The Economic Feasibility of Using Hydrogen Peroxide for the Enhanced Oxidation and Removal of Nitrogen Oxides from Coal-Fired Power Plant Flue Gases.

Research at the University of Central Florida has determined that the injection of hydrogen peroxide (H2O2) into a simulated flue gas stream effectively oxidizes NO to NO2, and NO2 to HNO2 and HNO3. These oxides of nitrogen are much more soluble in water than NO, and therefore may be more easily scrubbed from the flue gas in a typical wet scrubber. Oxidation and NOx removal efficiencies of greater than 90% were demonstrated in the laboratory. An economic comparison between the H2O2 injection-wet scrubbing method and the selective catalytic reduction (SCR) method of NOx removal was conducted for a design base case and a variety of alternative cases. This study illustrates the trade-off between capital and operating costs for the two alternatives. The single largest factor in determining whether the total cost of the H2O2 injection-wet scrubbing method compares favorably with the total cost of the SCR method is the H2O2:NOx molar ratio. At the H2O2:NOx molar ratio demonstrated in the laboratory (1.92:1.0), the H2O2 injection-wet scrubbing method of NOx removal was shown to be uneconomical. However, the molar ratio in a full-size coal-fired power plant could be lower than that found in the laboratory. Based on all the cost assumptions stated in this article, at a molar ratio of 1.37:1.0, the hydrogen peroxide injection method was calculated to be an economically feasible alternative to the SCR method for NOx control.