底物水解预处理对玉米秸秆发酵生物产氢的影响

Effect of hydrolysis pretreatment of corn stalk wastes on fermentation hydrogen production

水解预处理是影响纤维素类生物质发酵产氢效率的关键因素之一.在批式试验条件下,分别采用乳酸处理(方法A),生物处理(方法B)和生物/乳酸两步处理(方法C)方法对玉米秸秆进行糖化水解预处理;考察了水解预处理对产氢效率的影响.结果表明:经乳酸预处理、生物预处理和乳酸/生物两步处理的玉米秸秆的累积氢产量分别为132 mL/g,169 mL/g和191 mL/g;就玉米秸秆的产氢能力而言,预处理方法B和C明显优于A.其原因在于,经方法B和C预处理后玉米秸秆的半纤维素被水解成可溶性还原糖和乳酸,从而导致产氢能力提高;与此同时,经预处理的底物中的半纤维素降解也能有效地提高底物的产氢能力.

The hydrolysis pretreatment of the substrate plays a crucial role in conversion of corn stalk wastes into bio-hydrogen by fermentation.Thus batch tests were conducted to investigate the effect of hydrolysis pretreatment of corn stalk wastes on hydrogen yield,where the corn stalk wastes were saccharified and hydrolyzed with method A（lactic acid）,method B（biological route）,and method C（biology/lactic acid two-step route）,respectively.It was found that the corn stalk wastes pretreated with methods A,B,and C had a cumulative hydrogen yield of 132 mL/g,169 mL/g,and 191 mL/g at a substrate concentration of 15 g/L and initial pH of 7.0.The corn stalk wastes pretreated with methods B and C had higher hydrogen yields than that pretreated with method A.The reason might lie in that the hemicellulose in the corn stalk wastes were more efficiently hydrolyzed by methods B and C to generate soluble saccharides and lactic acid,resulting in increased hydrogen yields.Besides,the direct degradation of the hemicellulose in the corn stalk wastes also contributed to greatly increase hydrogen yield.