HFC-125与CFC-115的分离方法

研究了含五氟氯乙烷(CFC-115)的五氟乙烷(HFC-125)混合物中提纯HFC-125的方法。并用萃取精馏法将其分离提纯。萃取剂可以是环己酮、乙腈、硝基甲烷、丙酮与环己酮的混合物,乙酸乙酯与乙酸丁酯的混合物或工业乙醇和乙酸乙酯的混合物。用这些萃取剂可将CFC-115/HFC-125体系的相对挥发度提高至2.7以上。富集了HFC-125的萃取液经简单分馏即可得到精制的HFC-125。萃取剂可反复使用。采用此工艺的萃取精馏塔理论塔板数可降低至20块以下。该工艺已获中国发明专利(CN1120828C),并已在千吨级生产装置上实际应用。

Separation of HFC-125 and CFC-115

The purification of HFC-125 from a mixture of CFC-115 and HFC-125 can be achieved through extractive distillation.Effective extractive agents include cyclohexane,acetonitrile,nitromethane,mixture of acetone and cyclohexane,mixture of ethyl acetate and butyl acetate and mixture of industrial alcohol and ethyl acetate.These extractive agents improve the relative volatility of CFC-115/HFC-125 to above 2.7.High purity HFC-125 can be obtained from the extracting solution with simple distillation.Moreover,the extractive agents can be recycled.When this new technique was applied,the theoretical plate number of the extractive distillation tower can be reduced to less than 20.The technique has been granted a patent of China(CN1120828C) and has been applied in 1000 t/a device.