Biogas desulfurization and purification process

Abstract

The invention belongs to the technical field of biogas treatment, and particularly relates to a biogas desulfurization and purification process. Hydrogen sulfide in biogas is absorbed through an absorption tower, the liquid-gas ratio of an absorption liquid to the sulfur-containing biogas is (0.01-0.02):1, and the absorption liquid comprises water, complexing iron, complexing ferrous iron, N,N-dihydroxyethylpiperazine, 7-diethylamino-4-methylcoumarin, 2-hydroxymethyl-15-crown ether-5, sodium carbonate and a sodium bicarbonate buffer system, wherein the concentration of the iron element in thecomplexing iron is 300-800 mg / L, the concentration of the iron element in the complexing ferrous iron is 500-700 mg / L, the concentration of the N,N-dihydroxyethylpiperazine is 30-45 mg / L, the concentration of the 7-diethylamino-4-methylcoumarin is 3-6 mg / L, the concentration of the 7-diethylamino-4-methylcoumarin is 15-20 mg / L, and the pH value of the solution is controlled to be 7.5-9.0 through asodium carbonate and sodium bicarbonate buffer system. Compared with the prior art, the biogas desulfurization and purification process provided by the invention has the advantages of simple desulfurization process, high desulfurization efficiency and stable desulfurizer performance, and can be stored for a long time without deterioration.

Description

technical field [0001] The invention belongs to the technical field of biogas treatment, and in particular relates to a biogas desulfurization and purification process. Background technique [0002] Biogas generally contains 50-70% methane, 25-40% carbon dioxide, and a small amount of nitrogen, hydrogen, ammonia, hydrogen sulfide, phosphine, etc., depending on the organic components of the substrate and the state of digestion. For example: hydrogen sulfide usually only accounts for 0.005-0.08% in the biogas composition. When the sewage contains a lot of protein or sulfate, the content of hydrogen sulfide will increase significantly, and can reach about 1%. [0003] Hydrogen sulfide is a nerve agent. Also asphyxiating and irritating gas. The main targets of its toxic effects are the central nervous system and the respiratory system, which may also be accompanied by damage to multiple organs such as the heart. The tissues most sensitive to the toxic effects are the contact p...

AI Technical Summary

Problems solved by technology

[0004] However, the existing desulfurization process has problems such as cumbersome desulfurization process and low desulfurization efficiency. In addition, the existing desulfurization agent also has the problem of poor stability and is not easy to store for a long time

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