The present invention relates to activated carbon sorbents including nitrogen. In various embodiments, the present invention provides an activated carbon sorbent including a halogen- or halide-promoted activated carbon, the activated carbon sorbent particles including nitrogen in a surface layer of the sorbent particles. In various embodiments, the present invention provides a method of reducing the pollutant content in a pollutant-containing gas using the activated carbon sorbent. In various embodiments, the activated carbon sorbent can remove mercury from a mercury-containing gas that includes sulfur(VI) such as SO.sub.3 more efficiently than other sorbents.

A process where a gas, containing SO.sub.2 and O.sub.2 is brought in contact with a mixture of from 95% vol. to 50% vol. of activated carbon catalyst and from 5% vol. to 50% vol. of an inert filler material, where the SO.sub.2 is converted to H.sub.2SO.sub.4 on the activated carbon catalyst and is then washed from the activated carbon catalyst to obtain a H.sub.2SO.sub.4 solution.

A sorbent composition that is useful for injection into a flue gas stream of a coal burning furnace to efficiently remove mercury from the flue gas stream. The sorbent composition may include a sorbent with an associated ancillary catalyst component that is a catalytic metal, a precursor to a catalytic metal, a catalytic metal compound or a precursor to a catalytic metal compound. Alternatively, a catalytic metal or metal compound, or their precursors, may be admixed with the coal feedstock prior to or during combustion in the furnace, or may be independently injected into a flue gas stream. A catalytic promoter may also be used to enhance the performance of the catalytic metal or metal compound.

A sorbent composition that is useful for injection into a flue gas stream of a coal burning furnace to efficiently remove mercury from the flue gas stream. The sorbent composition may include a sorbent with an associated ancillary catalyst component that is a catalytic metal, a precursor to a catalytic metal, a catalytic metal compound or a precursor to a catalytic metal compound. Alternatively, a catalytic metal or metal compound, or their precursors, may be admixed with the coal feedstock prior to or during combustion in the furnace, or may be independently injected into a flue gas stream. A catalytic promoter may also be used to enhance the performance of the catalytic metal or metal compound.

A sorbent composition for removing mercury from flue gas is provided. The sorbent composition contains at least a powdered sorbent, an oxidant and a catalyst. Methods of cleaning flue gas are also provided, which includes injecting the sorbent composition into the flue gas, wherein the powdered sorbent has a fifty percent distribution particle size of from about 25 micrometers to about 75 micrometers.

The high temperature titanium-catalyst comprises a body, the body having a hot gas inlet and a hot gas outlet. The body comprises an array of titanium containing catalytic elements, wherein the array of titanium containing catalytic elements is arranged such that hot gas containing an amount of hexavalent chromium Cr(VI) may enter the body at the hot gas inlet, may pass through the array of titanium containing catalytic elements and may leave the body at the hot gas outlet. When the titanium-catalyst is in use, Cr(VI) in the hot gas containing an amount of Cr(VI) reacts with titanium oxide in a surface layer of the titanium containing catalytic elements, whereby the Cr(VI) is reduced to trivalent chromium Cr(III) thus reducing the amount of Cr(VI) in the hot gas containing an amount of Cr(VI).

A process where a gas, containing SO.sub.2 and O.sub.2 is brought in contact with a mixture of from 95% vol. to 50% vol. of activated carbon catalyst and from 5% vol. to 50% vol. of an inert filler material, where the SO.sub.2 is converted to H.sub.2SO.sub.4 on the activated carbon catalyst and is then washed from the activated carbon catalyst to obtain a H.sub.2SO.sub.4 solution.

A catalyst comprises a mixture of 95% vol. to 30% vol. of an activated carbon catalyst and from 5% vol. to 70% vol. of a filler material as well as a configuration of such a catalyst for the removal of SO.sub.2, heavy metals and/or dioxins form waste gas and liquids.

An exhaust gas treatment apparatus which includes a denitration device, a dust collector, and a desulfurization device in order, respectively, in a flow path of exhaust gas discharged from a boiler, wherein a heavy-metal component removal device is provided in the exhaust gas flow path between the dust collector and the desulfurization device. This device is provided with: an absorption tower including a nozzle which sprays acidic absorption liquid on the exhaust gas, a tank which stores liquid which has absorbed a heavy metal, and a pump which supplies the nozzle with the liquid in the tank; a neutralizing tank which neutralizes the liquid drawn from the absorption tower; and a separator which separates the neutralized liquid into a solid and a liquid component. Since a small amount of heavy metal can be removed in the absorption tower, re-emission of the heavy metal by the desulfurization device is prevented.

The present disclose is directed to a method for controlling iodine levels in wet scrubbers, and, in particular, recirculating wet scrubbers by removing the iodine from the scrubbing solution, such as by using ion exchange, absorption, adsorption, precipitation, filtration, solvent extraction, ion pair extraction, and an aqueous two-phase extraction.