| 摘要 |
PURPOSE:To decompose and remove NOx in high efficiency without releasing ammonia by installing the deNOx reactor having a deNOx catalyst layer at the inflow side of waste gas and aN ammonia decomposing catalyst layer at the outflow side of the waste gas and decomposing nitrogen oxide by adding ammonia at a preceding stage and decomposing excess ammonia using the catalyst at a post-stage. CONSTITUTION:The deNOx reactor 1 having the deNOx catalyst layer 2 at the inflow side of the waste gas and the ammonia decomposing catalyst layer 3 at the outflow side of the waste gas is installed, The NH3 more than reaction equivalent amount per NOx is added to decompose the NOx at the preceding stage, and excess NH3 is decomposed at the post-stage. The ammonia decomposing catalyst has the chemical composition (1.0+ or -0.6)R2O.(aM2O3.bAl2 O3).cMeO-NySiO2 (R is alkali metal ion and/or hydrogen ion, M is VIII group element, etc., Me is alkali earth metal, a+b=1.0, a>=0, b>=0, c>=0, (y/c)>12, y>12) in a dehydrated state, and the catalyst contains copper, etc., in the crystalline silicate having a specified X-ray diffraction pattern. |
