The invention relates to a system for recycling fluidized bed boiler bed material, comprising: a. a bottom ash removal device for removing bed material from a fluidized bed boiler, b. a mechanical classifier (10) comprising a mesh size from 200 to 1,000 μm designed to separate a coarse and a fine particle size fraction, c. a magnetic separator (12) designed to magnetically classify the fine particle fraction from the mechanical classifier, d. a device for recirculating the magnetic particle fraction into the boiler. The invention allows effective recirculation and reuse of ilmenite bed material.

The invention relates to a system for recycling fluidized bed boiler bed material, comprising: a. a bottom ash removal device for removing bed material from a fluidized bed boiler, b. a mechanical classifier (10) comprising a mesh size from 200 to 1,000 μm designed to separate a coarse and a fine particle size fraction, c. a magnetic separator (12) designed to magnetically classify the fine particle fraction from the mechanical classifier, d. a device for recirculating the magnetic particle fraction into the boiler. The invention allows effective recirculation and reuse of ilmenite bed material.

The invention relates to an oxygen carrier solid, its preparation and its use in a method of combustion of a hydrocarbon feedstock by active mass chemical-looping oxidation-reduction, i.e. chemical-looping combustion (CLC). The solid, which is in the form of particles, comprises an oxidation-reduction active mass composed of metal oxide(s) dispersed in a ceramic matrix comprising at least at least one feldspar or feldspathoid with a melting point higher than 1500° C., such as celsian, and has, initially, a specific macroporous texture. The oxygen carrier solid is prepared from a precursor of the ceramic matrix, obtained from a macroporous zeolitic material with zeolite crystals of a specific size, and a precursor of the oxidation-reduction active mass.

The invention relates to an oxygen carrier solid, its preparation and its use in a method of combustion of a hydrocarbon feedstock by active mass chemical-looping oxidation-reduction, i.e. chemical-looping combustion (CLC). The solid, which is in the form of particles, comprises an oxidation-reduction active mass composed of metal oxide(s) dispersed in a ceramic matrix comprising at least at least one feldspar or feldspathoid with a melting point higher than 1500° C., such as celsian, and has, initially, a specific macroporous texture. The oxygen carrier solid is prepared from a precursor of the ceramic matrix, obtained from a macroporous zeolitic material with zeolite crystals of a specific size, and a precursor of the oxidation-reduction active mass.

Systems and methods for coupling a chemical looping arrangement and a supercritical CO.sub.2 cycle are provided. The system includes a fuel reactor, an air reactor, a compressor, first and second heat exchangers, and a turbine. The fuel reactor is configured to heat fuel and oxygen carriers resulting in reformed or combusted fuel and reduced oxygen carriers. The air reactor is configured to re-oxidize the reduced oxygen carriers via an air stream. The air stream, fuel, and oxygen carriers are heated via a series of preheaters prior to their entry into the air and fuel reactors. The compressor is configured to increase the pressure of a CO.sub.2 stream to create a supercritical CO.sub.2 stream. The first and second heat exchangers are configured to heat the supercritical CO.sub.2 stream, and the turbine is configured to expand the heated supercritical CO.sub.2 stream to generate power.

Systems and methods for coupling a chemical looping arrangement and a supercritical CO.sub.2 cycle are provided. The system includes a fuel reactor, an air reactor, a compressor, first and second heat exchangers, and a turbine. The fuel reactor is configured to heat fuel and oxygen carriers resulting in reformed or combusted fuel and reduced oxygen carriers. The air reactor is configured to re-oxidize the reduced oxygen carriers via an air stream. The air stream, fuel, and oxygen carriers are heated via a series of preheaters prior to their entry into the air and fuel reactors. The compressor is configured to increase the pressure of a CO.sub.2 stream to create a supercritical CO.sub.2 stream. The first and second heat exchangers are configured to heat the supercritical CO.sub.2 stream, and the turbine is configured to expand the heated supercritical CO.sub.2 stream to generate power.

A catalyst regenerator according to an embodiment of the present invention, as a catalyst regenerator that regenerates a coked catalyst separated from a product produced in an endothermic catalytic reaction of a fluidized bed reactor, includes: a reaction chamber that includes a regeneration space, receives the coked catalyst from a standpipe connected to the regeneration space, and discharges a regenerated catalyst to an outlet; a fuel supplier that is connected to the reaction chamber to inject a fuel for combustion into the regeneration space; and a fuel supplier that is connected to the reaction chamber to inject an air for combustion into the regeneration space, wherein the fuel injected from the fuel supplier is a reformed fuel containing hydrogen and carbon monoxide.

A method for fluidizing a spent catalyst in a regenerator during a combustion process. The combustor includes a vessel and an air distributor. The air distributor includes an air grid and a plurality of first nozzles extending from the air grid. Spent catalyst is introduced into the vessel. Air is provided to the vessel via the plurality of first nozzles at a base combustion air rate. Additional air is provided to the vessels via a plurality of second nozzles of a fluffing air distributor at a fluffing air rate that is between 0.5 wt % and 10 wt % of the base combustion air rate to fluidize the catalyst. The second nozzles have outlets that are disposed below the air grid and above a bottom head of the vessel.

A method for fluidizing a spent catalyst in a regenerator during a combustion process. The combustor includes a vessel and an air distributor. The air distributor includes an air grid and a plurality of first nozzles extending from the air grid. Spent catalyst is introduced into the vessel. Air is provided to the vessel via the plurality of first nozzles at a base combustion air rate. Additional air is provided to the vessels via a plurality of second nozzles of a fluffing air distributor at a fluffing air rate that is between 0.5 wt % and 10 wt % of the base combustion air rate to fluidize the catalyst. The second nozzles have outlets that are disposed below the air grid and above a bottom head of the vessel.

A system for removing impurities from post-combustion gas includes an oxidizer and a reducer operatively connected to the oxidizer, the reducer configured to receive the post-combustion gas. The system further includes a CLOU material capable of selective circulation between the oxidizer and reducer. The CLOU material further oxidizes impurities present in the post-combustion gas to reduce or remove the same.