A raw material composition for producing oxygen carriers includes a first component which is one or more of nickel oxide and nickel hydroxide and a second component which is one or more of boehmite, cerium oxide, cerium hydroxide, magnesium oxide, magnesium hydroxide, and titanium oxide, wherein, when the first component is nickel oxide, the second component includes cerium hydroxide. Such a raw material composition for producing oxygen carriers of the present invention is formed into oxygen carriers according to an oxygen carrier producing method, which will be described below, by adjusting the composition, formulation of raw materials, and degree of homogenization. Then, it is possible to produce oxygen carriers having physical properties such as a shape, a particle size, and a particle distribution suitable for a fluidized bed process or a high speed fluidized bed process and having improved wear-resistance, long-term durability, and oxygen transfer performance.

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.

The present invention relates to a CLC and operation method thereof equipped with a loop seal separator using magnetic oxygen carrier particles and a magnetic separator. And more particularly, the present invention relates to a loop seal separator using magnetic oxygen carrier particles and a magnetic separator, wherein the loop seal separator comprises a duct into which the ash and magnetic oxygen carrier particles, discharged from a reducer, flow; a magnetic separator to separate the ash from the magnetic oxygen carrier particles, flowing into the duct, by magnetic material; an ash discharge pipe to discharge the ash, separated by the magnetic separator; and an oxygen-carrier-particle discharge pipe to encourage the magnetic oxygen carrier particles, separated by the magnetic separator, to flow into an oxidizer.

Provided are systems and methods for transport vehicles using recyclable metallic fuels. The method includes capturing fuel products, including a metal oxide and unburnt fuel from the combustion of a metallic fuel, storing the unburnt metallic fuel and the fuel products, and recycling the metal oxide to recreate the metallic fuel and/or byproducts. Heat generated by the combustion and/or sintering of the metallic fuel may be transferred to a working fluid to drive the production of electricity and/or to provide propulsion in land, air and water vehicles and spacecraft. Furthermore, the thermal energy harvesting system may be used to generate electricity. The system includes a thermal (heat) engine having an induction heating assembly for heating the metallic fuel. Processes for complete combustion of the metallic fuel and recycling the metallic fuel in a sintering loop are described.

A process for producing black powder oxygen carriers for use in a chemical looping combustion unit includes the steps of: (a) removing and collecting the black powder waste material that was formed in a gas pipeline; (b) pre-treating the collected black powder to adjust its spherical shape to avoid attrition and fines production; and (c) activating the black powder to increase its reactivity rate and produce the black powder oxygen carrier that is suitable for use in the chemical looping combustion process as an oxygen carrier.

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.

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.

The invention relates to a method and to a device for chemical looping combustion CLC of a solid hydrocarbon feed wherein it is proposed to inject the solid hydrocarbon feed so as to limit any occurrence of sticking of the feed to the walls of the injection device. The solid feed is fed into a conveying zone operating under fluidized bed conditions and opening into a combustion reactor. A fluidization gas is injected into this conveying zone while controlling the flow of gas in such a way that the superficial velocity of the gas in the conveying zone is higher than the terminal velocity of the solid hydrocarbon feed particles and the terminal velocity of solid particles present in the combustion reactor, and while controlling the fluidization gas temperature in such a way that the temperature in the conveying zone is less than or equal to 500 C.

The present invention provides a method and system (1) for producing oxygen. Oxygen-carrier particles are transferred between a reduction process (10) and an oxidation process (15) connected to form a chemical looping process. The reduction process produces oxygen-depleted carrier particles and an exhaust gas mixture. Oxygen is separated from the exhaust gas mixture, preferably by a condenser (5). The oxygen-depleted carrier particles are returned to the oxidation process for regenerating the oxygen-depleted carrier particles with oxygen. The reduction process is performed during a first time period and the oxidation process is performed in a second time period.

The invention relates to a process and to a unit for chemical looping oxidation-reduction combustion of a hydrocarbon feed, wherein heat exchanges are controlled through a level variation of a dense fluidized bed of active mass particles in an external heat exchanger (E1, E2), positioned on a transport line carrying particles circulating between a reduction zone (210) and an oxidation zone (200) for the particles in the chemical loop. The bed level variation is allowed through controlled application of a pressure drop on a fluidization gas outlet in the heat exchanger, said pressure drop being compensated by the level variation of an active mass particle bed in a reservoir zone provided on the particle circuit in the chemical loop.