Preparation method of perfluoropropane

Abstract

The invention discloses a preparation method of perfluoropropane. The preparation method comprises following steps: S1, hexafluoropropene and diluted fluorine gas are uniformly mixed at a certain molar ratio so as to obtain a mixed raw material gas; S2, the mixed raw material gas is delivered into a fixed bed reactor containing a cobalt catalyst at an appropriate temperature under appropriate pressure conditions for reaction so as to obtain a mixed gas containing perfluoropropane; S3, the mixed gas containing perfluoropropane is delivered into an alkaline washing tower and an absorber successively for treatment so as to remove a trace of fluorine gas, hydrogen fluoride, and water, and obtain crude perfluoropropane; and S4, the crude perfluoropropane is delivered into a rectification systemfor further refining so as to obtain high purity perfluoropropane. The beneficial effects are that: hexafluoropropene is taken as a preparation raw material, perfluoropropane is prepared via additionreaction of hexafluoropropene with diluted fluorine gas under the action of the cobalt catalyst, the raw material conversion rate is high, yield is high, selectivity is high, the preparation method is simple, production cost is low, operation is convenient, reaction temperature is low, and energy consumption is low.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for preparing octafluoropropane with high raw material conversion rate, high yield, low cost and simple process. Background technique [0002] Octafluoropropane, also known as perfluoropropane, was first prepared in 1937 by American chemists Simons and Block by reacting fluorine gas and carbon in the presence of a catalyst. Octafluoropropane is currently a widely used fluorocarbon gas. It is often used as an etching or cleaning gas in the semiconductor device production process in the semiconductor industry. It can also be used as an ultrasound contrast agent in the medical industry. In addition, it is often used in other industries. One of the components of the refrigerant mixture. [0003] Regarding the preparation of octafluoropropane, the current main synthetic routes include direct gas-phase fluorination of hydrocarbons (patent US5406008), electrolytic fluorination...

AI Technical Summary

Problems solved by technology

The method is divided into two steps, first cobalt difluoride is fluorinated into cobalt trifluoride, and then reacted with hexafluoropropylene, which requires two reactors in continuous production, one for fluorination and one for reaction, which makes the process relatively It is cumbersome and complicated to operate; in addition, in the production process, due to the continuous cycle conversion between cobalt trifluoride and cobalt difluoride, the fluorinating agent is constantly changing due to the size of the internal molecular structure, which may easily cause the fluorinating agent in the fixed bed reactor Pulverization occurs, and the fluorinating agent needs to be replaced frequently

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