Purification method of, 1, 1-difluoroethane

Abstract

Crude 1,1-difluoroethane containing at least one compound selected from the group consisting of unsaturated compounds each having two carbon atoms within the molecule and saturated chlorine-containing compounds each having two carbon atoms within the molecule is brought into contact with a zeolite and / or a carbonaceous adsorbent, or crude 1,1-difluoroethane containing hydrogen fluoride and, as impurities, at least one compound selected from the group consisting of unsaturated compounds each having two carbon atoms within the molecule is brought into contact with a fluorination catalyst in a gas phase state. High-purity 1,1-difluoroethane usable as a cryogenic refrigerant, or as an etching gas, can be produced in an industrially advantageous manner.

Description

technical field [0001] The present invention relates to a purification method, production method and use of 1,1-difluoroethane. Background technique [0002] 1,1-Difluoroethane (CH 3 CHF 2 ) have attracted attention as, for example, cryogenic refrigerants or etching gases. [0003] For the production and purification methods of 1,1-difluoroethane, the following methods are generally employed, such as (1) a method of reducing chlorinated fluorinated hydrocarbons with hydrogen in the presence of a catalyst (see Japanese Unexamined Patent Publication No. 7 -126197 (JP-A-7-126197)), and (2) reacting chlorine in the gas phase by using a fluorination catalyst and reacting unsaturated compounds contained as impurities with oxides of copper, cobalt, silver, magnesium, etc. Ethylene (CH 2 =CHCl), 1-chloro-1-fluoroethane and other fluorinated methods (see European Unexamined Patent Publication No. 0370688). [0004] For example, CH produced by the method of reacting 1,1-dichloroe...

AI Technical Summary

Problems solved by technology

However, the purification method by extractive distillation requires many expensive facilities such as distillation towers, which disadvantageously results in high equipment costs, etc.

Also, the purification method using hydrogen has problems such as high equipment cost and short catalyst life due to use of combustibles

In addition, hydrogen chloride is produced, therefore, the lifetime of the catalyst is shortened