Desulfurization and denitration method using chlorine dioxide

A desulfurization and denitration method using chlorine dioxide, which comprises:

• step (1) of adding an aqueous solution of a chlorate, an aqueous solution of a peroxide, and an aqueous solution of sulfuric acid to a chlorine dioxide generator for a reaction to obtain gaseous chlorine dioxide, and mixing the gaseous chlorine dioxide with air to obtain a mixed gas, wherein the gaseous chlorine dioxide accounts for 4-10 vol % of the mixed gas;
• step (2) of letting the mixed gas come into contact with a flue gas in a flue gas conduit before the flue gas enters a desulfurization and denitration tower, to obtain an oxidized flue gas, wherein a molar ratio of the gaseous chlorine dioxide in the mixed gas passed to the flue gas conduit per unit time to nitric oxide in the flue gas passed to the flue gas conduit per unit time is 1-1.8;
• and
• step (3) of passing the oxidized flue gas to the desulfurization and denitration tower and mixing the oxidized flue gas with a spray of an alkaline absorbent dry powder, and spraying water into the desulfurization and denitration tower to obtain a desulfurized and denitrated flue gas;
• wherein in step (2), the flue gas has a flow rate of 6-15 m/s in the flue gas conduit, and a duration of letting the mixed gas come into contact with the flue gas in the flue gas conduit before the flue gas enters the desulfurization and denitration tower is 1-3s.