An integrated process for low-temperature flue gas desulfurization, denitrification and ammonia removal

Abstract

The invention relates to an integrated low-temperature flue gas desulfurization, denitration and ammonia removal process suitable for the desulphurization and the denitration of coke oven flue waste gas of which flue gas temperature is greater than 180 DEG C and the content of SO2 is less than 150 mg / Nm3. According to the process, dry desulphurization is performed before denitration according to a fluidized principle, ammonia gas produced by evaporating residual ammonia water at an ammonia evaporation workshop section in a coking plant is used as a reducing agent, a cloth bag combining with an ammonia removal catalyst composite structure is used as a dust removing and denitration manner, and during efficient desulphurization and denitration, an escape amount of ammonia is controlled to be lower than a national emission standard value. Compared with the prior art, the process has the benefits that 1), the integrated desulphurization, denitration and ammonia removal efficiency is high; 2) the denitration manner is unique, and the structural form of equipment is advanced; 3) ash removal is simple; 4) the energy is saved, and the operating cost and the once investment are reduced; 5) residual ammonia water in a coal gas purification process is fully recycled; 6) the residual heat is fully recycled.

Description

technical field [0001] The invention relates to the technical field of harmless treatment of low-temperature flue gas, in particular to an integrated process for desulfurization, denitrification and ammonia removal of low-temperature flue gas. Background technique [0002] NH 3 -SCR (Selective Catalytic Reduction) denitrification technology is mature and reliable, and has been widely used in power plants. The flue gas temperature of the power plant is between 350°C and 400°C, and the denitrification efficiency can reach 90% under this temperature condition, and due to the high flue gas temperature, SO 2 converted to SO 3 The amount is very small, SO 2 The effect on denitrification efficiency is negligible. Power plants generally adopt denitrification first, waste heat recovery from flue gas, and low-temperature desulfurization later. [0003] The exhaust gas temperature of the coke oven flue in the coking plant is generally between 180°C and 250°C; SO 2 The content is ...

AI Technical Summary

Problems solved by technology

Although the above problems can be solved by heating the exhaust gas of the coke oven flue, it will cause energy waste and increase the primary investment and operating costs

So far, there is no public information on coke oven flue gas denitrification technology

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