金属离子助催化稀酸水解纤维素工艺的研究

Study on the Hydrolysis of Cellulose Co-catalyzed by Metal Ions under Dilute Sulfuric Acid

以小麦秸秆为原料,采用正交试验考察了硫酸浓度、Fe2+浓度、反应温度和反应时间等因素对稀酸水解纤维素的还原糖得率的影响,得到了优化的纤维素水解反应工艺组合:反应温度180℃,Fe2+浓度0.0375mol/L,硫酸质量分数1%,反应时间90min。研究了Fe2+、Ni2+、Na+、Mg2+四种金属离子对稀酸水解纤维素制备还原糖的影响,结果表明,金属离子能明显提高稀酸水解纤维素的转化率和还原糖得率,其助催化作用的大小依次为:Fe2+>Na+>Ni2+>Mg2+,Fe2+对稀酸水解小麦秸秆制备还原糖的催化效果最佳,还原糖得率最高可达73.05%,纤维素转化率达到85.79%。

It was investigated that wheat straw was hydrolyzed catalyzed by dilute sulfuric acid by using orthogonal experiments. The optimal combination of factors was that the sulfuric acid concentration was 1%（w%）, the Fe^2＋ concentration Was 0.0375 mol/L, the temperature was 180℃ and the residence time was 90 min. The effects of Fe^2＋, Ni^2＋, Na^＋ and Mg^2＋ on the yield of sugar and conversion of cellulose were investigated. It showed that all the metal ions had obviously increased the yield of sugar and the conversion of cellulose in the order： Fe^2＋〉Na^＋〉Ni^2＋〉Mg^2＋. There was a maximum as Fe^2＋ was added, which the yield of sugar and the conversion of cellulose reached 73.05% and 85.79%, respectively.