四甲基胍催化碳酸丙烯酯与乙醇酯交换合成碳酸二乙酯

Synthesis of Diethyl Carbonate by Transesterification of Propylene Carbonate and Ethanol Catalyzed by Tetramethyl-Guanidine

采用半连续操作方式，对四甲基胍（TMG）催化碳酸丙烯酯（PC）与乙醇酯交换合成碳酸二乙酯（DEC）反应进行了研究，重点考察了操作条件对合成DEC反应的影响。实验结果表明，TMG催化合成DEC的适宜反应条件为：催化剂用量为初始反应物质量的2．6％，乙醇与PC的摩尔比为10，反应温度80～85℃，反应时间为8h，乙醇滴加速率为1．5mL／min，全回流时间为0。在此条件下，PC转化率为95．8％，DEC收率为90．7％，DEC选择性为94．7％；说明TMG对PC与乙醇酯交换合成DEC反应具有良好的催化性能。

Synthesis of diethyl carbonate （DEC） through transesterification of propylene carbonate （PC） and ethanol over tetramethyl-guanidine（TMG） catalyst was studied in a set of semi-continuous apparatus. The influences of the reaction conditions on the DEC synthesis were investigated. Under the suitable reaction conditions of mass fraction of catalyst 2.6% （based on mass of the initial reactants）, mole ratio of ethanol to PC 10, reaction temperature 80 -85 ℃, reaction time 8 h, drip feed rate of ethanol 1.5 mL/min and total reflux time 0, the conversion of PC, the yield and the selectivity of DEC were 95.8 %, 90.7 % and 94.7 %, respectively.