酸碱结合预处理对水稻秸秆纤维素乙醇转化率的影响

以水稻秸秆为原料．在常温常压条件下分别用乙酸、过氧化氢、乙酸-过氧化氢（PPA）、氢氧化钠-PAA进行预处理，然后加入纤维素酶和酵母进行异步发酵产乙醇。结果表明，酸碱结合（氢氧化钠～PPA）处理后的固体得率显著低于乙酸或过氧化氢的单独处理，固体得率和纤维素水解后产生的葡萄糖浓度呈负相关；氢氧化钠-PAA处理能有效去除水稻秸秆中的木质素．大幅提高纤维素水解率和乙醇转化率；用10％氢氧化钠-PAA室温浸泡处理水稻秸秆48h与用5％氢氧化钠-PAA90℃处理水稻秸秆1．5h具有同样的效果。

Effect of Pretreatment of Alkali Combined with Acid on Ethanol Conversion Rate of Cellulose from Rice Straw

Acetic acid, hydrogen peroxide, acetic acid-hydrogen peroxide （PPA）, and sodium hydroxide-PAA were used for pretreatment of rice straw at normal pressure and temperature. Cellulase and yeast were added for ethanol production by asynchronous fermentation. The experimental results showed that the solid yield after pretreatment of alkali combined with acid was much lower than that after pretreatment with either acetic acid or hydrogen peroxide. The solid yield demonstrated a negative correlation trend with the hydrolytic glucose con- centration. The sodium hydroxide-PAA pretreatment could effectively remove the lignin and enhance the hy- drolysis rate of cellulose as well as the ethanol conversion rate. It was found that the process of pretreating rice straw with 5% sodium hydroxide-PAA at 90 ℃ for 1.5 h could be replaced by soaking rice straw in 10% sodi- um hydroxide-PAA at room temperature for 48 h.