Contaminant occurrence, identification and control in a pilot-scale corn fiber to ethanol conversion process.

While interest in bioethanol production from lignocellulosic feedstocks is increasing, there is still relatively little pilot-plant data and operating experience available for this emerging industry. A series of batch and continuous fermentation runs were performed in a pilot-plant, some lasting up to six weeks, in which corn fiber-derived sugars were fermented to ethanol using glucose-fermenting and recombinant glucose/xylose-fermenting yeasts. However, contamination by Lactobacillus bacteria was a common occurrence during these runs.

A bioethanol process development unit: initial operating experiences and results with a corn fiber feedstock.

Interest in bioethanol production from lignocellulosic feedstocks for use as an alternative fuel is increasing, but near-term commercialization will require a low cost feedstock. One such feedstock, corn fiber, was tested in the US Department of Energy (DOE)/National Renewable Energy Laboratory (NREL) bioethanol pilot plant for the purpose of testing integrated equipment operation and generating performance data. During initial runs in 1995, the plant was operated for two runs lasting 10 and 15 days each and utilized unit operations for feedstock handling, pretreatment by dilute sulfuric-acid hydrolysis, yeast inoculum production, and simultaneous saccharification and fermentation using a commercially available cellulase enzyme.