Reduction of nitrogen oxides with a flue gas desulphurization residue

If the desulphurization product is separated together with the fly ash from the flue gas, the increased content of heavy metals can prohibit a general use. In this paper a new route for utilization is described for a desulphurization residue produced in the refinery of Schwechat. Due to the fly ash content the residue has higher concentrations of vanadium and nickel and hence has to be disposed of as hazardous waste underground. During the research it was shown, that this desulphurization residue is suitable for reduction of nitrogen oxides in the flue gas of a cement plant.