Tail gas treatment method based on ammonia desulfurization

Abstract

The invention discloses a tail gas treatment method based on ammonia desulfurization, and relates to the field of tail gas treatment. The tail gas treatment method based on ammonia desulfurization comprises the following steps: burning tail gas to be treated to convert sulfur contained in the tail gas into SO2, converting the SO2 into SO3 through oxidation, cooling the tail gas containing SO3, reacting the cooled tail gas with ammonia water to obtain ammonium sulfate, and discharging the ammonium sulfate; and finally, cooling and demisting the reacted tail gas, discharging the tail gas after the tail gas reaches the standard, and re-burning the tail gas if the tail gas does not reach the standard, and carrying out the steps. The reaction of SO3 and ammonium sulfate is irreversible reaction, the reaction conversion rate is high, the higher desulfurization efficiency can be realized in the treatment process, the concentration of SO3 in the discharged gas is less than 5mg / m<3>, the concentration of SO2 is less than 200mg / m<3>, and the discharged gas reaches the national standard, while the desulfurization rate is generally difficult to exceed 95% when the conventional SO2 is used for preparing ammonium sulfate for desulfurization.

Description

technical field [0001] The invention relates to the technical field of tail gas treatment, in particular to a tail gas treatment method based on ammonia desulfurization. Background technique [0002] In petrochemical, coal chemical and other production processes, the sulfur in raw materials is finally converted into tail gas containing hydrogen sulfide during the processing process. Hydrogen sulfide is a very harmful substance to safety and the environment. It must be treated or recycled before being discharged. , for some plants with by-product liquid ammonia or ammonia water, such as coal low-temperature low-pressure gasification to natural gas plant, due to consideration of the sale and outlet of liquid ammonia or ammonia water, ammonia desulfurization process can be used to remove all or part of the acid gas The sulfur is converted to ammonium sulfate. Usually, for a small-scale sulfur recovery system with an annual capacity of less than several thousand tons, all the a...

AI Technical Summary

Problems solved by technology

[0003] Conventional ammonia desulfurization process for SO 2 The absorption efficiency is low, generally only about 90-95%. In some tail gas emission factories with low sulfur content, the tail gas after desulfurization can meet the emission standards, but in factories with high sulfur content, usually after tail gas incineration SO 2 Concentration reaches 2~3%, so high SO 2 The concentration cannot meet the emission standard by the conventional ammonia desulfurization process

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