Method for removing residual chlorine gas in tail gas in production processes of chloroacetic acid

Abstract

The invention discloses a method for removing residual chlorine in the tail gas during the production process of chloroactic acid. A device adopted by the method comprises a reaction absorption tower; the process of the method is that the tail gas generated in a chlorinating reactor enters the reaction absorption tower from the bottom of the absorption tower through a condenser; acetic acid whichis one of the chlorinating reaction raw materials is used as absorbent which enters the absorption tower from the top part of the reaction absorption tower; the tail gas and the absorbent carry out areflux contact reaction in the tower and the operation is circularly carried out; when the chlorine content in the tail gas achieves the standard, the tail gas is sent to a saturated hydrochloride solution washing tower; the absorbing solution at the bottom of the saturated hydrochloride solution washing tower is used as the raw materials in the next chlorinating reaction. The method of the invention has simple devices, mild operation conditions, requires no desorption operation and disposal of absorbent, thus saving the equipment expense and operation expense, also has high utilization ratioof chlorine resource and is beneficial for environmental protection.

Description

technical field [0001] The invention relates to a method for removing residual chlorine in tail gas in the production process of chloroacetic acid, in particular to a tail gas treatment technology in the production process of organic chlorination. Background technique [0002] In many organic chlorination processes, it involves the step of directly introducing chlorine gas into the material for reaction, and the tail gas generated in this step contains a large amount of by-product hydrogen chloride gas and part of unreacted chlorine gas. Most of the domestic use of single-stage adiabatic absorption method to refine hydrogen chloride into hydrochloric acid. However, when the chlorine in the mixed gas enters the absorption system, it will affect the color and concentration of hydrochloric acid. The product quality of hydrochloric acid is not high, and it can only be used for metal pickling, and the added value is very low. Part of the unreacted chlorine gas cannot be directly...

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Problems solved by technology

[0006] The above methods all have long process flow and complex equipment, and the temperature and pressure of the absorption / desorption operation must be controlled, which is too high for general small-scale chlorination units.

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