Absorption solution for removing sulfides and carbon dioxide from natural gas

Abstract

The invention belongs to the field of gas purification and provides a novel absorption solution for removing H2S, COS, mercaptan, thioether and other sulfides, as well as CO2 from natural gas. The absorption solution contains a hindered amine, an alcohol amine, N-methylacetamide, a salt type catalyst and deionized water, wherein the concentration of the alcohol amine is 15-40% (wt), and the concentration of the hindered amine is 10-60% (wt); the hindered amine can be a single steric hindered amine or a mixture of a variety of steric hindered amines, and the hindered amine is a non-linear alcohol amine type compound bringing one or more steric hindered structures on nitrogen atoms; the concentration of the N-methylacetamide is 5-30% (wt); the concentration of the salt type catalyst is 0.1-5%. Compared with a traditional alcohol amine solvent, the absorption solution provided by the invention has the significant advantages of high desulfurization rate, low energy consumption for regeneration, good stability, cheap price and the like.

Description

technical field [0001] The invention belongs to the field of gas purification, in particular to removing H from natural gas 2 S, COS, mercaptan, sulfide and other sulfides and CO 2 of the absorbent. Background technique [0002] The natural gas extracted from the gas field contains H 2 S, COS, mercaptan, sulfide and other sulfides and CO 2 , H 2 S is highly toxic, H 2 The presence of S will not only corrode the pipeline and equipment; the high concentration of CO 2 It will reduce the calorific value of natural gas; on the one hand, COS will poison the catalyst of the downstream chemical process with natural gas as raw material, and on the other hand, COS discharged into the atmosphere without treatment can form SO 2 , to promote photochemical reactions and bring about serious environmental problems. At the same time sulfides have an unacceptable odor even at extremely low concentration levels. Therefore, natural gas must be desulfurized and carbon dioxide removed bef...

AI Technical Summary

Problems solved by technology

[0004] The above method has the characteristics that the price of the solvent is relatively expensive, and the purification effect cannot be satisfied.