Disclosed is a method for enhanced fuel combustion to maximize the capture of by-product carbon dioxide. According to various embodiments of the invention, a method for combusting fuel in a two-stage process is provided, which includes in-situ oxygen generation. In-situ oxygen generation allows for the operation of a second oxidation stage to further combust fuel, thus maximizing fuel conversion efficiency. The integrated oxygen generation also provides an increased secondary reactor temperature, thereby improving the overall thermal efficiency of the process. The means of in-situ oxygen is not restricted to one particular embodiment, and can occur using an oxygen generation reactor, an ion transport membrane, or both. A system configured to the second stage combustion method is also disclosed.

The invention concerns a CLC process, and its installation, producing high purity dinitrogen, comprising: (a) the combustion of a hydrocarbon feed by reduction of a redox active mass brought into contact with the feed, (b) a first step for oxidation of the reduced active mass (25) obtained from step (a) in contact with a fraction of a depleted air stream (21b), in order to produce a high purity stream of dinitrogen (28) and a stream of partially re-oxidized active mass (26); (c) a second step for oxidation of the stream of active mass (26) in contact with air (20) in order to produce a stream of depleted air and a stream of re-oxidized active mass (24) for use in step (a); (d) dividing the stream of depleted air obtained at the end of step (c) in order to form the fraction of depleted air used in step (b) and a fraction complementary to the depleted air extracted from the CLC.

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 chemical looping combustion (CLC) based power generation, particularly using liquid fuel, ensures substantially complete fuel combustion and provides electrical efficiency without exposing metal oxide based oxygen carrier to high temperature redox process. An integrated fuel gasification (reforming)-CLC-followed by power generation model is provided involving (i) a gasification island, (ii) CLC island, (iii) heat recovery unit, and (iv) power generation system. To improve electrical efficiency, a fraction of the gasified fuel may be directly fed, or bypass the CLC, to a combustor upstream of one or more gas turbines. This splitting approach ensures higher temperature (efficiency) in the gas turbine inlet. The inert mass ratio, air flow rate to the oxidation reactor, and pressure of the system may be tailored to affect the performance of the integrated CLC system and process.

A process for recovering sulfur from a tail gas stream comprising the steps of providing a tail gas stream to a chemical looping combustion (CLC) unit, the tail gas stream comprising a sulfide component, providing an oxygen carrier to the CLC unit, the oxygen carrier comprising a calcium carbonate, providing an air stream to the CLC unit, the air stream comprising oxygen, and reacting the sulfide component in the CLC unit with the calcium compound and the air to produce a product effluent, the product effluent comprising calcium sulfate.

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.

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 hi 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.

Wet impregnation of active metal precursors into porous substrates, together with selective adsorption of the precursors on the pore surfaces, enables transition metal oxides derived from the precursors to disperse throughout the substrate, even at the nanoscale, without increased sintering or agglomeration, thereby forming oxygen carriers suitable for chemical looping. The porous substrate can be an oxide, for example SiO.sub.2. The oxygen carriers can comprise relatively large oxide loadings of over about 20 wt % and exhibit high reactivity over many regeneration cycles with substantially no loss in oxygen transport capacity or decrease in kinetics. The use of multiple transition metal oxides, for example NiO in addition to CuO, can greatly enhance chemical looping performance.

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).