Abstract: The present invention relates to a process for removing nitrogen oxides, sulfur oxides, mercury and mercuric oxide from gas streams such as furnace or utility boiler flue gas streams, particularly those derived from coal-fired utility boilers, or from a gas stream from another pollutant abatement process. Ozone will react with the impurities in the gas stream to form mercuric oxide and higher oxides of nitrogen which can be removed by scrubber means. Additionally, and alternatively, the present invention provides for the use of ozone and ultraviolet radiation to remove nitrogen oxides, sulfur oxides and mercury from gas streams.

Abstract: The present invention relates to a process for removing nitrogen oxides, sulfur dioxides and mercury from gas streams such as furnace or utility boiler flue gas streams, particularly those derived from coal-fired utility boilers. A stream containing relatively low concentration of ozone from an ozone concentrator is feed to a barrier discharge reactor. Nitrogen oxides and mercury in the flue gas are oxidized by oxygen and hydroxyl radicals formed in the reactor. The flue gas is then directed to a reactor duct along with the ozone at a greater concentration wherein the remaining nitrogen oxides and mercury in the gas stream will react with the ozone to form nitric acid, nitric acid precursors, mixtures thereof and mercuric oxide. These impurities can then be removed from the gas stream by use of an aqueous scrubber, a wet electrostatic precipitator, a dry scrubber or a semi-dry scrubber.

Abstract: The present invention relates to a process for removing nitrogen oxides, sulfur oxides, mercury and mercuric oxide from gas streams such as furnace or utility boiler flue gas streams, particularly those derived from coal-fired utility boilers, or from a gas stream from another pollutant abatement process. Ozone will react with the impurities in the gas stream to form mercuric oxide and higher oxides of nitrogen which can be removed by scrubber means. Additionally, and alternatively, the present invention provides for the use of ozone and ultraviolet radiation to remove nitrogen oxides, sulfur oxides and mercury from gas streams.

Abstract: Sulfur compounds present as sulfides and mercaptans in spent caustic streams from refinery and petrochemical processes are oxidized by contacting them with an oxygen-containing gas in a packed column recycle reactor.