Method for recovering hydrogen chloride gas in production process of chlorodifluoromethane and device

Abstract

The invention discloses a method for recovering hydrogen chloride gas in production process of chlorodifluoromethane. The organic mixture of hydrogen chloride obtained in the chlorodifluoromethane production process and chlorodifluoromethane is led into a hydrogen chloride rectifying tower; after rectifying, hydrogen chloride is discharged from the top of the tower; the obtained hydrogen chloride is condensed to obtain liquid-phase hydrogen chloride and gas-phase hydrogen chloride, wherein, the liquid-phase hydrogen chloride flows back to the rectifying tower, and trace of fluorinion of the gas-phase hydrogen chloride is removed by a subsequent defluorination device so as to obtain hydrogen chloride gas. The invention can effectively recover by-product hydrogen chloride gas in the chlorodifluoromethane production process and comprehensively utilize hydrogen chloride gas to make waste profitable; in addition, the invention prevents parts of hydrogen chloride gas from volatilizing, prevents hydrochloric acid from polluting ambient environment and prevents hydrochloric acid from corroding devices and ducts.

Description

technical field [0001] The invention relates to a method and a device for recovering hydrogen chloride gas from the production of chlorodifluoromethane. Background technique [0002] In the process of producing chlorodifluoromethane by using chloroform and anhydrous hydrofluoric acid under the action of catalyst antimony pentachloride, a large amount of by-product HCl is produced, which is 0.84 times that of the product chlorofluoromethane. At present, it is commonly used to carry out three-stage absorption of hydrogen chloride gas by water absorption method, and absorb it into low-concentration hydrochloric acid for sale or treatment. However, hydrogen chloride gas is a volatile gas. In the process of absorbing into hydrochloric acid, part of the gas will inevitably volatilize, which will seriously affect the environment and personal health. Moreover, hydrochloric acid will seriously corrode the surrounding environment, equipment and pipelines. At the same time, the hydroge...

AI Technical Summary

Problems solved by technology

However, hydrogen chloride gas is a volatile gas. In the process of absorbing into hydrochloric acid, part of the gas will inevitably volatilize, which will seriously affect the environment and personal health. Moreover, hydrochloric acid will seriously corrode the surrounding environment, equipment and pipelines. At the same time, the hydrogen chloride itself In terms of value, its economic value has not been reflected

Images