Method for removing carbon dioxide from hydrogen sulfide acid gas by using buffer solution

Abstract

The invention discloses a method for removing carbon dioxide from a hydrogen sulfide acid gas by using a buffer solution and belongs to the technical field of decarburization. The method comprises the following steps of: firstly carrying out mixing reaction on a buffer solution containing sodium hydroxide and sodium bicarbonate and a nondecarburized hydrogen sulfide acid gas to absorb carbon dioxide and part of hydrogen sulfide in the acid gas so as to obtain decarburized rich liquid containing sodium bicarbonate and sodium hydrosulfide; then heating the decarburized rich liquid, so that sodium hydrosulfide in the decarburized rich liquid is subjected to a hydrolysis reaction and is converted into sodium hydroxide, sodium hydroxide produced by the hydrolysis reaction reacts with free alkali and sodium bicarbonate in the decarburized rich liquid to produce sodium carbonate, carbon dioxide in the acid gas is finally converted into a sodium carbonate salt to be fixed and hydrogen sulfide produced by the hydrolysis reaction is absorbed into the acid gas. By using the method, carbon dioxide can be effectively removed from the acid gas and converted into a useful product of sodium carbonate salt and the decarburization rate reaches 60%-90%.

Description

Technical field: [0001] The invention belongs to the technical field of decarbonization, and in particular relates to a method for removing carbon dioxide from hydrogen sulfide acid gas with a buffer solution. Background technique: [0002] In coal chemical industry, petrochemical industry, natural gas chemical industry, chemical fertilizer industry and other chemical industries, gas purification and separation are important technologies in various chemical processes, among which gas decarbonization technology is widely used in chemical fertilizer industry, flue gas separation, synthesis gas purification and other processes . However, gas decarbonization technology and desulfurization technology at home and abroad are related, that is to say, gas has decarbonization function while desulfurization. According to the technical category, it can be divided into dry desulfurization and decarbonization and wet desulfurization and decarbonization. The dry method uses solid adsorben...

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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