Ultralow-temperature flue gas SCR denitration system and process

Abstract

The invention relates to the technical field of waste gas purification processes and systems, in particular to an ultralow-temperature flue gas SCR denitration system and a process. The system comprises a denitration system, an ammonia spraying system, a heat exchange system, a denitration purging system and a denitration thermal desorption system; an inlet of the denitration system is communicated with an inlet flue gas pipeline; the ammonia spraying system is connected into an ammonia spraying grid in an inlet flue of the denitration system, a compressed air storage tank and a dilution fan are connected with an inlet pipeline of the heat exchange system, an outlet of the heat exchanger system is communicated with a urea pyrolysis device and the denitration purging device in the ammonia spraying system, the inlet flue is communicated with an inlet pipeline of the denitration thermal desorption system, and in the purging proess, the compressed air is not cold; reaction with a catalystis carried out in washing, so that catalyst dust accumulation blockage can be reduced; the air at an inlet of the urea pyrolysis device is not cold, so that energy consumption of a hot blast stove isreduced, and ultra-long continuous working time of ultra-low temperature catalysis is guaranteed.

Description

technical field [0001] The invention relates to the technical field of waste gas purification technology and system, in particular to an ultra-low temperature flue gas SCR denitrification system and technology. Background technique [0002] The control of nitrogen oxide emissions in non-power industries (including self-provided power stations) has encountered great difficulties, because industrial boilers (kilns) and furnace equipment in non-power industries (such as: industrial boilers, glass ceramic furnaces, cement furnaces, steel furnaces) Metallurgical sintering furnaces, coking and petrochemical system cracking equipment, etc.) flue gas and exhaust gas from processes involving the production and use of nitric acid have a discharge temperature in the range of 120°C to 300°C, while the working temperature of medium-temperature SCR denitrification catalysts currently used in the power industry It is 300°C to 400°C. Therefore, it is difficult to directly use medium-temper...

AI Technical Summary

Problems solved by technology

Therefore, it is difficult to directly use medium-temperature (300°C-400°C) SCR catalytic process for NO in non-power industries. x emission control

The purification efficiency of selective non-catalytic reduction (SNCR) nitrogen oxides is low, and it is difficult to meet strict emission standards. Therefore, ultra-low temperature and low-temperature SCR are the main engineering technologies to achieve the goal of the "Air Pollution Prevention and Control Action Plan"

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