New control technology for nitrogen oxide emissions from stationary combustion sources

Researchers from the University of Central Florida and NASA recently completed a joint study of a new control technology for nitrogen oxide (NO{sub x}) emissions. The new technology was designed for use on stationary combustion sources where the flue gas stream is greater than 900 F. The study was conducted on the flue gases from an industrial boiler. The new technology incorporates liquid injection of hydrogen peroxide (H{sub 2}O{sub 2}) into the hot gas stream followed by caustic scrubbing. The parameters addressed in this study were NO{sub x} (100--800 ppm), H{sub 2}O{sub 2} (50--3,600 ppm), sulfur dioxide (100--900 ppm), and temperature (830 F-- 1,030 F). The concentration of the H{sub 2}O{sub 2} used in this study was 50%. Nitric oxide (NO) conversions of 90--97% for H{sub 2}O{sub 2}:NO molar ratios of 1:1 were achieved. The effects of sulfur dioxide on conversion efficiency were found to be synergistic for H{sub 2}O{sub 2}:NO molar ratios of less than 1:1 and insignificant for molar ratios of 1:1 or greater. Follow-on studies are underway to investigate rate constants for the reactions involved in this process, scrubber design parameters, and modifications to this technology for low temperature flue gas streams, and to further investigate themore » nitrogen speciation observed in the process.« less