THE EFFECT OF CH4, H2O AND SO2 ON THE NO REDUCTION WITH C3H6

NO reduction experiments were carried out in a fixed-bed reactor loade d with metal/alumina catalysts. Two hydrocarbons, methane and propene, were used as the reducing agents for the NO reduction. The former hyd rocarbon exhibited relatively low NOx conversions and it was burned at high temperatures. The addition of methane to a propene-containing fe ed gas stream did not cause any inhibition or enhancement on the NO re duction activity over the Pt/alumina catalyst. The presence of water i n the feed gas stream caused a small, reversible, inhibition effect ov er the Pt/, Cu/ and Ni/alumina catalysts. The maximum NO conversion wa s measured over Ni/alumina, followed by that over Cu/ and Pt/alumina. The peak temperature varied with the catalyst, but it was not affected by the addition of water to the feed gas stream. The presence of SO2 in the feed gas stream did not affect the NOx conversion over Pt/alumi na, it caused a significant irreversible loss of activity over other m etal/alumina catalysts and it enhanced the activity of Rh/alumina. (C) 1998 Elsevier Science B.V.