1. 1 Ethanol Production from the Mixture of Cotton Gin Waste and Recycled Paper Sludge by Simultaneous Saccharification and Fermentation Jiacheng Shen and Foster A. Agblevor Department of BSE Virginia Tech Jan. 2008

2. 2 Ethanol Production from Lignocellulosic Materials Lignocellulosic materials Ethanol production from biomass Two steps Polysaccharides  Monosaccharides  Ethanol Two operating modes Separate hydrolysis and fermentation (SHF) Simultaneous saccharification and fermentation (SSF)

3. 3 Advantages and Disadvantages of SHF and SSF The advantage of SHF Optimal operation conditions of two units The disadvantage of SHF Inhibition of enzyme from sugars The advantages of SSF Less inhibition to enzyme Lower capital costs than SHF Higher productivity The disadvantage of SSF Non-optimal conditions of hydrolysis and fermentation

4. 4 CGW and RPS CGW and RPS: two wastes. 2.04 million tons of CGW 4 million tons of RPS Produce 383 million-liter ethanol About 2.74 % of USA ethanol production in 2006

5. 5 Disposal Methods of CGW and RPS Land filling and land application Limitation of land supply Contamination of groundwater and surface water Incineration Low heating value Air pollution from particle and gaseous pollutants

6. 6 Objectives To analyze the components of the mixture of steam-explosion CGW and RSP To investigate the bioconversion of the mixtures of CGW and RPS to ethanol by simultaneous saccharification and fermentation at two enzyme loadings To study the effects of by-products on ethanol yield

7. 7 Experimental Methods Analysis of components of the mixture 1)Acid-insoluble lignin ASTM E1721-95 2)Ash ASTM E1755-95 3)Carbohydrate ASTME1721-95 Simultaneous Saccharification and Fermentation 1) The mixtures of CGW and RPS +Steam explosion (Severity factor 3.83) 2) Novozymes enzyme + Yeast of S. cerevisiae at buffer of pH 4.8 and 36 o C 3) Ethanol, sugars, and by-products measured by HPLC

8. 8 Results Components of the steam-explosion mixture

9. 9 Results (cont.) Glucose, xylose, and ethanol concentrations with time in SSF

10. 10 Results (cont.) By-product concentrations with time in SSF

11. 11 Results (cont.) The maximum yield, theoretical yield and productivity at two enzyme loadings.

12. 12 Conclusions Ethanol production from the carbohydrates in CGW and RPS by SSF process. The maximum yield, theoretical yield, and productivity were 0.184, 0.754, and 0.00383. No significant effect of enzyme loading increase on the final ethanol concentration. A new way to produce bioethanol from industrial wastes as well as solve the waste disposal problem.

13. 13 Thank you Questions? Acknowledgments We acknowledge the NSF under contract No. 0420577 and Xethanol Inc. for providing the financial support for this project.