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

A high-temperature calcination and reducing agent technology, applied in the field of air pollutant NOx treatment, can solve the problems of high resource consumption, inactivation, secondary environmental pollution, etc., and achieve the effect of convenient installation and use, and reducing waste

Active Publication Date: 2014-12-03
凌庭生
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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

Method used

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] (1), preparation of carbon-based reducing agent:

[0047] with CO doped 2 The high-temperature air is used as the heat source to pyrolyze raw coal at high temperature, and water or steam is used as a means to adjust the temperature of the reducing gas and reduce the unburned solid carbon suspended in the reducing gas to produce gaseous reducing components mainly composed of carbon monoxide and hydrogen. Carbon-based reducing agent, the chemical equation of the reaction process is:

[0048]

[0049]

[0050] The high-temperature air comes from the tertiary air from the kiln head of the calcining rotary kiln, the air temperature is 900°C, and the added CO 2 CO2 with a concentration of 40% at 150°C after denitrification and purification in this system (at the outlet of the denitrification fan) 2 The volume ratio of flue gas and high-temperature air is 1:4, and then the flue gas enters the high-temperature calcination system in two ways for NOx reduction.

[0051] ...

Embodiment 2

[0061] (1), preparation of carbon-based reducing agent:

[0062] The tertiary wind of the high-temperature calcined carbonate of the rotary kiln is used as the heat source of the carbon reducing agent preparation device through conditioning and temperature control, and the conventional biomass pyrolysis method is used to pretreat the biomass carbon raw material (CxOyHz) in the gasifier Preparation of carbon-based reducing agent by high-temperature pyrolysis; the chemical equation of the reaction process is:

[0063]

[0064] The tertiary wind for the production of cement clinker by carbonate calcination is tempered and temperature controlled-mainly to reduce O 2 content, a moderate increase in CO 2 content, meeting the oxygen deficient condition in the gasifier, the air temperature is 900°C, rich in CO 2 , pyrolyze raw coal or biomass fuel into CO+H in the gasifier under oxygen-deficient conditions 2 , because the temperature of the flue gas used for pyrolysis is adjusta...

Embodiment 3

[0074] (1), the use of CO doped 2 The high-temperature air is used as the heat source to pyrolyze raw coal at high temperature, and water or steam is used as a means to adjust the temperature of the reducing gas and reduce the unburned solid carbon suspended in the reducing gas to produce gaseous reducing components mainly composed of carbon monoxide and hydrogen. Carbon-based reducing agent, the chemical equation of the reaction process is:

[0075]

[0076]

[0077] The high-temperature air comes from the tertiary air from the kiln head of the calcining rotary kiln, the air temperature is 1000°C, and the added CO 2 CO2 with a concentration of 40% at 220°C after denitrification and purification in this system (at the outlet of the denitrification fan) 2 The volume ratio of flue gas and high-temperature air is 1:5, and then the flue gas enters the high-temperature calcination system in two ways for NOx reduction.

[0078](2), primary denitrification combustion

[0079...

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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...

Claims

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Application Information

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IPC IPC(8): B01D53/56B01D53/75C01B21/02
CPCY02P20/10Y02P20/129
Inventor 凌庭生凌俊儒吴扬
Owner 凌庭生
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