A method for transferring thermal energy to a separate endothermic process includes: (a) providing a carbon dioxide (CO.sub.2) stream and a carbonaceous fuel to a heater; (b) reacting the carbonaceous fuel in the heater to produce a heated stream; (c) transferring heat from the heated stream to the separate endothermic process; (d) separating the CO.sub.2 stream from the heated stream after (c); and (e) recycling the CO.sub.2 stream to the heater after (d).

A cylindrical burner apparatus and method which produce low noise levels and are not dependent upon a blower, or natural draft, for providing combustion air flow. A flow of combustion air is induced into a rearward end of a burner tube and a swirling flame is produced in the tube by discharging a gas fuel from a plurality of discharge ports located in the tube.

A burner and methods of using the burner. The burner utilizes bypass conduits to separate the combustion air that is passed to the primary combustion zone into two or more portions. The two portions are injected into the primary combustion zone at different points so as to reduce the flame temperature. A NOx reducing medium may be mixed with the combustion air in the bypass conduit. The NOx reducing medium may be flue gases from a combustion chamber having the primary combustion zone.

A double chambers boiler system with oxygen-enriched combustion is provided, relating to fields of thermal power engineering and mechanical manufacturing. The double chambers boiler system includes a boiler furnace subassembly and a combustion control subassembly. The boiler furnace subassembly includes a combustion chamber and a heat exchange chamber. The heat exchange chamber is arranged above the combustion chamber. A high temperature flue gas outlet is arranged between the combustion chamber and the heat exchange chamber. The combustion control subassembly includes a burner, a pure oxygen injector and a fuel injector. The double chambers boiler system with oxygen-enriched combustion is able to simultaneously solve problems of improving a combustion efficiency and reducing an emission concentration of NO.sub.x.

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.

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.

A burner apparatus and method which provide an increased amount of internal flue recirculation for reducing NO.sub.x emissions by ejecting a series of surrounding primary fuel streams and also ejecting on one or more subsequent series of surrounding fuel streams outside of the burner wall toward the burner combustion wherein each succeeding series of surrounding fuel streams must travel a greater distance to the combustion zone and each series of surrounding fuel streams must contact one or more radial impact structures provided on the exterior of the burner wall.

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.

A burner operating with flameless combustion, comprising a system for sucking the recycling flue gases directly from the combustion chamber by means of an ejector fed with the comburent, a heat exchange system positioned between the recycling flue gases and the comburent, a system for injecting the fuel directly into the recycling flue gases, the latter comprising or not comprising the comburent with formation of a mixture of fuel-recycling flue gases-comburent in the zone around the outlet of the comburent ejector and following introduction of the mixture into the combustion chamber.

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.