Method for producing 1,1,3-trichloropropene by liquid-phase dehydrochlorination of 1,1,1,3-tetrachloropropane and recovering catalyst

Abstract

The invention discloses a method for producing 1,1,3-trichloropropene by liquid-phase homogeneous dehydrochlorination of 1,1,1,3-tetrachloropropane. The method comprises the following steps: using iron p-toluenesulfonate as a catalyst, carrying out heating dehydrochlorination on 1,1,1,3-tetrachloropropane in a stirred tank reactor to produce 1,1,3-trichloropropene, and adding an extractant after the reaction to recover the catalyst iron p-toluenesulfonate. The catalyst is good in activity, high in selectivity, easy to separate and recycle and environmentally friendly, after the reaction is finished, the catalyst is extracted and recycled through a solvent, waste solid emission is reduced, and the activity of the recycled catalyst is kept unchanged.

Description

technical field [0001] The invention relates to a method for liquid-phase dehydrochlorination of 1,1,1,3-tetrachloropropane, in particular to a liquid-phase dehydrochlorination of 1,1,1,3-tetrachloropropane to produce 1,1,3-trichloropropene and Catalyst recovery method. Background technique [0002] 1,1,3-Trichloropropene is a colorless liquid at normal temperature and pressure, with a density of 1.376g / cm 3 , with a boiling point of 131.5°C, it is an important intermediate for the synthesis of 2,3,3,3-tetrafluoropropene (HFO-1234yf), a new environmentally friendly refrigerant. With the emergence of ozone depletion and global warming, HFO-1234yf, a new environmentally friendly refrigerant, will gradually replace CFCs and HCFCs. [0003] Currently, 1,1,3-trichloropropene is mainly prepared by dechlorination of 1,1,1,3-tetrachloropropane. For example, 1,1,1,3-tetrachloropropane is prepared by dehydrochlorination with lye under the action of a phase transfer catalyst. This m...

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Problems solved by technology

For example, 1,1,1,3-tetrachloropropane is prepared by dehydrochlorination with lye under the action of a phase transfer catalyst. This method produces a lot of salty wastewater and waste solids, and the treatment cost is high.

CN110511112A discloses a gas-phase 1,1,1,3-tetrachloropropane empty pipe cracking technology, but the gas-phase dehydrochlorination reaction temperature is high, energy consumption is large, the material is easily decomposed at high temperature, and coke deposits on the pipe wall affect heat transfer

CN110511112A uses molecular sieve-supported catalyst gas-phase catalytic dehydrochlorination to prepare 1,1,3-trichloropropene, but because the olefin produced is unstable at high temperature, it is easy to coke on the surface of the catalyst, resulting in frequent regeneration of the catalyst, and the high-temperature regeneration process is prone to light gas

CN103119005A and CN105026346A respectively disclose aluminum trichloride and ferric chloride to catalyze 1,1,1,3-tetrachloropropane liquid-phase dehydrochlorination technology, because the activity of the two catalysts is high, the high boiling produced in the reaction is more, In addition, aluminum trichloride and ferric chloride are used for homogeneous catalyst dehydrochlorination. Because the catalyst is easily hydrolyzed and unstable, it is difficult to separate the catalyst from the system. Increased the processing cost of "three wastes"