| 摘要 |
PURPOSE:Catalyst compositions for converting NOx to harmless N2 and H2O by catalytic reduction of NOx effectively and economically with ammonia as reducing agent. CONSTITUTION:Catalyst compositions for use in the reduction of NOx present in the waste gases from internal combustion exgine or combustion furnace of boiler, etc., are those having the formula I. The a/b ratio of mother components a CaO. bSiO2 should be 2-5/6 in view of their molding character and catalyst strength. The y value of [a CaO.bSiO2]x.[H2O]y should be as small as possible from a viewpoint of fireproof, and y/x should be practically less than 1. With regard to z value of active components [cFe2(SO4)3.dFeO3]Z, z/x should be in the range of 1/80 to 1/4, since a value of less than 1/80 has little effect and a value of more than 1/4 does not show the improvement in the activity. The c/d value of the active components should be in the range of 1 to 6, since the activity in a value of less than 1 at below 300 deg.C is poor and the resistance to head in a value of more than 6 is poor. |
