Process for the selective catalytic reduction of nitrogen oxides in industrial effluents, at low temperature.

摘要

The system consists of layers of different catalysts, between which is situated a catalyst with active phase made by interaction of oxides of copper and aluminium, or of copper, nickel and aluminium. This catalyst is made by (a) impregnation of an aluminous support with aq. solns. of mixts. of copper and nickel salts, (b) sepn. of the solid, (c) drying the solid for more than 1 hour, and (d) treatment in air at 400-600 deg.C for 1-6 hours to convert the impregnated salts into the active salts. The support then contains 80-97 wt.% of aluminium oxide and less than 0.05% alkali oxides and alkaline earths. The copper and nickel salts are nitrates with Cu:Ni ratio of 10:1.