| 摘要 |
PURPOSE: To efficiently remove nitrogen oxides in exhaust gas. CONSTITUTION: In the method for catalytically removing nitrogen oxides by introducing the exhaust gas containing nitrogen oxides to a reactor, in which a catalyst is packed, with the use of ammonia as a reducing agent, one bed of a denitrating catalyst 1 is provided in the upstream side of exhaust gas flow and an ammonia decomposing catalyst 2 using a crystalline silicate, which has a specific chemical composition and X-ray diffraction pattern, as a carrier and a specific noble metal as an active metal is provided in the succeeding flow. And the denitration catalyst layer 3 having ammonia decomposing function is provided in the further succeeding flow and ammonia equal to or above reaction equibrium of nitrogen oxide in the exhaust gas is added to remove nitrogen oxide in the exhaust gas. |
