Method for preparing sodium hydrosulfide from hydrogen sulfide acid gas containing carbon dioxide

Abstract

The invention discloses a method for preparing sodium hydrosulfide from hydrogen sulfide acid gas containing carbon dioxide, which belongs to the technical field of decarburization. The method comprises the following steps of firstly, mixing buffer solution containing sodium hydroxide and sodium bicarbonate with non-decarburized hydrogen sulfide acid gas to react and absorb carbon dioxide and hydrogen sulfide in the acid gas, so as to obtain decarburized pregnant solution, and then, heating the decarburized pregnant solution to make the sodium hydrosulfide in the decarburized pregnant solution hydrolyze and change into sodium hydroxide, wherein the sodium hydroxide generated by hydrolysis reaction reacts with free alkali and sodium bicarbonate in the decarburized pregnant solution to generate sodium carbonate; conveying the hydrogen sulfide acid gas without carbon dioxide into a tubular mixing reactor, performing reverse absorption with circulated alkali liquor to obtain pregnant solution containing sodium hydrosulfide, evaporating and concentrating the pregnant solution containing sodium hydrosulfide to obtain sodium hydrosulfide products of different levels. The method provided by the invention can remove carbon dioxide from hydrogen sulfide acid gas, and quality of the sodium hydrosulfide product prepared from the decarburized acid gas is controllable and adjustable.

Description

Technical field: [0001] The invention belongs to the technical field of decarbonization, and in particular relates to a method for preparing sodium hydrosulfide by utilizing hydrogen sulfide acid gas containing carbon dioxide. Background technique: [0002] The method of absorbing hydrogen sulfide with alkali sulfide (sodium Na) is commonly used in domestic production of sodium hydrosulfide. The traditional preparation methods of sodium sulfide include coal reduction sodium sulfate, barium sulfide by-product method, gas reduction sodium sulfate method, caustic soda absorption hydrogen sulfide method, etc. At present, the basic method of domestic production of industrial sodium hydrosulfide is to absorb hydrogen sulfide gas with sodium sulfide solution to produce sodium hydrosulfide. The domestic production of sodium sulfide basically adopts the carbon reduction sodium sulfate method. The main raw materials are mirabilite and coal. The process technology is simple, but the r...

AI Technical Summary

Problems solved by technology

It can be seen that the alcohol amine method is a traditional decarbonization and desulfurization technology. For sour gas occasions where hydrogen sulfide and carbon dioxide exist at the same time, the MDEA solution cannot clearly separate hydrogen sulfide and carbon dioxide.

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