A method for reducing the emission of contaminants by a furnace is provided. The method includes forming a bed from a stream of fuel within the furnace; fluidizing the bed with flue gas from the furnace; and heating the fuel within the bed so as to generate char, ash and contaminants. The method further includes capturing the contaminants via the ash.

The present disclosure is directed to systems and methods for high flame temperature oxy-combustion that enables the capture of CO.sub.2 cost effectively. One part of the presently disclosed subject matter comprises an annular shroud burner which utilizes a supply of undiluted oxygen and minimal flue gas recycle to generate a high flame temperature to maximize efficiency. The annular shroud burner may deliver oxygen into a combustion zone where mixing of the oxygen and a stream of fuel occurs. Flue gas recycled from the exit of the combustion system serves the dual purpose of conveying the coal into the reaction zone, as well as providing local cooling and protection from high incident heat fluxes through the novel shroud cooling design. The annular shroud burner may be configured to produce an axial jet flame that controls the rate of mixing of oxygen and fuel, thereby extending the heat release. Oxygen and coal may be mixed in a ratio such that peak flame temperatures exceed 4,500° F. (2,482° C.) while the flow of recycled flue gas is regulated to control flame temperature and protect burner components and near-burner surfaces.

The invention comprises: a) first comburent supplying means (18) connected to the lower part of the oxidation chamber, for introducing pressurized oxygenated gas in the oxidation chamber at a speed that comprises a tangential component; b) a particle recirculation system, which comprises: a particle separator (24) on the upper part of the oxidation chamber for trapping hot particles of ash and unburned material, and a transportation system (25) for transferring trapped particles from the particle separator (24) to the base of the oxidation chamber; and c) a gas recirculation system comprising: a sucker (26) for suctioning combustion gases from the upper part of the oxidation chamber, and pipes (27) for transferring the suctioned gases to the base of the oxidation chamber. It provides an optimized thermal transfer that reduces the emission of pollutants in waste recovery.

The present disclosure is directed to systems and methods for high flame temperature oxy-combustion that enables the capture of CO.sub.2 cost effectively. One part of the presently disclosed subject matter comprises an annular shroud burner which utilizes a supply of undiluted oxygen and minimal flue gas recycle to generate a high flame temperature to maximize efficiency. The annular shroud burner may deliver oxygen into a combustion zone where mixing of the oxygen and a stream of fuel occurs. Flue gas recycled from the exit of the combustion system serves the dual purpose of conveying the coal into the reaction zone, as well as providing local cooling and protection from high incident heat fluxes through the novel shroud cooling design. The annular shroud burner may be configured to produce an axial jet flame that controls the rate of mixing of oxygen and fuel, thereby extending the heat release. Oxygen and coal may be mixed in a ratio such that peak flame temperatures exceed 4,500 F. (2,482 C.) while the flow of recycled flue gas is regulated to control flame temperature and protect burner components and near-burner surfaces.

A method for reducing the emission of contaminants by a furnace is provided. The method includes forming a bed from a stream of fuel within the furnace; fluidizing the bed with flue gas from the furnace; and heating the fuel within the bed so as to generate char, ash and contaminants. The method further includes capturing the contaminants via the ash.

In a method for the combustion management in firing installations, in which a primary combustion gas quantity is conveyed through the fuel into a primary combustion area, part of the waste gas flow is extracted in the rear grate area and returned to the combustion process in the form of internal recirculation gas. In this case, no secondary combustion air is supplied between the grate and the supply of the internal recirculation gas. A firing installation for carrying out this method features nozzles above the firing grate such that no air supply is arranged between the firing grate and the nozzles.

The pre-mix burner assembly includes a jet pump comprising a combustion air tube, a flue gas inlet, and a suction chamber. The combustion air tube has an inlet and a tapered nozzle, and it is connected to a combustion gas fan. The flue gas inlet is connected to the suction chamber and the furnace chamber or other flue gas source. The suction chamber surrounds the combustion air tube, and it has a jet pump nozzle with a discharge. The combustion air exiting the combustion air nozzle creates a negative pressure in the suction chamber and draws flue gas into the suction chamber. There is a burner housing positioned downstream of the jet pump discharge. There is a fuel gas inlet connected to a mixing tube in the burner housing, and a burner block connected to the outlet of the burner housing.

The pre-mix burner assembly includes a jet pump comprising a combustion air tube, a flue gas inlet, and a suction chamber. The combustion air tube has an inlet and a tapered nozzle, and it is connected to a combustion gas fan. The flue gas inlet is connected to the suction chamber and the furnace chamber or other flue gas source. The suction chamber surrounds the combustion air tube, and it has a jet pump nozzle with a discharge. The combustion air exiting the combustion air nozzle creates a negative pressure in the suction chamber and draws flue gas into the suction chamber. There is a burner housing positioned downstream of the jet pump discharge. There is a fuel gas inlet connected to a mixing tube in the burner housing, and a burner block connected to the outlet of the burner housing.

A supercritical steam generator includes a downdraft furnace enclosure, a hopper tunnel, and a convection pass enclosure, with the hopper tunnel joining the downdraft furnace enclosure and convection pass enclosure together. Flue gas passes down through the downdraft furnace enclosure through the hopper tunnel and up through the convection pass enclosure. This structure permits the outlet steam terminals, which provide access to the resultant supercritical steam and/or reheat steam, to be located at a base of the steam generator rather than at the top of the steam generator as with conventional boilers. This reduces the length of the steam leads from the steam generator to a steam turbine that produces electricity using the supercritical steam.

A carbon sequestration system includes a furnace having an oxy-combustion burner, a mill configured to receive a fuel and to provide the fuel to the oxy-combustion burner, a waste heat recovery exchanger configured to receive a flue gas from the furnace, the flue gas ultimately supplied to one or more of an overfire air port of the furnace, the oxy-combustion burner, the mill, and a CO.sub.2 purification unit, the CO.sub.2 purification unit configured to produce a purified CO.sub.2 stream.