NOX CONTROL BY CATALYTIC COMBUSTION OF NATURAL-GAS

The formation and destruction of NOx in the catalytic combustion of methane have been studied using a series of La1-xSrxCoO3 catalysts. The emissions of NOx are less than 3 ppm under lean combustion conditions at temperatures as high as 1000 degrees C. The NOx concentration increases as the temperature is increased above that needed for complete methane conversion. CO concentration is negligible at this temperature. The characterization of catalysts by temperature-programmed desorption (TPD) and temperature-programmed reduction (TPR) shows changes in their oxidation-reduction properties due to Sr substitution which in turn affects the performance for methane combustion and NOx reduction.