Two-stage biological desulfuration device of marsh gas

Abstract

The invention discloses a biological desulfuration device for removing hydrogen sulfide in marsh gas. The biological desulfuration device comprises an absorption tower for removing hydrogen sulfide and a device composed of an oxidation tank, a settling tank, a clear liquid tank and a circulating pump. Marsh gas enters the absorption tower from a gas inlet, the alkalescent absorption liquid is uniformly sprayed on a packing layer through spray headers of a water distributor, the marsh gas is in countercurrent contact with the absorption liquid when passing through the packing layer upwards, and the hydrogen sulfide in the marsh gas is dissolved in the alkalescent absorption liquid and reacts with the alkalescent absorption liquid; the absorption liquid flows into the oxidation tank from a liquid outlet at the lower part of the absorption tower, and aerates the liquid in the oxidation tank through an air pump, the content of dissolved oxygen of the absorption liquid is controlled at the same time, and the sulfide in the absorption liquid generates elemental sulfur under the oxidation of colorless sulfur bacteria; the liquid in the oxidation tank overflows and enters the settling tank, most elemental sulfur is settled to the bottom of the settling tank and discharged and recovered; and supernatant liquor overflows and enters the clear liquid tank, and is pumped into the absorption tower as a desulfurization agent for reuse through the circulating pump. The device has the advantages of simple structure, convenience for operation, safety in operation, high desulfuration efficiency and the like.

Description

technical field [0001] The invention relates to a device for removing hydrogen sulfide in biogas, more specifically, the invention relates to an efficient and stable two-stage biogas biological desulfurization device. Background technique [0002] In addition to methane and carbon dioxide, the biogas produced by anaerobic fermentation of various organic substances also has some sulfur compounds (the content of H2S is 0.1%-2%). Although the proportion of H2S in the composition of biogas is very small, because the H2S in the biogas burns to generate SO2, it can combine with the water vapor in the combustion products to form sulfurous acid, which will cause corrosion on the metal surface of the combustion equipment; in addition, there are A large amount of water vapor exists, and the water and H2S in the biogas work together to accelerate the corrosion and blockage of metal pipes, valves and flow meters. When biogas is used for power generation and as biogas, sulfur compounds ...

AI Technical Summary

Problems solved by technology

This device is a kind of biological desulfurization integrated equipment. Although it is simple to manufacture and operate and has good desulfurization effect, it has the following problems: 1. The air and biogas of this device enter the desulfurization tower through the same port, and the biogas and air are mixed. Together, there is a great potential safety hazard. The entry of a large amount of air will increase the CO2 content of the biogas after desulfurization and affect the use of biogas.

2. Although the device is equipped with an oxygen measuring probe, which can measure and control the oxygen content in the gas, it cannot accurately control the dissolved oxygen content of the solution in the packing layer in the tower. Excessive dissolved oxygen will oxidize some elemental sulfur into SO42-, Cause the accumulation of SO42-, affecting the desulfurization effect

3. During the desulfurization process of the integrated biological desulfurization device, the generated elemental sulfur will gradually block the packing layer, increase the pressure drop of biogas in the desulfurization tower, and affect the removal rate of sulfide

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