National Bioenergy Center, National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, CO 80401, United States.
Bioresour Technol. 2011 Jan;102(2):1240-5. doi: 10.1016/j.biortech.2010.08.024. Epub 2010 Aug 12.
Dilute-acid pretreatment of lignocellulosic biomass enhances the ability of enzymes to hydrolyze cellulose to glucose, but produces many toxic compounds that inhibit fermentation of sugars to ethanol. The objective of this study was to compare the effectiveness of treating hydrolysate liquor with Ca(OH)2 and NH4OH for improving ethanol yields. Corn stover was pretreated in a pilot-scale reactor and then the liquor fraction (hydrolysate) was extracted and treated with various amounts of Ca(OH)2 or NH4OH at several temperatures. Glucose and xylose in the treated liquor were fermented to ethanol using a glucose-xylose fermenting bacteria, Zymomonas mobilis 8b. Sugar losses up to 10% occurred during treatment with Ca(OH)2, but these losses were two to fourfold lower with NH4OH treatment. Ethanol yields for NH4OH-treated hydrolysate were 33% greater than those achieved in Ca(OH)2-treated hydrolysate and pH adjustment to either 6.0 or 8.5 with NH4OH prior to fermentation produced equivalent ethanol yields.
稀酸预处理木质纤维素生物质可以提高酶水解纤维素生成葡萄糖的能力，但会产生许多抑制糖发酵生成乙醇的有毒化合物。本研究旨在比较用 Ca(OH)2 和 NH4OH 处理水解液以提高乙醇产量的效果。在中试规模的反应器中预处理玉米秸秆，然后提取并在不同温度下用不同量的 Ca(OH)2 或 NH4OH 处理液体部分（水解液）。用葡萄糖-木糖发酵菌 Zymomonas mobilis 8b 将处理后的液体中的葡萄糖和木糖发酵成乙醇。用 Ca(OH)2 处理会导致高达 10%的糖损失，但用 NH4OH 处理时损失要低两到四倍。用 NH4OH 处理的水解液的乙醇产量比用 Ca(OH)2 处理的水解液高 33%，并且在用 NH4OH 调节 pH 值至 6.0 或 8.5 后进行发酵，乙醇产量相当。
