Fast pyrolysis of lignin. Elma Gyftopoulou Bio-Energy Research Group PyNe Meeting, Vicenza, 12 October 2007

Transcription

1 Fast pyrolysis of lignin Elma Gyftopoulou Bio-Energy Research Group PyNe Meeting, Vicenza, 12 ctober

2 Lignin Lignin is usually considered as a polyphenolic material having an amorphous structure, which arises from an enzymeinitiated dehydrogenative polymerisation of coniferyl (a), sinapyl (b) and trans-p-coumaryl (c) alcohols. Me Me Me a b c

3 Biomass components & structure Structure of plant cell wall Middle Lamella Pectin Primary Cell Wall Cellulose microfibrils Cross-linking hemicellulose Plasma membrane

4 Lignin 1 Asian lignin (India) Sulfur-free lignin obtained from annually renewed nonwoody plants (wheat straw and sarkanda grass (Saccharum munja)) Co-product in the manufacture of pulp for printing and writing papers Pulping method is the soda pulping process (aqueous Na), lignin is recovered by precipitation followed by purification, washing and drying

5 Lignin 2 ETEK (Sweden) Residue from ethanol production by weak acid and possibly enzymatic hydrolysis. It is similar to commercial hydrolytic lignin from speciality chemical suppliers in that some sugar components are degraded Commercial hydrolytic lignin is made by strong acid hydrolysis to produce fermentable sugars from wood Due to the harsh conditions the lignin is structurally altered and contains sugar degradation derived compounds, extractives and inorganic compounds

6 Asian lignin properties Solids Content 95+% Composition (dry basis) >94% Lignin, 4% Protein, <2% Hemicelluloses Sugar, <4% Ash, <0.2% Cellulose Elemental Analysis 61% C., 31%, 7% H, 0.9% N, <0.03% S ph (10% slurry) Functional groups 8-10% Carboxyl, 2-3% Aromatic, 3-4% Aliphatic Particle size Approx microns Molecular weight M N 1000 daltons, M W daltons Appearance Low odour, brown powder Thermal Behavior Softening temperature ~ C Bulk density 450 kg/m3 Solubility Very low solubility in water, high solubility in aqueous alkali, CMF, 2-methoxyethanol, Furfuryl alcohol, 90% acetone/10% water

7 Elemental and ash analysis % C H N S Ash Asian ETEK

8 100 % Py-GCMS of Asian lignin H Main pyrolysis products: 2-methoxy-4-vinyl phenol 2-methoxy-4-methyl phenol 2-methoxy phenol 2,6-dimethoxy phenol 1,2,3-trimethoxybenzene 1,2,3-trimethoxy-5- methylbenzene 2,6-dimethoxy-4-(2-propenyl)- phenol 2,5-dimethyl furan Time, min.

9 Py-GCMS of ETEK lignin 100 Main degradation products: H 2-methoxy-4-methyl phenol 2-methoxy phenol 2-methoxy-4-vinylphenol 4-hydroxy-2-methoxybenzaldehyde % furfural, cyclopentane/hexane derivatives levoglucosan H anhydrosugars (traces) H Time, min.

10 100 TGA comparison 80 Weight loss (%) ETEK ASIAN Temperature ( o C)

11 10 DTG comparison 8 -dm/dt 6 4 ETEK ASIAN Temperature ( o C)

12 100 g/h test rig

13 Feeding problems Continuous feeding unsuitable Batch feeding solutions 1st solution 2nd solution

14 Trials with Asian lignin Run 205, 2 valves feeding system Reactor T: 533 o C g lignin fed 90 min run No increase in the pressure drop in the reactor No char collected in the cyclone, all in the reactor Bed agglomerated Unpyrolysed lignin in the ESP Heavy tar in the condenser ESP top view lignin deposition ESP wire with lignin deposited

15 Trials with Asian lignin Run 212, valve and rod feeding system Reactor T: 534 o C 9.42 g lignin fed As soon as the first grams of lignin were fed, the pressure drop in the reactor increased to 115 in H 2 After 30 min no fluidisation gas was going through the bed at all The bed solidified completely

16 Asian lignin pre-treatment Asian lignin Mixing Heating up Suspension Dough like Ethanol 80 o C Drying Particles Before (<100 microns) After (355 to 1000 microns) Paul de Wild PyNe News (22) June 2007

17 Run 229 Trial with Asian lignin particles Reactor T:530 o C 70 min run 100 g lignin fed After 70 min there was a sudden increase in the pressure drop in the reactor indicating solidification of the bed Solid bed Char removed from the bed

18 Run 229 (Asian) Condenser with heavy tar deposits il pot 1 il pot 2

19 Run 229 (Asian) ESP body ESP wire ESP internals bottom

20 Run 229 (Asian) Mass balance (dry feed basis) g % Total pyrolysis liquids rganics Reaction water Char Gas CLSURE 85.7

21 Normalised gas composition Gas composition (vol.%) Methane Carbon dioxide Ethene Ethane Hydrogen Propene Carbon monoxide Propane N-Butane

22 Trial with ETEK lignin run 213 Run 213, valve and rod feeding system Reactor T: 504 o C, 75 min run 44g lignin fed Bio-oil collected in oil pot 1 No high pressure drop and no restriction to the fluidising gas flow Agglomerated bed, probably like honey-comb Char il pot 1 ETEK lignin

23 Run ETEK lignin Mass balance (dry feed basis) g % Total pyrolysis liquids rganics Reaction water Char Gas CLSURE 95.1

24 Normalised gas composition (vol. %) Gas composition (vol. %) Methane Carbon Dioxide Ethene Ethane Hydrogen Propene Carbon monoxide Propane N-Butane

25 Summary Asian lignin Asian lignin bubbles as soon as it is fed in the reactor and forms highly porous char that causes bed agglomeration No char is collected by the cyclone Heavy tar is collected in the condenser, only partially dissolves in acetone Because of the very small particle size (<100 microns) part of the lignin fed escapes from the reactor without decomposition and ends up in the ESP ETEK lignin ETEK lignin behaves like high lignin wood No char is collected by the cyclone Bed agglomeration also occurs, but it is less severe

26 Acknowledgements Michael Probert, MEng student Daniel Nowakowski Guozhan Jiang

27 Thank you for your attention!