Donghai Wang, Ph.D.

Associate ProfessorBiological and Agricultural Engineering

Kansas State UniversityManhattan, KS 66506

Biofuel from Cellulosic Biomass

Kansas State University Bioenergy Symposium

April 27-28, 2011 Manhattan, KS

Contents

Current ethanol situation in the US

Challenges of cellulosic ethanol

Current research on cellulosic ethanol

Our ongoing research on cellulosic ethanol

Cellulosic biomass to biofuel

Cellulosic biomass

U.S. potential biomass resources

Source: RFA

As 2/25/2010, US has 27 cellulosicethanol projects under developmentand construction (19 companies), butno cellulosic ethanol on market yet.

Current US ethanol production

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Production

Historic U.S. fuel Ethanol Production

Sorghum

~3.5%Corn

~96%

In 2010, US ethanol production reached 13.23 billions of gallons.

13.23 B Gal

DOE technical strategy (2005)

I. Research - energy crops, cost production, feedstock deconstruction, fermentation to ethanol and recovery

II. Technology development -enhance sugars, minimize lignin and inhibitors, improved enzymes, co-fermenation of C-5 and C-6,

III. System integration –creation of fully consolidated biorefinery systems and commercialization.

According the DOE road map, the production cost of cellulosic ethanol shouldbe at $1.07/gal by 2012.

Source: NREL

Challenges of cellulosic ethanol

Biomass quality- better composition and structures

Pretreatment- low cost and less Inhibitors

Enzymes- effective enzymes for both C6 and C5

Enzyme cost- 3 cents for corn and 30-50 cents for biomass

Capital cost- $1.25-1.5 for corn and $4.3-5.44 for biomass

Ethanol (%)- 14-20% for corn and 4-5% for biomass

Ethanol yield/ton- 100 gal for corn and 70-80 gal for biomass

Transportation cost- low for corn and high for biomass

Effect of treatment on chemical structure and composition

Treatments Increase surface area

Decrystalize cellulose

Remove hemicellulose

Remove lignin

Uncatalyst steam explosion Y Y

Liquid hot water Y ND Y

pH controlled hot water Y ND Y

Flow-liquid hot water Y ND Y Y

Dilute acid Y Y

Flow-through acid Y Y Y

Ammonia fiber explosion

Y Y Y Y

ARP (ammonia recycled percolation)

Y Y Y Y

Lime Y ND Y Y

Y-major effect, Y-minor effect, and ND-not determined.

Cellulosic biomass pretreatment

Mass balance: AFEX vs dilute acid

M. lau, C. Gunawan and B. Dale*. Biotechnology for Biofuels 2009, 2:30

Biomass hydrolysis and sugar yield

Sugar yield: AFEX vs dilute acid

M. lau, C. Gunawan and B. Dale*. Biotechnology for Biofuels 2009, 2:30

Cellulosic biomass pretreatment

Residual solids energy content: AFEX vs dilute acid

M. lau, C. Gunawan and B. Dale*. Biotechnology for Biofuels 2009, 2:30

Ethanol Fermentation

Lau et al. Biotechnology for Biofuels 2010, 3:11

Enzymes for ethanol Fermentation

Novozymes said its new Cellic® CTec2 enzymes enable the biofuel industry to produce cellulosic ethanol at a price below US $2.00 per gallon.

Genencor said its Accellerase® DUET product line will achieve higher sugar and biofuel yields, often at 3-fold lower dosing, and it is feedstock- and pretreatment-flexible.

Cellulose (%) Hemicellulose (%) Lignin (%) Soluble Sugar (%)

PS sorghum 35.7±0.8 19.8±0.8 11.7±0.3 17.5±0.5

Corn Stovera 36.1 – 40.8 26 – 35 17.2 – 21 NR

Switchgrassb 32 – 36.6 21.5 – 26.6 18.5 – 21.4 NR

Wheat strawc 37.1 – 48.6 23.2 – 31.7 18.2 – 19.2 NR

a Lloyd and Wyman 2005; Zeng 2007; Zhao et al. 2009; b Alizadeh et al. 2005; Suryawati et al. 2008; Xu et al. 2010; c Sun and Chen 2008; Zhu et al. 2006; NR: not reported.

Forage sorghum biomass

Sorghum biomass - PS sorghum grows primarily in semiarid and drier parts of the world

PS sorghum produces much more dry mass per acre (80 Mg ha-1, 65% MC) than corn

Significant amount of soluble sugar

Low lignin content

Bioconversion processing design

Acid Liquid

Wet mass

Washing solution

SSF

Ethanol

CO2

Residue

Sulfuric Acid

Pretreatment

Sorghum Biomass

Wash & DryPowder

<=2 mmGrind

Composition analysis

Structure Analysis

Sorghum biomass bioconversion process design

Pretreatment: 0.5, 1.0 and 1.5 % dilute acid at 140 C for 30 min. SSF: Simultaneous saccharification and fermentation (S.Cerevisiae) SHF : Separate hydrolysis and fermentation (E.Coli KO11) SSF: Simultaneous saccharification and fermentation (E.Coli KO11)

Cellulose recovery after pretreatment

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Eff iciency Yield

Cellulose hydrolysis efficiency

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Effect of fermentation time on SSF: (A) with constant temperature at 38 °C, and (B) with variable-temperature at 50°C for 6h enzymatic hydrolysis and 30°C for SSF.

Effect of fermentation temperature and buffer concentration on ethanol yield

38 C with 0.05 % buffer 50-30 C with 0.05 % buffer

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Effect of buffer concentrationon ethanol yield

Mass balance of the designed process

Mass balance of sorghum biomass ethanol

Alkyl-sulfonic acid nanoparticles (AS)Perfluroalkyl-sulfonic acid nanoparticles (PFS)

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CH2CH3 CH3CH2

CH3CH2 CH2CH3

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Acid-functionalized nanoparticles for

cellulose hydrolysis

Performance and reusability of acid-functionalized nanoparticles on cellobiose hydrolysis.

L. Pana et al. 2011

Recovery of acid-functionalized metal nanoparticles

Nanoparticles can be recovered and reused.

Leidy Peña Duque. Acid functionalized nanoparticles for hydrolysis of lignocellulosicfeedstocks. Biological and Agricultural Engineering, Kansas State University.

Acknowledgement

Wang’s research group

Research collaborators: Drs. S. Staggenborg, K. Hohn, R. Madl, Y. Shi, P. Vadlani, R. Nelson, B. Rooney,

Center for Sustainable Energy, KSU

Companies: Novozymes, Inc., Genencor (A DaniscoDivision),