光热法制备氯代碳酸乙烯酯的工艺条件和反应动力学

Process Conditions and Reaction Kinetics for The Preparationof Chloroethylene Carbonate by Photothermal Method

氯代碳酸乙烯酯(CEC)主要用于锂电池电解液添加剂和有机合成中间体,其工业化生产一直是合成化学中研究的课题。本文利用碳酸乙烯酯(EC)为原料,在紫外光和加热条件下,通入氯气,生成氯代碳酸乙烯酯。通过改变反应时间、反应温度和氯气流量,用气相色谱方法测量EC转化率和CEC收率,系统地研究了工艺条件对光热法制备CEC过程的影响。结果表明:反应时间、反应温度和氯气流量对CEC的合成过程都有十分重要的影响。综合考虑CEC收率和副产物收率,选择最佳工艺条件为:反应时间4 h,反应温度85℃,氯气流量80 mL/min。通过加入自由基抑制剂,确定了制备CEC的过程为自由基反应。通过研究不同时间原料的转化率,确定了该反应为一级动力学反应,该反应的活化能为37.65 kJ/mol。

With the advancement of the lithium battery industry, the demand for vinyl carbonate (VC) as an organic film forming additive is gradually increasing. Chlorinated ethylene carbonate (CEC) is mainly used as an additive in lithium battery electrolytes and as an intermediate in organic synthesis. Consequently, it becomes imperative to conduct research on the CEC, which serves as one of raw materials for VC synthesis. The raw material ethylene carbonate (EC) was subjected to chlorination under ultraviolet light and heating conditions to produce CEC. The effects of process conditions on the preparation of CEC by photothermal method were systematically investigated through variations in reaction time, reaction temperature and chlorine flow rate. The EC conversion and CEC yield were measured using gas chromatography. The results demonstrated that the reaction time, reaction temperature and chlorine flow rate exert significant influences on the synthesis process of CEC. Considering both CEC yield and by-product yield, the optimal process conditions were determined as follows: reaction time 4 h, reaction temperature 85 ℃, and chlorine flow rate 80 mL/min. The preparation of CEC was determined to involve a free radical reaction through the addition of free radical inhibitors. By investigating the conversion rate of the feedstock at various times intervals, it was established that the reaction follows first-order kinetic.