Method for reducing NOx in high-temperature calcination by SCR denitration technology adopting carbon-series reduction agent.

Abstract

The invention provides a method for reducing NOx in high-temperature calcination by an SCR denitration technology adopting a carbon-series reduction agent. The method comprises the steps of preparing the carbon-series reduction agent, carrying out primary denitration burning, and then carrying out secondary denitration in an SCR catalyst tower. A gaseous carbon-series reduction agent mainly adopting CO and H2 is prepared, one part of the gaseous carbon-series reduction agent is used for carrying out primary high-temperature denitration at a high-temperature flue gas outlet in material calcination process to reduce the NOx in the high-temperature flue gas into inert N2NOx, and the reduction rate is about 30%; the other part of the gaseous carbon-series reduction agent is used for secondary catalytic denitration in the SCR denitration tower, and the reduction rate of the NOx is more than or equal to 50%. Compared with the prior art, the method provided by the invention has the advantages that the denitration reaction temperature is very low and is 220-410 DEG C, and excessive NO exists, so that the risk of escape of trace amount reduction gases such as CO and H2 together along with waste gas is greatly reduced; and the discharged waste gas subjected to denitration treatment passes through material crushing and grinding equipment, the residual heat of the waste gas is utilized for heating and drying materials, so that the energy-efficiency utilization rate of the whole system is increased.

Description

technical field [0001] The invention belongs to the field of waste gas treatment, in particular to the treatment technology of air pollutant NOx discharged from high-temperature flue gas. Background technique [0002] Cement is an important building material, and the annual social demand exceeds 2 billion tons. The air pollution caused by the nitrogen oxides emitted from the calcination of cement clinker required for the production of cement seriously threatens the environment. The clinker calcination and sintering system in cement production is an important part of cement production. The system is mainly composed of four parts: preheater, calciner, rotary kiln, and grate cooler: the raw cement is preheated by the preheater, and then decomposed After furnace decomposition and gas-solid separation, the decomposed raw meal enters the kiln, and the decomposition rate of the raw meal entering the kiln is generally controlled at 90-95%. The gas is from bottom to top. The heat r...

AI Technical Summary

Problems solved by technology

[0005] However, ammonia reductant SCR denitrification technology consumes high value of resources (ammonia), ammonia is explosive and poisonous, and escape will cause secondary environmental pollution, which is inconvenient to store and use, and NH 3 When the dosage is large, the ammonium salt produced in the flue gas will cause the catalyst to deactivate and shorten the service life of the catalyst when working at a high denitrification temperature

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