| 摘要 |
PURPOSE: To provide a method for denitrating exhaust gas which can prevent lowering of performance of a denitration catalyst due to an alkali metal component or alkaline earth metal component in exhaust gas. CONSTITUTION: Ammonia is injected into combustion exhaust gas of a fuel containing an alkali metal or alkaline earth metal such as wood or peat to bring the gas into contact with a denitration catalyst thereby to remove nitrogen oxides in the exhaust gas. Inorganic powder of one or more selected from among SiO2 , Al2 O3 , SiO2 .Al2 O3 , TiO2 and zeolite is injected into an exhaust gas flue on the upstream side of the denitration catalyst to adsorption-remove mists of alkali metal components or alkaline earth metal components, and nitrogen oxides in the exhaust gas are removed by the denitration catalyst on the downstream side of the gas. The injecting amount of the inorganic powder corresponds to 10-100% of the amount of dust in the exhaust gas and a injection point of the powder is set in such a manner that the time it takes for the injected powder to reach the catalyst is 0.1 second or more. |
