A method and apparatus for reducing NO.sub.x emissions in a coal burning furnace of a power plant without utilizing techniques downstream of the furnace, such as SCR and SNCR, is provided. In a primary combustion zone, a fuel is combusted in the presence of a first oxidant gas comprised substantially of N.sub.2, to produce a first effluent gas that include one or more NO.sub.x species. Downstream a re-burn zone is operated in a sub-stoichiometric manner, combusting a second fuel in presence of the first effluent gas and a second oxidant wherein the second oxidant gas comprises a stream of oxygen. The effluent gas from the re-burn zone is introduced to overfire airflow so as to establish a super-stoichiometric zone prior to discharged from the furnace.
FEDERALLY SPONSORED RESEARCH/DEVELOPMENT STATEMENT
 This invention was conceived under government contract RCD1459. The United States Government, Department of Energy, may retain certain rights to this invention.