| 摘要 |
PURPOSE:To efficiently remove nitrogen oxides by passing a waste gas mixed with a reducing agent through a reaction vessel packed with a reducing catalyst having ammonia adsorbing power to reduce the nitrogen oxides and also to make a leaked ammonia adsorbed and passing the waste gas from an opposite direction when a amount of ammonia adsorption of the catalyst approaches to a breakpoint. CONSTITUTION:The waste gas adding the reducing agent (e.g. ammonia) is fed from a gas port opening 2 of a catalytic reducing reaction vessel 1 packed with the reducing catalyst having ammonia adsorbing power to reduce a nitrogen oxides in the waste gas, and an excess reducing agent is adsorbed on the catalyst, and a treated gas is discharged from the gas port opening 3. Then, when the amount of ammonia adsorption of the catalyst approaches to the breakpoint or when it reaches the breakpoint, the feed from the gas port opening 3 and the discharge from the gas port opening 2 of the waste gas mixed with a reducing agent are switched, and the nitrogen oxides are reduced by using an adsorbed ammonia and the excess reducing agent is adsorbed on the catalyst. And, when the amount of ammonia adsorption of the catalyst approaches to the breakpoint, a state is returned to an original state. |
