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.

According to one or more embodiments described herein, a method for dehydrogenating hydrocarbons may include passing a hydrocarbon feed comprising one or more alkanes or alkyl aromatics into a fluidized bed reactor, contacting the hydrocarbon feed with a dehydrogenation catalyst in the fluidized bed reactor to produce a dehydrogenated product and hydrogen, and contacting the hydrogen with an oxygen-rich oxygen carrier material in the fluidized bed reactor to combust the hydrogen and form an oxygen-diminished oxygen carrier material. In additional embodiments, a dual-purpose material may be utilized which has dehydrogenation catalyst and oxygen carrying functionality.

A combustion system with surface-less heat energy exchange for efficient heat energy capture and lower pollutant emission, comprising: a first line feeding an oxygen-rich reactive; a second line feeding a hydrogen fuel; a vessel containing feed-water, a combustion enclosure without a bottom wall submersed into the feed water contained in a vessel, the combustion enclosure configured to receive the feed from each of the first and second line and combust a mixture of the two feeds in a pocket formed between an inner top and side walls of the combustion enclosure and a top surface of the feed-water contained in the vessel; and the combustion within the pocket yielding a high temperature and pressure combustion product and by-product directly into the feed-water of the vessel.

The invention relates to a method for operating a fluidized bed boiler, comprising: a) setting the ratio of secondary oxygen containing gas to primary oxygen containing fluidizing gas to a value ranging from 0.0 to 0.8; b) carrying out the combustion of fuel with a fluidized bed comprising ilmenite particle; and to a fluidized bed boiler.

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 a combustion engine and to a process for producing energy by means of expansion work in combustion engines. The invention is based on the problem of providing a possibility for supplying oxygen to the combustion space of a self-compacting combustion engine in an energy-efficient manner. According to the invention, with an arrangement for carrying out an intensified combustion for automatically increasing pressure of the combustion gases and using them in a combustion engine for performing mechanical work, the above-stated problem is solved in that an oxygen storage material is present in the combustion space so that a self-compressing combustion process is made possible by storing the oxygen in the oxygen storage material in the combustion space.

An oxygen fired fluidized bed combustor system (Oxy-FBC) is provided. The system provides means of producing a nearly pure stream of carbon dioxide for storage at high efficiency by controlling the oxygen content within certain regions of the combustor to control the rate of heat release allowing efficient transfer of heat from the combustor to the boiler tubes while avoiding excessively high temperatures that will cause ash melting, and simultaneously remove sulphur from the combustor via sorbents such as limestone and dolomite. The present invention utilizes a coarse oxygen carrier bed material to distribute heat and oxygen throughout an Oxy-FBC, while injecting fine sulphur sorbent that will continuously be removed from the bed.

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.

The invention is directed to a system for energy storage including a heat transfer fluid (HTF) tank containing a HTF such as water; a chemical combustion reactor that is at least partially filled with a metal and/or an oxide thereof, and that includes a gas inlet and a gas outlet; wherein the chemical combustion reactor is at least partially submerged in the HTF within the HTF tank.

Systems and methods are provided for enhancement of gaseous CLC in a fixed-bed process, marked by an increase in CO.sub.2 capture efficiency and oxygen carrier utilization, while reducing disadvantages of a conventional fixed-bed operation. The disclosed systems/methods provide a CLC fixed-bed reactor design in which the direction of the fuel gas is intermittently reversed during a single fuel oxidation step. In this reverse-flow mode, oxygen carrier reduction reactions are displaced over the ends of the reactor, which increases contact between fuel and oxidized solids and alleviates and/or mitigates problems of carbon deposition encountered by most oxygen carriers.