Method for preparing trans-1,2-dichloroethylene

A dichloroethylene and cis technology, applied in the field of preparation of trans 1,2-dichloroethylene, can solve problems such as large output of trichloroethylene, and achieve the effects of simple process, easy separation and purification

Inactive Publication Date: 2018-07-20
JUHUA GROUP TECH CENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This method deacidifies and dehydrates the low boiling matter, and then distills the product. Although this method can...

Method used

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  • Method for preparing trans-1,2-dichloroethylene
  • Method for preparing trans-1,2-dichloroethylene

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preparation example Construction

[0014] A preparation method of trans-1,2-dichloroethylene of the present invention comprises the following steps: cis-1,2-dichloroethylene is isomerized under the action of a transposition catalyst to obtain trans-1,2-dichloroethylene , the reaction temperature is 150-250°C, the residence time is 0.5-5s, the reaction pressure is normal pressure, and the product formed by the reaction is purified by rectification to obtain trans-1,2-dichloroethylene, and the transposition catalyst is Al 2 o 3 The main catalyst is a metal additive added to the main catalyst, wherein the metal additive accounts for 0.5% to 5%. Preferably, the metal additive is one of Ti, Cr, Fe, Ni and Zn. Preferably, the reaction The temperature is 180-230°C. The reaction temperature has a great influence on the performance of the conversion catalyst. If the reaction temperature is too high, the conversion rate of cis-1,2-dichloroethylene will increase, but the conversion rate of trans-1,2-dichloroethylene will ...

Embodiment 1

[0017] A certain amount of Zn / Al 2 o 3 The transposition catalyst is loaded into the tubular reactor, and the auxiliary agent accounts for 1.5%. The cis-1,2-dichloroethylene is vaporized and injected into the tubular reactor for reaction. The reaction temperature is 220°C, and the residence time is In 2.5s, the reaction pressure was at normal pressure, and the crude product formed was collected by cooling, rectified and purified to obtain pure trans-1,2-dichloroethylene.

[0018] During the reaction, the cracked gas generated in the tubular reactor was analyzed, and the analysis results are shown in Table 1.

Embodiment 2

[0020] A certain amount of Ti / Al 2 o 3 The transposition catalyst is loaded into the tubular reactor, and the auxiliary agent accounts for 5%. The cis-1,2-dichloroethylene is vaporized and injected into the tubular reactor for reaction. The reaction temperature is 250°C, and the residence time is In 2.5s, the reaction pressure was at normal pressure, and the crude product formed was collected by cooling, rectified and purified to obtain pure trans-1,2-dichloroethylene.

[0021] During the reaction, the cracked gas generated in the tubular reactor was analyzed, and the analysis results are shown in Table 1.

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Abstract

The invention discloses a method for preparing trans-1,2-dichloroethylene. The method includes the steps that isomerization of cis-1,2-dichloroethylene is performed under the action of a transpositioncatalyst to obtain trans-1,2-dichloroethylene, the reaction temperature is 150-250 DEG C, the residence time is 0.5-5 h, the reaction pressure is normal pressure, and the product obtained by the reaction undergoes purification by rectification to obtain trans-1,2-dichloroethylene. The transposition catalyst is adopted to perform cis-trans isomerization of 1,2-dichloroethylene, the process is simple, the product is easy to separate and purify, and the generated crude product undergoes operations of rectification and purification and the like to obtain the pure trans-1,2-dichloroethylene.

Description

technical field [0001] The invention relates to a preparation method of trans-1,2-dichloroethylene. Background technique [0002] Trans-1,2-dichloroethylene can be used as a solvent for paints, resins, waxes, rubber, and cellulose acetate, as well as for dry cleaning agents, insecticides, fungicides, anesthetics, low-temperature extractants and refrigerants, and for the preparation of Varnishes and rubber solutions, etc. In recent years, trans-1,2-dichloroethylene has been used as a foaming agent for polyurethane. With the deepening of research, trans-1,2-dichloroethylene has become more and more widely used. Studies have shown that trans-1,2-dichloroethylene can not only be used in organic solvents and low-temperature extractant industries, but also has no destructive effect on the atmosphere. Therefore, with the increasing awareness of environmental protection, vigorously developing trans-1,2-dichloroethylene products has obvious economic and social benefits. [0003] ...

Claims

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Application Information

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IPC IPC(8): C07C21/073C07C17/358
CPCC07B2200/09C07C17/358C07C21/073
Inventor 张万宏马利勇
Owner JUHUA GROUP TECH CENT
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