Novel approaches to control emissions, from marine diesel and gas-turbine engines

Environmental regulations on emission from ocean-going and stationary gas turbines and diesel engines used for marine (Navy) propulsion and auxiliary power have revived interest in studies on fundamental mechanisms of pollutant formation and innovative approaches on mitigating them. The U.S. Office of Naval Research sponsored several related research projects. The projects include reduced chemistry formulations, which result in substantial reduction in computing times, lean partial prernixing that can simultaneously reduce NOx and UHC, steam-assisted or oxygen enriched-air atomization, electrostatic atomization, selective noncatalytic reduction, nonthermal plasma remediation with easy on and off capability with about 70% NOx reduction, and porous inserts in which 30 to 60% reductions in NOx have been demonstrated. Some of the techniques produce steady flames and improve pattern factor, thus providing stable combustor operation. The fundamental understanding obtained is applicable to emission control from combustion systems in general. The accomplishments made by the various investigators who participated in this research effort constitute the subject matter of this paper.