Method for refining hydrogen chloride gas

Abstract

The invention provides a method for refining a hydrogen chloride gas and aims to provide a refining method with simple process flow, high hydrogen-removing rate and capacities of reducing refining procedures and saving energy cost. The method comprises the following steps of: measuring hydrogen content of the hydrogen chloride gas by using a hydrogen on-line monitoring instrument; under the condition that the hydrogen content does not exceed 14 percent (v / v), measuring the volume of the hydrogen-containing hydrogen chloride gas and the volume of oxygen / air respectively by using a flowmeter; adding a small amount of excess oxygen into the reaction, so that the molar ratio of the hydrogen to the oxygen is controlled to be 2:1-1.2, wherein the hydrogen and the oxygen enter the pipeline and are mixed uniformly; performing combustion reaction on the hydrogen and the oxygen in the reaction region in a combustor to generate water vapor and remove the hydrogen; and drying the purified hydrogen chloride gas and entering the next step, namely the high-temperature chlorinated alkane production procedure. The hydrogen content of the processed hydrogen chloride gas can be reduced to below 0.16 percent (v / v). The problems of subsequent treatment of a large amount of diluted hydrochloric acid and environmental pollution are solved.

Description

technical field [0001] The invention relates to a method for refining hydrogen chloride gas. Background technique [0002] In the production process of hydrogen chloride gas produced by combustion method using chlorine and hydrogen as raw materials, a slight excess of hydrogen is often used in order to completely burn the highly toxic chlorine gas. This makes the prepared hydrogen chloride gas often contain 6-14% (v / v) of hydrogen. In the process of producing chlorinated alkanes using hydrogen chloride gas and methanol as raw materials, hydrogen in hydrogen chloride gas is insoluble in methanol solution and does not participate in the reaction. Hydrogen will accumulate in the upper part of the reactor, and when the concentration reaches its explosion limit range When it is very easy to explode, it brings serious safety hazards to the production of chlorinated alkanes. Therefore, it is usually necessary to refine the hydrogen chloride gas containing hydrogen to remove hydrog...

AI Technical Summary

Problems solved by technology

This process mainly has the following two problems: 1. When the desorption tower is heated to precipitate hydrogen chloride gas, a large amount of steam is needed for heating, resulting in excessive production energy costs and waste of resources

The disadvantage of this method is that the hydrogen / oxygen ratio in the hydrogen removal process is not easy to control, and it is easy to bring unsafe hazards and hydrogen cannot be completely removed.

When heating to precipitate hydrogen chloride gas, it needs to consume a large amount of steam for heating, resulting in high production energy costs and waste of resources. The by-product dilute hydrochloric acid is large, which will cause serious pollution to the environment.

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