Oxidative absorption method for removing NOx and SO2 in flue gas simultaneously

Abstract

The invention discloses an oxidative absorption method for removing NOx and SO2 in flue gas simultaneously and belongs to the field of flue gas pollution control. The method comprises steps as follows: to-be-purified flue gas is introduced into a reaction device, SO2 and NOx flue gas are sufficiently contacted with an oxidative absorption solution for an oxidative absorption reaction, and finally,the flue gas is purified and discharged; the oxidative absorption solution is prepared from calcium peroxide and persulfate, and a mole ratio of persulfate to calcium peroxide in the solution is 0.15-1.5. The method for wet oxidative absorption of NOx and SO2 has strong oxidization and strong alkali absorption capabilities, and 100% SO2 removing efficiency and 70% or higher NOx removing efficiency can be realized, and the highest NOx removing efficiency even reaches 95%. With adoption of the method, NOx and SO2 in the same wet washing device can be removed simultaneously, and the method has the characteristics of being high in removing efficiency and low in cost, preventing secondary pollution and realizing recyclability of resources and the like.

Description

technical field

[0001] The invention relates to a method for simultaneously removing NO in flue gas x and SO 2 The oxidation absorption method belongs to the subfield of flue gas pollution control in the field of environmental protection technology. Background technique

[0002] my country's primary energy is mainly coal. With the continuous development and utilization of clean energy such as natural gas, solar energy, and wind energy, the proportion of coal demand has declined, but it still accounts for more than 60%. SO emissions from coal combustion 2 and NO x Gaseous pollutants such as gaseous pollutants can cause a series of environmental problems such as acid rain, photochemical smog, and eutrophication of water bodies. They are also the culprits of smog, which seriously endanger human health and the ecological environment. In the face of increasingly serious environmental pollution, the Chinese government has proposed that coal-fired boilers meet the emission stan...

Examples

Embodiment 1

[0052] For a 35 t boiler, the flue gas volume is 35000 m 3 / h, flue gas temperature 120 ℃, NO in flue gas x and SO 2 Concentrations are 200 mg / m 3 and 1000 mg / m 3 , using a turbid mixture containing 0.1 mol / L sodium persulfate and 0.2 mol / L calcium peroxide uniformly mixed as an oxidation absorbent for simultaneous wet desulfurization and denitrification, fully contacting with the flue gas in the spray tower, the liquid gas The ratio is 10~20, and the reaction temperature is 50°C. The denitrification efficiency and desulfurization efficiency can be achieved by 80% and 100%, respectively, by testing the purified flue gas.

[0053] The industrial prices of sodium persulfate and 70% calcium peroxide are 6,500 yuan / t and 6,000 yuan / t, respectively. The cost of wet desulfurization and denitrification operation for one day is equivalent to the cost of 1 ton of fuel increased by about 40 yuan.

Embodiment 2

[0055] For a 35 t boiler, the flue gas volume is 35000 m 3 / h, flue gas temperature 120 ℃, NO in flue gas x and SO 2 Concentrations are 200 mg / m 3 and 1000 mg / m 3 , using a turbid mixture containing 0.1 mol / L ammonium persulfate and 0.2 mol / L calcium peroxide uniformly mixed as an oxidation absorbent for simultaneous wet desulfurization and denitrification, fully contacting with the flue gas in the spray tower, the liquid gas The ratio is 10~20, and the reaction temperature is 50°C. The denitrification efficiency and desulfurization efficiency can be achieved by 70% and 100%, respectively, by testing the purified flue gas.

[0056] The industrial prices of ammonium persulfate and 70% calcium peroxide are 4,500 yuan / t and 6,000 yuan / t, respectively. The cost of wet simultaneous desulfurization and denitrification operation for one day is equivalent to the cost of 1 ton of fuel increased by about 30 yuan.

technical field

[0001] The invention relates to a method for simultaneously removing NO in flue gas x and SO 2 The oxidation absorption method belongs to the subfield of flue gas pollution control in the field of environmental protection technology. Background technique

[0002] my country's primary energy is mainly coal. With the continuous development and utilization of clean energy such as natural gas, solar energy, and wind energy, the proportion of coal demand has declined, but it still accounts for more than 60%. SO emissions from coal combustion 2 and NO x Gaseous pollutants such as gaseous pollutants can cause a series of environmental problems such as acid rain, photochemical smog, and eutrophication of water bodies. They are also the culprits of smog, which seriously endanger human health and the ecological environment. In the face of increasingly serious environmental pollution, the Chinese government has proposed that coal-fired boilers meet the emission stan...

Examples

Embodiment 1

[0052] For a 35 t boiler, the flue gas volume is 35000 m 3 / h, flue gas temperature 120 ℃, NO in flue gas x and SO 2 Concentrations are 200 mg / m 3 and 1000 mg / m 3 , using a turbid mixture containing 0.1 mol / L sodium persulfate and 0.2 mol / L calcium peroxide uniformly mixed as an oxidation absorbent for simultaneous wet desulfurization and denitrification, fully contacting with the flue gas in the spray tower, the liquid gas The ratio is 10~20, and the reaction temperature is 50°C. The denitrification efficiency and desulfurization efficiency can be achieved by 80% and 100%, respectively, by testing the purified flue gas.

[0053] The industrial prices of sodium persulfate and 70% calcium peroxide are 6,500 yuan / t and 6,000 yuan / t, respectively. The cost of wet desulfurization and denitrification operation for one day is equivalent to the cost of 1 ton of fuel increased by about 40 yuan.

Embodiment 2

[0055] For a 35 t boiler, the flue gas volume is 35000 m 3 / h, flue gas temperature 120 ℃, NO in flue gas x and SO 2 Concentrations are 200 mg / m 3 and 1000 mg / m 3 , using a turbid mixture containing 0.1 mol / L ammonium persulfate and 0.2 mol / L calcium peroxide uniformly mixed as an oxidation absorbent for simultaneous wet desulfurization and denitrification, fully contacting with the flue gas in the spray tower, the liquid gas The ratio is 10~20, and the reaction temperature is 50°C. The denitrification efficiency and desulfurization efficiency can be achieved by 70% and 100%, respectively, by testing the purified flue gas.

[0056] The industrial prices of ammonium persulfate and 70% calcium peroxide are 4,500 yuan / t and 6,000 yuan / t, respectively. The cost of wet simultaneous desulfurization and denitrification operation for one day is equivalent to the cost of 1 ton of fuel increased by about 30 yuan.