A kind of method that methyl chloride prepares vinyl chloride monomer

Abstract

The invention discloses a method of using chloromethane to prepare a vinyl chloride monomer. The vinyl chloride monomer is prepared by enabling chloromethane to react with oxygen in the existence of a catalyst with the methane oxidation coupled reaction activity, wherein the reaction equation is 4CH3Cl plus O2 to generate 2C2H3Cl plus 2H2O plus 2HCl; the molar ratio of chloromethane to oxygen is 1:(0.1-10); the reaction temperature is 300-900 DEG C; the reaction pressure is 1-10 atm. The method disclosed by the invention is wide in source of the raw materials, low in prices, and low in production cost; the selectivity of the vinyl chloride monomer is high; the method is a novel technology for synthesizing the vinyl chloride monomer and suitable for popularization and application.

Description

technical field [0001] The invention relates to a method for preparing vinyl chloride monomer, in particular to a method for preparing vinyl chloride monomer by coupling reaction of methyl chloride with oxygen. Background technique [0002] Vinyl chloride (CH 2 CHCl) is an important monomer used in polymer chemical industry, and is widely used in the production of polyvinyl chloride (PVC) in industry. At present, the industrial production of vinyl chloride monomer mainly includes two process routes: acetylene method and ethylene method. [0003] The acetylene method uses acetylene and hydrogen chloride as raw materials, and reacts to synthesize vinyl chloride monomer under the action of mercury catalyst (mercury chloride loaded on activated carbon), and the vinyl chloride monomer is polymerized to obtain PVC. The process of the method is simple, the conversion rate of acetylene is higher than 98%, and the selectivity of vinyl chloride is higher than 99%, which is the earli...

AI Technical Summary

Problems solved by technology

In the vinyl chloride monomer synthesis process of the ethylene method, the reaction temperature of the ethylene dichloride pyrolysis furnace is only 500-550°C, while in the French patent FR2711649, methyl chloride and chlorine need to be reacted at a high temperature of 700-1300°C. This will inevitably require higher corrosion resistance and high temperature tolerance of the reaction device, which will greatly increase the investment cost of the reaction device

[0031] (2) Poor route feasibility

U.S. Patent No. 7,253,328 provides a new idea for the synthesis of vinyl chloride from methane chloride, and theoretically analyzes the synthesis of vinyl chloride from methylene chloride and dichloromethane, but does not give specific examples

In fact, follow-up studies conducted by domestic researchers have shown that it is difficult to find a suitable catalyst that can convert methyl chloride and methylene chloride into vinyl chloride.

It shows that so far, it is very difficult for the new synthesis process of vinyl chloride provided by this patent to change from theory to reality

[0032] (3) Low selectivity of vinyl chloride

The high-temperature thermal cracking route of methyl chloride and chlorine gas given in French patent FR2711649 can obtain about 30% selectivity of vinyl chloride. Other new technological routes are whether methyl chloride or methylene chloride is reacted alone at 450°C under the action of a catalyst, or chlorine Methane undergoes oxidative pyrolysis reaction at 900-1200°C in the presence of oxygen, and the selectivity of vinyl chloride obtained is lower than 10%, which is basically of no practical value

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