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 solid fuel burner is provided with a guide member arranged on an outer circumferential section of a distal end of a first gas nozzle so as to guide a fluid flowing through a second flow passage outward in a radial direction; and a contraction forming member that is arranged on an upstream side of the guide member with respect to the flow direction of the second flow passage so as to reduce the cross sectional area of the second flow passage. An outer diameter of the guide member is formed to be smaller than an inner diameter of an outer peripheral wall of a second gas nozzle. The first gas nozzle, the guide member, and the contraction forming member are configured so as to be integrally attachable/detachable along an axial direction of the first gas nozzle toward the outside of a furnace.

A method of operating a furnace having a firing system is disclosed. The method includes providing a solid fuel to a sieve; separating the fuel into a portion and a second portion; providing a first portion of a flue gas to a first fuel dryer comprising a first duct; providing the first portion of fuel to the first duct, and drying the first portion of fuel therein; conveying the first portion of fuel through the first duct to the furnace; burning the first portion of fuel with firing system; conveying the second portion of fuel and a second portion of the flue gas to a second fuel dryer in a lower portion of the furnace, providing the second portion of fuel to a mill; pulverizing the second portion of fuel with the mill; conveying the second portion of fuel to the furnace; and burning the second portion of fuel.

An integrated chemical looping air separation unit (5) in a large-scale oxy-fuel power generating plant takes a portion of recycled flue gas (6) via a recycling conduit (7) through a heat exchanger (8) to a reduction reactor (9). The reduction reactor (9) exchanges oxidized metal oxide with an oxidation reactor (11) via transfer means (10) which return reduced metal oxide from the reduction reactor (9) to the oxidation reactor (11). This enables the reduction reactor (9) to feed a mixture of oxygen and recycled flue gas into the boiler (13) of the power generating plant in a more energy efficient manner than conventional oxy-fuel power plants using air separation units.

A burner including a first pulverized coal entrained fluid flow conduit; an inner hydrogen conduit; and a hydrogen oxidant conduit positioned between the first pulverized coal entrained fluid flow conduit and the inner hydrogen conduit; an outlet of the inner hydrogen conduit positioned a first distance from an outlet of the hydrogen oxidant conduit such that hydrogen output from the outlet of the inner hydrogen conduit passes through a portion of the hydrogen oxidant conduit to the outlet of the hydrogen oxidant conduit; and the outlet of the hydrogen oxidant conduit being a second distance from an outlet of the first pulverized coal entrained fluid flow conduit such that the hydrogen and the hydrogen oxidant output from the outlet of the hydrogen oxidant conduit passes through a portion of the first pulverized coal entrained fluid flow conduit for being output from the burner.

The present invention relates to a device and a method for chemical looping combustion, for which the end of the intake duct (4) opening out within the chamber of the separator (1) is inclined with respect to a horizontal plane (H).

A modular boiler system for implementing fuel combustion is provided. The system includes a first boiler and a second boiler of a plurality of boilers, an oxygen input unit, a fuel input unit, a recycled flue gas input unit, and a flue gas separator. The first boiler receives oxygen from the oxygen input unit, fuel from the fuel input unit, and recycled flue gas from the recycled flue gas input unit. The first boiler outputs intra-system flue gas. The flue gas separator separates the intra-system flue gas into a first and second flue gas stream, transfers the first flue gas stream to the second boiler, and transfers the second flue gas stream to a gas cleaning system. The second boiler receives oxygen from the oxygen input unit, fuel from the fuel input unit, and the first flue gas stream from the flue gas separator.

In an oxyfuel combustion boiler system, nitrogen gas separated by an air separation unit (ASU) is supplied as carrier gas to a pulverizer for drying and pulverization of fuel. A fluid mixture of the nitrogen gas from the pulverizer with pulverized fuel is supplied to a powder separation device where the pulverized fuel is separated. The separated pulverized fuel is mixed with the primary recirculated flue gas and supplied to a burner.

An apparatus is provided for combining oxygen and fuel to produce a mixture to be burned in a burner. The oxygen-fuel mixture is ignited in a fuel-ignition zone in a flame chamber to produce a flame.

A combustion system is provided for an oxy-combustion furnace. The combustion system includes at least one windbox mountable on the oxy-combustion furnace and having at least one main firing location. At least one primary inlet is positioned in the at least one main firing location for conveying fuel and the first oxidant into the oxy-combustion furnace. At least one secondary inlet is positioned in the at least one main firing location for conveying the second oxidant into the oxy-combustion furnace. The at least one secondary inlet is angularly offset from the at least one primary inlet.