A flue gas desulfurization unit is converted from operating with lime or magnesium enhanced lime under inhibited oxidation into a unit that operates using limestone under inhibited oxidation conditions. A ball mill grinding unit may be installed to crush the limestone thereby producing a suspended slurry of fine limestone particles which is pumped to the reaction vessel. When installed, the ball mill may be installed in the process immediately downstream of the existing slaking equipment. The suspended solution may be maintained at a pH in the range of 3.0 to 6.5, optimally at approximately 5.0 to increase the dissolution rate of the limestone reagent produced by the ball mill. The post-conversion process may also require the addition of organic acids and oxidation inhibitors to achieve better SO.sub.2 removal from the flue gas.

A flue gas treatment device is provided. A wet electrostatic precipitator and a flue gas heater are integrated in an integrated flue housing of the flue gas treatment device, thus the occupied area of the flue gas treatment device is smaller than that of the solution with devices being arranged separately. Furthermore, since a bidirectional transition flue is not required to be arranged in the integrated flue housing, the flue gas has a good flow uniformity, and further it is not required to arrange a flow equalization orifice plate in the flue, thus the flue gas has a small resistance, thereby reducing the power consumption of the draught fan and increasing the efficiency of the power plant.

The invention relates to a process for removing a target gas from a gas stream rich in the target gas and to an absorbent solution for absorbing a gas, such as carbon dioxide, from a gas stream. The invention involves the use of a photoactive compound that is convertible from a first state to a second state upon irradiation to facilitate removal or collection of a target gas from a gas stream.

Systems and methods for the use of highly reactive hydrated lime (HRH) in circulating dry scrubbers (CDS) to remove sulfur dioxide (SO.sub.2) from the flue gas.

Processes for the treatment of waste streams from the hydroconversion of heavy hydrocarbons containing additives and catalysts are described. At least one of the SHC pitch stream, SDA pitch stream, and the heavy residue stream is sent to a thermal oxidation system. The metals in the SHC and SDA pitch streams and the heavy residue stream are oxidized and can be easily recovered as clean powdered metal oxides which can be reused or sold. The processes produce chemicals which can be recovered and sold.

A process for treating effluent streams in a naphtha complex is described. One or more of the sour water stripping unit for the NHT sour water from the NHT, the amine treatment unit and the caustic treatment unit for the NHT stripper off-gas, the caustic scrubber unit or other chloride treatment unit for the off-gas from the C.sub.5-C.sub.6 isomerization zone and the C.sub.4 isomerization zone, and the caustic scrubber unit or other chloride treatment unit for the regenerator off-gas are replaced with a thermal oxidation system.

A process for the treatment of sulfidic spent caustic, conditioned catalyst regeneration vent gas, C4 isomerization off gas, various and hydrocarbon containing liquid and gaseous streams in addition to toxic containing streams like cyanidic off gas and waste water in a propane/butane dehydrogenation complex is described. Various effluent streams are combined in appropriate collection vessels, including an off-gas knockout drum, a hydrocarbon buffer vessel, a spent caustic buffer vessel, an optional a waste water buffer vessel, and a fuel gas knockout drum. Streams from these vessels are sent to a thermal oxidation system.

A process for the treatment of sulfidic spent caustic, conditioned catalyst regeneration vent gas, C4 isomerization off gas, various and hydrocarbon containing liquid and gaseous streams in addition to toxic containing streams like cyanidic off gas and waste water in a propane/butane dehydrogenation complex is described. Various effluent streams are combined in appropriate collection vessels, including an off-gas knockout drum, a hydrocarbon buffer vessel, a spent caustic buffer vessel, an optional a waste water buffer vessel, and a fuel gas knockout drum. Streams from these vessels are sent to a thermal oxidation system.

A process for the treatment of waste water, spent air, and hydrocarbon containing liquid and gaseous streams in the cumene/phenol complex is described. Various effluent streams are combined in appropriate collection vessels, including a spent air knockout drum, a hydrocarbon buffer vessel, a fuel gas knockout drum, a phenolic water vessel, and a non-phenolic water vessel. Streams from these vessels are sent to a thermal oxidation system.

A process for the treatment of waste water, spent air, and hydrocarbon containing liquid and gaseous streams in the cumene/phenol complex is described. Various effluent streams are combined in appropriate collection vessels, including a spent air knockout drum, a hydrocarbon buffer vessel, a fuel gas knockout drum, a phenolic water vessel, and a non-phenolic water vessel. Streams from these vessels are sent to a thermal oxidation system.