Studies On Engineering Scale-up For Technology Of HFC-125 Synthesis

The wide use of Freons in 1980's results in the serious destruction of the ozone layer and global warming which greatly threat to human existence. To protect the ozone layer, The Montreal Protocol on Substances that Deplete the Ozone Layer came into effect in 1987 and in 1989 China joined the protocol later on. With the gradual phase out of Freons, it becomes more and more urgent to find a substitute for the freon product.This article focuses on the synthesis of one Freon substitute-1,1,1,2,2-pentafluroethane (HFC-125). In this study, the influences of the reaction condition to the reaction result such as reaction temperature, pressure, reaction time and the ratio of starting materials were investigated and consequently the optimum reaction conditions were determined. Furthermore pilot plant was designed and operated on the basis of the study. Meanwhile the methods for regeneration of the catalyst and the stability of the catalytic activity were fully studied. The synthetic path and parameters for the industrial manufacture of this product are given in this article too.The results show that the reaction temperature, time and the ratios of the starting materials have great impact on the reaction results while the reaction pressure has less impact. The optimum conditions for HFC-125 synthesis are given as follows: reaction temperature of 320, ambient pressure, ratio of starting materials of 4 and contact time of 48second. The preferred method for catalyst regeneration is that the deactivated catalyst treated with diluted air and hydrogen fluoride followed by treatment of hydrogen. The catalyst could be generated repeatedly for sixtimes while the reaction results kept to meet the industrial requirement and long catalyst life. The result of this study will lay a base for the design and operation of the commercial equipment.