摘要
以玉米秸秆为原料,研究稀硫酸-氢氧化钙联合预处理秸秆制备燃料乙醇的方法。玉米秸秆经稀硫酸预处理、固液分离后得到的预水解液(主要含有木糖)进行戊糖发酵;而残渣采用氢氧化钙进一步预处理后,经酶水解得到的葡萄糖进行己糖发酵,从而实现戊糖和己糖分开发酵产乙醇。研究结果表明,玉米秸秆稀硫酸预处理最佳条件为:硫酸用量1.00%(以绝干玉米秸秆计),反应温度130℃,反应时间70 min,此时木聚糖水解得率为80.45%;采用树干毕赤酵母对玉米秸秆稀硫酸预水解液原液、浓缩液Ⅰ(浓度为原液的2倍)和浓缩液Ⅱ(浓度为原液的3.5倍)进行戊糖发酵,乙醇得率分别为82.52%、85.13%和73.64%。氢氧化钙进一步预处理玉米秸秆稀硫酸预处理渣的最佳条件为:氢氧化钙用量0.125 g/g(以绝干玉米秸秆计),反应温度90℃,时间24 h,此时纤维素酶水解得率为84.92%;采用酿酒酵母对两步预处理残渣的酶水解液原液、浓缩液Ⅲ和浓缩液Ⅳ(浓度为原液的2倍和3倍)进行己糖发酵,乙醇得率分别为92.22%、91.89%和85.54%。
Corn stover pretreated by dilute sulfuric acid and calcium hydroxide was used to produce fuel ethanol. The pre- hydrolyzate obtained from dilute sulfuric acid pretreated corn stover was mainly composed by xylose, which could be fermented to produce ethanol. The solid residue were further pretreated by calcium hydroxide and then hydrolyzated to glucose with cellulase for hexose fermentation. Based on this process, the glucose and xylose could be converted to ethanol, respectively. The optimal dilute sulfuric acid pretreatment could be obtained as the corn stover was pretreated by 1.00% sulfuric acid （ based on dry corn stover） ,rat 130 ^（2 for 70 min and the xylan hydrolysis yield was 80.45%. The ethanol yields of pentose fermentation of the unconcentrated,l-fold concentrated and 2. 5-folds concentrated pre-hydrolyzates by P. stipitis were 82. 52%, 85. 13% and 73.64% , respectively. The optimal further pretreatment with calcium hydroxide were conducted as the solid residues were treated by 0. 125g/g calcium hydroxide （ based on dry corn stover）, at 90℃ for 24 h. The cellulose enzymatic hydrolysis yield was 84.92%. The hexose ethanol fermentation yields of the two-step pretreated residue enzymatic hydrolyzates of unconcentrated, 1-fold concentrated and 2-folds concentrated by S. cerevisiae were 92.22% ,91.89% and 85.54% , respectively.
出处
《林产化学与工业》
EI
CAS
CSCD
北大核心
2015年第6期89-95,共7页
Chemistry and Industry of Forest Products
基金
国家自然科学基金资助项目(31100432)
教育部高等学校博士学科点专项科研基金项目(20113204120013)
江苏高校优势学科建设工程资助项目(无编号)
关键词
燃料乙醇
玉米秸秆
预处理
己糖发酵
戊糖发酵
fuel ethanol
corn stover
pretreatment
pentose fermentation
hexose fermentation
