Ionic Liquids as Catalysts for Sulfuric Acid Production and Cleaning of Flue Gases

The present paper is concerned with catalytic pollution abatement of sulfur and nitrogen oxides in flue gases from industrial sources. Especially fundamental and applied research on industrial catalysts and their model systems is presented with regards to cleaning of flue gases from fossil fuel based power plants and plants producing sulfuric acid. Combined DeSOx and DeNOx processes are very common installations in power plants in the industrialized world since both contaminants cause “acid rain”, leading to destruction of forests and lakes as well as corrosion of ancient and modern constructions. In most cases SOX is removed by wet limestone scrubbing of power plant flue gases, but new waste is produced. However, catalytic conversion by reaction (1): and finally absorption of SO3 to obtain H2SO4 of commercial grade, is an attractive alternative. The technology has been developed [1] by Haldor Tops0e A/S, as the so called SNOX process, where NOX is removed as well by catalytic conversion upstream of the SO2/SO3 converter.