The process of preparing difluoroethane from acetylene

The conventional production process of 1,1-difluoroethane is to use acetylene as raw material and react with hydrogen fluoride under the action of catalyst (such as boron trifluoride, fluorosulfonic acid, antimony pentafluoride). The reaction formula is as follows: The process flow of CHCH + 2HF---- CH3CHF2 is that purified and dried acetylene is sent into a reactor equipped with a catalyst (such as fluorosulfonic acid) and hydrogen fluoride, and reacts at a certain pressure and temperature to generate 1,1-difluoroethane. After water washing, alkali washing, and acid removal, the gas phase material is compressed into a liquid phase material, and is obtained after fractionation and purification. The reaction is semi-continuous. Liquid hydrogen fluoride is added to the reactor, while gaseous acetylene is continuously passed into the reactor. When the conversion rate is lower than 60% (in the second-stage reaction, the conversion rate in the first-stage reactor), the reaction is stopped, the remaining material in the reactor (usually called residue) is discharged, the catalyst and hydrogen fluoride are re-added, and the reaction starts again. The shortcomings of the above production process are: The reaction between acetylene and hydrogen fluoride is an exothermic reaction. The accumulation of a large amount of generated heat in the reactor will inevitably have an adverse effect on the reaction, making it difficult to control the reaction. The life and activity of the catalyst will be reduced, which in turn will lead to a decrease in conversion rate and yield. Measures should be taken during the production process to transfer the heat generated in a timely manner. Shandong Dongyue Chemical Co., Ltd. proposed a method to improve production equipment in patent CN1994985. The equipment can release the heat released by the reaction in a timely manner, the reaction temperature is easy to control, and can ensure a high reaction conversion rate and product yield.

I remember there was an article introducing the catalyst deactivation factor of F152a, which mentioned reducing water and adding a small amount of other catalysts.

I strongly look forward to the original poster sharing further information.