The present disclosure is directed to the use of elemental or speciated iodine and bromine to control total mercury emissions.

A multi-functional composition of matter that is useful for injection into a flue gas stream to rapidly and efficiently remove mercury from the flue gas streams, particularly at above average flue stream temperatures of about 340° F. or higher. The multi-functional composition of matter may include a fixed carbon content of at least about 20 wt. %, a mineral content of from about 20 wt. % to about 50 wt. %, a sum of micropore plus mesopore volume of at least about 0.20 cc/g, a micropore volume to mesopore volume ratio of at least about 0.7, and a tapped density of not greater than about 0.575 g/ml. These compositions may be further characterized by number of particles per gram of the composition of matter such that the composition may have at least about 0.8 billion particles per gram, or even as many as 1.5 billion particles per gram. These physical and chemical properties may enhance (1) the oxidation reaction kinetics for the oxidation of mercury species, (2) frequency of contact events, and (3) capture and sequestration of mercury, to achieve efficient mercury capture by the composition even in high temperature flue gas streams.

The present disclosure is directed to the use of elemental or speciated iodine and bromine to control total mercury emissions.

The present disclosure is directed to the use of elemental or speciated iodine and bromine to control total mercury emissions.

A multi-functional composition of matter that is useful for injection into a flue gas stream to rapidly and efficiently remove mercury from the flue gas streams, particularly at above average flue stream temperatures of about 340° F. or higher. The multi-functional composition of matter may include a fixed carbon content of at least about 20 wt. %, a mineral content of from about 20 wt. % to about 50 wt. %, a sum of micropore plus mesopore volume of at least about 0.20 cc/g, a micropore volume to mesopore volume ratio of at least about 0.7, and a tapped density of not greater than about 0.575 g/ml. These compositions may be further characterized by number of particles per gram of the composition of matter such that the composition may have at least about 0.8 billion particles per gram, or even as many as 1.5 billion particles per gram. These physical and chemical properties may enhance (1) the oxidation reaction kinetics for the oxidation of mercury species, (2) frequency of contact events, and (3) capture and sequestration of mercury, to achieve efficient mercury capture by the composition even in high temperature flue gas streams.

The present disclosure is directed to the use of elemental or speciated iodine and bromine to control total mercury emissions.

Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

The disclosure relates generally to reducing mercury emissions from a coal power plant. Specifically, a method for treating a gas stream containing mercury is provided that includes injecting a mercury oxidant or absorbent and a carrying agent into a gas stream that was produced by heating or burning a carbonaceous fuel comprising mercury. The carrying agent vaporizes after being injected into the gas stream. The mercury oxidant or absorbent and a carrying agent may be injected before passing the gas stream into a gas scrubber.

Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

Several embodiments of the present technology are directed to the removal of one or more air pollutants using cooling and/or calcium-containing particles. In some embodiments, a method for removing air pollutants comprises flowing a gas stream having calcium-containing particles and one or more of mercury or hydrochloric acid molecules, and cooling the gas stream, thereby causing at least a portion of the calcium-containing particles to adsorb to the mercury and/or hydrochloric acid molecules in the gas stream. The method can further comprise, after cooling the gas stream, filtering the gas stream to remove at least a portion of the calcium-containing particles having adsorbed mercury and hydrochloric acid.