液相氟化催化合成二氟甲烷反应机理及腐蚀性(待续)  

Reaction Mechanism in Liquid Phase Fluorinated Catalytic Synthesizing Difluoromethane and the Corrosivity

作　　者：欧阳豪[1] 贺辉龙 周黎旸 钟依均[1] 

机构地区：[1]浙江师范大学物理化学研究所,浙江金华321004 [2]浙江衢化氟化有限公司,浙江衢州324004

出　　处：《化工生产与技术》2011年第6期8-11,7,共4页Chemical Production and Technology

摘　　要：介绍了第3代氟制冷剂二氟甲烷的性质和用途。分别从化学反应热力学和反应动力学角度分析了二氯甲烷液相氟化反应,指出选择适宜的反应温度可以获得较优的二氯甲烷转化率和二氟甲烷选择性;提出二氯甲烷液相氟化催化合成二氟甲烷的双分子亲核取代反应机理,并归纳了烷基结构和多氯代甲烷、离去基团的碱性、溶剂化作用、亲核试剂的亲和力、液相-气相平衡、Lewis酸强弱等方面对该氯氟交换反应速率的影响,认为该反应过程中会形成一个缓慢地腐蚀反应器质材的混合液体超强酸体系。As the third generation refrigerant,the properties and applications of difluoromethane(HFC-32) were reviewed briefly in this paper.The liquid phase fluorinated dichloromethane was analyzed both chemical reaction thermodynamics and reaction kinetics,indicated that opting the appropriate reaction temperature could obtain superior dichloromethane conversion and difluoromethane selectivity;A bimolecular nucleophilic substitution reaction was proposed as the reaction mechanism model and also summarized the effects of this Cl/F exchanged reaction rate,for instance: alkyl structures,polychlorinated methane,alkalinity of the leaving groups,solvation,nucleophilic affinity,liquid-vapor equilibrium,acidity strength of Lewis acid and so on.In this process,it formed a mixed liquid superacid system which corroded tardily reactor materials.

关 键 词：液相氟化催化 二氟甲烷 反应机理 质材 腐蚀性 

分 类 号：TQ222.217[化学工程—有机化工]