Pretreatment Options for Refining Lignocelluloses

Juergen Puls vTI-Institute for Wood Technology and Wood Biology Hamburg

IEA Task 42 Workshop on Biorefineries Outline 1. Raw material basis 2. Lignocellulose composition 3. Pulping processes for biorefineries? 4. Pretreatment processes with options for component separation 5. Lignocellulose biorefinery based on organosolv pretreatment 6. as the high-value product of the lignocellulose biorefinery 7. Conclusion

J. Puls: IEA Task 42 Workshop on Biorefineries Storage of Wood in Forest (billion m³) 3.0

2.5 Germany 2.0 Annual increment: 60 mill. m³ Annual harvest: 42 mill. m³ 1.5

1.0

0.5

0 s d nd a France Finlan Belaru Norway Germany Sweden Switzerl

J. Puls: IEA Task 42 Workshop on Biorefineries Characteristic differences between softwood, hardwood, and residues of annual plants

Softwood Hardwood Annual plants

1.) Galactoglucomannan (15-20%) Acetyl-4-0-MeGluA-Xylan (20-30%) Feruloyl- & p-Coumaroyl (Hexosane) (Pentosane) substituted Arabino-4-0- • Partly high acetyl content MeGluA-Xylan (18-35%) (Beech: 6% ) (Pentosane)

2.) Ara-4-0-MeGluA-Xylan (8-12%) (Pentosane)

• Partly high proportion of extractives • Partly high ash content • Small acetyl content Strongly cross-linked lignin (28-30%) Less cross-linked lignin (18-22%) Least cross-linked lignin (10-22%)

J. Puls: IEA Task 42 Workshop on Biorefineries Mills and Pulp Production in Germany

Capacity Mill Process Raw material Integration (t / year) Alfeld (SAPPI) Mg-Sulphite Spruce 75.000 yes Beech 40.000 Ehingen (SAPPI) Mg-Sulphite Buche 100.000 yes Spruce 30.000 Mannheim (SCA) Mg-Sulphite Spruce 180.000 yes Beech 40.000 Stockstadt (SAPPI) Mg-Sulphite Beech 140.000 yes

Blankenstein (Mercer) Kraft Spruce/ 300.000 no Pine Stendal (Mercer) Kraft Pine/ 550.000 no Spruce/ total capacity (t / year) 1,455.000

J. Puls: IEA Task 42 Workshop on Biorefineries Chemical Pulping: Major reaction during sulphite pulping

Lignin is affected by Polysaccharides are effected by hydrolysis sulfonation

Hemicelluloses are less stable under acid conditions compared to

J. Puls: IEA Task 42 Workshop on Biorefineries Chemical pulping: Kraft cooking

Wood Digestion Pulp

NaSH Calcination NaOH HS-Lignin RCOOH Na S NaO-Lignin Ca(OH) 2 2 CaO Recausticizing Evaporation Na-, S losses

CaCO 3 Na 2S Lime kiln Na CO 2 3 Energy

CaCO 3 make-up

Recovery boiler

Na 2SO 4 make-up

J. Puls: IEA Task 42 Workshop on Biorefineries Sugars from lignocelluloses by enzymatic hydrolysis after phys./chem. pretreatment

Lactose/Glucose Enzyme production

Lignocellulose

Pretreatment Hydrolysis

Ball milling, differential Lignin speed mill,

Steaming, NaOH, NH 3 , Acids, Organic solvents, Fermentation Destillation Wastetreatment Ionic liquids

Ethanol

J. Puls: IEA Task 42 Workshop on Biorefineries Autohydrolysis concepts applying steam or water

Iotech-Verfahren (1980): Steam 220- 240°C, 30 sec, explosion like expansion Steaming Extraction (1979): Steam 170-200°C, 5-10 min. Semi continuous feeder Stake Process (1978): Steam ca. 200°C. Patented feeder similar to an extruder Hydrothermolysis (1976): Autohydrolysis in liquid phase: Stake II Feeder Hemicelluloses at about 200°C, Cellulose at 260°C. Hydrothermolysis according to Bobletter

J. Puls: IEA Task 42 Workshop on Biorefineries Steaming Extraction

Wood chips Straw, Spelts  Effective pretreatment for Steam pretreatment enzymatic hydrolysis  Incomplete component separation Fibres

Water wash Hemis

Cellolignin

NaOH-Extraction Lignin

Cellulose J. Puls: IEA Task 42 Workshop on Biorefineries Steaming pretreatment followed by H2O-Extraction

Steaming (~200°C, 10 min.) A B Hemicellulose Fragments after Steaming for 10 min. provides autohydrolysis conditions; sudden pressure release opens densily packed cell wall in its structure A 170 °C Steaming effects pH drop by cleavage of acetyl, fragmentation of 190 °C polysaccharides by autohydrolysis B, 210 °C melting and coagulation of lignin into droplets C (Gel filtration on TSK HW40 + HW50) This process in addition to hemicellulose removal increases the inner surface area, improving the C D accessibility for hydrolytic enzymes. Only lignin-rich middle lamella material is left after treatment with cellulases D

J. Puls: IEA Task 42 Workshop on Biorefineries Steaming of straw: Fibre & liquid phase after steaming

• Fibre is rich in C6 sugars and lignin • Lignin is obtained as • Aqueous phase mainly residue after hydrolysis contains C5 sugars

J. Puls: IEA Task 42 Workshop on Biorefineries Innovative use of municipal liquid and solid waste

Gelbwasser Altholz; Grauwasser Regenwasser Küchenabfälle Grüngut & Braunwasser Grüngut mit Lignocellulosen Schadstoffen Vakuum- Vakuum- technologie technologie

N-Nitrifikation, Pflanzen- Enzyme Zerkleinerung Konzentration Kläranlage H2- & CH 4- (Trocknung) Mech. treatment Steaming &

P-Fällung Gärung & CH 4-Gärung -Ferm

N-Strippung, Konzentration Verbrennung Pelletising Komposting Organischer Verschiedene Aschedünger Humusprodukte Brauchwasser Feststoffdünger N- & P-Dünger Baustoff Humusdünger Flüssigdünger Thermische H2 Futtermittel Energie CH 4 CH 4 C2H5OH Heat Electricity Fuel J. Puls: IEA Task 42 Workshop on Biorefineries Unusual component separation by MEA pretreatment

Wood Chips

Monoethanolamine-Water pulping

Lignin selectively dissolved

Filtration Cellulose + Hemis

Lignin + MEA

MEA-Recovery

Lignin

J. Puls: IEA Task 42 Workshop on Biorefineries Special case MEA-pretreatment

 Monoethanolamine selectively dissolves lignin from cell wall material  No carbohydrate degradation even under harsh conditions

Monosaccharide composition of beech (left) and pulp (right) after MEA-pretreatment

J. Puls: IEA Task 42 Workshop on Biorefineries Possible biorefinery approach for component separation of lignocelluloses: Application of ionic liquids tio Beech wood solubility

Beech bark solubitity Liquor:Wood Ratio

• Ethylmethylimidazolium ethylphosphonate was the best IL solubilizing bark from beech • Ethylmethylimidazolium tricyanamide besides the corresponding chloride was most efficient in solubilizing beechwood. • Results obtained for ethylmethylimidazolium acetate are given for reasons of comparison (Collaboration with Solvent Innovation, now a Merck company) Caramelisation applying BMIMCl with decreasing IL:Wood Ra

J. Puls: IEA Task 42 Workshop on Biorefineries Organosolv-pretreatment Organosolv pulping processes have been developed to avoid disadvantages of existing processes, specially with regard to the need of extremely large production units due to complicated chemical recovery systems

• Phenol-pulping (Batelle Geneva) • Alcohol-water-pulping (Alcell, Organocell-, Lignocell-Bioraff) • Acetic acid/ pulping (Acetosolv, Formacell, Milox) • Monoethanolamine-pulping (MEA)

The Alcell-process in Newcastle/Canada was in operation for about 10 years from 1991, based on aspen wood (capacity 1500 t lignin per year) The Organocell-process in Kelheim/Germany started operation in 1992, based on spruce (capacity 430 t pulp per day) The other processes have never reached the industrial scale.

J. Puls: IEA Task 42 Workshop on Biorefineries Wood Chips Alcohol-Water-Pulping

Alcohol-Water-Pulping

Fibers (cellulose), Lignin + Hemis dissolved

Cellulose Filtration  Delignification ability is increased with chain Lignin + Hemis dissolved lengths of alcohols  Nearly complete component separation possible Alcohol recovery for hardwoods (beech, poplar) Lignin precipitates Unsufficient delignification for softwoods Hemis remain dissolved (spruce, pine)

Filtration Lignin

Hemis in water J. Puls, M. Sinner, H.H. Dietrichs in: Mitteil. BFH Bd.130 (1980) p.119, Kommissionsverlag Max Wiedebusch Hamburg

J. Puls: IEA Task 42 Workshop on Biorefineries Alcohol-Water Pulping of Beechwood

Alcohol Boiling Yield Xylose Glucose Lignin point °C % in fibres, based on starting material

Starting 100 22.7 42.6 22.1 material

Methanol 64.7 59.7 11.5 36.3 8.8

Ethanol 78.3 54.0 9.4 36.6 7.6

1-Propanol 97.4 52.6 8.4 36.6 7.6

1-Butanol 117.5 51.6 5.9 36.3 6.4

1-Pentanol 138.0 50.0 4.5 37.3 6.9

Alcohol : water = 1:1; 60 min; 180°C

J. Puls: IEA Task 42 Workshop on Biorefineries vTI-HTB organosolv pretreatment devices 4 x 10L and 1x 30 L digesters

4 reaction rooms: each 10 L

4x 10LPulping digester 1x 30LPulping digester

J. Puls: IEA Task 42 Workshop on Biorefineries Hardwood biorefinery Process steps and products

Wood & bark

Extraction with alcohol

Ethanol-water pulping

Component separation

Hemi- Extracts Cellulose

Enzymatic Enzymatic Enzymatic modification hydrolysis hydrolysis

Extrac- Xylose Glucose Lignin tives AcOH

Pharmcological Plattform chemicals Materials products etc. J. Puls: IEA Task 42 Workshop on Biorefineries Pulping & enzymatic hydrolysis Selection of alternative process conditions

170 °C 180 °C 190 °C ( ( % wood) 4 4 SO 2 H

Time (h) Time (h) Time (h)

Variant with H2SO 4: 170 °C; 2 h; 0.94% H 2SO 4

Variant without H2SO 4: 190 °C; 4 h; no H 2SO 4

J. Puls: IEA Task 42 Workshop on Biorefineries Recovered hemicellulose fraction HPAEC-chromatographic analysis

600

e s 500 o Major hemicellulose in beech is l Pulping without H 2SO 4 y

X Pulping with H 2SO 4 acetyl-4-0-methylglucuronoxylan (25%)

400 Acetyl groups are completely cleaved off in the organosolv pulping process 300 Xylan main chain is fragmented into oligo- Xylooligomers saccharides in the absence of catalyst 200

e Detector signal [mA] signal Detector s e Sulphuric acid addition converts xylan into o t e s c s o o a l c xylose and traces of xylobiose n a u e i l s 100 b G G o a r n

A n a

M 0 0 5 10 15 20 25 30 Time [min]

J. Puls: IEA Task 42 Workshop on Biorefineries OH-Groups per C 900 - Units Comparison of different

Starting OH OH material phen alip h

Lignocell. Biorefinery (+ Beech 84 65 Kat.) Acetosolv Poplar 61 63 Formacell Aspen 81 36

Alcell Mixed hardwood 71 50

Milox Birch 63 23 Steaming Poplar 55 61

Kraft Mixed softwood 55 62

B. Saake 2009 & ILI Round Robin 2007

J. Puls: IEA Task 42 Workshop on Biorefineries Possible use of organosolv lignins Comparative hydropyrolysis of poplar wood and poplar lignin

[PAPPEL] TIC #1

5 .0 e 5

4 .0 e 5 Production of mixed phenols

3 .0 e 5 Poplar wood chips

2 .0 e 5

1 .0 e 5

[OP18620] TIC #1

1 0 .0 0 2 0 .0 0 3 0 .0 0 4 0 .0 0 5 0 .0 0 6 0 .0 0 7 0 .0 0 8 0 .0 0

6 .0 e 5

4 .0 e 5 Alcell lignin from poplar

2 .0 e 5

1 0 .0 0 2 0 .0 0 3 0 .0 0 4 0 .0 0 5 0 .0 0 6 0 .0 0 7 0 .0 0 8 0 .0 0 J. Puls: IEA Task 42 Workshop on Biorefineries D. Meier 2009 Possible use of organosolv lignins Substitution of polyacrylnitrile (PAN) for carbon fibre production • At present carbon fibres are produced by pyrolysis of polyacrylnitrile (PAN) • PAN itself and the whole process are too expensive for common applications • Use of lignin could reduce production costs • Impurities (polysaccharides, salts, org. acids may initiate bubble formation during electro spinning • Simple procedures for lignin purification must be developed

J. Holladay/Pacific Northwest National Laboratory, 2006

J. Puls: IEA Task 42 Workshop on Biorefineries Conclusion & Perspectives:

• To our best knowledge organosolv pulping is one of the promising options for component separation including a material use for lignin • High saccharification rates of beechwood polysaccharides can be obtained by high pulping temperatures or by addition of acids at lower temperatures • Co-pulping of wood and bark has been systematically investigated. Presence of bark has no negative effect on sacharification rate and lignin utilization • Balancing and characterisation of all components (lignin, furans, acetic acid etc.) has been performed • Plans for upscaling the process are underway J. Puls: IEA Task 42 Workshop on Biorefineries