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.

Device (10) for injecting powders into a furnace pipe (500), comprising a chamber (230) connected to a peripheral pipe (220) and, on the other hand, to the said furnace pipe via the said peripheral pipe (220), which comprises a first part (221) of diameter DP1, and a second part (222) of diameter DP2, having a downstream end (222a) and intended to be in communication with the furnace pipe, and a powder conveying pipe (120) which has a diameter DT and a downstream end (121), characterized in that the second part of the peripheral pipe has a length Lthe diameter (DP2) of the second part of the peripheral pipe, and in that the diameter (DT) and the diameter (DP2) are connected by the relationship 0<DP2DT< DT.

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.

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.

This boiler has a flue in which a reducing agent supplying device and a selective reduction catalyst are provided, a bypass flow path bypassing economizers is provided, and a first closing device partially closing the bypass flow path and a second closing device partially closing the flue are also provided. A plurality of first closing members, serving as the first closing device, are provided along the direction in which exhaust gas flows through the flue at a predetermined spacing in the width direction of the flue. A plurality of second closing members, serving as the second closing device are provided along the vertical direction at a predetermined spacing in the width direction of the flue. The first closing members and the second closing members are arranged so as to be displaced from each other in the width direction of the flue.

This boiler has a flue in which a reducing agent supplying device and a selective reduction catalyst are provided, a bypass flow path bypassing economizers is provided, and a first closing device partially closing the bypass flow path and a second closing device partially closing the flue are also provided. A plurality of first closing members, serving as the first closing device, are provided along the direction in which exhaust gas flows through the flue at a predetermined spacing in the width direction of the flue. A plurality of second closing members, serving as the second closing device are provided along the vertical direction at a predetermined spacing in the width direction of the flue. The first closing members and the second closing members are arranged so as to be displaced from each other in the width direction of the flue.

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 stream. The multi-functional composition of matter may include a fixed carbon sorbent and minerals, halogens in the form of halide salts, as well as other physical and chemical properties to enhance (1) the oxidation reaction kinetics for the oxidation of mercury species and (2) the mass diffusion kinetics of the mercury species.

A flue gas additive is provided that includes both a nitrogenous component to reduce gas phase nitrogen oxides and a halogen-containing component to oxidize gas phase elemental mercury.

Sorbent compositions containing calcium and iodine are added to coal to mitigate the release of mercury and/or other harmful elements into the environment during combustion of coal containing natural levels of mercury.

Sorbent compositions containing calcium and iodine are added to coal to mitigate the release of mercury and/or other harmful elements into the environment during combustion of coal containing natural levels of mercury.