Method for preparing 1,1,1,3,3,3-hexafluoroacetone by gas phase fluorination

Abstract

The invention discloses a method for preparing 1,1,1,3,3,3-hexafluoroacetone by gas phase fluorination. The method comprises that 1,1,1,3,3,3-hexachloroacetone as a raw material undergoes a one-step gas phase fluorination reaction in the presence of a fluorination catalyst at a reaction temperature of 300 DEG C to produce 1,1,1,3,3,3-hexafluoroacetone, wherein a mole ratio of hydrogen fluoride to the organic matter is 10: 1 and contact time is 10s. The fluorination catalyst is a ferric compound-loaded catalyst. A preparation method of the fluorination catalyst comprises utilizing alumina, magnesium oxide or calcium oxide as carriers, dipping the carriers in an iron soluble salt and one of soluble salts of metal cocatalysts such as copper, manganese, zinc, nickel, cobalt and lanthanum to obtain a catalyst precursor with a mass ratio of iron to the carriers of 2-20% and cocatalyst content of 0.5-2wt%, and carrying out drying, roasting and HF fluorination. The prepared fluorination catalyst has the characteristics of environment-friendliness, low price, good catalytic activity, good stability and regeneration easiness. The method realizes high-selectivity synthesis of the 1,1,1,3,3,3-hexafluoroacetone.

Description

technical field [0001] The present invention relates to a kind of preparation method of 1,1,1,3,3,3-hexafluoroacetone, especially to a kind of using hydrogen fluoride and 1,1,1,3,3,3-hexachloroacetone as raw materials, in The invention relates to a preparation method for obtaining 1,1,1,3,3,3-hexafluoroacetone by gas-phase fluorination reaction in the presence of a fluorination catalyst. Background technique [0002] Hexafluoroacetone (CF 3 COCF 3 ,HFA) is the simplest perfluoroketone compound, and it is also an important fluorine-containing intermediate with a wide range of uses. At present, hexafluoroacetone has been widely used in the fields of medicine, pesticide and synthetic materials, especially as a raw material for the synthesis of polymer materials in special fields, which has profound significance. [0003] French patent FR1372549 reported that under the action of a catalyst composed of a trivalent chromium compound, at 350-450°C, hexachloroacetone and hydrogen...

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Problems solved by technology

However, the catalysts used in this method are all chromium-based catalysts, which have the problems of high reaction temperature, low product yield, and difficult separation of products, which limit its industrial application.

In addition, it has been proved that chromium compounds are toxic and can cause damage to the human digestive tract and kidneys, and high-valent chromium has a strong carcinogenic effect, and its production and use will cause harm to humans and the environment. At the same time, the thermal stability of chromium-containing catalysts is poor , the catalytic activity of the catalyst at high temperature cannot be guaranteed

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