Biogas desulfurization method in series of wet method with dry method

Abstract

The invention discloses a biogas desulfurization method in series of a wet method with a dry method, which comprises the following steps: crude gas is boosted by a fan and enters a wet desulphurization tower after the temperature is lowered by a cooling tower; in the countercurrent contact process of crude gas and a desulfurization solution in the tower and a catalyst, most of impurities such as hydrogen sulfide are removed, and then the biogas is subjected to the dry desulfurization again after the moisture is separated through a dehydrating tower to further remove hydrogen sulfide so as to be lowered below 15 mg/Nm<3> to enter a biogas cabinet for use, and a rich fluid containing H2S is recycled in a regeneration tank. The method disclosed by the invention has the advantages of large treatment amount, stable treatment effect, high sulfur recovery rate, easily regenerated desulfurizer and long service life, and ensures that the hydrogen sulfide content of biogas meets the use requirements. The service life of the equipment pipeline in the biogas industrial application can be prolonged, the environmental problem of secondary pollution in use of biogas is eliminated, and a guarantee for further purifying and utilizing biogas is provided.

Description

technical field [0001] The invention belongs to the technical field of gas desulfurization, and in particular relates to a biogas desulfurization purification process in which a wet method and a dry method are connected in series. Background technique [0002] Anaerobic treatment of organic sewage produces a large amount of biogas, the main component of which is CH 4 and CO 2 , and a small amount of H 2 S gas, H 2 S is a highly toxic hazardous substance, and H 2 S dissolved in water vapor to produce hydrogen sulfuric acid will cause serious corrosion to gas pipelines, gas storage cabinets and gas equipment, shortening the service life of equipment and pipelines. In addition, the H in biogas 2 S burns to produce SO 2 , it can combine with water to transform into highly acidic sulfurous acid mist, pollute the environment, and affect human health. Therefore, my country's gas standards stipulate that when using biogas energy, the hydrogen sulfide content in the biogas gas ...

AI Technical Summary

Problems solved by technology

Wet desulfurization is to use a specific solvent to contact the raw material gas to remove hydrogen sulfide. This method is generally used to deal with large-scale crude desulfurization with high sulfur content, but it also has the disadvantages of low sulfur capacity and poor purification accuracy. Generally, organic sulfur cannot be removed, and the methods that can be applied include pressurized water washing method, alkali absorption method, iron solution absorption method, tannin (tannin) method, etc.

In addition, the new biogas desulfurization process also has methods such as membrane separation desulfurization and biological desulfurization, but the operation and maintenance costs are high and difficult, and they have not been widely used in industry

However, in the large-scale industrial application of biogas, there is no application process with high capacity, high precision, low cost and maximum recovery of sulfur resources.

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