弱碱性过氧化预处理对稻草秸秆酶解糖化的影响

为了提高稻草秸秆的酶解糖化率,对稻草秸秆弱碱性过氧化预处理条件进行了优化。结果表明:弱碱性过氧化预处理降低了稻草秸秆中木质素的含量,提高了纤维素的含量。最优预处理条件为温度40 ℃,时间24 h,H₂O₂质量分数为2.0 %,在此条件下稻草秸秆的酶解糖化率达到了83.23 %,而在相同酶解条件下,预处理温度30 ℃、时间24 h、 2.0 % NaOH处理后稻草秸秆的酶解糖化率为70.38 %。弱碱性过氧化预处理稻草秸秆的糖化率明显高于碱性预处理稻草秸秆的糖化率。同时试验结果表明,木质素的除去率与H₂O₂质量分数有关。当H₂O₂质量分数大于2.0 %后,H₂O₂对木质素的除去选择性降低,木质素的除去率基本保持不变,却增加了半纤维素的损失。

Effects of Mild Alkaline Peroxide Pretreatment on Enzymatic Saccharification of Rice Straw

Mild alkaline peroxide pretreatment conditions for rice straw were optimized with a view to increase the ratio of enzymatic saccharification.The results showed that the mild alkaline peroxide pretreatment reduced the content of lignin and increased the content of cellulose of rice straw.The optimal pretreament conditions were as follows ： temperature 40 ℃,reaction time 24 h,hydrogen peroxide 2.0 %.Under the optimal conditions,the enzymatic saccharification ratio of the mild alkaline peroxide pretreated rice straw was 83.23 %.The enzymatic saccharification ratio of rice straw pretreated by the alkaline with 2.0 % NaOH,temperature 30 ℃,time 24 h was 70.38 %.The enzymatic saccharification ratio of the mild alkaline peroxide pretreated rice straw is higher evidently than that of the alkaline pretreated rice straw.The results also showed that the removal efficiency of lignin was affected by the mass fraction of hydrogen peroxide.When the mass fraction of hydrogen peroxide is greater than 2.0 %,the selectivity of lignin removal is decreased.Lignin removal remains unchanged,but the loss ratio of hemicelluloses is increased.