Background Research and Market Analysis

• Ethanol is a bio-based, renewable oxygenated fuel (Saha)

• Used as a fuel oxygenate

• Lignocellulosic feedstocks need to be utilized

• 77% of the energy in the carbohydrates of the feedstock is recovered as ethanol (Aden)

• 86% reduction of greenhouse gas emissions would result per gallon of gasoline displaced by lignocellulosic ethanol (Lu)

• For 2010 start-up date to be economically feasible, selling price of ethanol must be $1.07 per gallon (Aden)

• In the US gasoline currently sells for $2.63 per gallon on average

Process Flow Diagram

Pre-Treatment

VesselResidence Time Size

Hours m3

Pre-Steam Vessel 0.33 609Hydrolysis Vessel 0.17 2032

Flash 0.25 2159Overlime Vessel 1.0 324

pH Adjustor Vessel 1 4.0 1396pH Adjustor Vessel 2 4.0 1396

•Dilute Acid Hydrolysis

•Contaminants:• Acetic Acid• Furfural• Hydroxymethyl furfural

(HMF)

•Contaminant Removal:• Flash• Overliming

References1. Aden, A., M. Ruth, K. Ibsen, J. Jechura, K. Neeves, J. Sheehan, B. Wallace, L. Montague, A. Slayton, and J.

Lukas. Lignocellulosic Biomass to Ethanol Process Design and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis for Corn Stover. National Renewable Energy Laboratory, 2002. Print.

2. Dombek, K. M., and L. O. Ingram. "Ethanol Production during Batch Fermentation with Saccharomyces cerevisiae: Changes in Glycolytic Enzymes and Internal pH." Applied and Environmental Microbiology 53.6 (1987): 1286-291. Department of Microbiology and Cell Science, University of Florida, Gainesville. Web. 6 Dec. 2009.

3. Jin, Yong-Su, Hal Alper, Yea-Tyng Yang, and Gregory Stephanopoulos. "Improvement of Xylose Uptake and Ethanol Production in Recombinant Saccharomyces cerevisiae through an Inverse Metabolic Engineering Approach." Applied and Environmental Microbiology 71.21 (2005): 8249-256. Department of Chemical Engineering, Massachusetts Institute of Technology. Web. 4 Dec. 2009.

4. Lu, Yulin, and Nathan S. Mosier. "Current Technologies for Fuel Ethanol Production from Lignocellulosic Plant Biomass." Genetic Improvement of Bioenergy Crops. Ed. Wilfred Vermerris. Gainesville, FL: Springer, 2008. 161-77. Print.

5. Watanabe, Seiya, Ahmed Abu Saleh, Seung Pil Pack, Narayana Annaluru, Tsutomu Kodaki, and Keisuke Makino. "Ethanol Production from xylose by recombinant Saccharomyces cerevisiae expressing protein-engineered NADH-preferring xylose reductase from Pichia stipitis." Microbiology 153 (2007): 3044-054. Kyoto University. Web. 6 Dec. 2009.

6. Saha, Badal C., Loren B Iten, Michael A. Cotta, and Y. Victor Wu. "Dilute acid pretreatment, enzymatic saccharification and fermentation of wheat straw to ethanol." Process Biochemistry 40. (2005): 3693-3700. Web. 23 Nov 2009. <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THB4GG8W36&_user=616288&_coverDate=12%2F31%2F2005&_rdoc=1&_fmt=full&_orig=search&_cdi=5278&_sort=d&_docanchor=&view=c&_searchStrId=1103726729&_rerunOrigin=scholar.google&_acct=C000032378&_version=1&_urlVersion=0&_userid=616288&md5=233641a1566ae099176bcf36cdbe1356#secx1>.