Process and equipment for preparing monochloromethane from hydrogen chloride gas containing carbon dioxide

Abstract

The invention relates to the field of C1 chemistry and particularly relates to technology and equipment for preparing methane chloride from a carbon dioxide-containing hydrogen chloride gas. The equipment mainly comprises a reaction system, an absorbing-washing-recycling system, a drying system, a compression system and a refining system. The technology comprises the following steps: preheating carbon dioxide-containing hydrogen chloride and methanol respectively and feeding into the reaction system to generate methane chloride in the reaction system; feeding the methane chloride reaction gasinto the absorbing-washing-recycling system; performing cooling and washing to condense the unreacted hydrochloric acid and methanol and the water generated by the reaction; returning the methanol tothe reaction system through an absorption tower; performing washing and absorption, and feeding the methane chloride into the drying system to remove the water, trace methanol and the dimethyl ether generated by the reaction; pressurizing the methane chloride by a compressor and feeding into the refining system to obtain a methane chloride product, and discharging the tail gas up to standard or utilizing the tail gas in other ways. Compared with a method of absorbing the carbon dioxide-containing hydrogen chloride tail gas and then decomposing to obtain hydrogen chloride, the method provided by the invention has the advantages of low energy consumption and low operation cost.

Description

technical field [0001] The invention relates to the field of carbon-chemical industry, in particular to a process for preparing monochloromethane from hydrogen chloride gas containing carbon dioxide. Background technique [0002] Chloromethane is mostly generated by the reaction of high-purity hydrogen chloride and methanol. When the raw material hydrogen chloride contains inert gas, since the monochloromethane containing inert gas is condensed and separated, the inert gas after separation contains a relatively high amount of monochloromethane. This part is inert. The cost of gas treatment to meet the standard is very high, so when hydrogen chloride containing inert gas is used as the raw material for producing monochloromethane, the hydrogen chloride containing inert gas is usually absorbed with dilute hydrochloric acid to form concentrated hydrochloric acid, and then the hydrogen chloride is resolved by heating concentrated hydrochloric acid to obtain high Pure hydrogen ch...

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Problems solved by technology

[0002] Chloromethane is mostly generated by the reaction of high-purity hydrogen chloride and methanol. When the raw material hydrogen chloride contains inert gas, since the monochloromethane containing inert gas is condensed and separated, the inert gas after separation contains a relatively high amount of monochloromethane. This part is inert. The cost of gas treatment to meet the standard is very high, so when hydrogen chloride containing inert gas is used as the raw material for producing monochloromethane, the hydrogen chloride containing inert gas is usually absorbed with dilute hydrochloric acid to form concentrated hydrochloric acid, and then the hydrogen chloride is resolved by heating concentrated hydrochloric acid to obtain high Pure hydrogen chloride, and then react with methanol to obtain monochloromethane, although this side obtains high-purity hydrogen chloride, but the energy consumption is high, and the production cost of monochloromethane is relatively high

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