Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 16, 2000
Publication Date: N/A
Technical Abstract: Various lignocellulosic agricultural residues such as corn fiber, corn stover, rice straw, wheat straw, and sugarcane bagasse and energy crops such as switchgrass are available as low-cost feedstock for production of biofuels and value-added chemicals by fermentation. The process of converting cellulose to ethanol includes feedstock pretreatment, enzymatic saccharification, fermentation, and product recovery. At present, no commercial process exists in the USA for such manufacturing, although efforts are underway. Success depends primarily on the development of an effective pretreatment process for decrystallizing cellulose, allowing rapid enzyme accessibility, as well as highly efficient enzymes for conversion of cellulose to glucose. Pretreatment options include dilute acid, steam explosion, ammonia fiber explosion (AFEX), alkali, and alkaline peroxide treatment. Currently, the cost of cellulase enzymes is 50 cents per gallon of ethanol produced from pretreated lignocellulosic substrates. Research emphasis is being directed towards lowering the cellulase enzyme cost by 10 fold. The strategies to decrease the enzyme cost include: (i) increase catalytic efficiency, (ii) decrease feedback inhibition, (iii) reduce non-specific binding, and (iv) improve thermal stability. In this presentation, the current state of technology research and process development in the United States and efforts to bring this technology into the market place will be reviewed.