METHOD FOR REMOVING NITROGEN OXIDE CONTAINED IN EXHAUST GAS

摘要

PURPOSE:To highly maintain the degree of removal for NOx contained in exhaust gas even in such a case that NO/NO2 molar ratio is a prescribed value or below by adding hydrocarbon contg. oxygen to exhaust gas and reducing NO2 into NO partially and subjecting the mixture to catalytic reduction. CONSTITUTION:Oxygen containing hydrocarbon such as CH3OH is added to exhaust gas wherein the greater part of NOx exists as NO2 and one part of NO2 is reduced to NO and thereafter NH3 is injected and the mixture is passed through a reaction tube packed with a catalyst such as TiO2-V2O5 series. Both gas wherein one part of NO2 is reduced to NO and NH3 are brought into contact with the catalyst and allowed to react with each other and NOx is decomposed to nitrogen and water.