AN IMPROVED THERMAL SELECTIVE NONCATALYTIC NOX REDUCTION TECHNIQUE FOR STATIONARY SOURCES

SELECTIVE NO REDUCTION TECHNIQUES INVOLVING THE INJECTION OFNITROGEN-CONTAINING COMPOUNDS, SUCH AS AMMONIA, TO COMBUSTION PRODUCTS OVER A RELATIVELY NARROW TEMPERATURE RANGE HAVE BEEN USED FOR SOME TIME. SYSTEMS HAVE BEEN INSTALLED ON GAS-, OIL-, AND COAL-FIRED BOILERS, ON PROCESS HEATERS, AND ON MUNICIPAL WASTE INCINERATORS. HOWEVER, THESE SYSTEMS ARE LIMITED IN THEIR CONTROL EFFECTIVENESS. THERMAL SELECTIVE REDUCTION TECHNIQUES ARE EFFECTIVE ONLY INA NARROW TEMPERATURE WINDOW. IN LARGE SYSTEMS, THIS WINDOW MAY SHIFT AS THE COMBUSTOR OPERATION CHANGES, REDUCING EFFECTIVENESS AND ASSURING AMMONIA SLIP. REACTION ENGINEERING INTERNATIONAL'S PREVIOUS RESEARCH STUDIES SUGGEST THAT THERE ARE WAYS TO INCREASE THE EFFECTIVENESS OF SELECTIVE THERMAL REDUCTION TECHNIQUES. THE OBJECTIVE OF THE PHASE I RESEARCH PROGRAM IS TO EXTEND THE UNDERSTANDING OF THE INFLUENCE OF CO/H2/O2 CONCENTRATIONS ON THE REDUCTION OF NOX BY SELECTIVE REDUCINGREAGENTS IN ORDER TO DEFINE THE PROCESS REQUIREMENTS FOR THEIMPROVED CONTROL TECHNIQUE. THE SPECIFIC GOALS OF PHASE I ARE TO: (1) CONDUCT A SERIES OF PARAMETRIC EXPERIMENTS UNDER WELL DEFINED CONDITIONS TO ESTABLISH THE PARAMETERS CONTROLLING NOX REDUCTION WHEN USING VARIOUS NITROGEN-REDUCING REAGENTS IN THE PRESENCE OF CARBON MONOXIDE, HYDROGEN, AND OXYGEN; (2) DETERMINE THE CONCENTRATIONS OF CO, N2O, NO, AND REDUCED NITROGEN SPECIES IN THE EFFLUENT GASES; (3) DETERMINE WHY SOLID REAGENTS ARE MORE EFFECTIVE THAN GASEOUS REAGENTS; AND (4) MODIFY AN EXISTING MODEL TO DESCRIBE THE RESULTS OF THE EXPERIMENTS.