms.

The polymer stored within the microorganisms still needs to be extracted before it can be further processed. Various extraction methods aimed at breaking down the cell walls exist, including mechanical processes (e.g. centrifugation), chemical processes (e.g. organic solvents, acids, bases) and biological processes (e.g. enzymes).

Figure 9. PHAs stored inside bacteria

Benefits and Drawbacks: The benefits of applying the PHAs production technology for the treatment of a paper mill’s process water depend on the choices made with regard to the business model implemented. Three main possibilities can be distinguished here:

“Buy and Operate” model; a paper mill invests in and operates a PHAs-producing wastewater treatment installation. A completely new business is added to the mill’s activities, entailing the production of PHAs-enriched biomass, as the extraction of the biopolymer is a process that, in order to be economically feasible, needs to be carried out at a scale larger than the amount of material available even within a large paper mill. The enriched biomass can therefore be supplied to centralised extraction

facilities that collect material from several neighbouring producers

“Outsource” model; a third party invests in a PHAs-producing wastewater treatment installation on the site of the paper mill and is also responsible for the subsequent steps (extraction, sales)

“COD supplier” model; the paper mill offers its process water to a third party as a feedstock for PHAs production and thus acts as a COD supplier

Based on the scenario selected, the paper mill can benefit in the following ways:

Creating a new source of income, either in the form of enriched biomass (“Buy and Operate” model) or in the form of COD in its process water (“COD supplier” model); COD in process water is thus converted from a cost factor to a source of additional profits

Creating the conditions for closing the internal water loop, a possibility present in all three scenarios. Up to now, paper mills that wish to reuse their process water are faced with problems of smell, slime formation, etc. due to the increased biological activity in water with high COD loads. This creates problems in the process and the working environment and entails significant costs for biocides intended to control this biological activity. Adding a PHAs-producing “bio-kidney” to the mill’s water loop can deliver clean water back to the production process, while eliminating all problems associated with a closed water loop, and offer a new product/source of income

The main drawback associated with this valorisation route is the currently low level of development of a PHAs market. The industrial production of PHAs is based exclusively on the utilisation of pure microbial cultures of genetically modified microorganisms or natural PHAs producers, which require a sterile environment, for the conversion of the selected raw materials in order to maintain good control over the process and the end product. Given the very specific requirements that must be met (sugar or glucose as feedstock, pure cultures, sterile environment, axenic reactors, etc.), the production costs are high, which has an adverse effect on the product price and on the competitiveness of these biopolymers. Moving towards production on the basis of mixed microbial cultures that utilise side streams as feedstock can immensely improve the competitiveness of PHAs but this is a gradual process that will require a number of years before leading to a fully developed PHAs market and value chain. One option in the meantime could be to apply the technology as a “bio-kidney” in order to reap the benefits of a closed water loop, while finding stop-gap applications for the enriched biomass (e.g. internal use in paper production).

A further potential benefit of the PHAs route could be their possible utilisation as a raw material for the PBI, thus potentially making circular patterns possible, with the sector producing PHAs from its side streams and then using them internally in its production process. Some work has been carried out with regard to the improvement of barrier properties (against oxygen, water and oil) by means of PHB coating with encouraging results. Research has been aimed towards the use of PHAs dispersions as binders for pigment coatings that improve smoothness, optical properties and printability, replacing non-biobased polymers. At a commercial level, Metabolix is working on PHAs latex coatings (e.g. for coffee cups, but also for wax-coated board boxes for transporting wet produce) that will replace non-biodegradable polymers, thus ensuring the repulpability of the paper product. Besides applications under research or development, Shenzhen Ecomann already offers commercially a PHAs compound for extrusion coating of paper products. This product serves as an example of an advantage of PHAs over PE in terms of processing parametres. Polyethylene resin, namely, requires a much higher temperature (around 300 °C) for extrusion coating of paper compared to PHAs resin (165-175 °C). When working with heat-sensitive additives, such as active compounds added to novel packaging systems, this can be an important issue. The main attraction of PHAs as a component for paper coatings is of course their biodegradability, which ensures full recyclability of the end product as well as opportunities for the marketing of paper products as being completely “green”. More

research and development work is, however, still needed in this field.

Technology Readiness Level: Pilot scale installations for PHAs production out of wastewater or secondary sludge have been operational within various sectors, including municipal wastewater treatment, the food industry and the paper industry.

Experiences in the Paper and Board industry: The Dutch paper industry has been a front-runner in evaluating the potential of PHAs production as a process water valorisation route. DS Smith Paper De Hoop, Eska and Smurfit Kappa Roermond Papier have cooperated with AnoxKaldnes (subsidiary of Veolia Water Technologies) in evaluating on laboratory scale the potential of their process waters as PHAs sources, while Eska has served as the site for a pilot-scale installation developed by the Technical University of Delft and Paques.

Literature/websites: http://www.kcpk.nl/algemeen/bijeenkomsten/presentaties/20140508-jan-ravenstijn-pha-is-it-here-to-stay

http://www.metabolix.com/blog/working-towards-a-truly-degradable-coffee-cup-metabolix-pha-latex-for-paper-coating/

Bengtsson S, Werker A, Christensson M, Welander T. Production of polyhydroxyalkanoates by activated sludge treating a paper mill wastewater, Bioresource Technology, 99, pp.509-516, 2008

Jiang Y, Marang L, Tamis J, van Loosdrecht MCM, Dijkman H, Kleerebezem R. Waste to resource: Converting paper mill wastewater to bioplastic, Water Research, 46, pp.5517-5530, 2012

Vähä-Nissi M, Laine C, Talja R, Mikkonen H, Hyvärinen S, Harlin A. Aqueous dispersions from biodegradable/renewable polymers, paper presented at the 2010 TAPPI Polymers Laminations Adhesives Coatings Extrusion (PLACE) Conference, Albuquerque (available at: http://www.tappi.org/content/events/10PLACE/Aqueous.pdf)

Manandhar S, Dagnon K, D’Souza N. A Study of mechanical properties of polyhydroxyalkanoates (PHAs) coated on kraft paper, paper presented at the 37th Annual Conference of the North American Thermal Analysis Society (NATAS), Lubbock, 2009

Title: Alginates production

Raw material type: Process water.

Short description: A new aerobic wastewater treatment technology, Nereda, has been developed in the Netherlands, substituting conventional activated sludge with aerobic granular sludge. The new process offers several improvements as a water treatment technology for municipal and industrial facilities, while producing alginate-like exopolysaccharides (ALE) as a by-product that could have applications, among others, within the PBI.

Intermediate and end products: ALE is the by-product of the Nereda wastewater treatment process; the granular sludge containing the ALE could be viewed as an intermediate product if applications for it without the extraction of the ALE can be found.

Process: The characteristic that separates the Nereda wastewater treatment process from conventional aerobic activated sludge treatment is the formation of sludge granules instead of flocs. Granular sludge has certain advantages compared to activated sludge flocs, such as improved settling and the formation of a structured matrix for biomass growth; this contains spheres with anaerobic, aerobic and anoxic conditions, which are populated by different microorganisms including phosphate accumulating organisms (PAO), nitrifiers, denitrifiers and glycogen accumulating organisms (GAO). This allows for a simultaneous execution of the processes required for nutrient removal and provides the foundation for a simple process with minimal space requirements.

Nereda uses an optimised sequencing batch reactor (SBR) cycle in which the four steps of a typical SBR cycle are reduced to three:

1. Simultaneous fill/draw; during this stage the wastewater is pumped into the reactor and at the same time the effluent is drawn

2. Aeration; biological conversion takes place during the aeration phase. The outer layer of the granules is aerobic and accumulates nitrifying bacteria. This forms nitrate that is then denitrified in the anoxic core of the granules. Phosphorous uptake occurs in the final step

3. Sedimentation; following the biological processes, a sedimentation phase separates the clear effluent from the sludge. The time for phase separation is short due to the settling properties of the granular sludge. The system is then ready for a new cycle

Figure 10. The 3-step Nereda wastewater treatment process (source: Royal HaskoningDHV)

The granular sludge of the Nereda process contains 15-25% ALE, which can be extracted by means of technologies currently utilised for alginate extraction from seaweed. Besides being a valuable by-product in itself, the extraction of the ALE reduces excess sludge volumes and improves the dewatering and digestibility of the remaining excess sludge. As a rule of thumb, 2.5 kg of ALE per person-equivalent per year can be produced at a Nereda wastewater treatment plant, which means that a 400,000 person-equivalent plant could produce 1,000 tonnes of ALE annually.

Benefits and Drawbacks: The benefits of implementing the Nereda technology can be divided into two categories; the benefits generated when the technology is judged purely on its wastewater treatment merits, and those stemming from the extraction and further valorisation of ALE in granular sludge.

As a wastewater treatment option, Nereda offers a range of benefits compared to conventional aerobic installations. These include the following:

Lower operational costs; less mechanical equipment (e.g. pumping stations) is needed due to the simplicity of the process, thus reducing energy consumption by 25-35%. Costs for process chemicals are also much lower

Lower initial investment; again due to the need for less mechanical equipment, but also due to reduced tank volumes as a result of the more concentrated biomass

Lower space requirements; Nereda treatment plants can be up to 75% smaller than conventional installations due to operations being concentrated in a single tank and the redundancy of a large part of the conventional mechanical equipment

It should be mentioned that applying the Nereda technology is possible in both completely new treatment plants and when retrofitting existing facilities; in the latter case, the retrofit can lead to increased plant capacity and/or improved effluent quality. Furthermore, it is possible

to use “hybrid” systems, where the Nereda process cooperates with conventional aerobic treatment. In this case part of the influent is treated by each technology and the surplus granular sludge can be used for the inoculation of the aerobic activated sludge in order to improve its performance and settling characteristics.

When the scope of Nereda is extended to being seen as a process water valorisation technology, the extraction of value from the content of the process water in the form of an ALE product becomes its added benefit. This content has so far been mostly removed, in order to comply with effluent regulations, but often without a useful application, the most notable exception being the production of biogas in anaerobic wastewater treatment installations. The Nereda process offers an alternative to this. ALE is considered as a product with possible applications in the textile sector, where alginates are already in use, in agriculture and land management, while new outlets are also being considered (e.g. bioplastics). Even more significant for the PBI, however, is the potential use of ALE within its own production processes, primarily as a biobased sizing agent. Work in this direction is ongoing and is based on the use of alginates from seaweed as an additive by the Asian paper industry. A circular pattern, where the PBI can produce a material necessary for its own processes from its own side streams, is therefore a conceivable possibility for the future, depending on the outcome of ongoing research into ALE application.

Figure 11. The water barrier effect of ALE on cellulosic fibres; a: Cellulosic fibre networks are porous and water easily penetrates them; b: ALE forms a film on the cellulosic fibre network, with hydrophobic groups repulsing water droplets (source: Lin et al., 2015)

Technology Readiness Level: Nereda is already operational in several installations worldwide, primarily in municipal wastewater treatment facilities. For industrial users its references are limited to the food sector, but the technology has been tested successfully on paper industry process water at pilot scale and no significant challenges are expected regarding its full-size application (see also retrofitting and “hybrid” scenarios above). The first ALE extraction installation, with an annual capacity of 150-200 tonnes, is planned for 2017, while research on ALE applications (including within the PBI) is ongoing.

Experiences in the Paper and Board industry: So far there are no cases of commercial Nereda installations within the PBI or of commercial application of ALE within the sector. Alginates from seaweed, however, are already used by the PBI; an example is the Scogin alginate product of the US chemicals producer FMC BioPolymer, which is applied in surface sizing and coating.

Literature/websites: http://www.royalhaskoningdhv.com/en-gb/nereda

Lin YM, Nierop KGJ, Girbal-Neuhauser E, Adriaanse M, van Loosdrecht MCM. Sustainable polysaccharide-based biomaterial recovered from waste aerobic granular sludge as a surface coating material, Sustainable Materials and Technologies, 4, pp. 24-29, 2015

Title: Incineration

Raw material type: Suitable for all types of sludges (primary and secondary wastewater treatment sludges, deinking sludge) and for fine rejects.

Short description: Incinerating PBI side streams for the generation of steam and electricity has become one of the most commonly applied side stream disposal methods in Europe despite the fact that the high moisture and ash contents of PBI sludges are unfavourable for this process. The utilisation of fluidised bed technology has been beneficial due to the ability of such combustors to better handle high ash and moisture streams.

Intermediate and end products: Steam as an intermediate product when the goal is electricity generation or as an end product when used internally by the paper mill, and electricity as an end product by utilising the generated steam.

Process: In a typical setup in a paper mill environment, the sludge after some pre-treatment (if necessary, e.g. pressing for dewatering/increasing the solids content, mixing of different sludge types or of sludge with other materials, etc.) is fed to a fluidised bed combustor. This usually consists of a cylindrical refractory-lined vessel, where the fluidising air is introduced and uniformly dispersed. The sludge burns on a fluidised bed of inert material (e.g. sand, limestone), while in the upper section of the vessel oxidation of any unburnt organic matter takes place. The conditions within the vessel provide for complete, controlled and uniform combustion and for a significant combustion efficiency improvement, especially for high-moisture fuels. Emissions from fluidised bed combustors are lower than those of other conventional technologies due to the absence of a flame front, the lower and uniformly distributed combustion temperatures and the low amount of excess air within the combustor. High combustion efficiency lowers CO in flue gases and desulphurisation/denitrification processes are available for further reducing the emission of pollutants. The high thermal inertia of the combustor limits temperature fluctuations due to variations of fuel feeding rates and/or heating value and ensures quick start-up after short stoppages. Maintenance requirements are generally reduced owing to the absence of moving parts.

Combustor fumes can subsequently pass through a heat recovery steam generator; the generated steam can expand in a steam turbine for electricity generation.

Benefits and Drawbacks: The main benefits of incineration are considered to be energy recovery from PBI side streams and the reduction of waste volumes to be disposed of. Energy recovery can reduce the reliance of the paper mill on other fuels and generate additional income for the company (even in the range of millions of euros annually) by offering electricity to the grid, especially when generous state economic incentives are present.

On the other hand, the realisation of an on-site incineration facility requires a high capital investment, still needs disposal or valorisation routes for the remaining ash and must comply to the local air emissions regulations. Furthermore, the very high moisture content of PBI side streams means that at least dewatering will be necessary in order to facilitate a self-sustaining combustion.

Technology Readiness Level: Various types of incinerators, including fluidised bed ones, have been commercially available for years.

Experiences in the Paper and Board industry: Some examples of on-site side stream incineration include Parenco (the Netherlands), Papierfabrik Utzenstorf (Switzerland), Stora Enso Langerbrugge (Belgium), Metsä Tissue Katrinefors (Sweden) and Mayr-Melnhof Hirschwang (Austria).

Literature/websites: http://www.siemens.com/press/en/pressrelease/?press=/en/pr_cc/2006/06_jun/02065046_1387997.htm

Caputo AC, Pelagagge PM. Waste-to-energy plant for paper industry sludges disposal: technical-economic study, Journal of Hazardous Materials, B81, pp. 265-283, 2001

Title: Gasification

Raw material type: Suitable for both sludges and rejects.

Short description: Gasification usually involves the partial oxidation of the input material by air, oxygen and/or steam for the production of synthesis gas, which is mainly composed of CO, CO2, CH4, H2O and N2. This is a more versatile energy carrier than heat and can also serve as a feedstock for the production of chemicals.

Intermediate and end products: Syngas can be seen as an end product, when it is used in internal combustion engines for electricity generation, or as an intermediate that can be converted into other types of fuel via the Fischer-Tropsch process or into chemicals (methane, methanol, dimethyl ether) via catalytic processes.

Figure 12. Possible applications of syngas (Source: Waste to Energy Systems)

Process: In a fluidised bed gasifier the feedstock is injected into either a bubbling or circulating bed of sand or a mixture of char and another inorganic heating or catalytic medium (e.g. dolomite). Rapid heating rates achieve gasification temperatures almost instantaneously. The oxidising agent (air, oxygen-enriched air, CO2, steam or a combination of the above) provides the fluidising medium and participates in the gasification reactions.

In a proposed setup for the gasification of the rejects of a paper mill, the first step has been defined as the pre-treatment of the rejects. This is required in order that the input corresponds to the requirements of the selected gasification technology; in the case of fluidised bed gasifiers, for example, the rejects can be fed as fluff or pellets, but with a size of <30 mm, their moisture content should be <40%, and the presence of heavy inert components (e.g. glass, metal, etc.) should be avoided. The above means that the pre-treatment steps required may entail sieving, magnetic removal of metals, shredding, etc., while drying may or may not be required depending on the local situation. The pre-treated rejects are subsequently fed to the reactor, which has a temperature of about 800 OC and is

also fed with air as an oxidising and fluidising medium. The produced syngas is cooled from about 800 OC to about 500 OC, with the reclaimed heat being utilised for hot air supply to the gasifier and for the combustion of the syngas. Ash and particulate matter are removed from the syngas in order to minimise the maintenance needs of the boiler that uses it as fuel, while other impurities (sulfur, chlorine, heavy metals) can be removed from the exhaust gas after the combustion instead of from the fuel itself.

It is doubtful whether the utilisation of syngas can easily take place in a gas turbine without extensive gas cleaning beforehand, which means that (co-)combustion in a steam boiler is an easier solution. Another limiting factor for use in a gas turbine is the lower caloric value of syngas compared to natural gas (5 MJ/m3 compared to 31 MJ/m3). The inhomogeneity of the rejects is expected to be problematic with regard to the conversion of syngas to other products (methanol, Fischer-Tropsch fuels).

Benefits and Drawbacks: The main benefits of gasification are considered to be energy recovery from PBI side streams and the reduction of waste volumes to be disposed of. Energy recovery can both reduce the reliance of the paper mill on other fuels, or even generate additional incomes for the company by offering electricity to the grid, especially in countries where generous state economic incentives are available.

On the other hand, an on-site gasification facility requires a high capital investment for its realisation and must comply to the local air emissions regulations. Furthermore, the very specific requirements set by various gasification technologies with regard to the characteristics of the input mean that various forms of pre-treatment will be necessary, depending on the local situation (sludges or rejects, moisture contents, etc.). Pelletisation of the fuel or mixing with other fuels (e.g. wood chips) may also be necessary or advantageous.

Technology Readiness Level: Gasification is a mature technology, with roughly 300 plants operating worldwide comprising around 700 gasifiers (primarily for coal, but with biomass and waste streams expected to grow in significance). About 25% of worldwide ammonia production and 30% of worldwide methanol production are based on gasification.

Experiences in the Paper and Board industry: The first known application of gasification in the PBI can be found in the Netherlands, where Eska will bring by the end of 2016 into operation a reject gasifier supplied by Leroux & Lotz. The facility will be processing 25,000 tonnes of rejects annually in a fluidised bed installation; the produced syngas will be used for steam generation for the paper mill, reducing its natural gas consumption by 18 Mm3/year.

Figure 13. The reject gasification installation of Eska (Source: Leroux & Lotz)

Literature/websites: http://www.gasification-syngas.org/resources/the-gasification-industry/

http://www.kcpk.nl/algemeen/bijeenkomsten/presentaties/20160203-vg-middag-sessie (sheets 25-40)

Ouadi M. Sustainable energy from paper industry wastes, Aston University, 2012 (available here: https://core.ac.uk/download/files/7/9636633.pdf)

Title: Pyrolysis

Raw material type: Suitable for both sludges and rejects.

Short description: Pyrolysis refers to the thermal decomposition of organic matter in the complete absence of oxygen. When applied to biomass or waste streams it can increase energy density, thus making energy transportation much more efficient. In the context of the paper industry, pyrolysis can serve as a conversion as well as a separation technique, as it can convert the organic content (fibres, plastics) of side streams into fuels (pyrolysis oil, pyrolysis gas) while reclaiming the inorganic content (metals, minerals) in a clean form.

Intermediate and end products: The main products of a pyrolysis process (pyrolysis oil and gas) can be seen as either end products that can be used as fuels for heat and power generation or as intermediates when the goal is the production of other types of fuels or chemicals. A pyrolysis oil refinery has been proposed, which will be able to produce a wide range of products through the fractionation of pyrolysis oil; possibilities include pyrolytic lignin for the replacement of fossil phenols and bitumen, pyrolytic sugars as feedstock for other chemicals, acetic acid, etc.

Process: The main process parametres that can influence the outcome of a pyrolysis process are the temperature reached (generally between 280 and 850 OC), the heating rate and the residence time; variations of these will have an influence on the ratios of the main pyrolysis products: liquid (oil), gaseous (gas) and solid (char).

In the context of the PBI, a distinction can be made between the pyrolysis of mixed rejects and that of sludge. In both cases it is the organic content of the feedstock, namely the plastics in the case of mixed rejects and the cellulosic matter in the case of sludges, that is converted into pyrolysis gas within the reactor. The inorganic matter, namely metals in the case of mixed rejects and mineral fillers in the case of sludges, is reclaimed as a clean secondary product of the process in both cases. The pyrolysis gas is subsequently partially condensed into pyrolysis oil. Part of the produced oil and/or gas, as well as any char produced in the process, can be used to supply the energy needed for the pyrolysis process itself, while the remaining oil and/or gas can either be used as fuel within the paper mill (e.g. in a dual-fuel diesel engine) or offered to third parties. Some pre-treatment may be required prior to feeding the side stream to the reactor, depending on the type of material (e.g. shredding and drying for rejects, drying for sludges).

Figure 14. The reject pyrolysis concept of Alucha (Source: Alucha)

Benefits and Drawbacks: Pyrolysis can be advantageous for the PBI primarily with regard to reclaiming energy out of the side streams and reducing the volumes of waste that need to be disposed of. The pyrolysis oil and/or gas can help reduce the dependence of the paper mill to fossil fuels, thus lowering the energy bill of the paper producer, or generate additional income by offering to third parties either the fuels directly or the power generated on-site via their utilisation. The secondary products of side stream pyrolysis can also generate income for the paper mill: reclaimed metals from reject pyrolysis can be offered to metal recyclers, and reclaimed minerals from sludge pyrolysis can either be offered to sectors that use such raw materials or, if they are of sufficient quality, can be reused by the paper industry, substituting “fresh” inorganic fillers.

A drawback of the pyrolysis process is that it requires a feedstock with a very low moisture content (<10%), which means that evaporative drying of the side stream will be required. Depending on the local situation, however, this may be performed by means of locally available waste heat, or by utilising energy from the produced oil/gas/char. Another potential shortcoming is the quality of the produced oil. This may contain partially cracked compounds with a high molecular weight, resulting in a viscous oil that could be problematic in storage/handling thus requiring an upgrade before use as fuel. Pyrolysis oil from deinking sludge was found to be miscible with biodiesel and the blend of sufficient quality so as to allow a diesel engine to achieve its full power.

Technology Readiness Level: Pyrolysis is a mature technology with many installations operating worldwide, processing a wide array of feedstocks (e.g. plastics, old tires, wood, empty fruit bunch, etc.).

Experiences in the Paper and Board industry: The first full scale pyrolysis installation within the PBI, supplied by Alucha, has operated within the former Stora Enso Barcelona mill (currently Barcelona Cartonboard), where it has been used for the processing of mixed rejects (plastic and aluminium) from the recycling of beverage cartons as a fibre source. Alucha is furthermore working in close cooperation with SCA for the development (currently on pilot scale) of PBI sludge pyrolysis.

Waste

preparation

system (screening,

shredding, drying)

Metals / Minerals

Reactor

Gas

Condensation

system

Heat (for drying)

Rejects Pyrolysis oil & gas

Generator

(electricity)

Boiler

(steam)

(Petro-)Chemical

industry

(chemicals, fuels)

ALUCHA PYROLYSIS PROCESS

Literature/websites: http://www.alucha.com/

http://www.storaenso.com/newsandmedia/from-juice-carton-to-car-parts

Ouadi M. Sustainable energy from paper industry wastes, Aston University, 2012 (available here: https://core.ac.uk/download/files/7/9636633.pdf)

Title: Anaerobic digestion

Raw material type: Anaerobic digestion has already been widely applied for wastewater treatment but is also being considered as an option for PBI biosolids (waste activated sludge from aerobic wastewater treatment).

Short description: Anaerobic digestion refers to a series of processes during which microorganisms break down organic matter in the absence of oxygen.

Intermediate and end products: The primary end product of anaerobic digestion (of both wastewater and sludge) is biogas, which can either cover part of the internal energy demand of the paper mill or be offered to third parties. In the case of waste activated sludge, the digestate from anaerobic digestion contains compounds of high agronomic value and could be further processed into commercial fertilisers.

Process: The key stages of anaerobic digestion are the following:

Hydrolysis; the breaking down of high-molecular-weight polymeric components of organic matter into their monomers (sugars, fatty acids, amino acids)

Acidogenesis; the further breakdown of the monomers by acidogenic bacteria. Volatile fatty acids are formed, as well as NH3, CO2 and H2S

Acetogenesis; further digestion of molecules created in the previous stage with production mainly of acetic acid and also CO2 and H2

Methanogenesis; intermediate products from the preceding stages are converted into CH4, CO2 and H2O. The remaining material (digestate or sludge) consists of indigestible organic matter and the remains of dead microorganisms

Wastewater treatment plants of paper mills have been using anaerobic digestion for many years. The main bottleneck for the anaerobic digestion of waste activated sludge is the hydrolysis of complex organic matter; slow and incomplete hydrolysis results in a long period of sludge retention (20-30 days), and large reactors and high investment costs. This could be overcome by means of the thermal, mechanical, chemical or biological pre-treatment of the sludge, which would enhance its anaerobic digestibility. Examples of such sludge pre-treatment include the Thermal Hydrolysis Process of Cambi (CambiTHP), in which sludge is pre-treated with high-pressure steam, and the MicroSludge concept of Paradigm Environmental Technologies, where a high-pressure homogeniser is used for disrupting microbial cells in waste activated sludge.

Benefits and Drawbacks: In the case of anaerobic digestion as an option for PBI wastewater treatment, the main benefit of the process is the production of biogas. In PfR-utilising mills, anaerobic digestion can achieve a 58-90% COD removal, while generating 0.24-0.4 m3 CH4 per kg COD removed. This happens while 0.02 tonnes of sludge per tonne of removed COD are generated, compared to 0.4-1 tonne of sludge per tonne of removed COD in aerobic wastewater treatment. Anaerobic water treatment, however, usually needs

to be combined with aerobic treatment in order to produce an effluent of sufficient quality for release into surface water. A benefit of combining aerobic and anaerobic wastewater treatment is the limited space requirements; these can be 25-50% of the space required for aerobic treatment alone.

The proposed anaerobic digestion of PBI biosolids can also reduce their volumes to be disposed of by 30-70%. Furthermore, it can improve their dewatering, thus leading to reduced polymer use, while the produced reject water is rich in nutrients and could be recirculated back to the activated sludge process so as to reduce the need for the addition of extra nutrients. In mills where primary and biological sludge are mixed for dewatering (e.g. prior to on-site incineration), diverting the biosludge to anaerobic digestion can be beneficial for the mechanical dewatering of primary sludge and the efficiency of sludge incineration.

Technology Readiness Level: Anaerobic digestion as a wastewater treatment method is well established; as a sludge treatment solution it has not yet been implemented within the PBI, although it is widely applied in the case of excess sludge from municipal wastewater treatment facilities (often in co-digestion with other materials). Various technological solutions for the pre-treatment of PBI biosolids aimed at improved digestibility thereof have been proposed and are currently in various levels of development or market introduction.

Experiences in the Paper and Board industry: Some indicative examples of anaerobic digestion facilities for wastewater treatment within the PBI include the following: Industriewater Eerbeek (the Netherlands, wastewater treatment plant serving three neighbouring paper mills), Smurfit Kappa Roermond Papier (the Netherlands), Smurfit Kappa SSK (United Kingdom), DS Smith Paper Lucca (Italy), Sappi Stockstadt (Germany), Sappi Lanaken (Belgium). The only operational example of anaerobic digestion of waste activated sludge in the broader pulp and paper sector can be found in Norway, where Borregaard has implemented it in its Sarpsborg speciality cellulose plant, combined with the CambiTHP pre-treatment technology.

Literature/websites: Meyer T, Edwards EA. Anaerobic digestion of pulp and paper mill wastewater and sludge, Water Research, 65, pp. 321-349, 2014

Stephenson R, Mahmood T, Elliot A, O’Connor B, Eskicioglu C, Saha M, Ericksen B. How Microsludge® and anaerobic digestion or aerobic stabilization of Waste Activated Sludge can save on sludge management costs, Journal of Science and Technology for Forest Products and Processes, 2(1), pp. 26-31, 2012 (available here: http://www.paptac.ca/J-FOR/J-FOR_Vol2-issue1.pdf)

Title: Secondary fuels production

Raw material type: PBI rejects.

Short description: Rejects from the stock preparation in paper mills utilising PfR as their raw material can be converted into various forms of secondary fuels (e.g. fluff or pellets) to be co-fired at energy generation plants or by other industrial users.

Intermediate and end products: The secondary fuel is the end product of this valorisation route, without any intermediate products.

Process: The examples of fluff and fuel pellets from rejects as applied by two Dutch paper mills will be described for the purposes of this report.

For the production of fluff, rejects undergo an initial selection so as to remove glass, metal and other large objects. The next stages of the process include dewatering in a screw press, disc screening, metal extraction and crushing before returning to the screening cycle. The screening accept is subsequently subjected to ferrous metal removal and drying for the production of the fluff in its final form. The fluff has a final dry matter content of about 90% and a caloric value of 20-30 MJ/kg. The heat for its drying is mainly provided by the utilisation of paper machine condensate.

For the production of fuel pellets from rejects, on the other hand, the rejects are dewatered in screw compactors, the compressed mass having a dry matter content of over 60%. Sieving separates the larger particles (>30 mm), which are cut into smaller fragments in a shredder. The sieve also loosens the compacted mass, which allows magnetic removal of remaining iron particles. After re-mixing of the shredded particles, the organic mass dries in a rotating drum dryer, where the dry matter content is increased to 93%. While the heaviest particles remain behind in the dryer, the light fraction is transported by the drying air and reclaimed in a separator and two cyclones. About 66% of the drying air returns to the dryer. Finally, the product, still at a high temperature, passes through a pelletiser. The pellets are cooled in a counter-flow air cooler to 5 °C above outside air temperature. The drying air from the drum dryer and the counter-flow dryer is discharged through a gas scrubber, where dust and odours are removed. The fuel pellets have a caloric value of 23.7 MJ/kg and can be co-fired with coal, oil or natural gas in blast furnaces, cement kilns, etc.

Benefits and Drawbacks: A benefit of the secondary fuels route is that it attaches some value to rejects which, due to their heterogeneity, appear to have limited valorisation options available. The use of waste heat available in the paper mill for the drying required is another positive aspect of the process. This route requires however a significant investment for the production of a material that could be faced with price volatility; it is possible that the paper mill may need to pay a gate fee to the users of the reject-derived fuel, but it is also possible, depending on the market situation, that the paper mill receives a positive price for this product.

Technology Readiness Level: Secondary fuel production from rejects has been operational for several years.

Experiences in the Paper and Board industry: The examples mentioned above correspond to two Dutch paper mills, namely DS Smith Paper De Hoop (fluff) and Smurfit Kappa Roermond Papier (pellets with the commercial name Rofire).

Figure 15. Rofire fuel pellets produced by Smurfit Kappa Roermond Papier

Literature/websites:

Maximum value from paper for recycling Towards a multi-product paper mill

Project report

Report by: Kenniscentrum Papier en Karton (KCPK) – Marc Marsidi, Annita Westenbroek Confederation of European Paper Industries (CEPI) - Jori Ringman-Beck

Launched at the European Paper Week 2011 (REC/054/10)

Appendix 2. Maximum value from paper for recycling: Towards a multi-product paper mill

2

Published by CEPI aisbl Confederation of European Paper Industries 250 Avenue Louise (post box 80) 1050 Brussels Belgium Tel: +32 2 627 49 11 Fax: +32 2 646 81 37 mail@cepi.org www.cepi.org August 2011

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Foreword Waste is not just a problem which needs regulation to ensure least harmful disposal. It is also a resource. Recognition of this was one of the most important changes in the EU waste law set in the Thematic Strategy on waste in 2006 and the revised Waste Directive 2008/98/EC. This change was strongly advocated by many, paper industry in particular, as we felt that the best practices in industry were not at all supported by the out-dated legal framework. Paper recycling is the most natural thing to do, but only some years back it was not a priority for the policy. Now the Commission is setting EU onto the path of transforming our economy: the Roadmap to resource efficient Europe1 was published in September.

Europe has the world's highest net imports of resources per person, and its open economy relies heavily on imported raw materials and energy.

Secure access to resources has become an increasingly strategic economic issue, while possible negative social and environmental impacts on third countries

constitute an additional concern.

Improving the reuse of raw materials through greater 'industrial symbiosis' (where the waste of some firms is used as a resource for others) across the EU

could save €1.4bn a year and generate €1.6bn in sales - EU Roadmap to Resource Efficiency (2011)

Where CEPI was a pioneer in recycling – implementing a recycling society in Europe decades before the term even was coined – it now is taking the challenge of using even more carefully the materials we have in our hands: even the reject from paper recycling can still include valuable resources. With the continuously increasing recycling rate the fibre yield from recycling is bound to decline, producing continuously more reject. As prices of paper for recycling and cost of reject management are ever increasing, the move to seeing the value of reject is also economically important. Like we have done before regarding fibres, paper for recycling should be seen as a source of many valuable components that can be used for the production of additional high value products alongside with paper. The compilation of techniques – in total 21 – for the most common by-streams in paper recycling is just a start: we wanted to show what is already possible and commercially available. There are more examples of extracting value from recycling rejects, and new techniques are being developed. This search for added value is also one of the guiding principles in the CEPI Roadmap 2050 for the European forest fibre industry2. In order to achieve economies of scale necessary to be economically feasible, and ensuring sufficient material streams, paper mills may need to join up in clusters, even with other sectors, in industrial symbiosis. Such ideas will be further developed when unfolding the CEPI 2050 Roadmap in the upcoming years. The work has already started! Brussels, November 2011 Teresa Presas Director General, CEPI 1 http://ec.europa.eu/environment/resource_efficiency/pdf/com2011_571.pdf 2 The forest fibre industry “Unfold the future”: 2050 Roadmap to a low carbon bio-economy, CEPI 2011.

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Executive summary Obtaining maximum value per unit of paper for recycling3 is an important aspect of paper production. This importance will in the future be even greater, as demand for biomass increases because of demand from sectors that were traditionally not based on wood such as the energy and chemical sector, resulting in higher biomass prices. Obtaining maximum (economic) value per unit of paper for recycling may become a determining factor for paper production to be profitable.

During paper recycling various solid by-streams are formed which contain unwanted materials or useful materials that are accidentally removed from the production line. These streams are currently considered by many as rejects that need to be disposed at least possible costs.

In order to stay competitive and become an increasingly sustainable industrial sector the paper industry needs to radically change its production process and mind-set concerning by-streams. Paper recycling by-streams should in the future no longer be considered as (costly) streams that, next to valuable fibres, contain disturbing contaminants for paper making that need to be removed as waste or inactivated. Instead, paper for recycling should be regarded as a source of many valuable components that can be used for the production of other high value products in addition to paper

This study focuses on identifying useful applications for the occurring solid by-streams4 (see For own use the paper mills can use energy conversion options, separate the fibres from the foil fraction (in coarse rejects), use sludges as feedstock for production of lower paper grades, recycle minerals from sludge ashes.

The use of the application technologies can often either be performed externally (central) or on-site. In both cases the technological installation can be owned by either the paper mill or a third party. In order to achieve economies of scale necessary to be economically feasible, paper mills and/or third parties can form clusters.

3 This report uses the term “paper for recycling” instead of the earlier term “recovered paper”. 4 On that note, this report only refers to by-streams from paper production as opposed to waste-streams, in order to emphasize the potential value of these streams.

5

Table 1, overleaf). Recovery of the valuable components of these streams can result in the potential production of new marketable bio-products (bio-energy, bio-materials, etc.).

The technologies listed in Table 1 are discussed in this report and each is explained in further detail in fact sheets in Annex I to this report.

The amount of technologies that focus on creating value from paper production rejects is growing, indicating the general acknowledgment of the value of current waste streams. This trend will continue as the climate saving ambitions and environmental legislation continues to pressure use of fossil fuel and waste of primary material. Therefore, new fact sheets will be added to the Annex II as the users or suppliers of those technologies inform CEPI about it.

The types of application technologies vary greatly, from use as feedstock in production, converted into energy or energy carriers, to use in their current state. The technologies vary from conventional (composting, incineration) methods to highly innovative (fermentation, separation) technologies.

For own use the paper mills can use energy conversion options, separate the fibres from the foil fraction (in coarse rejects), use sludges as feedstock for production of lower paper grades, recycle minerals from sludge ashes.

The use of the application technologies can often either be performed externally (central) or on-site. In both cases the technological installation can be owned by either the paper mill or a third party. In order to achieve economies of scale necessary to be economically feasible, paper mills and/or third parties can form clusters.

6

Table 1: Applications for by-streams

Applies to: On-site or

external DeinkingEffluent sludge

Coarse rejects

Screen rejects

Use of by- streams as such Land management options (land spreading, land restoration) n/a x x

Absorbent, animal bedding n/a x Anti-dust n/a x Conversion to product Land management options (composting) Unknown x x Feedstock for other paper grades External x x x Pyrolysis (chemicals) On-site ? ? x ? Feedstock for softboard production External x x x Feedstock for hybrid MDF External x x Feedstock for cement bonded sludge board production External x x

Feedstock for tiles External x x For use in cement/asphalt/etc. production External x x x Fibre/plastic recovery Both x Synthetic Calcium Carbonate Both x x Bio-BTX Confidential ? ? ? ? Hydrolysis to fermentation feedstock (higher added value chemicals) Both x x x

CDEM Both x x Conversion to energy Gasification Both x Supercritical gasification Unknown x x x Combustion Both x x x x Conversion to energy carrier Direct digestion Both x x x Pyrolysis (oil) On-site ? ? x ? Torrefaction External* ? ? x Hydrolysis to fermentation feedstock (bio-ethanol, bio-methane) Both x x x

Secondary fuel Both x

*On-site potential is unknown

7

The future

Underlying report only summarizes application options for solid reject. Identifying the value of other paper mills waste streams (liquid, gaseous, heat), would further increase the economical value to be gained from recycled paper. Heat losses can be captured, unwanted but valuable components from the water circuit could be isolated, etc. By- streams are full of components that may be unwanted in the paper production process but quite often are of high value for other industries.

The ambition of ‘valorisation of waste streams’ even limits the view on possible innovations that can lead to a higher value out of the paper recycling raw material. Instead, the ambition ‘Increasing the economic value of recycled paper’ leads to new routes of isolating other high added value components from the pulp, components that currently end up in the paper with no benefit to its quality specifications.

Legislation

The renewed European Waste Directive provides a useful framework for organising the paper industry in the way described above; for the first time the materials in waste are not seen only as a waste management problem, but also as a valuable resource. Furthermore, the Directive now provides the essential clarity between what is waste and what can be considered a by-product. Commission has provided guidance5 on distinguishing between waste and by-products: this guidance includes a helpful decision tree that can be used by paper-mills for any by-stream they have. REACH regulation, however, will have to be taken into consideration, too.

5 Interpretative Communication on waste and by-products (COM(2007) 59 final) http://eur-lex.europa.eu/LexUriServ/site/en/com/2007/com2007_0059en01.pdf

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Table of contents

1. INTRODUCTION 10

1.1. Background 10

1.2. Objective 12

2. APPROACH 13

2.1. Tasks 13

2.2. Economic and environmental aspects 13

2.3. Limitations to the scope 14

3. SOLID BY-STREAMS 15

3.1. Introduction 15

3.2. Volumes of solid by-streams in Europe 16

3.3. Compositions and energy content of solid by-streams 18

4. INVENTORY OF APPLICATION TECHNOLOGIES 19

4.1. Introduction 19

4.2. Description of the technologies 21

4.3. Summary of technology characteristics 27

5. CONCLUSIONS 31

6. THE FUTURE 32

7. REFERENCES 34

ANNEX I: FACT SHEETS 36

1. Land management options 37

2. Absorbent, animal bedding 40

3. Anti-dust agent 41

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4. Feedstock for other paper grades 42

5. Pyrolysis oil 44

6. Feedstock for softboard 47

7. Hybrid MDF 49

8. Cement bonded sludge board 51

9. Tiles 53

10. Use for cement/asphalt/etc. production 55

11. Fibre/plastics recovery 56

12. Synthetic calcium carbonate 58

13. Bio-BTX 60

14. Hydrolysis to fermentation feedstock 61

15. CDEM 63

16. Gasification 66

17. Supercritical gasification 68

18. Combustion 70

19. Direct digestion 72

20. Torrefaction 75

21. Secondary fuel 77 ANNEX II: ADDITIONAL FACT SHEETS 80

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1. Introduction

1.1. Background To maximize the efficient use of wood material and limit its impact on biomass availability, the paper industry prolongs the life of its wood resources by reusing old paper as feedstock in its production process. As recycling of old paper has steadily increased over the last decades in Europe, today paper for recycling forms an important raw material for most of the European paper industry. During paper production using paper for recycling various solid by-streams6 are formed which contain unwanted materials or useful materials that are accidentally removed from the production line. These solid by-streams are disposed of by third parties for a gate-fee or disposed of on-site by e.g. incineration. Obtaining maximum value per unit of paper for recycling is an important aspect of paper production. This importance will in the future be even greater, as demand for biomass increases because of demand from (traditionally not-wood based) sectors such as the energy and chemical sector, resulting in higher biomass prices. Obtaining maximum (economic) value per unit of paper for recycling may become a determining factor for paper production to be profitable.

Solid by-streams in the papermaking process can vary greatly and can be classified into different groups (see Figure 1). All by-streams contain potentially valuable elements, especially with the development of new isolation and conversion technologies.

Paper mill by-streams:

Solid others•Pellets•Refiner plates

Solid from pulp and water treatment•Fibers•Plastics•Chemicals•Ink•Minerals

Gaseous•Heat•CO2•Organic compounds•Water vapor

Liquid (water)•Organic compounds•Heat•Nutrients

High value products

Figure 1: Overview of paper mill by-streams

6 Although these streams are often referred to as waste streams, this report denotes them as by-streams in this report to emphasize the potential value that they contain.

This study focuses on solid by-streams from pulp and water treatment to increase value of paper for recycling.

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Maximum value of solid by-streams It is expected that the current value obtained from using paper for recycling is only a fraction of the full potential value of paper for recycling. Solid by-streams from pulping and water treatment occur in high volumes and material losses of these streams are significant. The value from paper for recycling can be strongly increased, when the potential value of the by-streams is utilised. This value is currently lost as the by-streams are treated as waste streams. In order to stay economically competitive and become a more sustainable industrial sector the paper and board industry needs to radically change its production process and mind-set concerning by-streams. Paper recycling by-streams should in the future no longer be considered as (costly) streams that, next to valuable fibres, contain disturbing contaminants for paper making that need to be removed as waste or inactivated. Instead, paper for recycling should be regarded as a source of many valuable components that can be used for the production of additional high value products in addition to paper (see Figure 2).

Recovered paper Paper and board

Waste streams (€ costs) :•Plastics•Ink•Stickies•Fibres•Etc.

Recovered paper Paper and board

By-products (€ profit )•Energy?•Chemicals?•Feedstock for other industries?•Etc.Towards a multi-product mill

Figure 2: Schematic overview of current and potential future recycled paper production Research on the composition of by-streams from pulping and water treatment of recycled paper production has shown that there is significant potential value in these streams, as they contain useful elements that can potentially be used for production of high value products, paper production (fibres) or energy conversion. Best-practice paper producers are currently applying part of their rejects from solid by-streams for useful applications such as onsite energy conversion or as re-use as feedstock for paper production. However, even these best practices are still far from gaining maximum value of sources of paper for recycling. The identification of interesting new by-products from a paper mill requires the awareness of the potential value of the by-streams and its individual components.

This report provides a broad overview of options to create additional value from solid by-streams that are available or currently under development.

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Legislation To create added value from solid by-streams non-technological factors that hinder the usage of the by-streams contents such as restrictive legislation also need to be taken into account. Legislation concerning waste, and in particular its implementation in national and local permitting, is often not designed to take the usage of by-streams in consideration. Because of this, current legislation often hinders the usage of by-streams as production facilities e.g. require permits in order to process the material as waste. In such cases utilization of by-streams from paper recycling is both difficult and delaying (e.g. because of long permit procedures) or simply not possible, to a great loss to resource efficiency.

1.2. Objective The objective of this report is: To provide an overview of possible applications, both industrially applied technologies as technologies that are in development, which can increase the economic and environmental value of paper production by-streams. This report focuses on:

• The major solid by- streams produced in the paper industry • Identifying and categorizing recovery options and identifying to which paper production solid by- stream they apply • Creating fact sheets for each technology in which general economical, legislative and technological information are presented for each option • Legislation relevant to application of solid by-streams

Report layout This report will continue in chapter 2 with a description of the used research approach. In Chapter 3 an overview of the solid by-streams that are produced in the paper industry is presented along with figures on the volumes and compositions of these by-streams in Europe. A short summary and categorized overview of the application technologies that were found during this study is presented in chapter 4. Chapter 5 provides the conclusion. Finally, chapter 6 contains a discussion of the future of paper production by-streams. Fact sheets containing more detailed information on each application technology are provided in the Annex I. More fact sheets on additional technologies are progressively added to Annex II.

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2. Approach

2.1. Tasks This report shows the results of three tasks: Task 1: Create an overview of by-streams of paper recycling production in Europe In this task information from both desk study and data from CEPI was used to determine the type of solid by-streams created during paper recycling production in Europe. For each by-stream the volumes per country were determined as well as the composition of the by-stream. Task 2: Create an overview of application technologies for solid by-streams In this task a desk study was performed in combination with available knowledge from the CEPI and KCPK network to create a list of application options that can be used for paper production solid by-streams. Information for each application technology was obtained by desk study and/or contact with the industrial firm or knowledge institute that utilizes/researches the application option. Task 3: Creating fact sheets for each application technology For each application technology it was determined to which type of solid by-stream the technology applies as well as general information regarding the process, legislations, environmental implications and finances. The information was inserted into fact sheets.

2.2. Economic and environmental aspects The production of new products from the by- streams has both an economic value as a sustainability value. By-streams need to be managed within paper mills. The costs for land filling and waste disposal are high. By using application technologies land filling costs are reduced. Potentially the application technology can even create a net profit. The economic value is the result of the avoided management costs and the market value of the additional product. The sustainability value comes from the avoided usage of other resources for feedstock, avoided use of fossil resources for energy production and (if relevant) less energy requirement for the production of the by-product in comparison to energy intensity of the product which is substituted (e.g. energy use for production of cement by providing a cement substitute).

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2.3. Limitations to the scope

• Due to the large diversity in waste management options (and associated costs) and the (often) unavailability of information on exact costs and benefits of the technologies, the exact economic added value cannot be determined.

• Due to complexity of determining the added sustainable value of using by-

streams, the added sustainable value is not quantified. This prevents comparison of the sustainable value between the presented application technologies and incorrect conclusions.

• Considering the impact on the environment, this study focuses on the

impact of the technology on energy use. Although there are many different types of indicators to determine the influence on sustainability, information on most of these indicators would require more extensive research.

• The list of application technologies is inherently not exhaustive as

development of technologies takes place world-wide and in an increasingly fast pace. The inventory of technologies in this report provides a good representation of the total range of available technologies, and indicates the wide acknowledgement of the potential of solid by-streams to be converted to higher value added applications.

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3. Solid by-streams

3.1. Introduction In paper making solid by-streams are produced during various production steps such as: pulping, high density cleaning, prescreening (flotation), forward cleaning (fine screening, reverse cleaning), and whitewater clarification. The solid by-streams can be divided into

• Primary sludge • Secondary sludge • Deinking sludge • Coarse rejects • Screen rejects

Primary and secondary sludge are generated from the residue water treatment unit from respectively a mechanical-chemical or a biological method. Secondary sludge is therefore also called biological sludge. Both contain organic matter, for primary sludge mainly cellulose, and minerals. Often they are then mixed together resulting in a “mixed sludge”. Secondary sludge from anaerobic waste water treatment quite often has value as start-up sludge. Deinking sludge is generated during recycling of paper (except for packaging production). Separation between ink and fibres is driven by “flotation” process, where foam is collected on the surface of flotation cells. The generated deinking sludge contains minerals, ink and cellulose fibres (that are too small to be withhold by filters). Coarse rejects are produced during early filtration steps in which large non-fibre materials such as plastics are removed. These rejects also still contain cellulose fibres. Screen rejects are produced during filtration steps with screens with very small slots to remove pulp possibly containing stickies that might disturb the production process and quality of end product. Screen rejects have a high content of cellulose fibre.

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3.2. Volumes of solid by-streams in Europe Table 2 provides an overview of the volumes of solid by-streams produced in (recycled) paper production in Europe. The screen rejects volumes are not included because there is insufficient country specific data for these by-streams. Also, the composition and volume of these streams are dependent upon the collected paper for recycling material7. The quality of recyclate varies per country and can also vary over time. Table 2: Overview of by-stream volumes of paper production in Europe (2008 figures8). Source: Information provided by CEPI (Environment data) and COST e-48

Country Deinking sludge

(ktondry) Effluent sludge

(ktondry))

Other sludge

(ktondry)) Coarse rejects

(ktondry)

Austria 0 656 0 64 Belgium 116 67 0 25

Czech Republic 4 44 7 21 Finland 134 466 72 67 France 402 473 5 185

Germany 1.457 729 0 325 Hungary 10

Italy 83 138 0 138 Netherlands 51 24 66 74

Norway 41 55 5 Poland 33 61 72

Portugal 18 Romania

Slovak Republic 40 27 42 Spain 198 133 124 127

Sweden 190 230 110 40 Switzerland 67 26 0 30

United Kingdom 556 90 4 119

Total 3.372 3.219 507 1.243

7 This is also true for coarse rejects. 8 Note that for the countries that did not provide CEPI with 2008 data, the volumes of the last year for which they provided this data was used.

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Table 3 provides an overview of the current use for disposal of the solid by-streams in Europe. Table 3: Disposal methods for by- streams9 in 2008 (information from CEPI10)

Country Total by- streams (kton)

Landfill (kton)

Incineration (kton)

used on land (kton)

Reuse in industrial

processes (kton)

Austria 656 0 495 0 161

Belgium 183 0 132 51 0

Czech Republic 54 7 3 27 17

Finland 671 43 415 36 177

France 880 25 235 400 220

Germany 2.186 0 1.171 182 833

Hungary

Italy* 359 78 103 101 77

Netherlands 141 0 7 0 134

Norway 99 13 72 7 7

Poland 165 2 19 79 65

Portugal 307

Romania

Slovak Republic 109 11 9 33 56

Spain* 455 75 10 186 184

Sweden 460 4 306 120 30

Switzerland* 93 39 18 13 24

United Kingdom 650 8 286 288 68

Total 7.469 305 3.281 1.523 2.053

% Of total 100% 4% 46% 21% 29%

*Italy: figures include coarse rejects Spain: split estimated by CEPI Switzerland: 2006 figures

9 This information is not available on reject type level. 10 Note that for the countries that did not provide CEPI with 2008 data, the volumes of the last year for which they provided this data was used.

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3.3. Compositions and energy content of solid by-streams This paragraph provides overviews of the composition (Table 4), overview of the energy content (Table 5) and composition of the dry matter content (Table 6) of different solid by-streams. Information regarding the composition of by-streams is not available on national level for all European countries. Several sources (CEPI, KCPK, Ecofys) are used to define the average composition for each by-stream. The composition of the by- streams is depicted in the table below. Note that these figures can vary per individual mill as they depend highly on the input material as well as the specific end product characteristics. Table 4: Composition of sludges and rejects11

Dry solid (%) organic matter 12 (%)

mineral matter13 (%)

Primary sludge 50 40 60

Secondary (biological) sludge 40-50 50 50

Deinking sludge 56 50 50

Coarse rejects 55 92 8 Screen rejects 55 90 10

Table 5: Energy contents of sludges and rejects

Energy content (MJ/tonwet)

Primary sludge 2690

Secondary (biological) sludge 4000-5000

Deinking sludge 3000

Coarse rejects 12,000 Screen rejects 8,000

Table 6: Composition of dry matter content of solid by-streams

Content

Primary sludge Fibres, fillers, coating clay, calcium carbonate

Secondary (biological) sludge

Calcium carbonate, cupper, micro organisms, fibres, proteins.

Deinking sludge Cellulose fibres, calcium carbonate, kaolin, ink

Coarse rejects Recyclable fibres, wet strength fibres, plastics, wood, metal, others

Screen rejects Cellulose, plastics, hair, stickies

11 The composition can vary per paper mill. The figures in this table are an average based on different reports 12 Of dry content 13 Of dry content

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4. Inventory of application technologies

4.1. Introduction Until recently, landfilling has been a major route for sludge disposal. However, both the increase in sludge quality and the legislative framework are militating for other management options. Landfilling is currently no longer applied/allowed in most countries (see Table 3). The disposal tax is the major driver for finding alternative solutions. The application technologies described in this chapter form alternatives with (potentially) higher economic and sustainable value. Table 7 provides an overview of the application technologies that were identified during this study. The application technologies are categorized as:

• Use of by-streams as such • Conversion to product • Conversion to energy • Conversion to energy carrier

Use of by-streams as such The by-stream is the end product in its current state. No additional processes are required. Conversion to product The by-stream requires processing in order to acquire the end product(s). Depending on the technology a residual is left-over. Conversion to energy An energy conversion technology is used in order to convert the energy content of the by-stream into heat or electricity (or both). Depending on the technology a residual is left-over. Conversion to energy carrier The by-stream is converted into an energy carrier. This product can be used by the mill or by third parties as fuel. Depending on the technology a residual is left-over after the processing and/or the combustion of the product.

Table 7: Application technologies for solid by-streams 14

Applies to:

On-site or external Deinking

Effluent sludge

Coarse rejects

Screen rejects

Use of by- streams as such

1a Land management options (land spreading, land restoration) n/a x x

2 Absorbent, animal bedding n/a x

3 Anti-dust n/a x

Conversion to product

1b Land management options (composting) Unknown x x

4 Feedstock for other paper grades External x x x

5a Pyrolysis (chemicals) On-site ? ? x ?

6 Feedstock for softboard production External X x x

7 Feedstock for hybrid MDF External X x

8 Feedstock for cement bonded sludge board production External X x

9 Feedstock for tiles External X x

10 For use in cement/asphalt/etc. production External X x x

11 Fibre/plastic recovery Both x

12 Synthetic Calcium Carbonate Both X x 13 Bio-BTX Confidential ? ? ? ?

14a Hydrolysis to fermentation feedstock (higher added value chemicals) Both X x x

15 CDEM Both X x

Conversion to energy

16 Gasification Both x

17 Supercritical gasification Unknown X x x

18 Combustion Both X x x x

Conversion to energy carrier

19 Direct digestion Both X x x

5a Pyrolysis (oil) On-site ? ? x ?

20 Torrefaction External* ? ? x

14a Hydrolysis to fermentation feedstock (bio-ethanol, bio-methane) Both X x x

21 Secondary fuel Both x

*On-site potential is unknown

14 Note that some of the technologies can be both integrated in the processes of the paper mill or be used externally by a third party.

4.2. Description of the technologies

A short description of each technology is provided in this paragraph (in same order as Table 7). More detailed info is provided in the fact sheets (see Annex I).

1. Land management options Land restoration Land restoration covers the use of dried sludge as a product applied on derelict land, damaged industrial sites topsoil, during road constructions, topping of landfills, mine filling, etc. When aiming to increase soil quantity on the site, two techniques are observed: it can be either directly applied or mixed with the soil present on the site before application. Land spreading Land spreading is highly practiced in some countries (e.g. the UK) and recently recognised once again15 for its organic and mineral qualities. Valuable compounds present in sludge are reinserted into the soil, by transporting it, often in a cake form, from the mill to the fields, then either spread on the land as a thin layer or ploughed into the surface between crops (CEPI unpublished). Composting Factors inhibiting the land spreading of many paper mill wastes are their elevated carbon to nitrogen (C/N) ratios and relatively high Biochemical Oxygen Demands (BOD). Supplementary fertiliser additions are essential to prevent nitrogen immobilization and to provide sufficient nitrogen for crops. Composting pre-treatments will reduce C/N ratios. Composting will also reduce mass, volume and moisture contents benefiting handling, transportation and storage requirements. Overall, the process will produce a stable material, of low odour, with modest levels of nutrients (Tucker 2005). These land management options are industrially applied but not all are allowed in all countries due to e.g. certain contaminants in the sludges. The technology can be used for deinking and waste water treatment sludges.

2. Absorbent, animal bedding Waste water treatment reject can be transformed into animal bedding for barns. The material is similar to (previous industrially applied) kitty litter from by-streams. The main difference in these products is that the quality demands are lower for animal bedding and that no additives are needed to increase the absorption capacity of the end product. This technology is industrially applied. The technology can be used for waste water treatment sludge.

3. Anti-dust agent Waste water treatment sludge can be used as anti-dust agent by e.g. coal fired power plants.

15 Environment Agency, “Landspreading on agricultural land: nature and impact of paper wastes applied in England & Wales”, Science Report SC030181/SR, 2005.

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This technology is industrially applied. The technology can be used for waste water treatment sludge.

4. Feedstock for other paper grades

Deinking sludge and effluent sludge can be used for production of certain board products. This reduces feedstock costs, as deinking sludge can replace feedstock 1 to 1 (dry matter)16. The ratio of feedstock to deinking sludge that can be used depends on the type of end board product. Screen rejects can also be applied in small concentrations for production of solid board. The long fibres make screen rejects a promising reject stream. This technology is industrially applied. The technology can be used for deinking sludge, waste water treatment sludge and screen rejects.

5. Pyrolysis

Bio-oil obtained through pyrolysis can be used as a substitute for fossil fuels to generate heat, power and/or chemicals. Short-term applications are boilers and furnaces (including power stations), whereas turbines and diesel engines may become available on the somewhat longer term. Upgrading of the bio-oil to a transportation fuel is technically feasible, but needs further development. Transportation fuels such as methanol and Fischer-Tropsch fuels can be derived from the bio-oil through synthesis gas processes. Furthermore, there is a wide range of chemicals that can be extracted or derived from the bio-oil. The technology has not been industrially applied. Several commercial scale plants will be built in the near future. The technology can be used for coarse rejects and (perhaps) also for sludges and screen rejects (this requires further investigation considering the wetness, organic content and ash content of these by-streams).

6. Feedstock for softboard production

Softboard is a wood fibre based product that is often used as thermal/accoustic insulation, ceiling tiles and as in-fill product for timber frame construction. The wood fibres can be obtained from timber such as Eucalyptus (Gunnersens data sheet 2007), or from waste materials. According to Goroyias et al. (2004) softboard produced from paper by- streams containing around 80% sludge and 10% other fibres is possible. The other fibres can be either MDF fibre or virgin wood fibre. MDF fibre is preferred to achieve further cost savings. This technology has been proven on lab scale but has not been industrially applied. The technology can be used for deinking sludge, waste water treatment sludge and screen rejects.

7. Feedstock for hybrid medium-density fibreboard (MDF)

The relative high fibre content of dry sludge (45-50%) induced the idea of producing hybrid MDF. A content of 45% sludge in hybrid MDF proved feasible.

16 Confirmed by a mill that requested to remain anonymous.

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The hybrid MDF can be used in several applications in dry conditions where high internal bond strength is not required. (Goroyias et al. 2004) This technology has been proven on lab scale but has not been industrially applied. The technology can be used for deinking and waste water treatment sludge

8. Feedstock for cement bonded sludge board production

Up to 30% of sludge can replace the virgin wood fibre currently used in cement bonded particle board (it is assumed for now that the virgin wood fibre is similar to that used in softboard). Key advantages are strength, fire resistance and dimensional stability. Interest in this product has been expressed with applications suggested for exterior cladding, outdoor paving systems and suggestion for niche applications as fire surrounds (Goroyias et al. 2004) This technology has been proven on lab scale but has not been industrially applied. The technology can be used for deinking and waste water treatment sludge

9. Feedstock for tiles Using paper production sludges for production of floor tiles leads to a product which is warmer than ceramic tiles (but less suited for moist areas). The production of tiles from 80-85% sludge based on dry weight has been tested. It is unclear if the product fulfilled the required standards (EN316). Also the tile required significant amounts of MID resin (20%) to achieve the strength and hard wearing characteristics. This technology has been proven on lab scale but has not been industrially applied. The technology can be used for deinking and waste water treatment sludge

10. For use in cement/asphalt/etc. production The cement industry is an energy intensive sector with significant CO2 emissions. The paper industry can cooperate with the cement industry by providing substitute raw material17 as filler material or for incineration as fuel. Also other sectors such as e.g. the asphalt industry can be suited partners for use of solid by-streams from paper making. Ashes from e.g. incineration of coarse rejects or sludges is already used in the cement and asphalt industry for production (see e.g. CDEM). This technology can be used for paper sludges (filler material) or coarse rejects (RDF).

11. Fibre/plastics recovery There are different initiatives that focus on separating the foil and fibre fraction from coarse rejects. A paper mill in the Netherlands has developed its own technology, PhD Bartek Stawicki build and researched a lab scale coarse reject treater (Stawicki 2008) and the VAR (company focused on recycling in the Netherlands) has (together with a partner) developed a technology that can separate the fibre and plastic fraction of coarse 17 The status of this technology is unknown. Although many sources mention the potential of using paper sludges as substitute of fuel or input material for cement production, no confirmation of actual use of paper sludges as such for cement production.

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rejects from the paper industry. The separated fibres can be reused in board production process thereby saving transportation costs and feedstock costs. In this report the VAR’s technology will be used as example. The VAR technology has not been industrially applied (first commercial installation is currently (2010) being build). The technology can be used for coarse rejects.

12. Synthetic Calcium Carbonate The company CalciTech has developed a process for the production of synthetic calcium carbonate (SCC), an advanced form of precipitated calcium carbonate (PCC) (www.calcitech.com). The new process is able to separate paper sludge ash into an ultra pure calcium carbonate and a form of metakaolin. According to CalciTech the SCC recycled mineral has a positive influence on the gloss, brightness, opacity and printability of the coated paper end product. This is due to its narrow particle size distribution compared to PCC or GCC and its high brightness.

This technology is under development; on small scale, samples have been produced. The technology applies to ashes from the paper industry (residues from incineration of deinking and effluent sludges).

13. Bio-BTX

The Bio-BTX technology converts rejects into industrial grade benzene, toluene and xylene (BTX). The expected benefit using the Bio-BTX technology in comparison to e.g. incineration of the rejects is that more value added is created. BTX are the highest valued platform chemicals in the petro-chemical industries. The product can be used directly in existing chemical plants. This allows the production of green products with relatively small investments. This technology is under development. The concept is proven by small experiments. A pilot plant is yet to be built. The type of rejects to which the technology applies is confidential.

14. Hydrolysis to fermentation feedstock Many companies and institutes currently perform R&D on the development of economic processes for hydrolysis of ligno-cellulosic materials to individual sugars, intended to be used as (2nd generation) feedstock for fermentation processes towards bio-ethanol or higher added value bio-chemicals. Examples include enzyme aided hydrolysis (Novozymes18) and acid hydrolysis (Bio-Rights). In this report Bio-Rights will be used as example. The Bio-Rights technology is under development. The technology can be used for any by-stream that contains cellulose.

18 See internet article http://www.ethanolproducer.com/article.jsp?article_id=6373

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15. CDEM

Deinking sludge is suited for the production of mineral products. In The Netherlands Dutch mills initiated an installation (CDEM Holland BV) which converts deinking sludges into a mineral product with cement like properties (SenterNovem CDEM 2009). The mineral product, called TOP-crete, can be used in the construction of roads/foundations, concrete, or as feedstock for the production of sand-lime bricks (SenterNovem CDEM 2009). The technology can also be installed on-site. This technology is industrially applied. The technology can be used for deinking and waste water treatment sludges.

16. Gasification

World-wide there are already many gasification installations active. Rejects (refuse derived fuel and municipal solid waste) are also gasified. Motivations for use of gasification of rejects for industry are avoiding negative impact of high Natural gas prices, reluctance to use combustion (waste incinerator status), less residue after energy conversion than with combustion, using partly biomass and the fact that syn-gas from gasification can be used in existing CHP installation. This technology has not been industrially applied. The technology can be used for coarse rejects.

17. Supercritical gasification

The supercritical gasification technology is well suited for wet biomass streams. Currently a global estimation by the developers at the University of Twente is that streams containing at least 3% of organic material will prove energy neutral. Higher content of organic material will lead to an increasing positive netto output of energy. There is a threshold of maximum 50% solid material because of the viscosity. This technology is under development. The technology is expected to apply to sludges and coarse rejects.

18. Combustion for electricity production or steam production

Rejects can be used for the production of steam or electricity by combustion. Low moisture content and high calorific value are of importance here in the selection of useful by- streams. According to Dehue et al. (2006) coarse reject as well as screen rejects are by- stream that are well suited for energy recovery due to its high calorific value. Deinking sludge and effluent sludges have less potential but can still be incinerated for their energetic value. In Parenco the Netherlands a bio-boiler is used to incinerate all paper by- streams (deinking sludge, primary sludge, secondary sludge and plastics). This boiler is used in this report as an example.

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This technology is industrially applied. The technology can be used for deinking sludge, waste water treatment sludges and coarse rejects.

19. Direct digestion

Digesting is used by farmers and municipal sewage water plants as a relatively simple technique for a long time. The last decade biogas becomes a strong alternative for fossil fuel. The technology is developing rapidly and more and more attention is put into the pre-treatment processes. The produced biogas is cleaned and transferred into green natural gas. This can be inserted into the existing high-pressure gas distribution system. According to a report by Bioclear (Bioclear 2007) there is currently no industrial running application of digestion of solid by-streams19 in the paper industry20. The technology can be used for screen rejects, deinking rejects and secondary sludge. The digestion technology is being further developed towards production of higher added value chemicals (instead of biogas)

20. Torrefaction

Torrefaction can convert streams containing organic matter into a brittle product with high energy density. This product can be used in coal based power plants for co-incineration or as a substitute for wood pellets. There are no commercially operative torrefaction plants at this moment. In the Netherlands EQnomics has a daughter company “Foxcoal”. Driven by the fact that ¾ of the use of coal is used for electricity production, in which ¾ of that coal consists of “ketel” coals, and the expected increase in prices for waste management21, Foxcoal has researched the potential to convert by-streams from a.o. the paper industry into a secondary fuel (SRF) that can match the demands of large power plants. The characteristics of the SRF have to match those of powder coal. This technology has been proven on small scale, and is currently in the phase of upscaling. The technology can be used for coarse rejects and potentially sludges, although the latter option is unsure.

21. Secondary fuel22 Coarse rejects have a high calorific value and are therefore suitable as RDF. Qlyte (a spin-off of the company DSM) focuses on expanding the commercialization of the subcoal technology. This technology converts coarse rejects from paper production into high value fuel material (fluff, pellets or powder form). A working installation is running at the Smurfit Kappa Roermond (Netherlands) site since around 8 years. The main buyers of the subcoal are lime producing companies and cement producing companies. A

19 In the paper industry digestion is used for treatment of waste water. 20 There has been some activity in Spain concerning the use of digestion. 21 In Germany, the Netherlands and Sweden there are currently too many waste incineration plants. The large demand for material from these plants lowers the prices of waste management of waste streams. 22 Note that there are different ways of production of RDF in Europe. KCPK and CEPI are aware of this, but due to the limited time frame these other options have not been included in this report.

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potential future market lies in the electricity producing sector, as a powder form of the subcoal could replace powder coal currently used by some electricity producers23 This technology is industrially applied. The technology can be used for coarse rejects.

4.3. Summary of technology characteristics A short description of the economic and sustainability aspects of each application technology is provided in Table 8. Fact sheets of the technologies are provided in Annex I.

23 This has been tested and is applicable. One current barrier is that the great demand of an average electricity producer for co-incineration of the subcoal cannot be met due to lack of production capacity. In the future this may be resolved as a central subcoal producing facility can gain input of several paper producers their reject streams.

Table 8: Added value of application options (IA=Industrially applied, LP=Lab-scale proven, UD=Under development/research phase, PS=Pilot scale proven, UP=Up-scaling phase)

Status Economic aspects Sustainability aspects

Use of by- streams as such

1aLand management options (land spreading, land restoration)

IA Potentially lower gate fee Arguably has favourable effect on land due to organic and mineral components of sludges

2 Absorbent, animal bedding IA

Gate fee avoided and profits are made from selling of animal bedding. Investment costs for installation needed for drying and granulation of the by- stream.

Animal bedding replaces normally used straw and saw dust, which can potentially be used for energy production

3 Anti-dust IA Potentially lower gate fee Depends on what is currently used instead of sludges for anti-dust

Conversion to product

1b Land management options (composting) IA Potentially lower gate fee Arguably has favourable effect on land due to

organic and mineral components of sludges

4 Feedstock for other paper grades IA

Reduced need paper for recycling. Investment in pulper line suited for processing of sludge material needed. Delivery fee or costs from the receiving mill unknown.

Reduced need for paper for recycling. Increase in electricity demand (15 kWh/ton wet sludge)

5a Pyrolysis (chemicals) UP

Avoid gate fee and free feedstock. Negative side of by-streams is low quality of the feedstock (more water, more ash content and lower yield per ton). Investment costs for installation.

Pyrolysis oil is CO2 neutral, because residues are used. Only the transportation costs of the oil should be taken into account which is approx. 5 % of the total energy content.

6 Feedstock for softboard production LP Insufficient information Reduces demand for virgin wood fibre

7 Feedstock for hybrid MDF LP Insufficient information Reduces demand for virgin wood fibre

8Feedstock for cement bonded sludge board production

LP Insufficient information Reduces demand for virgin wood fibre

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9 Feedstock for tiles LP Insufficient information Avoidance of material use for normal tiles production

10For use in cement/asphalt/etc. production

IA Potentially lower gate fee When used as filler the material is reused thereby saving primary material.

11 Fibre/plastic recovery PS*

Estimated cost of installation around €600.000. Economic feasibility depends on current disposal costs, feedstock costs, disposal costs foil fraction, avoided transportation costs.

Reduce demand for paper for recycling. The separation process itself costs 23 kWh per ton reject material.

12 Synthetic Calcium Carbonate UP

A full scale plant with a capacity of 40.000 tonnes of SCC per annum has been designed and could be built on a 2000m2 area.

44tonnes of CO2 is sequestered for 100 tonnes of SCC produced.

13 Bio-BTX UD Confidential

The demand for fossil-based chemicals is reduced. Current production of these chemicals is highly energy-intensive (fossil BTX is made by naphta cracking).

14a

Hydrolysis to fermentation feedstock (higher added value chemicals)

UD Insufficient information Depending on the business plan, the product substitute range is: Ethanol, Buthanol, Methane, Bio-chemicals

15 CDEM IA

Paper mills pay a fee to CDEM in case of external installation. Example costs CDEM installation: initial investment 20 million euro, payback time around 5 years.

Production of electricity (110 kWh/ton wet sludge). Top-crete substitutes use of cement

Conversion to energy

16 Gasification IA** Large installations cost about 200-250 million euro. The payback time strongly depends on current gas prices and gate fee for RDF.

Reduces need for natural gas. Granulate residue replaces current needed material for road building. Some emissions that are emitted when using regular incineration is avoided due to the fact that clean syn gas is produced.

17 Supercritical gasification UD Unknown as the technology is still under development Unknown yet, requires further research

18 Combustion IA

External: gate fee costs. On-site: installation 240.000 ton annual costs 35-40 million euro. Payback time is 3-10 years depending on type of waste stream used, subsidies and energy

Demand for gas and electricity are reduced. Amount depends upon input of combustion installation (rejects, wood, sludges).

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prices/disposal costs.

Conversion to energy carrier

19 Direct digestion IA** Feasibility strongly depends on alternative disposal costs, cost of handling of digestate, economies of scale etc.

Demand for natural gas is reduced. Benefit to environment also depends on the use of the digestate

5b Pyrolysis (oil) UP

Avoid gate fee and free feedstock. Negative side of by-streams is low quality of the feedstock (more water, more ash content and lower yield per tonne). Investment costs for installation.

Pyrolysis oil is CO2 neutral, because residues are used. Only the transportation costs of the oil should be taken into account which is approx. 5 % of the total energy content.

20 Torrefaction PS Gate fee to be paid in case of external conversion. Avoiding use of coal in coal fired power plants

14b

Hydrolysis to fermentation feedstock (bio-ethanol, bio-methane)

UD Insufficient information Depending on the business plan, the product substitutes range is: Ethanol, Buthanol, Methane, heat, electricity.

21 Secondary fuel IA

Investment costs/licence cost when buying the turn key technology , avoiding disposal costs and profiting from selling subcoal. In case of solely conversion rejects to subcoal without ownership of installation, a gate fee has to be paid.

Depends on current used fuel of the lime and/or cement producer that uses the subcoal

*Pilot scale proven, first commercial application being build

**But not to paper production by-streams

5. Conclusions During paper recycling various solid by-streams are formed which contain unwanted materials or useful materials that are accidentally removed from the production line. These streams are currently considered by many as rejects that need to be disposed at least costs possible, while other potential application possibilities may be present which can generate more value from the reject streams. Proof of value from by-streams The growing amount of technologies that focus on creating value from paper production rejects indicates the general acknowledgement of the value from paper production by-streams. This trend will continue as the environmental legislation continues to pressure use of fossil fuel and waste of primary material. This situation provides the paper industry with pressure from high energy prices and feedstock prices on the one hand but also with the increase of the potential value per unit of paper for recycling on the other hand due to increasing demand for rejects or product from rejects by third-parties. The value from the by-streams therefore is of great importance to the economic feasibility of the paper production process. Applications for by-streams The types of application technologies for paper production by-streams vary greatly. The by-streams can be used as feedstock in production, converted into energy or energy carriers, or used in their current state. The technologies used to achieve these application forms also vary from conventional (composting, incineration) methods to highly innovative (fermentation to produce bio-chemicals) technologies. For own use the paper mills can use energy conversion options, separate the fibres from the foil fraction (in coarse rejects), use sludges as feedstock for production of lower paper grades, and recycle minerals from sludge ashes. On-site or central The use of the application technologies can often either be performed externally (central) or on-site. In both cases the technological installation can be owned by either the paper mill or a third party. Cluster forming In order to achieve economies of scale necessary to be economically feasible, paper mills and/or third parties can form clusters. This can ensure meeting the material input needed for large scale installations.

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6. The future

Not only solid by-streams can be used to generate high value products. Paper making has many other by-streams.

Currently by-streams in the paper industry can generally be classified into:

• Solid others • Solid by-streams removed from pulp and waste water treatment

operations • Liquid by-streams (e.g. waste water) • Gaseous by-streams (e.g. exhaust from CHP, drying section of paper

machine) • Furthermore, potential new by-streams may arise from changes in

production processes The opportunities for improving the production processes are nearly endless as for each by- stream applications can be found. Heat losses can be captured and used for low temperature processes or through innovation even used for high temperature processes. By extracting and isolating unwanted components from the water circuit enables both the production of additional high value by-products as well as the closing of the water circuit, thereby terminating the need for fresh water. “By-streams” are full of components that may be unwanted in the paper production process but are of high value for other industries; isolation of these components creates additional high-value by-products.

Paper mill by-streams:

Solid others•Pellets•Refiner plates

Solid from pulp and water treatment•Fibers•Plastics•Chemicals•Ink•Minerals

Gaseous•Heat•CO2•Organic compounds•Water vapor

Liquid (water)•Organic compounds•Heat•Nutrients

High value products

High value products

High value products

High value products

Figure 3: Maximum value in a multi-product mill

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This ambition also leads to more options:

- Isolation of valuable components out of pulp and process water - Changing the primary papermaking process in such a way that it creates by-

streams with higher value. Other options that make more value from a recycled paper mill:

- Reuse rest-heat from gaseous by- streams - Close the water loop (reuse water) - CO2-capture of CHP exhaust - Consider the potential market value of (sometimes detrimental) substances in the

(recycled) pulp: starch, stickies, fatty acids, ink components, coating components, etc.

- Consider removing more (fine) fibres from your process to be sold with value as fermentation feedstock and improve your own process efficiency.

The ambition of ‘valorisation of waste streams’ limits the view on possible innovations that can lead to a higher value out of the recovered paper raw material. Instead, the ambition to ‘Increasing the economical value of paper recycling’ should be used.

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7. References ASPAPEL (2007), Improvement of existing situation of recovered paper processing within paper industry, short scientific report Bioclear (2007), Vergisting van reststromen in de Nederlandse papier- en kartonindustrie, Eindrapportage Durest projectonderdeel vergisting CE (2000), Subcoal: an environmental assessment-co-firing of household plastic waste in a coal-fired power plant, after secondary separation, compared with co-firing of biomass, gasification and processing in a cement kiln and in a waste incineration plant, Final report CEPI (unpublished), Pulp and paper mill sludges: a resource for others Dehue B., Meuleman B. and D. Hanssen (2006), Omzetting van rejects uit de papier- en kartonindustrie naar energie op eigen terrein, Ecofys report, assignment of the VNP Dunster (2007), Paper sludge and paper sludge ash in Portland cement manufacture, WRT 177/ WR0115 Eurostat Softboard a (2009), http://epp.eurostat.ec.europa.eu/newxtweb/submitresultsextraction.do Eurostat Softboard b (2009), http://epp.eurostat.ec.europa.eu/newxtweb/submitformatselect.do Feropa (2009), Evolution of softboard production in Europe (1988-205), http://www.feropa.org/statisticsmain.htm#useNFB Goroyias G., Elias R. and M. Fan (2004), Research into using recycled waste paper residues in construction products, The waste & resources action programme Gunnersens data sheet (2007), Material safety data sheet, http://www.gunnersens.com.au/images/stories/products/msds_softboard.pdf Isoplaat (2008), website, http://www.isotex.ee/?lang=11 ManageEnergy (unknown), for NOVEM The Netherlands McKinsey (2007), presentation “Ensuring a successful contribution of European forest-based industries as a case study towards a sustainable industrial policy”, EU informal Council for European Competitiveness, Lisbon 21-Jul-2007 Mikuta A., No more rejects from paper and board recycling, COST e-48 short scientific report

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Schoen, L. et al, Mechanical separation of mixed plastics from household waste and energy recovery in a pulverized coal-fired power station, Technical Report 8035, APME, 2000 Scot G.M. and A. Smith (1995), Sludge characteristics and disposal alternatives for the pulp and paper industry, Proceedings of the 1995 international environmental conference 1995 May 7-10 SenterNovem CDEM (2009), http://www.senternovem.nl/milieutechnologie/projecten/cdem_holland_bv_van_de_afvalstof_papierresidu_tot_grond_en_hulpstof_voor_cement_en_betontoepassingen_0351-99-04-30-0004.asp Shouguang Evergreen IM (2008), website, http://www.alibaba.com/product-gs/212815848/Softboard_7mm_41mm_.html Stawicki, B. (2008), Selective materials management towards solid waste generated from recovered paper processing – essential factor in sustainable development in recycling branch of paper industry, Technical University of Lodz Faculty of Process Engineering and Environmental Protection Sundholm (1999), Paper making science and technology: mechanical pulping, published by Fapet OY Tauw (2008), Reststromen in de pappier- en kartonindustrie, Wet- en regelgeving voor nuttige toepassing, Report for Bumaga Tucker, P. (2005), Co-composting paper mill sludges with fruit and vegetable wastes, University of Paisley Voogt, N. 2010, communication WRAP (2006), A new approach to paper mill sludge, Published by Waste and Resources Action Programme

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Annex I: Fact sheets In this annex the fact sheets of each technology is provided. An explanation of the content of the fact sheets is provided below. Title: Name of the technology (current application status). Reject type: Type of solid by-streams to which the technology applies. Background: General description of the purpose of the technology. Process: Description of the processes of the technology. Finance: Description of the benefits and costs of the technology. Environment: Description of impact of the technology on the environment (with focus on saved energy). Experience of legislation: Users/Suppliers views on needed permits and other regulatory matters concerning the technology (may be changed with the implementation of new Waste Directive). Contact: Contact information of parties that utilize/develop/commercialize the technology.

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1. Land management options Title: Land management options (Industrially applied) Reject type: Sludges Background: Land restoration Land restoration covers the use of dried sludge as a product applied on derelict land, damaged industrial sites topsoil, or during road constructions, topping of landfills, mine filling, etc. When aiming to increase soil quantity on the site, two techniques are observed: it can be either directly applied or mixed with the soil present on the site before application. Land spreading Highly practiced in some countries (e.g. the UK) and recently recognised once again24 for its organic and mineral qualities. Valuable compounds present in sludge are reinserted into the soil, by transporting it, often in a cake form, from the mill to the fields, then either spread on the land as a thin layer or ploughed into the surface between crops (CEPI unpublished). Main practical difficulties of landspreading recovery for paper sludges consist of available land and transportation costs (CEPI unpublished). Composting Paper mill sludges have been composted successfully in the past, though both nitrogen and structural amendments are generally needed for the process (Tucker 2005). Composting of sludges can be attractive alternative to e.g. land spreading when legislation for use of untreated sludges becomes more stringent. Process: Land restoration The quantity of sludge usually applied can engage high amounts, as in some cases a thickness of cover can understand several centimeters over hectares of area. This solution can be expected to increase in future, as pulp and paper sludges offer sufficient quality levels, while other options are becoming more legally restricted. (CEPI unpublished) Land spreading Application, when permitted, is recognised as a soil fertilizer (cellulose and organic content) or as a soil improver (mineral matter content). Land spreading is regulated on the national or local level. Moreover, limed sludge is identified as an efficient mineral

24 Environment Agency, “Landspreading on agricultural land: nature and impact of paper wastes applied in England & Wales”, Science Report SC030181/SR, 2005.

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amendment which can mainly be used to correct the pH of acid soils. The carbonate, highly contained in paper sludge, is well known as a good long-term soil amendment25, compared to other treatments. The usability of the sludge for land spreading is highly dependent on the local conditions and the soil needs (CEPI unpublished). Composting Factors inhibiting the land spreading of many paper mill wastes are their elevated carbon to nitrogen (C/N) ratios and relatively high Biochemical Oxygen Demands (BOD). Supplementary fertiliser additions are essential to prevent nitrogen immobilization and to ensure sufficient nitrogen for crops. Composting pre-treatments will reduce C/N ratios. Composting will also reduce mass, volume and moisture contents benefiting handling, transportation and storage requirements. Overall, the process will produce a stable material, of low odour, with modest levels of nutrients (Tucker 2005). Finance: Gate fee is to be paid to party that accepts by-stream. Environment: Other benefits from land application, particularly accurate when considering threats on the European soil, includes improvement of soil microbiological activity, better water holding capacity, tilt and workability, etc. Soil improvement is particularly evident on sandy soils and in very dry seasons26. In practice, spreading is mostly accomplished on agricultural land, although forests and particularly plantation can also be an appropriate field27. All in all, this “natural cycle” of biological products used on land improve soil quality as well as reduces erosion risk (CEPI unpublished). There are no problems with using paper sludges for landspreading concerning heavy metal or organic pollutant content. Potential problems from landspreading come from the high C/N ratio that can cause immobilization of soil nitrogen and thus deprive crops from it. Nevertheless, low nitrogen content avoids nitrate leakage to the ground water28 on the other hand, which are often very pollutant (CEPI unpublished). Scientific research and best practices give clear indication on how to avoid N immobilization risks. Indeed, losses in yield due to paper sludge can be minimized in the first year by adding fertilizer N29. More practically is application of 30 to 50 kg of fertilizing N/hectare per 100 t/ha of sludge. Results indicate that in the second year after application there was very little or no N immobilization at all. Application should also take into account local conditions, such as weather, snow cover, soil needs, crops cultivated, etc. If adapted to conditions and applied early enough before agricultural cultivation, even without additional N, the N immobilization will not occur (CEPI unpublished).

25 Following acid rainfalls, several years ago, German authorities where driven to apply a carbonate amendment in forests. Instead of using chemicals, this contribution could be done by natural by-products such as paper mill sludges. 26 Davis R.D. and Rudd C., “Investigation of the Criteria for, and Guidance on, the Landspreading of Industrial waste”, Environmental Agency, Technical report, 1999. 27 INRA, “La forêt, une alternative pour recycler les boues de station d’épuration”, Bordeaux, 2004. 28 Guillet F., “Land application of pulp and paper industry sludge”, Investigacion y Technica del Papel, nº 148, p. 84. 29 Davis R.D. and Rudd C., “Investigation of the Criteria for, and Guidance on, the Landspreading of Industrial waste”, Environmental Agency, Technical report, 1999.

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Experience of legislation: Legislation on land spreading varies but in most EU countries this application option is banned (WRAP 2006). Contact: No firms were directly contacted for this fact sheet.

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2. Absorbent, animal bedding Title: Absorbent, animal bedding (Industrially applied). Reject type: Waste water treatment sludge. (Deinking sludge is likely to be unsuited due to heavy metal content and partly mixing with plastics. But should the levels of contamination be low enough than deinking sludge could potentially be used for animal bedding production.) Background: The waste water treatment reject is transformed into animal bedding for cowsheds. The material is similar to cat litter (also industrially applied). The main difference is that the quality demands are lower and that the absorption capacity is less important. Process: First pressing for dewatering of the material takes place. Then the product is granulated and dried. In the dryer the reject is almost completely dried (removing 60% moisture). Waste energy is used for this process because using gas or other primary energy sources is too expensive. Instead, waste heat from the combined heat and power (CHP) plant can be used. The flue gasses from the CHP are cooled by a closed water loop. The water loop warms up the inlet air temperature for the sludge dryer up to 110 oC. Depending on the outside air temperature more or less energy is needed. The average energy use is about 23 GJ per ton of dried product. Finance: The price for the material can help to make the process financially feasible. Aside from avoiding disposal costs added value is generated from the sales of the animal bedding product. Environment: Normally cowsheds use natural products such as saw dust and straw (which could also be used for e.g. sustainable energy production). Because the material out of the waste water plant contains rest fibres and chalk (calcium carbonate) it has an added value due to absorption and manure. Experience of legislation: Unknown. Contact: The paper mill which has provided the information for this fact sheet does not wish to have its name and contact data mentioned.

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3. Anti-dust agent Title: Anti-dust agent (Industrially applied). Reject type: Waste water treatment sludges. Background: As example we take Crown van Gelder (paper mill in the Netherlands). The waste water treatment sludge of Crown van Gelder is currently processed by a company that sells the sludge (e.g. to coal based power plants) as anti dust material. Process: The sludge at Crown van Gelder is further diluted to make the spreading easier. No other processes are required. Finance: The fee to the trader is lower than the fee to incineration plants for waste disposal in the case of Crown van Gelder. Environment: The sludge from paper mills is likely to replace sludges from other industries (e.g. the starch industry). Experience of legislation: Registration of the sludges is necessary. A specific waste stream code is assigned to the sludges of Crown van Gelder. For the waste disposing actor obtaining the required permits is necessary. Contact: Herman J.A. Jansen Head TPO/Project Manager Crown van Gelder N.V. Tel: +31 (0) 251-262207 Mobile: +31 (0) 6-53933642 Mail: h.jansen@cvg.nl

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4. Feedstock for other paper grades Title: Feedstock for other paper grades. Reject type: Anaerobe sludge, aerobe sludge, deinking sludge, screen rejects. Background: Deinking sludge and effluent sludge can be used for production of certain board products. This reduces feedstock costs, as the sludge potentially replaces feedstock 1 to 1 (dry matter). The ration of feedstock to sludge that can be used depends on the type of board product. There have been reports on paper products containing 10% of sludge. It has been reported that screening rejects can also be applied in small concentrations for production of solid board. The long fibres make screening rejects a promising reject stream. The high ash content however can result in problems with dewatering. Other problems include age of the material and biological activity (odour). Process: The sludges are inserted into the pulper using a separate line. So far there have been no reports on noticeable negative effects on the paper production process. There is also still ongoing research on the influence on the characteristics of the end product. Finance: Paper for recycling costs are saved as well as the total fee for land filling of the used by-stream as no leftover residues are created. Added costs through the influence of the use of sludge as feedstock on productions processes such as variations in energy consumption for drying have not been determined yet. Environment: Investments are needed in a pulper line suited for the processing of sludge material. Added energy use for reuse of deinking sludge is estimated to be around 15 kWh/tondeinkings lib. As previously mentioned, the exact influence on the production energy is unknown. Experience of legislation: Depending on the specific national legislation regarding waste treatment, a mill using waste streams from other mills may gain the status of waste disposer. A permit needs to be acquired for this. The application process for such a permit may have effect on the economical feasibility. However, as the used sludge stream is a mono-stream used under well defined conditions the legal aspects of using sludges should (in theory) not prove a large barrier (Tauw 2008).

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Contact: The paper mill which has provided the information for this fact sheet does not wish to have its name and contact data mentioned.

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5. Pyrolysis oil Title: Pyrolysis-oil (upscaling phase). Reject type: Any type of biomass can be used for pyrolysis, however it makes sense not to use wet biomass types (more than 60 % moisture) and because of sustainability issues there should be a focus on residues and not to use anything from the food chain. Background: Pyrolysis transforms difficult-to-handle biomass of different nature into a clean and uniform liquid, called pyrolysis oil. Pyrolysis-oil application Bio-oil can be used as a substitute for fossil fuels to generate heat, power and/or chemicals. Short-term applications are boilers and furnaces (including power stations), whereas turbines and diesel engines may become available on the somewhat longer term. Upgrading of the bio-oil to a transportation fuel is technically feasible and has been demonstrated on laboratory scale, but needs further development. Transportation fuels such as methanol and Fischer-Tropsch fuels can be derived from the bio-oil through synthesis gas processes. Furthermore, there is a wide range of chemicals that can be extracted or derived from the bio-oil. The key advantage of liquids from biomass is that its production can be de-coupled from any application. Pyrolysis oil can be a fuel as such or a feedstock for further processing. Application possibilities include gasification and further processing, combustion, diesel engine, chemical upgrading (hyrotreated oil), physical upgrading (removing tar), and isolation of chemicals (www.btgworld.com and www.btg-btl.com ). Fast pyrolysis application Fast pyrolysis is a process in which organic materials are rapidly heated to 450 - 600 °C in absence of air. Under these conditions, organic vapours, permanent gases and charcoal are produced. The vapours are condensed to pyrolysis oil. Typically, 50-75 wt.% of the feedstock is converted into pyrolysis oil. Pyrolysis oil can be used for the production of renewable/sustainable energy and chemicals. Its energy density is four to five times higher than the original solid material, which offers important logistic advantages. It is the intention to bring the pyrolysis technology to the biomass. As the character of the biomass is relatively small it is not foreseen that plants will be centralized. It makes sense to have the pyrolysis plants decentral and the upgrading of the oil will be central in a large plant. The technology has not been industrially applied although there are some larger commercial scale plants in the world. The business case has to be proved for energy and bio-refinery applications. Several commercial scale plants will be built in the near future. One 5 ton per hour plant will be built by BTG-BTL on the AkzoNobel premises in Hengelo and Xynergo (daughter of Norske Skog) will build a 8 tons per hour plant in Norway.

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Process: Pyrolysis oil See background, for more detailed information contact BTG (see contact information bottom of fact sheet). Fast pyrolysis BTG's fast pyrolysis technology is based on intensive mixing of biomass particles and hot sand particles in a modified rotating cone reactor. A wide variety of different feedstock can be processed in the pyrolysis process. Before entering the reactor, the particles must be reduced to a size below 6 mm, and its moisture content to below 10 wt.%. Normally, sufficient excess heat is available from the pyrolysis plant to dry the biomass from 40-50 wt% moisture to below 10 wt%. In the process up to 75 wt.% pyrolysis oil and only 25 wt.% char and gas are produced as primary products. Since no "inert" carrier gas is used the pyrolysis products are undiluted. This undiluted and hence small vapor flow results in downstream equipment of minimum size. In a condenser the vapor is rapidly cooled yielding the oil product and some permanent gases. In only a few seconds the biomass is transformed into pyrolysis oil. Charcoal and sand are recycled to a combustor, where charcoal is burned to reheat the sand. The permanent gases can be utilized in a gas engine to generate electricity or simply flared off. In principal, no external utilities are required. Finance: Due to the small number and limited scale of existing pyrolysis oil production units, the economics of a commercial scale unit can only be estimated. Costs of bio-oil production depend i.a. on feedstock (pre-treatment) costs, plant scale, type of technology etc. The use of solid by-streams has the advantage avoiding disposal costs and free feedstock. The negative side of using the by-streams is lower quality of the feedstock (more water, more ash content and lower yield per ton). The exact financial outcome will require more research. Environment: Pyrolysis oil is CO2 neutral, because residues are used. Only the transportation costs of the oil should be taken into account which is approx. 5 % of the total energy content. Experience of legislation: REACH is important. Every producer in Europe, producing more than 1000 tons per year has to apply for REACH. Contact: Gerhard Muggen Managing Director BTG Bioliquids BV Pyrolysis oil, the sustainable alternative! PO Box 835, 7500 AV Josink Esweg 34, 7545 PN

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Enschede, The Netherlands phone: +31 53 4862287 mobile: +31 6 20739802 e-mail: gerhard.muggen@btg-btl.com Web: www.btg-btl.com

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6. Feedstock for softboard Title: Softboard (Labscale proven). Reject type: Deinking sludge, primary sludge and screen rejects. Background: Softboard is a wood fibre based product that is often used as thermal/accoustic insulation, ceiling tiles and as in-fill product for timber frame construction. The wood fibres can be obtained from timber such as Eucalyptus (Gunnersens data sheet 2007), or from waste materials. According to Goroyias et al. (2004) softboard produced from paper waste streams containing around 80% sludge and 10% other fibres is possible. The other fibres can be either MDF fibre or virgin wood fibre. MDF fibre is preferred to achieve further cost savings. It is assumed that both primary and deinking sludge can be used for this application option due to their confirmed high amount of organic (fibres) content. Process:

Process flow diagram for softboard (Goroyias et al. 2004) Finance: Using sludge can replace virgin wood fibre. Virgin fibre costs are about £50-70/ton. The actual price per ton of by-stream cannot be estimated as it depends on the market. Environment: The energy savings by using the rejects are around 0.10 GJ/tonwet and 10 kWh/tonwet

30 Experience of legislation: Impact of using the rejects on health codes, waste handling permits, or REACH requires further investigation. Contact: Rob Elias Commercial manager

30 Assumption is that the fibres from the reject save the energy needed for the processing of wood chips normally used as feedstock.

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Centre University of Wales Tel: +44 (0)1248 388599 Email: r.m.elias@bangor.ac.uk

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7. Hybrid MDF Title: Feedstock for hybrid MDF (Labscale proven). Reject type: Sludges (deinking and waste water treatment). Background: The relative high fibre content of dry sludge (45-50%) induced the idea of producing hybrid MDF. A content of 45% sludge in hybrid MDF proved feasible. The hybrid MDF can be used in several applications in dry conditions where high internal bond strength is not required. (Goroyias et al. 2004). Process:

Process flow diagram for hybrid MDF (Goroyias et al. 2004) Finance: The sludge can replace virgin wood used in normal MDF production. Virgin fibre costs are about £50-70/ton. The actual price per ton of by-stream cannot be estimated as it depends on the market. Environment: The energy savings by using the rejects are around 0.10 GJ/tonwet and 10 kWh/tonwet

31 Experience of legislation: Impact of using the rejects on health codes, waste handling permits, or REACH requires further investigation. Contact: Rob Elias Commercial manager Centre University of Wales Tel: +44 (0)1248 388599

31 Assumption is that the fibres from the reject save the energy needed for the processing of wood chips normally used as feedstock.

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Email: r.m.elias@bangor.ac.uk

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8. Cement bonded sludge board Title: Cement bonded sludge board production (Labscale proven). Reject type: Sludges (deinking and primary). Background: Up to 30% of sludge can replace the virgin wood fibre currently used in cement bonded particle board. (It is assumed for now that the virgin wood fibre is similar to that used in softboard). Key advantages are strength, fire resistance and dimensional stability. Interest in this product has been expressed with applications suggested for exterior cladding, outdoor paving systems and suggestion for niche applications as fire surrounds (Goroyias et al. 2004). Process:

Process flow diagram for cement bonded sludge board (Goroyias et al. 2004) Finance: The sludge can replace virgin wood used in normal cement bonded sludge board production. Virgin fibre costs are about £50-70/ton. The actual price per ton of by-stream cannot be estimated as it depends on the market. Environment: The energy savings by using the rejects are around 0.10 GJ/tonwet and 10 kWh/tonwet

32 Experience of legislation: Impact of using the rejects on health codes, waste handling permits, or REACH requires further investigation.

32 Assumption is that the fibres from the reject save the energy needed for the processing of wood chips normally used as feedstock.

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Contact: Rob Elias Commercial manager Centre University of Wales Tel: +44 (0)1248 388599 Email: r.m.elias@bangor.ac.uk

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9. Tiles Title: Feedstock for tiles (Labscale proven). Reject type: Primary and deinking sludge. Background: The production of tiles from 80-85% sludge based on dry weight has been tested. It is unclear if the product fulfilled the required standards for fibreboards (EN316). Also the tile required significant amounts of MID resin (20%) to achieve the strength and hard wearing characteristics. This makes the overall product quite expensive (Goroyias et al. 2004). Process:

Process flow diagram for tiles (Goroyias et al. 2004) Finance: The added value cannot be estimated as it depends upon the market. Environment: The energy savings are thus far unknown due to lack of information on the energy intensity of the sludges to tiles process. Experience of legislation: Impact of using the rejects on health codes, waste handling permits, or REACH requires further investigation. Contact:

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Rob Elias Commercial manager Centre University of Wales Tel: +44 (0)1248 388599 Email: r.m.elias@bangor.ac.uk

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10. Use for cement/asphalt/etc. production Title: Use of paper sludges in cement /asphalt/etc. production (Exact application status unknown). Reject type: Paper sludge. Background: The cement industry is an energy intensive sector with significant CO2 emissions. The paper industry can cooperate with the cement industry by providing substitute raw material. Also for production of asphalt or other material with flexible feedstock solid by-streams can be used. Paper sludges can potentially be used for Portland cement production. The cement industry is willing to consider by-products as alternative fuels and/or ingredients that contribute to the recipe of the cement clinker. Main drivers are environmental policies and the desire to reduce primary fuel and material use (Dunster 2007). Paper production sludges can be used as raw material for the production of cement blocks. In cement block production the introduction of 2.5-5% of sludge has no significant negative impact on properties of the final product. Ashes from e.g. incineration of coarse rejects or sludges are already used in the cement industry and the asphalt industry for production. Process: No detailed description available. Finance: Gate fee is paid (Dunster 2007). Environment: In comparison to current practices (incineration and land filling) the material is reused thereby saving primary material. Experience of legislation: The sludge is classified as waste. Contact: No firms were directly contacted for this fact sheet.

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11. Fibre/plastics recovery Title: Fibre/plastics recovery (First commercial installation under construction). Reject type: Coarse rejects. Background: In this fact sheet the VAR technology is used as example. The VAR has together with a partner developed a technology that can separate the fibre and plastic fraction of coarse rejects from the paper industry. The separated fibres can be reused in board production process thereby saving transportation costs and feedstock costs. The plastic fraction can be incinerated with energy recovery, although increased plastic recycling systems in many countries have increased the development of higher added value applications for recycled plastics. Success of the technology depends on the application possibilities of the recovered fibre and the willingness of the paper companies to use these fibres. This technology has not been commercialised yet, but a first commercial application is currently being built. The technology has had extensive testing on several machines at VAR using the rejects of different paper mills. The machine has also been tested for other streams33 that could potentially provide feedstock for the paper industry. Process: The technology can be applied to reject streams as they are currently (after mechanical pressing) being disposed of to MSW or other processors of rejects. A detailed description of the process cannot be provided due to confidentiality reasons. The basics of the technology however involve the separation of a reject stream into a fibre and foil fraction in which the focus lies on avoiding damage to the fibres. The foil fraction and any unwanted contaminants are removed together. The process is executed under dry conditions. According to the calculations made by VAR roughly 95% of the fibres can be isolated from the reject stream. Some fibres are lost as a separate fraction and some will be lost in the foil fraction. The exact amount of fibres does not form a condition to the separation process (i.e. either 25% or 70% makes no difference to the process itself). What is important is the moisture content of the reject stream (the percentage of moisture content has a negative correlation with the efficiency of the separation process) and the presence of any large contaminants such as rubber or metals. Considering the moisture content, when mechanically dewatered the moisture content of the rejects is sufficiently low for the process. Finance: 33 Identity of the industries of these alternative streams is not mentioned due to confidentiality reasons

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Multiple business models are possible. In case of a paper mill with high amounts of rejects it can be possible to station the separation module onsite. In case of relatively low amounts of rejects per paper mill a centralised installation can be constructed which uses reject streams from multiple mills. Whether the paper mill becomes the owner of the installation and pays a licence fee to VAR or VAR is the owner of the installation themselves will have to be judged per paper mill. The estimated costs of the installation will be around €600.000,-. However the investment costs are highly dependant on the exact situation and the specific requirements of the paper mill. Economical feasibility depends on:

• Current disposal costs • Purchase costs of current feedstock • Disposal costs of foil fraction • Avoided transportation costs.

Environment: The process requires around 23 kWh per tonne of reject material. Experience of legislation: The impact from REACH regulation on the application of the VAR technology is at the moment uncertain. For now VAR assumes that as paper recycling mills acquire their waste streams under a certain European waste code, the recovered fibres from VAR could also be acquired by paper mills under a (to be determined) European waste code. Contact: VAR Sluinerweg 12 7384 SC Wilp - Achterhoek Tel. +31 (0)55 3018300 www.var.nl

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12. Synthetic calcium carbonate Title: Synthethic calcium carbonate (Up-scaling phase). Reject type: Deinking sludge or waste water treatment sludge ash. Background: The company CalciTech has developed a process for the production of synthetic calcium carbonate (SCC), an advanced form of precipitated calcium carbonate (PCC) (www.calcitech.com). The new process is able to separate paper sludge ash into an ultra pure calcium carbonate and a form of metakaolin. According to CalciTech the SCC recycled mineral has a positive influence on the gloss, brightness, opacity and printability of the coated paper end product. This is due to its narrow particle size distribution compared to PCC or GCC and its high brightness. A small scale plant located in Eastern Germany currently produces samples for customers interested in testing the SCC in their products (www.calcitech.com). Process: The sludge is first incinerated. The calcium oxide is then separated from the ashes using the CalciTech separation step. Then the calcium oxide is (using CO2) converted into SCC using the CalciTech conversion step. CalciTech estimate that about 30-40 kt of SCC will be obtained out of 500kt of paper for recycling. Finance: A full scale plant with a capacity of 40.000 tonnes of SCC per annum has been designed and could be built on a 2.000 m2 area. An on-site plant would avoid freight and handling costs. The CalciTech process eliminates the disposal costs of the sludge or ash. Environment: The process converts a waste product into two valuable product streams: SCC and metakaolin. 44 tonnes of CO2 is sequestered for 100 tonnes of SCC produced. The satellite concept eliminates the transport of raw materials and finished products. Experience of legislation: REACH: SCC has been registered as a SIEF application for calcium carbonate Enables mills to meet EU Directives on:

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- Waste 2008/98/EC - Integrated Pollution Prevention and Control IPPC 96/61/EC - Landfill 1999/31/EC. Contact: Michael Watts Marketing Director CalciTech Synthetic Minerals Europe Ltd 10, route de l’áeroport P.O Box 261 1215 Geneva Switzerland Tel : + 41 22 710 40 20 Mobile : + 41 79 376 60 97 Email : michael.watts@calcitech.com

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13. Bio-BTX Title: Bio-BTX (Under development). Reject type: Confidential information. Background: The technology converts rejects into industrial grade benzene, toluene and xylene (BTX). The expected benefit using the Bio-BTX technology in comparison to e.g. incineration of the rejects is that more value added is created. BTX are the highest valued platform chemicals in the petro-chemical industries. The product can be used directly in existing chemical plants. This allows the production of green products with relatively small investments. The exact business case (central plant, on-site installation) is confidential information The technology is not yet commercially available. The concept is proven by small scale experiments. A pilot plant has yet to be built. Process: The technology is based on a thermo-chemical conversion. Other information regarding this technology is mostly confidential. Finance: This information is confidential. Environment: The demand for fossil-based chemicals is reduced. As production of these chemicals is highly energy-intensive (fossil BTX is made by naphta cracking) it is expected that the Bio-BTX will save significant energy. Experience of legislation: This information is confidential. Contact: KNN advies Werfstraat 9712VN Groningen info@knnadvies.nl +31 50 317 5558

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14. Hydrolysis to fermentation feedstock Title: Hydrolysis to fermentation feedstock (Research phase). Reject type: Any reject type containing cellulose. Background: In this fact sheet Bio-Rights will be used as example. The company Bio-Rights is building (start in 2009) in a test installation in Hardenberg (the Netherlands) that will produce methane. The key technology is called the Gravity Pressure Vessel (GPV)34. The technology allows the production of bio-methane from different cellulose containing waste streams (e.g. wood and sawdust waste, household wastes, food processing industry waste, manure, grass etc.). The greatest innovation of the GPV is that the traditional batchproces of weak acid hydrolysis is converted into a continuous process. According to Bio Rights the process output and the process flow can be increased and decreased without problems. They also state that the system is very robust and due to its closed-off setup does not emit any gasses. Process: The Gravity Pressure Vessel is a tube with a closed-off outside pipe and an open inside pipe. These are inserted into a 700 meter deep well with an iron wall and a concrete foundation. The shaft is completely closed off and under vacuum (thermos flask). For the production, the cellulose fraction of the waste streams is isolated and grinded to (maximum) 40 millimeter size. The particles are mixed with water in tanks that are heated to 80 oC. The cellulose mixture is then pumped (about 10% dry matter content) to greater depths where the reactor chamber is located. Here the conversion of cellulose and hemi-cellulose into sugars takes place under high pressure in a weak acid environment. The whole stream of aldehydes, alcohols and sugars can after ample separation be transferred to an anaerobe digester to produce methane or bio-chemicals. Finance: No information. Environment: Depending on the business plan, the product substitution range is: Ethanol, Buthanol, Methane, heat, electricity. The hydrolysis and utilization in a fermentation or digesting plant is a simple reaction step and fully predictable. The GPV is a unique rector concept that gives high energy 34 The GPV is developed and patented by an American company called GeneSyst Int. Inc. In the US there are three projects under development using GPV. Bio-Rights has obtained from Genesyst Europe BV the license rights for the Benelux.

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transfer values, because of the vacuum insulated thermo bottle concept. Energy and mass balance available depend on specific raw material intake. Experience of legislation: For the building of the installation environmental and building permits are required. At the moment an environmental permit (waste processing a.o.) is already in place for the production of Ethanol and Methane. An addition to this for just Methane to come to an electric output of 8MW is applied for together with an addition to produce just Methane. A building permit (first part, GPV, intake and MBR reactors ) is in place. Contact: Bio Rights BV Noorwegenweg 8 7772 TB Hardenberg Tel: + 31 523 272 361 Email: genesysteu@yahoo.com

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15. CDEM Title: CDEM (Industrially applied). Reject type: Paper sludges (deinking and waste water treatment). Background: Deinking sludge is suited for production mineral products. In this fact sheet the CDEM plant is used as example. The CDEM plant was originally invested in by Dutch mills in anticipation to more restricting legislation and higher costs regarding disposal of their sludges. Separation of the fibres from the inorganic material for recycling was considered unfeasible due to the difficulty of separation and that the inorganic end product had low value due to the mix of calcium compounds and meta-kaolin (individually the inorganic materials are much more valuable). Application The mineral product, called TOP-crete, can be used in the construction of roads/foundations, concrete, or as feedstock for the production of sand-lime bricks (SenterNovem CDEM 2009). Europe Although there has been some interest for expansion, CDEM is thus far the only installation in Europe producing high quality cement substitution products from paper sludges. The technology can also be installed on-site. Process: In the CDEM-process the remaining water of the sludge is evaporated and the organic fraction incinerated (SenterNovem CDEM 2009). Conversion takes place in an exothermic reaction at around 800 oC. The input materials of in-organics, organics and water are turned into Meta-kaolinite, calcium carbonate, calcium-oxide and vapour. The surplus energy during the process can be used to meet heating or electricity demand of other facilities/houses (www.cdem.nl). The primary output is a stable, non-toxic cementitious mineral that can be sold as admixture to Portland cement or as a mercury sorbent in a coal-fired power stations (www.cdem.nl). CDEM processes around 185.000 ton (2009) of deinking sludge (wet) per year (www.cdem.nl) with a capacity of around 25 ton/h (Voogt 2010). Only paper process sludges are eligible to be used as input in CDEM (deinking sludge, fibre sludge and waste water treatment sludges). Differences with the method of combustion of deinking sludge and selling the residue as cement substitute is the quality. The process of low temperature (800oC) incineration of

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the paper sludges only (no other materials are processed) is specifically designed to avoid any chemical mineral reactions, therefore no fly ash is created. Focus of CDEM is on the end-product (Topcrete) while the focus of combustion is on energy production. Finance: After initial investments the paper mills withdrew their participation as stakeholder of the CDEM plant. The CDEM plant is therefore independent. For the disposal of their sludges the mills pay CDEM a fee (competitive market price). CDEM also processes waste sludges of other paper mills. Aside from disposal fees, CDEM acquires income from selling TOP-crete to the cement industry and from selling (green) electricity to the grid. The payback time of the plant is difficult to assess but is estimated to be around 5 years with an initial investment of around 20 million euros (Voogt 2010). A minimal scale size of around 100.000 ton sludge processing per year is required according to Voogt (2010) for the plant to be economically feasible. Environment: The incineration (fluidized bed) of the sludges produces heat that is used to produce steam. The steam is converted into electricity using a steam turbine. As the energy production is bio-based in can be considered CO2 neutral. The electricity output is netto35 roughly 110 kWh/ton sludge_wet (Voogt 2010). CDEM produces 28.000 MWh of electricity per year (www.cdem.nl). The TOP-crete also substitutes cement, which is a highly energy intensive product emitting about 0.8 ton CO2 per ton of cement (www.cdem.nl). Note however that the partial calcination of the calcium carbonate in the deinking sludge also releases CO2 emission. Therefore, the netto avoided CO2 emissions is less. This study only focuses on the avoided energy consumption, which for an average Portland cement production is considered to be 4 GJ/ton heat and 100 kWh/ton electricity. Experience of legislation: The input side of the CDEM concept involves legislation for waste incineration. However, due to the process inherent ability of capturing all harmful emissions within the end-product, this provides no problem. As all emissions are far beneath the legal conditions, no expensive material is required for cleaning of the flue gases. The output side involves REACH legislation. This is however only valid for the CDEM concern as they provide the new product, and does not concern paper makers that provide the input sludges. Also, for CDEM REACH provides relative little problems, as the process takes place at low temperatures which therefore ensure that no chemical formations take place. In other words, merely the volume ratio’s change but the components in the end-product are already known under REACH. Contact: MinPlus CDEM Nico Voogt 35 Electricity output after subtraction of initial needed energy for other processes.

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Meander 251, Arnhem-NL Phone: +31 26 7370 000 Mobile: +31 6 53 905 445 P.O. Box 5085 6802 EB Arnhem-NL Email: voogt@cdem.nl

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16. Gasification Title: Gasification36 (Industrially applied but not to paper production by-streams). Reject type: Coarse rejects. Background: Crown Van Gelder (the Netherlands) has investigated gasification technology. Main motivations for this were the high Natural gas prices (at that time), reluctance to use combustion (waste incinerator status), less residue after energy conversion than with combustion, partly biomass and the fact that syn-gas from gasification can be used in existing CHP installation. An advantage of gasification is the high energy density of the gas. Gasification takes place using low oxygen environment. This produces syn gas. One of the main issues of gasification at certain temperatures is the forming of tar during gasification. The gasification technology chosen by Crown Van Gelder has not shown problems with tar due to the higher process temperatures (about 1600oC). CVG researched the gasification of plastic/paper waste streams, because of their high calorific values (about 18 MJ/kg). Use of sludges after drying for gasification has been researched by Crown Van Gelder. This option did not appear to be economically feasible. It is expected that larger gasification installations will be able to handle wet sludges for co-gasification, but this requires additional calculations. The gasification process produces syngas which would also be used to replace an estimated 25% of the Natural gas use of CVG. World-wide there are already many gasification installations active. Gasification of rejects (refuse derived fuel and municipal solid waste) are also gasified. Mixing with other streams is possible but in the Netherlands there is insufficient capacity. Process: Gasification uses a fluidized bed in low-oxygen conditions and high temperatures to convert organic material into gasses. Depending on the process conditions either syn-gas or product-gas is produced. Syngas is used for further conversion such as Fischer-Tropsch reactions. Product-gas is used for combustion. The gasification technology researched by Crown Van Gelder will produce syn-gas which is combusted in the existing CHP and a new boiler. The new boiler produces steam which will be used to meet the heat demand of the drying section or be fully condensed in a steam turbine to generate electricity. A disadvantage is that the biomass stream in general cannot have a higher moisture content than 15%. Although some suppliers claim that their installation can handle up to 50% moisture content, there is relatively little experience with these installations (Dehue 2006). The technology chosen by Crown Van Gelder however can handle 25% moisture content (proven). About 6% of the material is leftover after conversion as inert granulate residue which can be used in road building works. 36 This fact sheet was composed based on conversations with Ecofys and Crown Van Gelder

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Finance: Large installation costs about 200-250 mln euro. The payback time depends strongly on the gas prices and the gate fee for Refuse Derived Fuel (RDF). Environment: Some emissions that are emitted when using regular incineration is avoided due to the fact that clean syn-gas is produced. Recovered energy reduces the need for natural gas. Granulate residue replaces current needed material for road building. Experience of legislation: Depending on the input of the gasification installation either national laws concerning emission conditions for combustion installations need to be followed or national laws concerning conditions for waste incineration plants. The gasification process has to comply with emission regulation for incineration. For example for the building of a gasification installation in the Netherlands a building permit and environmental permit is needed. The strictness of environmental legislation increases when building large installations. Contact: Herman J.A. Jansen Head TPO/Project Manager Crown Van Gelder N.V. Tel: +31 (0) 251-262207 Mobile: +31 (0) 6-53933642 Mail: h.jansen@cvg.nl

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17. Supercritical gasification Title: Supercritical gasification (research phase). Reject type: Sludges, coarse rejects. Background: The supercritical gasification technology is well suited for wet biomass streams. Currently a global estimation by the developers at the University of Twente is that streams containing at least 3% of organic material will prove energy neutral. Higher content of organic material will lead to an increasing positive net output of energy. There is a threshold of maximum of 50% solid material because of the viscosity. Advantages are:

• The technology is suitable for efficient processing of biomass with high moisture content

• Utilization of different kinds of biomass as an energy source • Depending on feed composition, complete gasification can be achieved with in a

short reaction time. • The formation of tar and char depends on feed, -conditions, reactor design and

catalysts. • Product gas is available at high pressure in a single step process, thereby

avoiding the cost of expensive gas compression • High energy conversion efficiency is achieved by avoiding the process of drying

step • Selectivity towards methane, hydrogen, or syngas can be steered with

temperature, pressure and using proper catalysts (www.utwente.nl) The technology is still under development. A full-time running micro-scale installation (2.5 liter/hr) has proven successful. Feeding solid biomass or slurries requires a larger scale installation, which is not yet available. Batch tests to investigate gasification conditions and efficiency are possible. Process development work will be required to make the process continuous. Process: The process takes place at supercritical conditions, at temperatures above 374 oC and pressures above 22.3 MPa. Under these conditions water behaves like an adjustable solvent and biomass gets rapidly decomposed by hydrolysis. Because the cleavage products of biomass dissolve in the supercritical water, tar and coke formation is minimized. The technology produces energy rich gases such as hydrogen, synthesis gas or syn-gas (a mixture of CO and H2) and methane from the wet biomass. An important element is the heat recovery of the energy of the outgoing stream. It is estimated that around 90% of the heat can be recovered by heat transfer between the outgoing and ingoing stream.

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Finance: No information. Environment: No information. Experience of legislation: No information. Contact: DR.IR. D.W.F. BRILMAN University of Twente TNW/TCCB Meander 222 PO Box 217 7500 AE Enschede The Netherlands Telephone: +31-53-489 2141 Mob : +31-53-489 6969 Fax: +31-53-489 4738 e-mail: wim.brilman@utwente.nl

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18. Combustion

Title: Combustion (Industrially applied). Reject type: Coarse rejects, deinking sludge, waste water treatment sludge, screen rejects. Background: According to Dehue et al. (2006) coarse reject (rejects from the screening phase of paper recycling process) is a waste stream that is well suited for energy recovery due to its high calorific value. In the Netherlands these waste stream are available in significant quantities. Deinking sludge and effluent sludges have less potential but can still be incinerated for their energetic value. In this fact sheet the combustion of coarse rejects at Parenco (paper mill in the Netherlands) is used as an example. Process: In Parenco the Netherlands a bio-boiler is used to incinerate all paper waste streams (deinking sludge, primary sludge, secondary sludge and rejects). After removing ferro metals from the paper recycling rejects they are crushed and mixed with other components (such as wood and sludge) and stored. The sludges (deinking, waste water treatment sludge) are first mixed and pressed to obtain 50-60% dry matter and then fed to the boiler. The boiler can handle up to 390 tonnes per day of dried solid fuel. The installation can handle 30 ton/hour (approximately 240.000 ton annually). The boiler produces max. 48 MW thermal and max. 15MWe electricity by using a backpressure steam turbine. The low pressure steam (3 bars) is consumed internally in the process. After incineration ashes are leftover (about 30% of original volume). These can be landfilled or used for production of cement, asphalt or ground improvement. Finance: According to Dehue et al. (2006) it is economically favorable to incinerate coarse rejects for the production of low-pressure steam instead of electricity. Important is to note the chloride content of coarse rejects streams, this percentage can vary between paper mills. High chloride content can potentially lead to corrosion problems at especially high-temperature steam production. Electricity production requires such high-temperature conditions (Dehue et al. 2006). This in combination with significantly higher investment costs for a electricity producing facility in comparison to a low pressure steam producing facility make the usage of coarse rejects for steam production favorable. The investment in the incineration installation by Parenco was, when it was built (2003-2004), around 35-40 million euro. The payback time varies from 3-10 years depending on 1) the type of waste streams used, 2) any forms of subsidies, 3) savings on energy/disposal costs. In the case of Parenco the annual savings from reject incineration are around 800.000 euro (16.000 rejects per year).

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The ashes are given to the cement industry. Currently this still requires a disposal fee, but Parenco has indicated that this may change from costs to profit in the future. Environment: The exact impact of the energy generation is difficult to determine as a large amount of the input comes from wood, sludges and rejects. Experience of legislation: New REACH legislation will affect Parenco procedures as mineral products are included. Contact: Norske Skog Parenco B.V. Veerweg 1 6871 AV Renkum Tel: +31 (0) 317- 36 19 91 Email: nsp@norskeskog.com Website: www.norskeskog.com

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19. Direct digestion Title: Direct digestion (Industrially applied, but not to paper production rest streams37). Reject type: Screening rejects, deinking sludge, secondary sludge and (possibly) primary sludge. Background: Digesting is used by farmers and municipal sewage water plants as a relatively simple technique for a long time. The last decade biogas becomes a strong alternative for fossil fuel. The technology is developing rapidly and more and more attention is put into the pre-treatment processes. The produced biogas is cleaned and transferred into green natural gas. This can be inserted into the existing high-pressure gas distribution system. In Groningen (Holland) the Dutch government is supporting the start of the “Groningen Biogas Centre”, a knowledge centre where taller digesting units (10 to 150 m3) are used to execute tests. The project is set-up and coordinated by PROCES-Groningen. This company has performed research for the last 10 years in the field of digesting and biogas. They are leading in the area of pre-treatment of organic biomass as a preparation step before digesting biomass into biogas. The main results of PROCES are a strong increase of the efficiency in biogas production and an increase of the capacity of the digesters. Both effects count positively in the financial calculations of digesters. (www.proces.nl) Some components of paper production rest streams such as calcium compounds can interfere with the digestion process, making them less suited. (Bioclear 2007) According to a report by Bioclear (Bioclear 2007) there is no industrial application of digestion in the paper industry38.(www.bioclear.nl) Process: The biomass is inserted into a digestion tank. In the tank micro-organisms convert the digestible fraction into biogas. The biogas consists of methane, CO2 and low concentrations of other gases (e.g. water vapour). 3-5% of the organic material is used for the growth of the bacteria. After the digesting process a watery stream containing dry matter called the digestate is leftover. (Bioclear 2007) The scheme below shows all the steps in the digesting-biogas process. The colour varies from green (well known) to red (practically no knowledge available). The English version will be put on the PROCES website soon. Former digesting units only consisted of the number-3 block: the digester. They used to operate on waste and incidental feed flows. Modern digesters consist of 12 blocks and are fed with specific feed flows on a large scale. Digesting is becoming an industrial process. 37 Some streams that are digested sometimes contain paper. The largest stream of this type is the organic wet fraction of households. Also in some countries by-streams from the paper industry are co-digested with other streams. (Bioclear 2007) 38 There has been some activity in Spain concerning the use of digestion. This has not been further investigated due to lack of time.

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(www.proces.nl) The waste flows from paper industry look very promising as feed flow for digesting units. The flows are substantial, are constant and consist of high concentrations of organics. These are important parameters for economically building and operating a digesting unit. The final and exact lay-out of a digesting unit for paper-waste has to be determined through lab-scale tests. The amount of gas production from the stream depends upon its components. Pure cellulose is very good for digestion with a yield of about 800 m3/ton d.m.. However the expected yields for secondary sludge is around 150 m3/ton d.m., and for screening rejects and deinking rejects around 200 and 400 m3/ton d.m. Reason for this is content of non-digestible impurities and components that are less well digestible (e.g. lignin). (Bioclear 2007) It is suggested that the digestate of the process might be suitable for use for paper production. (Bioclear 2007). Finance: Currently the payback time of digestion of paper production by-streams is very long, even under favourable conditions such as high gas prices. To be economically feasible the disposal costs of the streams have to be high, biogas production yield needs to be improved and digestate needs to be applicable to preferably paper production (Bioclear 2007). Economic digesting can only be done when the yield of biogas in increased. The results of increasing yields are shown on the PROCES-lab. On chicken manure the yield went up from 18% to 55%; almost tripled. Economics of digesting systems are strongly depending on the cost of handling digestate. Environment:

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The produced bio-gas reduces the need for external (fossil) gas. Advantage to the environment will also depend upon the possibility to re-use the digestate. The process itself is hardly effecting environment. Experience of legislation: Building and environmental permits are required. Using bacteria as biogas producing organisms introduces the possibility of producing odour on a digesting plant. Attention should be given to this item. Contact: PROCES-Groningen B.V. Postbus 5077 9700 GB Groningen Visiting adress: Zernikeplein 11 9747 AS Groningen T: +31 (0)650-201-372 E: info@proces.nl I: http://www.proces.nl Bioclear Bezoekadres Rozenburglaan 13 9727 DL Groningen Postadres Postbus 2262 9704 CG Groningen Tel 050 5718455 Fax 050 5717920 Email info@bioclear.nl

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20. Torrefaction Title: Torrefaction (Pilot scale proven). Reject type: Coarse rejects (potential for sludges unclear yet). Background: In this fact sheet fox coal is used as an example. 75% of total world production of coal is used for power production. Since power is mainly made using steam coal, this is the design product for FoxCoal. Global power demand will double within 25 years and coal will stay to be the mayor fuel for it since it is the most abundantly available fossil fuel. FoxCoal has researched the potential to convert mixed waste streams from a.o. the paper industry into a fuel that equals the specifications of steam coal so it can be co-fired. Process: The FoxCoal process involves the torrefaction of the waste stream after removal of the metal fraction (which is sold) at temperatures between 200-400°C. The heat is generated by using the gasses that form during the torrefaction process creating an autotherm process. Using this process results in:

• Higher energy density (28 - 32 GJ/ton 1,3 * Gross Calorific Value on dry basis)• Hydrophobic material • Black • No forming of tar gasses (major problem in gasification installations)

Advantages to combustion on own site is:

• No residues (so less waste management costs) • No requirements for investing in expensive flue gas cleaning equipment (this way

the equipment of the power plant is used) • Chloride is partly captured by lime in paper and can be removed in a later stage

by washing. Only streams that have a minimum of 50% fibres with the plastics are interesting, as otherwise it would be better to simply recycle the plastic. Finance: This depends completely on the market. What are the power plants willing to give etc. Environment: Conversion of coarse rejects (wet) using the FoxCoal technology delivers a powder coal replacing product with a value of 11.2 GJ per ton coarse rejects (wet).

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Experience of legislation: The role of REACH is unclear yet. Uncertain whether the SRF is seen as waste or as a product under REACH. Contact: Walter Nonnekes Managing Director Emdenweg 3 Postbus 5121 9700 GC Groningen Tel: +31 (0)50 547 0566 Mob: +31 (0)6 1500 1601 Email: wno@foxcoal.nl Website: www.foxcoal.nl

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21. Secondary fuel

Title: Secondary fuel (Industrially applied). Reject type: Coarse rejects. Background: In this fact sheet Qlyte is used as an example. Qlyte is a spin-off from the company Dutch chemical and biotechnology company Royal DSM N.V. Qlyte focuses on expanding the commercialization of the Subcoal® technology. This technology converts coarse rejects from paper and cardboard production into a high quality fuel (fluff, pellets or powder form). A working installation has been running at the Smurfit Kappa Roermond site for around 8 years. The main buyers of the Subcoal® fuels are lime- and cement producing companies. A potential future market lies in the electricity producing sector, as the powder form of the Subcoal® can replace powder coal currently used by some electricity producers39 Process: The coarse rejects consist of roughly 50% water, and a mix of plastic, paper and other materials (e.g. metals, sand, rope fibre, wood shreds. The rejects are directly removed from the pulper and go into the process. Then after mechanical pressing the unwanted materials (metals, sand, pvc, water etc.) are removed by in subsequent steps. Then through thermal dewatering up to 10% water content a secondary fuel is obtained. Finally the product is pelletized. Typically this fuel has around 22-23 GJ/ton energy value (although this can vary depending on the composition of the coarse rejects). About 15% of this end energy value is needed for the total conversion process of reject to pellet. The composition of the coarse reject material may vary from 20%-80 %to 80%-20% ratio of plastic to cellulose (i.e. biomass). Advantages of converting the coarse rejects to Subcoal® are:

• The higher efficiency of energy use per ton of coarse rejects • Low ash content (making it ideal for use in amongst other lime production) • Low chlorine content • Stable composition of end product • Converting a waste stream into a valuable product for further use in proven

applications A Subcoal® producing installation is in operations at Smurfit Kappa Roermond for almost 8 years. The installation has low operation costs as virtually no personal is needed to run it. The installation produces approximately 16.000 ton Subcoal® per year from 35.000 ton of coarse rejects.

39 This has been tested and is applicable. One current barrier is that the great demand of an average electricity producer for co-incineration of the Subcoal® cannot be met due to lack of production capacity. In the future this may be resolved as a central Subcoal® producing facility can gain input of several paper producers their reject streams.

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A new installation is currently being built in Delfzijl, The Netherlands, which will use the reject streams of multiple paper mills. Estimated production is around 45.000 ton of Subcoal® from 80.000 ton coarse rejects per year. End-users of the Subcoal® will be lime- and cement factories in, among others, United Kingdom, Scandinavia and Germany. Projects for new Subcoal® installations in other European countries are also in progress. Finance: Qlyte offers two business cases. Either they supply the technology and installation as a total package (including marketing of the Subcoal® fuels) in which the paper mill becomes the owner of the installation and therefore gains profits from selling the pellets, resulting in a reduction of costs compared to the landfill or incineration of their coarse rejects. In the second option, Qlyte becomes the owner of the installation in which case Qlyte operates the plants and commercializes the Subcoal® fuels. Qlyte works with Siemens Paper and Pulp Technologies to deliver the process technology on a turn key basis. If the paper mill chooses to own the installation, they will pay a license fee to Qlyte. If Qlyte owns the installation paper mills typically pay a fee to Qlyte per ton for processing of the coarse rejects. This fee will be lower than the fee for incineration or land filling. Financial advantages are the avoidance of disposal costs and the sales income of the Subcoal® fuel. Benefits from avoiding disposal costs depend on the type of disposal and are also country specific (e.g. difference in land filling fees). Benefits from sales income depend upon regional prices for Subcoal® fuels. The total investment for the Rofire® plant is around €6.580.000 (ManageEenergy, SenterNovem, 2000). The payback period is about 4 years when including the reduction in waste disposal costs (ManageEnergy, SenterNovem, 2000). Environment: Conversion of coarse rejects using the Subcoal® technology produces netto 12.8 GJ per ton coarse reject (wet)40. Experience of legislation: At the moment Subcoal® still falls under the waste directive. Because of this the necessary permits41 and protocols are required for moving of the Subcoal® to its end users. Should the status eventually change from waste to product status, such administrative procedures will no longer be necessary. However, this will mean that Subcoal® production will likely fall under REACH regulation. This in turn will also result in administrative work as well as obligation to proofing safety of Subcoal® according to REACH regulation. It is unknown how this status will change in the near future. Future developments in legislation concerning reduction of landfilling and waste incineration are expected to further increase in Europe and therefore further strengthening the commercial attractiveness of Subcoal® production. 40 Environmentally, research has shown that creating subcoal® saves more energy than direct incineration (CE 2000 Schoen, et al, 2000.). 41 According to Qlyte obtaining of the environmental permit for their plant in The Netherland took around 8 months, which is a normal period of time for such permit trajects. This is mainly because as they do not incinerate the waste themselves they do not have to obey the more stringent waste incineration legislations.

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Contact: Qlyte Mohammed Nafid Haaksbergweg 7 1101 BP Amsterdam Tel: +31 (0) 20 2629490 Mobile: +31 (0) 6 15367771 Email: m.nafid@qlyte.com Website : www.qlyte.com

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Annex II: New Fact Sheets (to be added progressively as submitted to CEPI). In case you would like to submit a new Fact Sheet, please use the template below, filling all appropriate fields, and send it to Sophy Ashmead (s.ashmead@cepi.org) at CEPI. In this annex the fact sheets of each technology is provided. An explanation of the content of the fact sheets is provided below. Fields marked with * are obligatory. *Title: Name of the technology (current application status) *Reject type: Type of solid by-streams to which the technology applies *Background: General description of the purpose of the technology *Process: Description of the processes of the technology Finance: Description of the benefits and costs of the technology Environment: Description of impact of the technology on the environment (with focus on saved energy) Experience of legislation: Users/Suppliers views on needed permits and other regulatory matters concerning the technology (may be changed with the implementation of new Waste Directive) *Contact: Contact information of parties that utilize/develop/commercialize the technology (OBLIGATORY)