Comprehensive desulphurization technology in coal chemical industry

Abstract

The invention discloses a comprehensive desulphurization technology in the coal chemical industry. The comprehensive desulphurization technology comprises the following steps: acidic gas containing hydrogen sulfide and coming from a low-temperature methanol washing device burns to generate mixed gas, and the mixed gas is subjected to two stages of cooling to separate out liquid sulfur for producing solid sulfur; sulphuric mixed gas separated out after cooling is subjected to secondary combustion so that all sulphureous components in the mixed gas are changed into SO2, tail gas generated after combustion and boiler flue gas of a heating power station are fully mixed and enter a desulphurization tower, circulating liquid containing aqua ammonia is used as an absorbent to absorb SO2 in a countercurrent contact way and react to generate ammonium sulfite, and ammonium sulfite is further oxidized to change into ammonium sulfate; desulphurized and purified flue gas is discharged into air through a chimney; ammonium sulfate solution at the bottom of the desulphurization tower enters a circulation tank and is crystallized to form the ammonium sulfate product. The comprehensive desulphurization technology adopts a novel combined desulphurization technology to replace the traditional Klaus Scott or Super Claus technology, and can effectively lower investment, improve recovery rate of sulfur and reduce discharge of sulfur.

Description

technical field [0001] The invention belongs to the field of chemical industry, in particular to a combined desulfurization process utilizing Claus reaction and ammonia absorption reaction in the coal chemical industry. Background technique [0002] At present, many sulfur recovery technologies have been applied. According to the products, there are sulfur recovery to produce sulfur and sulfur recovery to produce sulfuric acid. The acid gas treatment process whose product is sulfur usually adopts the Claus sulfur recovery process, which is a mature process, and there are many kinds of processes, mainly including the traditional Claus process, catalytic oxidation super Claus, with SCOT tail gas Handled by Claus Craft. [0003] Due to the limitation of the equilibrium of the Claus reaction in the traditional Claus recovery process, the total sulfur recovery rate of the Claus process is generally around 95-98%, and the tail gas cannot meet the existing national environmental p...

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Problems solved by technology

[0003] Due to the limitation of the equilibrium of the Claus reaction in the traditional Claus recovery process, the total sulfur recovery rate of the Claus process is generally around 95-98%, and the tail gas cannot meet the existing national environmental protection standards

Later, in order to improve the sulfur recovery rate, the catalytic oxidation Super Claus process and the Super Claus process were developed. The reaction principle is basically the same, and the main purpose of the treatment is to reduce the sulfur content in the tail gas. The former uses selective catalytic oxidation. way, the latter uses a hydrogenation catalytic reactor to hydrogenate all sulfur elements into H 2 After S, select the oxidation catalyst again, H 2 S is oxidized to elemental sulfur. Although the total sulfur recovery rate can be increased to more than 99%, the H in the tail gas 2 The emission of S has not yet reached the requirements of the new national standard

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