碱和双氧水预处理玉米秸秆的试验研究

Experimental study on pretreatment of maize stalk cellulose with H_2O_2 and alkaline

研究了在5%NaOH中加入不同质量分数的双氧水时,对玉米秸秆的预处理效果;在预处理后的玉米秸秆中加入纤维素酶,考察此时酶解还原糖得率随预处理程度的变化;对浸泡时间、双氧水浓度、固液比3个因素进行单因素试验。试验结果表明,质量分数为2.5%的浓度下,糖得率最大;在2.5%H2O2浸泡24 h,固液比对酶解糖化几乎没有影响;当浸泡时间为24,72,96 h时,糖得率相差甚微。设计正交试验对预处理的条件进行优化,分析预处理玉米秸秆的各因素,以木质素去除率为基准参数,得到水解木质纤维素的适宜预处理条件:5%NaOH下加入质量分数为2.5%的双氧水,浸泡时间为72 h,固液比为1∶20。预处理后木质素的去除率为61.52%;加入纤维素酶酶解,还原糖得率为39.30%。

In this paper,the effect of different concentrations of H2O2 together with 5%NaOH solution on pretreatment of maize stalk was studied,After adding cellulase into the pretreated maize stalk,the changes of yield of enzymolysis reductive sugar was observed.The single factor tests have carried out on soaking time,H2O2 concentration and ratio of solid-liquid.The results showed that when the concentration of H2O2 is 2.5%,the yield of sugar is maximal;when soaking in H2O2 of 2.5% in concentration for 24 h,the impact of solid-liquid ratio on the enzymatic saccharification is ignorable,and when the soaking time is 24,72,96 h,there are little differences in the yield of sugar.Based on the lignin removal rate,the optimal condition of hydrolysis of lignocelluloses was obtained through analyzing the effects of various factors on maize stalk pretreatment,it is： add 2.5% mass fraction of H2O2 to 5% NaOH,the soaking time is 72 hours,the solid/water ratio is 1/20.The lignin removal rate is 61.52%.After adding cellulase for zymolysis,the yield of reductive sugar is 39.03%.