The. Hfc245fa

Because of the destruction to the ozone layer in the atmosphere,the productin of chlorofluorocarbon have been stopped and usages are cutting down in the developed countries. In China, it is reduced of product and resume of freon CFC11. HFC245fa is wellknown as the best substitute for CFC11 in the world, which is widely used as blowing agent, refregerants, cleaning agent, cleaning agent , aerosol propellant in the indutrial field.This paper has introduced the physico-chemical properties of HFC245fa, its application and the method for producing HFC245fa. It is key to have discussed the test course of HFC245fa, by trying optimum reaction condition have determined by changing raw material molar ratio , catalyst quantity, reaction temperature and the reaction pressure and solvent .By studying we think it is viable by two step reaction for preparing HFC245fa, which comprise: (1) 1, 1, 1, 3, 3-pentachloropropane can be prepared by telomerization of vinyl chloride and carbon tetrachloride in the presence of CuCl as a catalyst and an amine co-catalyst, at a temperature in the range between about 120-130℃, 8 hours of reaction time, in the mole ratio 0. 5-0. 7 of vinyl chloride to carbon tetrachloride. The conversion of vinyl chloride is about 90%, the selectivity of 1, 1, 1, 3, 3-pentachloropropane is more than 97%. (2) HFC245fa can be prepared by liquid fluorination reaction in the presence of antimony pentachloride as a catalyst, on concentration 20-30wt% of catalyst, at a temperature in the range between about 60-80℃,with a pressure 5 and 15 atmospheres, in the mole ratio 7-9 of hydrogen fluoride to 1, 1, 1, 3, 3-pentachloropropane. The selectivity of 1, 1, 1, 3, 3-pentachloropropane is more than 95%.To improved quality of the product, the impurity R1233zd is removed by contacting chlorine with 2-4 mols of the mixture in the presence of ultraviolet, the contact time is 100 second. the impurity R1233zd is controlled to below 20 ppm.Moreover, we provided the analysis method of 1,1,1,3,3-pentachloropropane and HFC245fa.Finally we carried out preliminary manufacture design of industrialization production about HFC245fa and established operation rules.