Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

The plant according to the invention includes a reactor including a combustion chamber in which a fuel is fired with an oxidant to form a carbon dioxide-containing flue gas stream. The plant also includes a waste heat recovery unit in fluid connection with the combustion chamber, configured to capture heat from the flue gas stream. The plant also includes a flue gas compression unit in fluid connection with the waste heat recovery unit, configured to increase the pressure of the flue gas stream. The plant also includes a scrubber in fluid connection with the flue gas compression unit, configured to remove sulphur oxides and/or nitrogen oxides from the flue gas stream and to cool flue gas stream by means of the scrubbing medium. The plant also includes an absorption unit in fluid connection with the scrubber, configured to absorb carbon dioxide from the flue gas stream.

A system for dispersing sorbents to treat or remove flue gas pollutants can include a dispersion device with a venturi having an inlet, a throat, and an outlet. A sorbent supply can provide sorbent material to the dispersion device. A flue gas duct carrying flue gas streams traveling through the flue gas duct can include a port for attachment of the dispersion device to the port. In operational use, the dispersion device may be attached to the duct such that ambient air is drawn into the dispersion device and through the venturi. The air moving through the dispersion device can interact with and disperse the sorbent material into the duct for treating pollutants.

The device for performing mechanical work and/or producing electrical or thermal energy, the energy necessary for operation is obtained from the oxidation of carbonaceous fuels into carbon dioxide and water. The device comprises means for compression and/or condensation of the exhaust gas, and storage means for receiving the compressed and/or condensed exhaust gas.

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.

A method for operating a flue gas purification system, comprising, in the flue gas purification system, equipped with a boiler which can burn oil fuel and coal fuel either simultaneously or switching therebetween, a denitration equipment having a reducing agent injector and a catalytic reactor, an inlet flue to guide flue gas discharged from the boiler to the denitration equipment, an outlet flue to guide flue gas discharged from the denitration equipment, a bypass flue which can guide flue gas from the inlet flue to the outlet flue so as to bypass the denitration equipment, and a bypass damper, opening the bypass damper and burning oil fuel in the boiler being in condition not yet suitable for coal combustion to allow the flue gas discharged from the boiler to dividedly flow to the denitration equipment and the bypass flue, switching the oil fuel to coal fuel when the boiler is in condition suitable for coal combustion to burn the coal fuel in the boiler, closing the bypass damper after switching the oil fuel to the coal fuel, and then injecting a reducing agent when the catalytic reactor is in condition suitable for a denitration reaction.

A control system, for controlling an injection amount of a reducing agent injected into exhaust gas flowing from a coal-fired boiler in a thermal power generation facility toward a denitrification reactor of a denitrification device, includes: a first predictor predicting a first concentration of nitrogen oxides in the exhaust gas flowing toward the denitrification reactor based on first operation data of the thermal power generation facility; and a control device controlling the injection amount based on a predicted value of the first concentration. The first operation data includes at least either one of second operation data and third operation data, the second operation data being operation data of one or more coal pulverizers provided in the thermal power generation facility, and the third operation data being operation data of the coal-fired boiler affected by variation in operation conditions of the one or more coal pulverizers.

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.

A method facilitates operation of an incinerator for solid fuel. The incinerator includes a device for separating ash from flue gas. The method includes collecting ash deposits originating from the flue gas, resulting in collected ash. To improve the flowability of the ash collected, the method further includes introducing a powdery additive material including i) clay and ii) calcium carbonate into the flue gas. At the location where the additive material is introduced, the flue gas has a temperature of at least 700° C. The additive is introduced with a rate R of at least 0.1 times the mass of ash in the stream of flue gas.

Methods, apparatuses, and systems related to electrochemical capture of Lewis acid gases from fluid mixtures are generally described. Certain embodiments are related to electrochemical methods involving selectively removing a first Lewis acid gas from a fluid mixture containing multiple types of Lewis acid gases (e.g., a first Lewis acid gas and a second Lewis acid gas). Certain embodiments are related to electrochemical systems comprising certain types of electroactive species having certain redox states in which the species is capable of binding a first Lewis acid gas but for which binding with a second Lewis acid gas is thermodynamically and/or kinetically unfavorable. The methods, apparatuses, and systems described herein may be useful in carbon capture and pollution mitigation applications.