Abstract: An ambient pressure gas turbine system is provided for mid-range power plants (for example, 1-4 MW) while achieving low NOx emission levels. The system includes a combustor that burns a hydrocarbon fuel at ambient pressure. A first heat exchanger upstream of the combustor heats the working fluid. A turbine downstream from the combustor expands combustion gases. The combustion gases are directed to the first heat exchanger for heat exchange with the working fluid and then to a compressor operative to compress the combustion gases. A second heat exchanger between the first heat exchanger and the compressor further cools the combustion gases to the compressor inlet temperature.

Abstract: An inverse combined steam-gas turbine cycle is disclosed. In the steam cycle, a fuel having a high nitrogen content such as coal or heavy fuel oil is burned in a boiler to raise steam to power a steam turbine. In the gas turbine cycle, a hydrocarbon fuel such as natural gas is burned in a gas combustor to power a gas turbine. The compressed exhaust gas (40. 42) from the steam cycle combustion is introduced into the gas combustor, where nitrogen oxides (NO.sub.x) in the exhaust gas may be reduced through reactions with the hydrocarbon fuel.

Abstract: Injection of additive such as ammonia or calcium compounds along with a small amount of hydrocarbon, preferably methane or natural gas, in a relatively high temperature region of the effluent stream for effectively reducing pollutants such as NO.sub.x and SO.sub.x. Preferably, injection is achieved by atomization of a liquid-form additive or additive solution with a small amount of gaseous hydrocarbon.

Abstract: An apparatus for detecting the presence of polycyclic aromatic hydrocarbons in the effluent of a turbulent commercial combustion system for monitoring or controlling the composition of the effluent. The apparatus is a system for directyl selectively detecting the presence in the effluent high molecular weight polycyclic aromatic compounds having five or more rings by laser induced fluorescence. The system includes an illuminating source of select fluorescence excitation of wavelengths that induces substantial fluorescence by high molecular weight polycyclic aromatic hydrocarbons in the gas phase.

Abstract: Low NO.sub.x burners for the combustion of gaseous, liquid and solid fuels. The fluid dynamic principle of radial stratification by the combustion of swirling flow and a strong radial gradient of the gas density in the transverse direction to the axis of flow rotation is used to damp turbulence near the burner and hence to increase the residence time of the fuel-rich pyrolyzing mixture before mixing with the rest of the combustion air to effect complete combustion.

Abstract: A gas-fired burner incorporating an air driven jet pump for mixing air, fuel, and recirculated flue gas is disclosed. The burner is configured for the staged introduction of combustion air to provide a fuel-rich combustion zone and a fuel-lean combustion zone. The burner achieves reduced NO.sub.x emission levels in high temperature applications which use preheated combustion air.

Abstract: A combustor capable of reducing the noxious emissions such as fuel bound and thermal nitrogen oxide products, during combustion of high nitrogen bearing and high aromatic content fuels is disclosed. The combustor includes a plurality of substantially concentric pipes defining annular passages with annular divergent nozzles. The divergent nozzles may be formed by rings having a venturi shaped axial section to facilitate fast mixing of axially supplied air between adjacent annular passages. The longitudinal spacing between at least two adjacent nozzles defines first and second divergent cavities. A fuel rich torodial vortex is formed in proximity to a central fuel jet in the first cavity and advantageously converts fuel bound nitrogen to N.sub.2. A fuel lean torodial vortex formed in the second cavity mixes hot combustion products with additional gaseous reactant to complete the combustion while avoiding locally high temperatures, and thus thermal NOx formation.

Abstract: A multi-annular swirl burner includes a plurality of overlapping tubular wall members which form a rich combustion zone and a lean combustion zone with a throat section therebetween. Annular passages are located between adjacent wall members, and vanes located therein input a tangential velocity to entering air. The tangential velocity of the swirling flows increases with increasing radius to produce centrifugal separating force on particulates moving from the rich combustion zone to the throat section. A collection system scavenges particulates from the throat section for disposal.