Reducing NO/sub x/ emissions at the burner, in the furnace, and after combustion

Strict federal and state regulations on oxides of nitrogen (NOx) are requiring new control technologies. The production of NOx, and current emission regulations at both state and federal levels are reviewed. Modifying combustion-process conditions is currently the most cost-effective and widely used practice for achieving moderate reduction in NOx emissions. Analyzed are control methods in burners and furnaces, the impact of different designs on emissions, and post-combustion emission control techniques. Due to the lack of operating experience with some of these control systems, several small-scale pilot studies are under way. These projects and other new control systems are summarized.