Enzymatic Hydrolysis of Poplar Pretreated by Ammonia Fiber Explosion
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Transcript of Enzymatic Hydrolysis of Poplar Pretreated by Ammonia Fiber Explosion
Enzymatic Hydrolysis of Poplar Pretreated by Ammonia Fiber Explosion
James F. Heidenreich, Tamika Bradshaw, Bruce E. Dale and Venkatesh Balan
BCRL, Department of Chemical Engineering and Materials Science, Michigan State University, E. Lansing, MI – 48824(www.everythingbiomass.org)
Hybrid Poplar advantages
• Relatively high productivity (18-26 dry Mg/(ha·year)
• Fast growing
• Widely available
• Pest-resistant
• Drought-resistant
• High density reduces cost of transportation
Populus nigra x Populus maximowiczii(Hardwood)
Comparing Biomasses
Glucan
Xylan Lignin
Poplar-II(High lignin)
43.8% 14.9% 29.1%
Poplar-I(Low
Lignin)45.1% 17.8% 21.3%
Corn Stover
37.7% 21.6% 18.6%
Switch-grass
33.5% 26.5% 18.1%
AFEX process Conditions:
Soaking/un soaking
Moisture in biomass ~50 to 70%
Temperature range 80-200 oC
BM : Ammonia loading 1: 0.6 -1: 2.0
Residence Time: 10 min.Hydrolysis Conditions
LAP009 (NREL Protocol)15ml reaction volume, 50 oC,1% BM
Enzymes: Spezyme CP and Multifect Xylanase 720 (Genencore)-Glucosidase (Novozyme)
0%
5%
10%
15%
20%
25%
30%
35%
80 90 100 110 120
72h
No soak - Xylan conversion
Temperature (oC)AFEX:1:1.2 biomass to NH3, 5 min.
0%
5%
10%
15%
20%
25%
80 90 100 110 120
72h
No Soak - Glucan conversion
Temperature (oC)
AFEX:1:1.2 biomass to NH3, 5 min.
0%
5%
10%
15%
20%
25%
80 90 100 110 120
72h 168h
Water soak - Glucan conversion
AFEX: 1:1.2 biomass to NH3, 10 min.
Temperature (oC)
0%
5%
10%
15%
20%
25%
30%
35%
80 90 100 110 120
72h 168h
Water soak - Xylan conversion
Temperature (oC)
AFEX: 1:1.2 biomass to NH3, 10 min.
Wet: Sample used immediately after AFEX, adjusted the pH to 4.8 by 1N HCl, followed by hydrolysis
Dry: Sampled dried in hood after AFEX overnight, adjusted the pH to 4.8 by 1N HCl, followed by hydrolysis
1AFEX: Doing AFEX reaction once
2AFEX: Doing AFEX reaction twice (consecutively)
Ammonium Hydroxide Soak- Glucan Conversion
0%
5%
10%
15%
20%
25%
wet dry wet dry wet dry wet dry
1 AFEX 2 AFEX 1 AFEX 2 AFEX
24 hour soak 168 hour soak
AFEX: 110°C, 1:1 biomass to NH3, 10 min
72h 168h
Water/
•Drying the sample AFEX results in high glucan Conversion
•Multiple AFEX does not improve the conversions
Other Strategy:
• Adding xylanase to increase xylose conversion and in turn to help glucan conversion
• To look for additives which can increase both glucan and xylan conversions
• Effect of oil addition during enzyme hydrolysis
0%
10%
20%
30%
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50%
noxylanase
11µLxylanase
noxylanase
11µLxylanase
noxylanase
11µLxylanase
noXylanase
Mineral Oil Corn Oil Tween noadditive
glucan xylan
Effect of Xylanase and additive after 168 hours of Hydrolysis
AFEX: 24h water soak, 120°C, 1:1.2 biomass to ammonia
Surfactant (Tween 80) 0.15g/g of dry biomass basis
AFEX Conditions
Mild conditions
Upto 120 oC, 1.0 : 1.2 Biomass to ammonia loading(pressure raise up to 300 psi)
Tough conditions
Upto 200 oC, 1.0 : 2.0 Biomass to ammonia loading(pressure raise up to 600 psi)
0%5%
10%15%20%
25%30%35%40%
120 140 160 180 200
72h 168h
Water soak - Glucan Conversion
Temperature (oC)
AFEX: 1:1 biomass to NH3, rinsed
Temperature and moisture conditions during AFEX
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2%
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10%
12%
1.50% 10% 30% 50% 70%
72h 168h
Moisture Content
AFEX: 1:0.8 biomass to NH3, 100 oC
Oven Dried - Glucan Conversion
High temperatureDuring AFEXImproves thepretreatment
Moisture has noEffect during AFEX pretreatment
Effect of Ammonia loading
0
10
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30
40
50
60
1:1, C, X, A 1:1.5, C, X, A 1:2, C, X, A UT, C, A, X
168h
72h
Water soaked, AFEX (180 oC)
(Biomass to ammonia loading)
% G
luca
n C
on
vers
ion
Increasing ammonia Loading has some influence on pretreatment
0
10
20
30
40
50
1:1, C, X, A 1:1.5, C, X, A 1:2, C, X, A UT, C, A, X
168h
72h
Water soaked, AFEX (180 oC)
% X
yla
n c
on
ve
rsio
n
(Biomass to ammonia loading)
To Brief:
• Poplar I (high lignin) shows resistance to hydrolysis
• Soaking followed by AFEX does help to increase hydrolysis
• Varying moisture during AFEX does not influence hydrolysis but, increasing temperature during AFEX has some influence
• Increasing the ammonia loading shows some improvement in pretreatment
• Addition of Xylanase and additives like tween 80 along with cellulase does increase the hydrolysis
Some results on Poplar I (low lignin)
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100168h
72h
Poplar (low lignin), soaked-AFEX
1:1 BM to ammonia 1:1.5 BM to ammonia
% G
luc
an
Co
nv
ers
ion
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100168h
72h
Poplar (low lignin), unsoaked-AFEX
1:1 BM to ammonia 1:1.5 BM to ammonia
% G
luc
an
Co
nv
ers
ion
ESCA Studies
Higher the O/C ratioLesser the lignin on the surface of poplar
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0.1
0.2
0.3
UntreatedPoplar
APR Poplar AFEX (120 oC) AFEX (160 oC)
O/C
ratio
ESCA Results on Poplar
0
0.01
0.02
0.03
Untreatedpoplar
ARP Poplar AFEX (120oC)
Gallic
Ferulic
% P
heno
lic E
quiv
alen
ts
Prussian Blue method
Conclusion:
AFEX conditionGlucan
conversionXylan
conversion
Poplar-II(High lignin)
1:5, 200 oC, 50% MC
50% 44%
Poplar-I(Low
Lignin)
1:1, 200 oC, 50% MC
83% 57%
Best AFEX conditions so for….
Wash stream after AFEX and before hydrolysis – to be analyzed
AcknowledgementAll the colleagues in my lab (BCRL Team)
CAFI-2 groupDr. Charles E. Wyman(Dartmouth College)Dr. Mark T. Holtzapple (Texas A & M University)Dr. Y. Y. Lee (Auburn University)Dr. Michael R. Ladisch (Purdue University)Dr. John N. Saddler (University of British Columbia)Dr. Richard Elander (National Renewable Research Laboratory)Dr. Mohammed Moniruzzaman (Genencor International)
United States Department of Agriculture
United States Department of Energy