Abstract: A method and apparatus for removing methane from ventilation air in a mining situation is provided by a carbonation reactor CAR which reacts a ventilation air methane stream VAR with a carbon dioxide scavenger to form a mineral carbonate which is passed to a calcination reactor CAL in which a regeneration reaction decomposes the mineral carbonate back to a mineral or mineral oxide. Additional heat may be added to the CAL by steam, solar energy or by burning drainage gas, natural gas, or coal. Steam or supercritical fluid given off by the CAR can be utilized for heating, cooling, or energy generation. The carbon dioxide scavenger can be any metal, metal oxide, mineral or mineral waste having a carbonation tendency, used in the process referred to as “Mineral Carbonate Looping Reactor” (MCLR), or can be stone dust from the mining site used in the process referred to as “Stone Dust Looping Reactor” (SDLR).

Abstract: Methane is removed from ventilation air by cycling metal or metal oxide particles in a chemical looping process in one or more reactors where the metal particles are alternately reduced and oxidized, and passing ventilation air through one or more of reactors to convert the air plus methane into reduced air, water and carbon dioxide. In one variation, a hydrogen generator and a regenerator are used to alternatively reduce and oxidize the particles such that ventilation air methane introduced into a combustor provided with hydrogen from the hydrogen generator can be processed in the regenerator to produce air, water and carbon dioxide. Other variations involve using three reactors in the chemical looping process, or an array of parallel inclined plates forming lamellas between upper and lower reactors to keep lighter particles in the upper oxidizer reactor and heavier particles in the lower reducer reactor.

Abstract: Methane is removed from ventilation air by cycling metal or metal oxide particles in a chemical looping process in one or more reactors where the metal particles are alternately reduced and oxidised, and passing ventilation air through one or more of said reactors to convert the air plus methane into reduced air plus water plus carbon dioxide. In one variation, ventilation air methane (VAM) is removed from ventilation air in coal mines using a chemical looping process to move metal or metal oxide particles between reactors such as a hydrogen generator (5) and a regenerator (7) to alternatively reduce and oxidise the particles such that VAM introduced into a combustor (6) provided with hydrogen from the hydrogen generator (5) can be processed in the regenerator (7) to produce air plus water plus carbon dioxide.

Abstract: A method of generating power from a heat source, said method including: compressing (10) a working fluid to increase its temperature; exchanging (11) heat between said working fluid and said heat source to superheat said working fluid; expanding (12) said superheated working fluid to drive a turbine, thereby reducing its temperature; condensing (13) said working fluid to further reduce its temperature: and returning said working fluid to said compressing step (10), the method further including the step (14) of regenerating the heat of said working fluid wherein working fluid passing between said compressing step (10) and said heat exchanging step (11) exchanges heat with working fluid passing between said expanding step (12) and said condensing step (13); wherein said steps are performed in a thermodynamic cycle (S1-S1?-S2-S3-S3?-S4) within a supercritical region (SC) above the saturation dome (A) of said working fluid, and wherein said heat regenerating step (14) is performed under isenthalpic conditions to

Abstract: A method of generating power from a heat source, said method including: compressing (10) a working fluid to increase its temperature; exchanging (11) heat between said working fluid and said heat source to superheat said working fluid; expanding (12) said superheated working fluid to drive a turbine, thereby reducing its temperature; condensing (13) said working fluid to further reduce its temperature: and returning said working fluid to said compressing step (10), the method further including the step (14) of regenerating the heat of said working fluid wherein working fluid passing between said compressing step (10) and said heat exchanging step (11) exchanges heat with working fluid passing between said expanding step (12) and said condensing step (13); wherein said steps are performed in a thermodynamic cycle (S1-S1?-S2-S3-S3?-S4) within a supercritical region (SC) above the saturation dome (A) of said working fluid, and wherein said heat regenerating step (14) is performed under isenthalpic conditions to