乙醇预处理麦秆的酶解性能研究

Enzymatic digestibility of ethanol pretreated wheat straw

采用H2SO4催化和自催化乙醇法对麦秆进行预处理,比较预处理后麦秆的主要化学组成、纤维素酶解性能和半同步糖化发酵生产乙醇特性,并进行物料衡算。结果表明:H2SO4催化和自催化乙醇预处理过程中纤维素固体回收率大于90%。添加非离子表面活性剂吐温20和吐温80没有显著提高H2SO4催化乙醇预处理后纤维素的酶解葡萄糖得率及半同步糖化发酵过程中乙醇的产量,而对自催化乙醇处理后麦秆的酶解和半同步糖化发酵过程有一定程度的促进作用,相应的酶解葡聚糖转化率由72.7%提高到85.0%,而半同步糖化发酵过程中乙醇质量浓度提高了11.4%。物料衡算结果表明:酸催化和自催化乙醇预处理后葡聚糖回收率分别为91.0%和95.4%;半同步糖化发酵生产乙醇的得率分别为10.4和11.6 g(按100 g原料计)。

Wheat straw was pretreated by sulfuric acid-catalyzed （ SAC） and auto-catalyzed （ AC） ethanol organosolv processes.The main chemical compositions, cellulose digestibility and ethanol production by hemi-simultaneous saccharification and fermentation （ hSSF ） of pretreated solids were compared.The results showed that SAC and AC pretreatments recovered more than 90% of cellulose as solid phase.Addition of non-ionic surfactants Tween 20 and Tween 80 did not significantly improve the enzymatic digestibility and ethanol production of SAC-pretreated wheat straw.However,they showed some positive effects on AC-pretreated wheat straw, with the corresponding enzymatic glucan conversion increased from 72.7% to 85.0% and ethanol concentration increased by 11.4%.Material balance analysis showed that glucan recoveries, as a solid phase, were 91.0% and 95.4% for SAC and AC pretreatments,respectively.Corresponding ethanol yields were 10.4 and 11.6 g per 100 g raw material during SSF process,respectively.