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Conversion of cellulose,
hemicellulose and lignin into platform
molecules: biotechnological
approach
Anders Frölander Gudbrand Rødsrud
Borregaard Industries Ltd,
Norway
EuroBioRef
Summer school
Lecce, Italy
18-24 September 2011
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Critical sources to replace fossile sources and
reduce CO2 footprint
Agricultural products
Lignocellulose
Algae
Metals & minerals
Green electricity • Hydropower • Solar Power • Wind power
Nuclear power
Gas and petroleum
Coal
Food
Feed
Plastics (Materials)
Chemicals
Building materials
Transport
Mechanical power
Heat
Organic waste
Geo-thermal
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Sulfite ethanol production all started in Sweden
• Experimentation with
fermentation of spent sulfite
liquor (SSL) started around 1903
• They soon found out they had to
neutralize with lime
Skutskär sulfite ethanol plant in Sweden started operation 1909
The worlds first sulfite ethanol plant The inventors of sulfite ethanol production
Gösta Ekström Hugo Wallin
Source: Persson, Bertil. Sulfitsprit. Förhoppningar och besvikelser under 100 år. Bjästa : DAUS Tryck & Media, 2007. ISBN: 91 7542 258-1.
Monosaccharide % of DM in SSL from Eucalyptus
% of DM in SSL from Spruce
Arabinose (C5) 0,3 0,8
Xylose (C5) 21,9 5,3
Galactose (C6) 1,6 2,1
Rhamnose (C6) 0,6 0,2
Glucose (C6) 1,6 3,7
Mannose (C6) 1,0 14,6
1
Sugar composition of spent sulfite liquor (SSL) from sulfite pulping
Spruce SSL
• 20,6% of DM is C6 sugars
• 77% of sugars are C6 sugars
Eucalyptus SSL
• 22,1% of DM is C5 sugars
• 82% of sugars are C5 sugars
Sulfite cooking
Filtration
Fibre SSL
33 sulfite ethanol plants in Sweden from 1909 until today
• First sulfite ethanol plant ever
opened 1909 in Skutskär, Sweden
• 33 plants have been in operation
in Sweden
• Only one in operation after 1983:
Domsjö, capacity of 15 000 m3/y
Source: Persson, Bertil. Sulfitsprit. Förhoppningar och besvikelser under 100 år. Bjästa : DAUS Tryck & Media, 2007. ISBN: 91 7542 258-1.
17 sulfite ethanol plants in Finland 1927 - 1977
Source: 1. Biorefining in the pulp and paper industry. Niemelä, Klaus. Flensburg : s.n., 2008. 5th European Biorefinery Symposium. 2. Kaukoranta, Antti. Sulfittispiriteollisuus Suomessa vuosina 1918-1978 (Eng:"Sulphite alcohol industry in Finland in 1918-1978"). s.l. : Paino Polar Oy, 1981. ISBN 951-9479-25-2. 3. Niemelä, Klaus. Private communication. s.l. : VTT TECHNICAL RESEARCH CENTRE OF FINLAND , 2010.
• Sulfite ethanol production was stopped in 1977 • The last sulfite mill in Finland stopped production in the early 1990’ies
Sulfite ethanol plants in Central Europe
• Attizholts (later Borregaard) in Switzerland
– Production from 1912 to 2008
– Capacity 13 mill litres
– Also produced yeast and yeast extracts
• M-Real in Hallein in Austria
– Sulfite ethanol production 1941 – 1988
– Capacity 6 mill litres
– Evaluating to restart production in 2016
• Kirov only plant still in operation in Russia
Source: 1) Borregaard internal files 2) Conference Austria April 2011 3) IEA Report: Status of 2nd Generation Biofuels Demonstration Facilities in June 2010, A REPORT TO IEA BIOENERGY TASK 39
Sulfite ethanol plants in USA
• Georgia Pacific
– Bellingham mill produced ethanol from 1976 –
2001
– Capacity 24 million liters
Source: 1) Katzen customer reference list (http://www.katzen.com/projects.html) 2) Borregaard internal files 3) Graf and Koehler, June 2000, OREGON CELLULOSE-ETHANOL STUDY, An evaluation of the potential for ethanol production in Oregon using cellulose-based feedstocks.
Hydrolysis of wood for ethanol, SCP and furfural
• Initially developed in Germany around
1900. Yields up to 190 L/mt dry wood
• Used in the USA during World War I and II
– Converted further to butadien for
rubber during WW II
• USSR 1935 – 1985: Construction of
– 18 Ethanol plants,
– 16 SCP yeast plants
– 15 furfural/xylitol plants
– Feedstock hardwood:softwood 6:4
• Technology: weak sulfuric acid (130 –
150°C), 1 or 2 step hydrolysis
• None are profitable without subsidies
Sources: Wood hydrolysis industry in the Soviet Union and Russia: What can be learned from the history? Rabinovich, M.L. Helsinki, September 2009. The 2nd Nordic Wood Biorefinery Conference (NWBC-2009), 111-120. Wikipedia contributors. Cellulosic ethanol. Wikipedia, The Free Encyclopedia. March 2, 2011, 16:08 UTC. Available at: http://en.wikipedia.org/w/index.php?title=Cellulosic_ethanol&oldid=416750931. Accessed March 8, 2011.
USSR wood hydrolysis plants 1935 -
Production of ethanol, SCP and furfural
Borregaard –
world’s largest producer of 2nd gen bioethanol
BRG capacity 20 mill litres of bioethanol pr year
1/3 as 99,5% and
2/3 as 96%
From hemicellulose from spruce in SSL (spent sulfite liquor)
Production started 1938
Yeast strain: Baker’s yeast,
Saccharomyces cerevisiae
Adapted to industrial SSL continuously since 1938
Source: 1. Brekke, A., Modahl, I.S. and Raadal, H.L. Konkurrentanalyser for cellulose, etanol, lignin og vanillin fra Borregaard (Eng: Competitive CO2 footprint analysis for cellulose, ethanol, lignin and vanillin from Borregaard). Fredrikstad : Ostforld Research, Des. 2008. Confidential report. Will be published. 2. Sutter, J. Life cycle inventories of petrochemical solvents. [red.] H.-J., Chudacoff, M., Hischier, R. Jungbluth, N., Osses, M. and Primas, A. Althaus. Life cycle inventories of chemicals. Final report ecoinvnet data v2.0. Duebendorf and St. Gallen : Swiss Centre for LCI, Empa - TSL, 2007, Vol. 8 / 22. 3. Jungbluth, N., Chudacoff, M., Dauriat, A., Dinkel, F., Doka, G., Faist Emmenegger, M., Gnansounou, E., Kljun, N., Speilmann, M., Stettler, C. and Sutter, J. Life cycle inventories of bioenergy. Final report ecoinvnet v2.0. Volume 17. . Duebendorf and Uster : Swiss Centre for LCI, ESU, 2007.
Comparison of CO2 footprint of ethanol produced in different ways
Sulfite ethanol production 2011
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Borregaard –
world’s most advanced biorefinery in operation
• Leading supplier of specialty cellulose
• Global leader in lignin performance chemicals, 50%+ market share
• Only producer of vanillin from lignocellulosics
• Production of lignocellulosic bioethanol since 1938
• World’s most advanced biorefinery in operation
Borregaard product tree
Prodction cont
Production stopped
Product tree from 2G bioethanol 1950 - 1980
n
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Composition of lignocellulosics
LIGNIN Binder 20- 30%
HEMICELLULOSE Various sugars 25-30%
CELLULOSE Fiber 35 - 45%
LIGNOCELLULOSICS contain: Lignin Cellulose Hemicellulose
Lignocellulosic biomass structure
Cellulose fibres for chemicals Width: μm Length: mm
Micro fibrillar cellulose Width: nm Length: μm - mm
Glucose monomers A few Ångstrøm
Planks M and cm
Logs Meters, m
Polymer chains
10 – 100 Å
Plant cells Width: μm - mm Length: mm
Cellulose
Cellulose
– Long chains of ONE type of ”beads” (polymer of glucose)
– Forming crystals - crystalline
– Same chemical structure in every plant
LIGNIN Binder 30%
HEMICELLULOSE Various sugars 25%
CELLULOSE Fiber 40%
Hemicellulose
Hemicellulose
– Long branched sugar chains
(polymer, polysaccharide)
– Amorphous
– Composition varies largely
from species to species
– C6 and/or C5 sugars
LIGNIN Binder 30%
HEMICELLULOSE Various sugars 25%
CELLULOSE Fiber 45%
Lignin
O
H3CO
O
O
OCH 3
O
H3CO
OH
H3CO
OH
HO
OH
HO
HO
HO
O
OCH 3
OH
O
H3CO
OH
HOO
H3CO
OH
OHH3CO
HO
O
OCH 3
O
O
OH
OCH 3
O
CH3O
OH
HOO
Carb.
O
HO
O
OH
OCH 3
HO O
OCH 3
OH
OH
OH
H3CO
HO
O
H3CO
HO
OCarb.
OH O
(Adler, 1977)
Lignin
– Branched long-chain molecule (polymer) made up of 3 types of monomers
– Amorphous (non-crystalline)
– Composition varies from species to species
– Is the binder in all plants gluing the cellulose fibres together
LIGNIN Binder 30%
HEMICELLULOSE Various sugars 25%
CELLULOSE Fiber 45%
Composition of some lignocellulosic feedstocks
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerob and aerob fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration
Biomass to products conversion options
Pre-
treatment
Separation
(Partly degraded)
Natural polymers
Chemical and/or
mechanical
processing
Liquefaction/
hydrolysis
- Enzymatic
- Weak acid
- Strong acid
Sugar
in solution
Fermentation
CCS
Chemical
conversion
Pyrolysis Extraction,
BCD Chemical &
Solvolysis Catalytic conversion
Purification
Gasification Catalytic synthesis
Refining, (CCS?)
Synthesis gas,
CO + H2
Marketable
products
- Biocehmicals
- Biomaterials
- Proteins
- Biofuels
- Energy
”Bio-monomers”
Combustion CO2, CCS
Heat, energy
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Sugar plattform path ways
Hydrolysis processes
• Dissolving celluose and hemicellulose leaving hydrolysis lignins undissolved
– Strong acid
– Weak acid
– Enzymatic
– Microbial
Pulping processes
• Dissolving lignin (and hemicellulose) leaving cellulose undissolved
– Kraft
– Soda
– Sulfite
– Solvent
– Extrusion
Lignin quality depends strongly on process and biomass source
Hemicellulose/xylan form and quality depends on process and biomass
Hydrolysis Lignin (S)
Hemi- Cellulose (L)
Cellulose (L)
Lignin (L)
Hemi- Cellulose (L)
Cellulose (S)
SOLID
SOLID
LIQUID
LIQUID
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Pretreatment processes
• Hydrolysis processes
– Strong acid pretreatment (low temp, large consumption of acids, need regeneration of acids, low yields): Weyland, TNO, BlueFire
– Weak acid pretreatment (high temp and pressure, creates large amounts of inhibitiors): SEKAB, Iogen
– Steam explosion (followed by enzymatic hydrolysis, also combined with acids or SO2): Abengoa, Inbicon, BioGasol, University of Lund, Andritz
• Microbial (microbes doing the whole job of hydrolysis and fermentation)
– Mascoma, Arbor Fuel etc.
– Solid state fermentation
• Pulping processes
– Kraft: evaluated by Innventia, most common commercial chemical pulping process
– Soda: evaluated by Innventia, old pulping process
– Sulfite: Borregaard, Wisconsin Uni. (SPORL), modified sulfite pulping processes
– Solvent/Organosolv : Lignol, CIM-V
– Extrusion: PureVision (autohydrolysis)
Formation of fermentation inhibitors
High temp, water, acidic conditions
Xylose
Glucose
Hemicellulose
Furfural
HMF – Hydroxymethyl furfural
Acetic acid
Steam explosion pretreatment
• http://www.youtube.com/watch?v=jpMAiyWoEFo
BALI™ – the holistic pretreatment process
• The pretreatment and separation process used in EuroBioRef for lignocellulosics Supplying sugars in solution
• A pretreatment process that enables production of valuable products out of all three main lignocellulosic components
– Cellulose
– Hemicellulose
– Lignin
• A pretreatment process that facilitates low cost hydrolysis of cellulose
– Low enzyme consumption (lignin inhibition avoided)
– Resirculation of enzymes (no adsorption to lignin)
Ligno-cellulose
BALI Pretreatment and
separation
Ethanol Chemicals C6
Lignin
Ethanol? Chemicals
Yeast
Performance chemicals
C5
BALI™ in a nutshell
BALI™ in a nutshell
pulp cellulases
hydrolysis fermentation
BALI™
Step 1: pretreatment & separation
Water soluble lignin
Pretreated and ”reactive” pulp
Bagasse or other biomass
Mass Balance of BALI™ pretreatment process
Flexibility from two optional processes
Bagasse
Lignin Hemicellulose Cellulose
BALI Acidic
BALI Alkaline
Lignin (L)
Hemi- Cellulose (S)
Cellulose (S) LIQUID
SOLID PULP
LIQUID
Lignin (L)
Hemi- Cellulose (L)
Cellulose (S)
SOLID PULP
BALI pilot plant
• Location: Borregaard Sarpsborg, Norway
• Flexible feedstock
• 1 metric ton dry matter/day
• Start-up Q2 2012
• Budget: 130 MNOK
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
BALI™
Step 2: Enzymatic hydrolysis to sugars in solution
Pretreated and ”reactive” pulp is hydrolyzed using cellulase enzymes
Hydrolysate = monosaccharides in solution
Cellulose hydrolysis
xylanases, mannanases, hemicellulases
Endoglucanase
b- glycosidase
Cellobiohydrolase
Enzymatic hydrolysis of BALI™ cellulose
Yield and Viscosity
4 → 6 h
Enzyme hydrolysis of BALI pulp –
better substrate than soda pulp
Enzymes not inhibited by residual lignins
Soda cooks 140-160 °C
120-180 min
BALI cooks
Enzymatic hydrolysis - carbohydrate conversion - dose response Accellerase DUET at 7% cellulose, 50°C, pH 5.0, 72h
0,00%
20,00%
40,00%
60,00%
80,00%
100,00%
120,00%
- 0,10 0,20 0,30 0,40 0,50 0,60
% t
ota
l car
bo
hyd
rate
co
nve
rsio
n
ml Accelerase DUET / g glucan
Reference (hardwood pulp)
BALI bagasse A
BALI bagasse B
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Fermentation
Established technology from 1G bioethanol
• Saccharomyces cereviciae
(Baker’s yeast)
– Only fermenting hexoses, not
pentoses
– Anaerobic fermentation for
production of ethanol
– Aerobic fermentation for
production of yeast cells
– GMOs for C5 fermentation
C6H12O6 —> 2 CH3CH2OH + 2 CO2
glucose ethanol carbon dioxide
Mw (w%) 46 (51%) 44 (49%)
Aerob fermentation
Reproduction and production of yeast/bacteria/chemicals
Example of simple aerob fermentation to yeast from pentoses with added nutrients:
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Technical challenges for 2nd generation bioethanol
• Low % of feedstock useful for ethanol production – Only approx. 40%- 45% of biomass can be converted to product
• Low yield in several process steps – Theoretically maximum 51% yield of ethanol from C6 sugars
– No industrial solution for fermenting C5 sugars to ethanol
– Several process steps with 80%-95% yield create loss and sidestreams
– Lignocellulosic biomass is recalcitrant to degradation – tough demands on pre-treatment and liquefaction/hydrolysis steps
– Sidestreams impure – challenge to convert into valuable products
Properties of hydrolysis lignins
IAR Reims G Rødsrud 8.9.2010 Borregaard
• Low Mw – high polydispersity
• Strongly condensed (high temp)
• Very few ß-O-4 bonds left – mainly C-C bonds
• Few –OH groups left
• Generally low O content relative to other lignins
• Water insoluble
• Low reactivity - hard to modify chemically at a reasonable cost
• Impurity level will be high
– hard to separate
– impure products
– many side streams
• NOT A GOOD STARTING POINT FOR CHEMICALS
BALI lignin is water soluble
BALI lignin is sulfonated and therefore highly water soluble at almost every pH Major challenge is to make high quality lignin specialty chemicals Extensive application tests have been conducted Possible uses: dispersing agent, soil conditioner, antioxidant, emulsion stabilizer, crystal modifier for batteries, dust control, binding agent, etc.
Lignosulfonate structure
At least one SO3- for every four C9 units needed to be water soluble
Properties of Lignosulfonates
MW 5,000 – 80,000 Da
Polydispersity 6-8
Sulfonate groups 0.6-1.2 per monomer
Organic sulfur 4-8%
Solubility soluble in water at all pH
insoluble in most organic solvents
Color light to dark brown
Delivery powder or
liquid form (40-50% DS)
Non-toxic: LD50 > 5 g/kg
Quality Softwood: good
Hardwood: medium
Annual plants: low
Intrinsic properties of lignosulfonates
In frequent use
• Binder
• Dispersing agent
• Emulsifier
• Complexing metal ions
Under exploration commercially
• Corrosion reduction
• Plant growth stimulation
• Antioxidant
Not in commercial use
• Flame retardant
• Resins (old, not in use any more)
• UV-absorption/UV-protectant
• Protein precipitation (old, not in use any more)
BALI - Examples of possible product mixes
41 46
15 16
5
8 20
24
18
5
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Acidic Neutral
Energy
CO2
Yeast
Ethanol
Lignin
% of incoming biomass + added chemicals
LS decreases viscosity in mortar and concrete
Flow table test
Lignosulfonate
- emulsifier and dispersing agent
stabilize emulsions disperse color pigments disperse pesticides
Future use: disperse carotenoids and fat soluble vitamins
Lignosulfonate in lead acid batteries
crystal growth modifier => better discharge/charge performance
Soil conditioner
Oxidation of lignosulfonate to vanillin
Copper catalyst is recycled due to strict limitations on copper in effluent
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Fermentation of C5 and C6 sugars from the BALI process
C6 sugars to ethanol (anaerobic)
• Absence of fermentation inhibitors
• High yields
C5 sugars to SCP – single cell proteins (aerobic)
• No inhibitors
• No toxic compunds
• Interesting yeast strains identified and tested
C5 sugars to ethanol (anaerobic)
• Hydrolysates under testing with many GMO microbes
Theoretical yield of ethanol from biomasses
How much do we gain from using GMO yeasts?
Outline
1. Introduction
2. History of second generation bioethanol production
3. World’s most advanced biorefinery – history and learning points
4. Lignocellulosic biomass
5. Biorefinery options
6. The biochemical route (sugar plattform)
7. Pretreatment processes
8. Hydrolysis of cellulose
9. Anaerobic and aerobic fermentation
10. Lignin options
11. Hemicellulose/pentose options
12. Process integration & closing remarks
Process flow for the BALI process
Integration into a 1st generation bioethanol plant
Economy of a biorefinery
• Higher turnover
BUT
• Also additional
manufacturing costs
and capital cost
Will it be more profitable ??????
Turnover for ethanol production and biorefineries
ROCE for a biorefinery compared to P&P
Sources: 1.CEPI. [Internett] http://www.cepi-sustainability.eu/uploads/graphs/CEPI_graph_18_3.eps. 2. [Internett] Poyry. http://www.poyry.com/linked/en/publications/FIC.pdf. 3. Orkla annual reports
Environmental Impact
Sources: 1. Directive 2009/28/EC of 23 April 2009 On the promotion of the use of energy from renewable sources and …. 2. Modahl, I.S., 2011, Klimagasspotensialet ved komprimering, transport og lagring av biologisk CO2. Screening LCA. Confidential report by Ostfoldforskning for Borregaard.
BALI
BALI + CCS
Future limit for advanced fuels in EU and US
Funding
• EuroBioRef
– Borregaard granted EUR 3.0 mill
funding (2010 – 2013)
– BALI pretreatment & hydrolysis
• Suprabio
– Borregaard granted EUR 1.1 mill
funding (2010 – 2013)
– Microfibrillar cellulose
• Biomass2Products – B2P
– Borregaard granted 2,3 mill EUR from
the Norwegian Research Council
(2009 – 2012)
• BALI·PILOT
– Borregaard granted EUR 7,25 mill
from Innovation Norway
(2011-2012)
BALI • PILOT
Acknowledgement
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007-2013) under grant agreement n°
241718 EuroBioRef.
Acknowledgement
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007-2013) under grant agreement n°
241640 SupraBio.
Acknowledgement
The research leading to these results has
received funding from the Norwegian Research
Council, the BIA programme, proj. no. 193217
Thank you
