ethanol production from the mixture of hemicellulose pre

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Ethanol Production from the Mixture of Hemicellulose Pre-hydrolysate and Paper Sludge

Li Kang , David Webster, Harry Cullinan and Y. Y. LeeDepartment of Chemical Engineering

Auburn University

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Outline

1. Introduction

2. Pre-extraction process

3. De-toxification of pre-hydrolysate

4. Separation hydrolysis and fermentation (SHF)

of pre-hydrolysate

5. Increasing the ethanol concentration

a. concentrated pre-hydrolysate

b. mixing pre-hydrolysate with paper sludge

6. Conclusion

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Current Kraft pulping process

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Black Liquor : 80% of hemicelluloses and ligninHeating Value: Hemicellulose (13.6 MJ/kg) Lignin (27 MJ/kg).

Cellulose38 - 50%

Hemicelluloses23 - 32%

Lignin15 - 25%

Other 5 -15%

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Proposed Kraft pulping process

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Water

Fresh PineWood Chip

Pre-hydrolysate

Extracted Wood Chip

M/K Laboratory Digester

500-mLCylindrical Batch (bomb)Digesters

2. Pre-extraction Process

Sung-Hoon Yoon, et al., Ind. Eng. Chem. Res., 2010, 49 (13), 5969–5976

Liquor/wood = 5.8 / 1, 170 °C

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0.00%0.01%0.01%0.02%0.02%0.03%0.03%0.04%

0.00%2.00%4.00%6.00%8.00%

10.00%12.00%14.00%16.00%

0 20 40 60 80 100

Cel

lulo

se L

oss

(%)

Wei

ght L

oss,

H

emic

ellu

lose

Los

s (%

)

Time (min)

Weight Loss Hemicellulose Loss Cellulose Loss

)180162(*

4.15Mannose)

180162(*cos Cellulose −= eGlu

CelluloseMannoseeGluGalactoseXyloseArabinose −++++= )180162(*)cos()

150132(*)( oseHemicellul

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The profile of weight , hemicellulose and cellulose loss versus extraction time

Yoon, S. H. and van Heiningen, A. , Journal of Industrial and Engineering Chemistry ,16 (1), 74-80, 2010BioPro Expo & Marketplace / Atlanta, GA / March 14-16, 2011

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Composition of pre-hydrolysate

Xyl2, 2.4 Gal2, 2.1

Man2, 9.1

Man, 0.6

Ara, 1.4Gal, 0.7Glu, 0.4

Xyl, 1.1

Ara2, 0.1

Glu2, 1.4

0.01.0

2.03.0

4.05.0

6.07.0

8.09.0

10.0S

ugar

s C

once

ntra

tion

(g/L

)

0.4

0.2

0.1

0.3

0.8

0.00.10.20.30.40.50.60.70.8

Acetic acid Acetyl group Levulinic acid HMF Furfural

Oth

er C

ompo

unds

(g/L

)

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Three stage pre-extraction process

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Water

Fresh Wood Chip

First StagePre-hydrolysate I

Second StagePre-hydrolysate II

Third StagePre-hydrolysate III

Make-up Water

Make-up Water

Fresh Wood Chip

Fresh Wood Chip

Extracted Wood Chip

Extracted Wood Chip

Extracted Wood Chip

FirstStage

I

SecondStage

II

ThirdStage

III

Fresh Wood Chip

Water

Extracted Wood Chip

Screw ReactorPre-hydrolysate

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Composition of pre-hydrolysate III after three-stage pre-extraction

Gal2, 3.9

Man2, 15.5

Man, 0.6Ara, 1.4Gal, 0.7Glu, 0.4

Xyl, 1.1Xyl2, 2.7

Ara2, 0.1

Glu2, 3.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0S

ugar

s C

once

ntra

tion

(g/L

)

1.4

1.0

0.20.5

2.6

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Acetic acid Acetyl group Levulinic acid HMF Furfural

Oth

er C

ompo

unds

(g/L

)

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Average composition of Woody biomass and main derived hydrolysis products

10J.R.M. Almeida, T. Modig, A. Petersson, B. Hahn-Hägerdal, G. Liden and M.F. Gorwa-Grauslund, J Chem Technol Biotechnol 82 (4) (2007), pp. 340–349

3. De-toxification of Pre-hydrolysate

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De-toxification test

0.00.40.81.21.62.02.42.83.2

200 250 300 350 400 450wavelength (nm)

Abs

orba

nce

untreated25 °C60 °C

11Vanillin(230nm) Furfural(278nm) HMF(284nm) p-Coumaric acid (308nm) Ferulic Acid (322nm) 4-hydroxyacetophenone (340nm)

UV-Vis Absorbance Changed During De-toxification Test

Overliming: Pre-hydrolysate III was added CaO to pH=10.0 , 25 °C or 60 °C for half hour, centrifuge, then adjust supernatant pH to 5.0 by adding 70% sulfuric acid.

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Composition change after de-toxification test

020

4060

80100

TotalSugar

Mannose+

Glucose

AceticAcid

Levulinicacid

HMF Furfural TotalSolublePhenolic

%

untreated 25 °C 60 °C

12

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4. Separate hydrolysis and fermentation (SHF) of pre-hydrolysate

0%

20%

40%

60%

80%

100%

Cellulase β-Glucosidase Xylanase Pectinase

48h

enzy

mat

ic d

iges

tibili

ty/%

Glucose Xylose Galactose Mannose

13Enzyme Loading: 25mg protein enzymes / g-mannose oligomer50 °C, pH=4.8BioPro Expo & Marketplace / Atlanta, GA / March 14-16, 2011

Fermentation of pre-hydrolysate III by Saccharomyces cerevisiae

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SHF conditionEnzymatic Hydrolysis:: 25mg protein Pectinase/ g-mannose oligomer and 50°C.Fermentation Conditions : 32°C, Saccharomyces cerevisiae D5A

0

2

4

6

8

10

12

0 20 40 60 80 100Time (h)

Etha

nol C

onc.

(g/L

)

untreated60 °C25 °C

0

1

2

3

4

5

0 20 40 60 80 100Time (h)

Glu

cose

Con

c. (g

/L)

untreated60 °C25 °C

02

46

810

1214

16

0 20 40 60 80 100Time (h)

Man

nose

Con

c. (g

/L)

untreated60 °C25 °C

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2694

20

246

146

4485

1141 55 76 63

050

100150200250300

Total Sugars(g/L)

Glu+Mann (g/L) EthanolConc.(g/L)

Yield (%)

III IV (2.2 ×) V (5.9 ×)

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Laboratory Scale: Rotary evaporator.-Total sugar concentration Increase. -Furfural and acetic acid are removed up to 90%. Industry Scale: Steam- Stripping or Flash Tank and Multiple-effect Evaporator (Kraft mill).

5. Increasing the ethanol concentration

a. concentrated pre-hydrolysate

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Kraft Paper Mill Sludges as a Feedstock

• 4.1 to 5 million tons sludge per year in U.S.- Incineration (greenhouse gas emission, low energy efficiency)- Landfill (greenhouse gas emission, limited land availability)

• Low/ Negative Cost ( 0 to 50$ per ton disposal cost)

• High Carbohydrate and Low Lignin Content (Kraft pulping process removes most of lignin and hemicellulose)

• Easily Digested by Cellulase (No need for expensive pretreatment)

b. mixing pre-hydrolysate

with paper sludge

BioPro Expo & Marketplace / Atlanta, GA / March 14-16, 2011

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Composition of various sludges

Primary Sludge is from Boise paper mill, Jackson, AL.

Kang,L., Wang,W., Lee, Y.Y., 2010. Appl. Biochem. Biotechnol. 161(1-8), 53-66.BioPro Expo & Marketplace / Atlanta, GA / March 14-16, 2011

Fermentation of pre-hydrolysate IIIwith paper sludge

Maximum Ethanol Yield (%) Maximum Ethanol Conc. (g/L)

Pre-hydrolysate III with paper sludge 71.5 (120h) 31.5

Pre-hydrolysate only 82.6 (48h) 10.3

Paper sludge only 73.4 (120h) 27.8

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Enzyme Loading: Cellulase (15FPU/g glucan) + Cellobiase (30CBU/g glucan)+ 25mg protein Pectinase/ g-mannose oligomerSolid Loading:15 g total solid /100ml work volumeSSF Conditions : 36°C, Saccharomyces cerevisiae D5A

0

5

10

15

20

25

30

35

0 24 48 72 96 120Time (h)

Etha

nol C

onc.

(g/L

)

Paper Sludge onlyPaper Sludge with Pre-hydrolysatePre-hydrolysate only

0%10%20%30%40%50%60%70%80%90%

0 24 48 72 96 120Time (h)

Etha

nil Y

ield

(%)

Paper Sludge onlyPaper Sludge with Pre-hydrolysatePre-hydrolysate only

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Fermentation of pre-hydrolysate with de-ashed sludge

Maximum Ethanol Yield (%) Maximum Ethanol Conc. (g/L)

Pre-hydrolysate III with de-ashed sludge 71.3 (120h) 40.1

De-ashed sludge only 75.2 (120h) 35.0

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Enzyme Loading: Cellulase (15FPU/g glucan) + Cellobiase (30CBU/g glucan)+ 25mg protein Pectinase/ g-mannose oligomerSolid Loading:15 g total solid /100ml work volumeSSF Conditions : 36°C, Saccharomyces cerevisiae D5A

05

1015202530354045

0 24 48 72 96 120Time (h)

Etha

nol C

onc.

(g/L

)

De-ashed sludge with pre-hydrolysate III

De-ashed sludge only

0%

10%

20%

30%

40%

50%

60%

70%

80%

0 24 48 72 96 120Time (h)

Etha

nol Y

ield

(%)

De-ashed sludge with pre-hydrolysate III

De-ashed sludge only

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Conclusion

• Combining pre-hydrolysate with sludge can more than double ethanol production

• Hemicellulose pre-hydrolysate can be converted to ethanol through de-toxification, enzymatic hydrolysis and fermentation processes.

• The fermentation of concentrated pre-hydrolysate can increase the ethanol concentration.

• The fermentation performance of the mixture of pre-hydrolysate with sludges has high efficiency and more practical. 20

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Acknowledgments

Vekanta Ramesh PallapoluUrvi KothariSuan ShiAllen SmithSung-Hoon YoonGopal Krishnagopalan

Alabama Center for Paper and Bioresource Engineering Boise Cascade, LLC Genencor International

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