A safe and efficient process for the preparation of difluoromethane in continuous flow  

作　　者：Tao Shen Xin Ge Hengjun Zhao Zhixiong Xu Shaofeng Tong Shaodong Zhou Chao Qian Xinzhi Chen 

机构地区：[1]College of Chemical and Biological Engineering,Zhejiang University,Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology,Hangzhou 310027,China [2]School of Chemical and Material Engineering,Jiangnan University,Wuxi 214122,China [3]Jiangsu Sanmei Chemical Co.,Ltd.,Nantong 226461,China

出　　处：《Chinese Journal of Chemical Engineering》2020年第7期1860-1865,共6页中国化学工程学报（英文版）

基　　金：financial support from the National Natural Science Foundation of China(21878265,21606104);the National Key Research and Development Program of China(2016YFB0301800)。

摘　　要：Difluoromethane is typically produced vialiquid-phase fluorination as performed in a batch reactor.However,this process suffers from some problems,e.g.,severe corrosion of the reactor,high safety risk,and the regeneration of the catalyst.In this paper,a flow process as performed in the tubular reactor was designed.The optimum conditions for continuous synthesis of difluoromethane were obtained as follows:the reaction temperature was 100℃,the molar ratio of dichloromethane to hydrogen fluoride was 1.6:1 and the reaction time was 300 s.The operation of the cyclic process was stable for 24 h with the conversion per pass of hydrogen fluoride up to 16.2%.The unreacted raw materials were easily reused.The deactivation of the common catalyst,antimony pentachloride,was investigated by catalyst concentration curve and XPS analysis.The approach proposed in this work is proven to be safe,efficient and low amount of catalyst.

关 键 词：Tubular reactor Continuous synthesis DIFLUOROMETHANE CATALYST 

分 类 号：TQ222.213[化学工程—有机化工] TQ426