反应-萃取技术合成碳酸二甲酯反应研究Ⅰ.萃取剂的筛选

将反应-萃取技术应用于甲醇和碳酸丙烯酯(PC)酯交换合成碳酸二甲酯(DMC)反应过程。对于以KOH为催化剂的均相反应．当以正辛烷为主萃取剂、邻苯二甲酸二辛酯(DOP)为助萃取剂，萃取相与反应相体积比为2．8：1．正辛烷与DOP体积比为1：1.5．催化剂占体系的重量百分率为3．0％．反应温度为50℃．反应时间为3h时，DMC的分配系数为1.07，DMC与甲醇的分离系数为7．75,DMC的收率为64．8％．选择性为76．0％。与未加萃取剂时相比，DMC收率提高了47．6％，选择性提高了26．7％。

Synthesis of Dimethyl Carbonate with Reactive Extraction Technology Ⅰ . Screening of Extractants

Reactive extraction technique was incorporated in the reaction of synthesizing dimethyl carbonate (DMC) by transesterification of methanol and propylene carbonate. A series of alkanes were tested as the extractants in the homogeneous reaction system catalyzed by KOH. The results showed that n-octane is a feasible extractant. On the basis of n-octane as the main extractant, bi(2-ethylhexyl) phthalate (DOP) was determined as the accessory extractant. By the optimization of the amounts of extratants, the volumetric ratio of extract phase to reaction phase was determined to be 1 : 2. 8, The optimal volumetric ratio of the main extratant and the accessory extractant is 1: 1. 5. The distribution coefficient of DMC is 1. 07, the DMC yield is 64. 8%, and the selectivity is 76. 0% under the above conditions. Comparing with the reaction without extractant, the DMC yield has increased by 47. 6% and the selectivity by 26. 7%.