A kind of preparation method of tetrafluoroethane catalyst

Abstract

The invention discloses a method for preparing a tetrafluoroethane catalyst. The steps are as follows: (1) Add a metal salt solution and a precipitant to a sedimentation tank to react to obtain reaction precipitation particles; (2) Aging and washing the reaction precipitation particles After drying, the catalyst precursor is obtained; (3) the catalyst is calcined in a calcining furnace; (4) the calcined catalyst is activated to obtain the final product for later use. The invention provides a technical solution for a preparation method of a tetrafluoroethane catalyst. The method is simple, has low labor intensity, and the prepared catalyst product has good quality and high activity, thereby effectively reducing the amount of reaction by-products generated in subsequent reactions, and at the same time The equipment and operation process of this treatment process are relatively simple, the operation is automated, the prepared catalyst has good repeatability, and the performance of the catalyst is stable, which improves economic benefits.

Description

technical field [0001] The invention relates to a preparation method of tetrafluoroethane catalyst. Background technique [0002] 1,1,1,2-Tetrafluoroethane (HFC-134a for short) is widely used in various refrigeration fields as a substitute for Freon refrigerants that can damage the atmospheric ozone layer. Economic Value. Major companies in the world have also spent a lot of financial and material resources to develop it, and applied for a large number of patents. Most of the current patents are based on the method of gas phase fluorination. Since the required reaction temperature is very high when prepared by the gas-phase fluorination method, and the conversion rate of each reaction is very low, the energy consumption in the reaction process is very large (Bell.S.L.USP 4129003). In addition, there is a large excess of hydrogen fluoride in the reaction process, and the reaction selectivity is unsatisfactory, which requires high conditions for product separation and purif...

AI Technical Summary

Problems solved by technology

This regeneration method has a better regeneration effect for most metal catalysts, but for structural fluorination catalysts, the regeneration effect is not ideal, and the activity of the regenerated catalyst can only reach 50% to 60% of the fresh catalyst

In addition, there are also problems such as the low specific surface area of ​​the fluorination catalyst, which leads to rapid decay of the catalytic activity of the catalyst and low selectivity of the target product.

In addition, although the patent discloses a method for activating the catalyst precursor by introducing a mixed gas of nitrogen and hydrogen, the induction period of the treated catalyst is still long, and the selectivity for the target product is low