Complete recovering technique for hydrochloride in industrial gas

Abstract

The present invention relates to a full recovery process of hydrogen chloride in industrial gas, comprising the following sequential steps: (1) After the industrial gas containing hydrogen chloride enters from the lower part of the combined absorption tower, after being absorbed by the water from the upper part, the concentration of 99% is obtained at the top of the tower Above industrial gas, concentrated hydrochloric acid is obtained at the bottom of the tower; the combined absorption tower comprises successively from bottom to top: a gas distribution area, a packing absorption area, a gas-liquid separation area, and a tray absorption area, and the bottom of the gas distribution area is provided with a gas inlet, There is a water inlet in the upper part of the absorption zone of the tray, and the industrial gas and water conduct heat and mass transfer in the combined absorption tower; (2) pass the concentrated hydrochloric acid into the concentrated acid desorption tower for desorption; (3) pass the dilute hydrochloric acid into the Desorption is carried out in the dilute acid desorption tower. The hydrogen chloride full recovery process of the present invention operates in multiple working conditions, can absorb all the hydrogen chloride and then convert it into synthetic raw material gas through desorption, realizes zero discharge, simplifies the process, and facilitates process control.

Description

(1) Technical field [0001] The invention relates to a process for fully recovering hydrogen chloride in industrial gas. (2) Background technology [0002] Existing industrial production often involves the recovery and treatment of hydrogen chloride in chlorinated products. For example, taking the excess hydrogen chloride treatment process in vinyl chloride production as an example, most domestic manufacturers use activated carbon for crude vinyl chloride to come out of the converter and enter the mercury remover. After adsorbing mercury vapor (mainly containing high-chloride mercury compounds), it enters the synthesis gas graphite cooler to cool the gas to about 40°C before entering the deacidification system consisting of 1 to 2 sieve tray towers to recover excess hydrogen chloride in the synthesis gas , to produce 25-30% by-product hydrochloric acid. The synthesis gas after acid production enters the water washing tower and the alkali washing tower for purification, absor...

AI Technical Summary

Problems solved by technology

[0008] E. Alkaline washing tower is not continuously operated, and the lye needs to be replaced regularly, which has a certain impact on the quality of vinyl chloride refining

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