Catalytic Reduction of Nitric Oxide with Hydrocarbons

Abstract

The catalytic reduction of nitric oxide with thirteen hydrocarbons NO+4m+n 1 N2 + 2m was studied by using a flow reactor (inside diameter12.0 mm) 4mn 4m+n at atmospheric pressure and temperatures ranging from 27O to 5500C. The catalysts were five kinds of coprecipitated binary metal oxides of 50 mol composition and Girdler's barium promoted copper chromite, G22 (average diameter: 1.0 mm), all of which were reduced with hydrogen at 5500C before use. Inlet gas concentrations were 1% NO-0.09--.. -1.20%balanced with N2, and the total gas flow rate was 500 N cm3/min for the oxide catalyst of 1.000 g. Under these conditions, the activity sequence of catalysts for bensene was CuOAlP8 Fe2O3-Cr2O2 CuO-Gr2O3 Co3O4-A1203 Fe2O3-A1203 G 22. The reactivity sequence over CuO-A1203 catalyst was alkylbensenes benzene ethylene n-octane iso-octan n-hexane methane. on the basis of the above results together with the report by Ault and Ayen (A. I. Ch. E. Journal, 17, 265 (1971)), it would be deduced that an increase of carbon number resulted in an reactivity sequence was acetylenic olefinic aromatic paraffinic hydrocarbons for the same carbon number. The reactivity seems to decreased with decreasing saturation. Comparing hydrocarbons with carbon monoxide, the reactivity of the former was extremely inferior at lower temperatures, but the reverse was true at higher temperatures