Wet selective desulfurization system and wet selective desulfurization method

Abstract

The invention discloses a wet selective desulfurization system. The wet selective desulfurization system comprises an absorption tower, a rich liquid tank, a sedimentation tank, an acid dissolving tank, an oxidation tank and a barren liquid tank which are sequentially communicated and form a closed loop structure. Meanwhile, the wet selective desulfurization system further comprises an acidification tank, wherein the acidification tank is arranged between the sedimentation tank and the barren liquid tank and is respectively communicated with the sedimentation tank and the barren liquid tank. The invention simultaneously discloses a wet selective desulfurization method which can be used for selectively absorbing hydrogen sulfide. According to the wet selective desulfurization system and the wet selective desulfurization method, the H2S absorption is strengthened effectively, and the CO2 absorption is weakened, so that the high-selectivity H2S absorption is realized; H2S can be effectively converted into elemental sulfur, so that the resource utilization efficiency is very high; meanwhile, during desulfurization, a supernatant in the sedimentation tank is subjected to acidification treatment by adopting the acidification tank, so that the acid and oxidation air consumption of the whole system can be reduced greatly; during separation, the operating efficiency of the whole system is very high, so that resources are saved, and the cost is reduced.

Description

technical field [0001] The invention relates to a desulfurization method, in particular to a wet selective desulfurization method, which belongs to the technical field of environmental chemistry. Background technique [0002] Methane-rich biomass gas, represented by biogas and landfill gas, is an important type of biomass energy. Biomass gas generally contains a high concentration of H 2 The S component needs to be desulfurized before being utilized. Wet desulfurization is a method that uses desulfurization liquid to absorb and separate H 2 The typical technical route for the desulfurization method of S component is wet catalytic oxidation desulfurization, that is, the use of alkaline absorption liquid added with liquid-phase catalytic oxidant to absorb and oxidize hydrogen sulfide into elemental sulfur for separation and recovery. However, there is an obvious shortcoming in this method, that is, there is a relatively high content of acid gas CO in biogas and landfill gas...

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Problems solved by technology

However, there is an obvious shortcoming in this method, that is, there is a relatively high content of acid gas CO in biogas and landfill gas. 2 (the content is generally between 20% and 30%), and the desulfurization liquid in the desulfurization absorption process is alkaline (pH value between 8 and 9), which causes part of the carbon dioxide to be absorbed by the desulfurization liquid during the desulfurization process. As a result, additional alkali consumption and non-renewable, resulting in unnecessary operating costs

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