The report gives results of an evaluation of combustion modification techniques for coal-, oil-, and gas-fired utility boilers, with repect to NOx control reduction effectiveness, operational impact, thermal efficiency impact, capital and annualized operating costs, and effect on emissions of pollutants other than NOx. For gas- and oil-fired boilers, 30 to 60% NOx reductions are achievable with the combined use of staged combustion, flue gas recirculation and low excess air at an annualized cost of $0.50 to $3.00/kW-yr. For retrofit control of existing coal-fired boilers, low NOx burners and/or staged combustion yields a 30 to 60% NOx reduction at an annualized cost of $0.40 to $1.20/kW-yr. For new sources, modified furnace design with low NOx burners and/or overfire air can achieve emission levels of 260 to 170 ng/J (40 to 60% reduction). Detailed emission tests on a 200 MW coal-fired boiler showed that changes in trace specie emissions due to combustion modifications were small compared to the benefit of reduced NOx emissions.

"Acruex/Energy and Environmental Division." "April 1980." Includes bibliographical references. "Contract no. 68-02-2160, program element no. EHE624A."

v. 1. Technical results -- v. 2. Appendices.