ARS | Publication request: Potential to Improve Dry Mill Economics by Increasing Ethanol Yield from Corn Fiber Residue

Submitted to: Biotechnology for Fuels and Chemicals Symposium Proceedings
Publication Type: Abstract
Publication Acceptance Date: May 7, 2003
Publication Date: May 7, 2003
Citation: NAGLE, N., TUCKER, M.P., DIEN, B.S., COTTA, M.A., HICKS, K.B., MOREAU, R.A., SINGH, V., NGUYEN, Q. POTENTIAL TO IMPROVE DRY MILL ECONOMICS BY INCREASING ETHANOL YIELD FROM CORN FIBER RESIDUE. 25TH SYMPOSIUM ON BIOTECHNOLOGY FOR FUELS AND CHEMICALS SYMPOSIUM. 2003. ABSTRACT P. 20.

Technical Abstract: Annual production of fuel ethanol is expected to reach five billion gallons by the year 2012. Currently, two methods are used to produce fuel ethanol: wet milling or dry milling of corn. The dry milling process is becoming more common due to the lowered capital required to build and operate these plants. One pathway to increasing efficiency and yield for the dry mill process is to remove the non-fermentable portion of the corn prior to fermentation, thereby increasing the fermentation capacity. The "Quick Germ-Quick Fiber Process" developed at the University of Illinois separates the corn germ and fiber prior to fermentation by soaking the kernels in hot water followed by germ and fiber milling. The residual corn fiber can be a potential source of co-products or further hydrolyzed to soluble carbohydrates for ethanol fermentation. This paper details the pretreatment and bioconversion of Quick Fiber to ethanol. Quick Fiber was pretreated using a batch Zipperclave reactor in a series of experiments to evaluate the effect of acid concentration, temperature, and time on sugar release. The pretreated material was then evaluated for the bioconversion potential using yeast under SSF conditions. Yields of ethanol reached 86% of theoretical for the C6 sugars in 72 hours. Co-products evaluation from the pretreated material focused on corn fiber oil as the primary product. Results indicate that Quick Fiber can be pretreated under modest severity and achieve high yields of ethanol based on the release of hydrolyzed sugars. These promising results need to be evaluated further for their effect on process economics for ethanol production.