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Show AFRC90 Paper 34 DEMONSTRATION OF RADIAN'S PATENTED HYBRID LOW NOx PROCESS Ronald D. Bell Senior Program Manager Radian Corporation Austin, Texas 78720 ABSTRACT ../ ./ Radian Corporation has successfully completed demonstratesting of its patented Hybrid Low NOx Cogeneration Process for a diesel application. The process reduces NOx to levels below 25 ppmv and CO to below 50 ppmv by utilizing an oxygen "burnout" step, a catalytic reduction step, and a catalytic oxidation step. In the reducing step, 1 to 5% excess fuel is fired in an afterburner at 2000 to 2500 F. Firing in the reducing mode results in essentially no oxygen leaving the high temperature zone of the afterburner; the CO and H2 formed here reduce NOx across the reduction catalyst. Excess CO and H2 are oxidized across the oxidation catalyst. Advantages of Radian's Hybrid Low NOx Cogeneration Process over currently available NOx reduction technologies include the following: NOx reduction to levels below 25 ppmv with destruction efficiencies of 99+% achievable; requires only fuel gas and ambient air for NOx reduction; can be readily retrofitted to conventional combustion processes; does not require ammonia or urea injection; and increases overall energy conversion efficiency because of low excess air requirements. INTRODUCTION This paper describes the demonstration testing of a patented process to reduce NOx emission levels in flue gas streams from various combustion processes to below 25 ppmv (dry, corrected to 3% 02). The process was originally tar-geted for gas-fired turbine and incinerator applications with NOx emission levels in the range of 150 to 250 ppmv. Preliminary tests documented the effectiveness of the process to reduce NOx levels in this range to less than 25 ppmv. However, similar reductions for initial NOx levels of 1000 to 2000 ppmv could not be achieved. Demonstration testing of the process was first performed during July 1989 at a test facility in Harima, Japan. The purpose of the test was to verify the process for the treatment of a diesel exhaust containing high levels of NOxt approximately 1500 to 1800 ppmv. "As Prepared for the Third ASME Fossil Fuel Combustion symposium" -1- |
