Method for continuously synthesizing 1, 1, 1, 3, 3-pentachloropropane

Abstract

The invention discloses a method for continuously synthesizing 1, 1, 1, 3, 3-pentachloropropane, which comprises the following steps: uniformly mixing carbon tetrachloride and vinyl chloride raw materials according to a certain ratio, pumping the mixture into a tubular reactor filled with an iron catalyst by using a pump, cooling the reaction discharged material by using a cold trap, collecting a reaction crude product, and distilling and rectifying the crude product to obtain the product, namely the 1, 1, 1, 3, 3-pentachloropropane. Unreacted materials enter the reactor to be recycled. Compared with the existing kettle-type intermittent or continuous reaction process, the method has the advantages of high catalytic reaction activity, low catalyst cost, wider selection, short reaction time, low by-product content, no need of subsequent separation of the catalyst, simple reaction process and equipment, and suitability for continuous industrial production.

Description

technical field [0001] The present invention relates to a preparation method of 1,1,1,3,3-pentachloropropane with molecular formula, in particular to the preparation of 1,1,1,3, Method for 3-Pentachloropropane. Background technique [0002] 1,1,1,3,3-Pentachloropropane is the raw material for the synthesis of 1,1,1,3,3-Pentafluoropropane (HFC-245fa), HFC-245fa is a new generation of environmentally friendly fluoride with an ODP value Zero, no potential damage to the atmosphere, can be used in a new generation of foaming agents, refrigerants and cleaning agents, and even can produce trifluoropropylene as a monomer for fluorosilicone rubber materials. HFC-245fa can eliminate hydrogen fluoride to obtain HFO-1234ze (1,3,3,3-tetrafluoropropene), which is also a new generation of environmentally friendly fluorohydroolefins with zero ODP value and no potential damage to the atmosphere. It is used as a new generation of refrigeration It can replace trifluoromethane and tetrafluoro...

AI Technical Summary

Problems solved by technology

Disadvantages of this process: (1) The telomerization reaction is a pressurized reaction, and it is difficult to design such a gap reaction. The output of a single kettle is too large, and the operation risk is high; (2) The reaction cycle is usually 5-10 hours, and the production efficiency is low. , the content of by-products is high, and the separation of iron powder catalyst is difficult, which affects the product quality and increases the cost of separation; (3) the reaction adopts mechanical stirring, which consumes a lot of electric energy

Patent 201410709721.X discloses a continuous reaction in a tubular reactor, but the main catalyst requires a composite iron material, and the co-catalyst is a phosphate or phosphite compound, and phosphorus will cause damage to the environment

Patent CN200510086571.2 discloses a tubular continuous reaction, but the main catalyst must be a composite metal catalyst, the co-catalyst is N-methylformamide, and the co-catalyst is single

[0005] In summary, the existing reported carbon tetrachloride and vinyl chloride telomerization process to synthesize 1,1,1,3,3-pentachloropropane is mainly kettle-type or kettle-type continuous, resulting in long reaction time and iron Difficult separation of powdered catalysts, serious back-mixing of materials, mechanical stirring is required, and large-scale production is difficult

There are also tubular continuous reports, but the main catalyst uses a composite metal catalyst, and the co-catalyst is single and also damages the environment.

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