超临界CO_2预处理耦合离子液体催化纤维素醇解制备甲基葡萄糖苷

Ionic liquid catalytic alcoholysis of cellulose to methyl glucosides promoted by supercritical CO_2 pretreatment

利用超临界CO_2(scCO_2)对微晶纤维素进行预处理,并采用功能化离子液体1-丙基磺酸-3-甲基咪唑硫酸氢盐([C_3SO_3Hmim]HSO_4)催化纤维素醇解生成甲基葡萄糖苷,考察了预处理温度、压力、时间及醇解温度、反应时间和催化剂用量等因素对甲基葡萄糖苷收率的影响。实验结果表明,scCO_2预处理过程可显著提高纤维素的醇解效率;scCO_2对微晶纤维素的最佳预处理条件为:140℃、25 MPa、处理时间2.0 h;当催化剂[C_3SO_3Hmim]HSO_4质量浓度为1.2 g/L时,在205℃下反应2.0 h,甲基葡萄糖苷收率最高值可达39.1%。

The microcrystalline cellulose（MCC） was pretreated by supercritical CO2（scCO2）. The prepared MCC was further converted into methyl glucosides（MG） in presence of methanol catalyzed by the functionalized ionic liquid 1-propylsulfonate-3-methylimidazolium hydrogensulfate（ [ C3SO3Hmim] · HSO4）. The effects of the pretreatment temperature, pressure, time, the alcoholysis temperature, reaction time and catalyst concentration on the yield of MG were investigated. The results showed that the scCO2 pretreatment process could significantly improve the alcoholysis efficiency of MCC. The optimum pretreatment conditions of MCC were as follows： 140 ℃, 25 MPa and treament time of 2.0 h. When pretreated cellulose was undergone alcoholysis, the highest MG yield of 39.1% can be obtained at the following conditions： the [C3SO3Hmim] HSO4concentration 1.2 g/L, 205 ℃ and the reaction time 2.0 h.