Abstract: Disclosed is a process for combustion of carbonaceous substances containing ash and sulfur in slagging combustors wherein the fraction of sulfur retained in the slag is enhanced, emissions of nitrogen oxide are reduced, and operating problems with the furnace are avoided. The process comprises control of slag within a temperature range of 2000.degree.-2500.degree. F., slag stoichiometry less than oxidizing, and gas phase stoichiometry near stoichiometric.

Abstract: An apparatus and method for reducing nitrogen oxide emissions from furnace flue gas is provided in which a pulse generator introduces natural gas, or other fluid fuel which has little or no fixed nitrogen, into the upper portion of the furnace. The fuel pulse reacts with the nitrogen oxide in the flue gas to form ammonia-like compounds and nitrogen gas. These ammonia-like compounds react with additional amounts of nitrogen oxide in the flue gas to form nitrogen gas, water vapor and carbon dioxide. In this manner, the amount of nitrogen oxide in the flue gas is reduced using a process which can be easily applied to retrofitted furnaces.

Abstract: An improved burner for reducing formation of nitric oxide in pulverized fuel furnaces, particularly coal furnaces. Aerodynamic spoilers extend into the wake of the primary air and fuel line to produce fuel-rich and air-rich zones near the burner. Less near-burner adiabatic combustion occurs and that which does occur, occurs fuel-rich. This reduces both the thermal formation of NO.sub.x and the chemically bound fuel nitrogen conversion to NO.sub.x. The improved apparatus may be readily added to existing burners with a minimum of modification, or incorporated into new burner designs.