A method for integrating dry process cement kiln flue gas desulfurization and denitrification

Abstract

The invention relates to a desulfurization and denitrification integrated method for dry-process cement kiln flue gas and belongs to the technical field of smoke pollutant control of the cement industry. The method comprises the following steps: firstly drying rice husk ash and carbide slag for 12-24 hours at the temperature of 60-105 DEG C; then uniformly mixing the rice husk ash and the carbideslag in different volume ratio ((1-9):1); and finally removing SO2 and NOx at the same time by utilizing the rice husk ash and the carbide slag under the conditions that temperature is 800-900 DEG C and oxygen concentration is 1%-5%, wherein the carbide slag can be matched as a cement raw material, oxide ash in the rice husk ash also can be taken as an ingredient of cement, and performance of thecement cannot be influenced; meanwhile, Ca in the carbide slag also can promote a process of reducing nitrogen oxides with carbon during desulfurization, and the rice husk ash also provides a larger reaction space for desulfurization and denitrification while C is utilized for denitrification, so that reaction is more full. The integrated method provided by the invention has simple technology, lowadsorption material cost and high desulfurization and denitrification efficiency.

Description

Technical field

[0001] The invention belongs to the technical field of flue gas pollutant control in the cement industry, and specifically relates to a method for realizing the integration of desulfurization and denitrification in a cement kiln calciner by using a calcium carbide slag / rice husk ash composite additive. Background technique

[0002] SO 2 NOx and NOx are the main atmospheric pollutants in the exhaust gas of cement industry kilns and are the main cause of acid rain. In addition, NOx can also cause a series of environmental problems such as smog, photochemical pollution and greenhouse effect. With the continuous improvement of environmental protection requirements, the "Cement Industry Air Pollutant Emission Standard" (GB 4915-2013) stipulates that: general area SO 2 And NOx emission limits are respectively 200mg / m 3 , 400mg / m 3 , Key area SO 2 And NOx emission limits are 100mg / m respectively 3 , 320mg / m 3 , Need to strictly control SO 2 And NOx emissions. Therefore, ...

Examples

Embodiment 1

[0026] The flue gas conditions are 1000ppmNO, 2000ppmSO 2 , 1% O 2 , N 2 To balance the gas, the total gas flow rate is 900ml / min and the temperature condition is 800℃. Rice husk ash and calcium carbide slag are mixed uniformly in a volume ratio of 9:1 and then added to a tube furnace with a diameter of 3cm. The denitration rate reaches 63.7%, the desulfurization rate reached 93.7%.

Embodiment 2

[0028] The flue gas conditions are 1000ppmNO, 2000ppmSO 2 , 1% O 2 , N 2 To balance the gas, the total gas flow rate is 900ml / min and the temperature condition is 900℃. Rice husk ash and calcium carbide slag are mixed uniformly in a volume ratio of 9:1 and then added to a tube furnace with a diameter of 3cm. The denitration rate reaches 63.2%, the desulfurization rate reaches 95.4%.

Embodiment 3

[0030] The flue gas conditions are 1000ppmNO, 2000ppmSO 2 , 1% O 2 , N 2 To balance the gas, the total gas flow rate is 900ml / min, and the temperature condition is 800℃. Rice husk ash and calcium carbide slag are mixed uniformly in a volume ratio of 6:1 and then added to a tube furnace with a diameter of 3cm. The denitration rate reaches 60.2%, the desulfurization rate reaches 94.1%.

Technical field

[0001] The invention belongs to the technical field of flue gas pollutant control in the cement industry, and specifically relates to a method for realizing the integration of desulfurization and denitrification in a cement kiln calciner by using a calcium carbide slag / rice husk ash composite additive. Background technique

[0002] SO 2 NOx and NOx are the main atmospheric pollutants in the exhaust gas of cement industry kilns and are the main cause of acid rain. In addition, NOx can also cause a series of environmental problems such as smog, photochemical pollution and greenhouse effect. With the continuous improvement of environmental protection requirements, the "Cement Industry Air Pollutant Emission Standard" (GB 4915-2013) stipulates that: general area SO 2 And NOx emission limits are respectively 200mg / m 3 , 400mg / m 3 , Key area SO 2 And NOx emission limits are 100mg / m respectively 3 , 320mg / m 3 , Need to strictly control SO 2 And NOx emissions. Therefore, ...

Examples

Embodiment 1

[0026] The flue gas conditions are 1000ppmNO, 2000ppmSO 2 , 1% O 2 , N 2 To balance the gas, the total gas flow rate is 900ml / min and the temperature condition is 800℃. Rice husk ash and calcium carbide slag are mixed uniformly in a volume ratio of 9:1 and then added to a tube furnace with a diameter of 3cm. The denitration rate reaches 63.7%, the desulfurization rate reached 93.7%.

Embodiment 2

[0028] The flue gas conditions are 1000ppmNO, 2000ppmSO 2 , 1% O 2 , N 2 To balance the gas, the total gas flow rate is 900ml / min and the temperature condition is 900℃. Rice husk ash and calcium carbide slag are mixed uniformly in a volume ratio of 9:1 and then added to a tube furnace with a diameter of 3cm. The denitration rate reaches 63.2%, the desulfurization rate reaches 95.4%.

Embodiment 3

[0030] The flue gas conditions are 1000ppmNO, 2000ppmSO 2 , 1% O 2 , N 2 To balance the gas, the total gas flow rate is 900ml / min, and the temperature condition is 800℃. Rice husk ash and calcium carbide slag are mixed uniformly in a volume ratio of 6:1 and then added to a tube furnace with a diameter of 3cm. The denitration rate reaches 60.2%, the desulfurization rate reaches 94.1%.

Images