酸性离子液体催化降解纤维素的研究

Cellulose degradation catalyzed by acid ionic liquids

以离子液体1-烯丙基-3-甲基咪唑氯盐([Amim]Cl)为溶剂,以咪唑类酸功能离子液体[Cnmim]HSO_4(n=2,3,4,5,6,7)为催化剂,在微波辅助加热条件下降解微晶纤维素(MCC),考察了反应温度、反应时间、催化剂用量、加水量、催化剂的哈米特酸度及种类等反应条件对MCC降解反应的影响。结果表明,酸性离子液体的催化效果与其酸性大小有关,其中[C_6mim]HSO_4的哈米特酸度值最小,酸性最强,作为催化剂时效果最佳,当[C_6mim]HSO_4的加入量为0.1 g,纤维素和催化剂的摩尔比为1∶1,反应温度为110℃,反应时间为40 min,加水量为70μL时,微晶纤维素转化率为100%,可还原糖收率为89.94%,葡萄糖收率高达46.24%。该反应使用常见的微波法,操作简单、方便、快速且无污染,与以往反应相比得到的葡萄糖收率较高,为在工业上应用提供了一种可行的方法。

Imidazolium based acid ionic liquids（ IBAILs） were used to catalyze the hydrolysis of cellulose in ionic liquid 1-allyl-3-methylimidazolium chloride via microwave-assisted irradiation. The effects of reaction temperature,reaction time,the catalyst dosage,amount of water and the type of catalysts on the degradation of cellulose were studied. The catalytic activity of IBAILs was showed to be relevant to their acidity,the [C_6mim]HSO_4acidity is best. The results indicated that [C6mim]HSO_4is an efficient catalyst for the degradation of cellulose. The cellulose can be completely converted with the highest TRS yield of89. 94% and glucose yield of 46. 24% under the condition of nMCC∶ n[C_6mim]HSO_4= 1 ∶ 1,the mass of[C_6mim] HSO_4= 0. 1 g,the dosage of water was 70 μL and reaction temperature 110 ℃ under microwave-assisted heating for 40 min. The reaction use microwave common method,simple and convenient operation,fast and no pollution,can get relative higher glucose yield than the old reaction. This study provides a feasible method to be widely used in industry.