Methods and systems for producing hydrogen substantially without greenhouse gas emissions, one method including producing a product gas comprising hydrogen and carbon dioxide from a hydrocarbon fuel source; separating hydrogen from the product gas to create a hydrogen product stream and a byproduct stream; injecting the byproduct stream into a reservoir containing mafic rock; and allowing components of the byproduct stream to react in situ with components of the mafic rock to precipitate and store components of the byproduct stream in the reservoir.

Methods and systems for producing hydrogen substantially without greenhouse gas emissions, one method including producing a product gas comprising hydrogen and carbon dioxide from a hydrocarbon fuel source; separating hydrogen from the product gas to create a hydrogen product stream and a byproduct stream; injecting the byproduct stream into a reservoir containing mafic rock; and allowing components of the byproduct stream to react in situ with components of the mafic rock to precipitate and store components of the byproduct stream in the reservoir.

A method for storing very high purity hydrogen in a salt cavern is provided. The method includes introducing a compressed very high purity hydrogen gas into a salt cavern, thereby producing a stored very high purity hydrogen gas; maintaining the stored very high purity hydrogen gas at a pressure greater than about 1.0 psi per linear foot of height within the cavern, and less than about 4.0 psi per linear foot of height within the cavern.

A method for storing very high purity hydrogen in a salt cavern is provided. The method includes introducing a compressed very high purity hydrogen gas into a salt cavern, thereby producing a stored very high purity hydrogen gas; maintaining the stored very high purity hydrogen gas at a pressure greater than about 1.0 psi per linear foot of height within the cavern, and less than about 4.0 psi per linear foot of height within the cavern.

Methods and systems for thermal energy storage and enhanced oil recovery are described herein. In some embodiments, natural gas may be injected down a well which has been previously hydraulically fractured to store thermal energy and to stimulate the well to greater hydrocarbon production.

A system and method for creating a subterranean storage facility at a location where there is underlying bedrock. A storage tank is provided that is formed from a cylindrical casing that is sealed with a top closure and a bottom closure. A first hole is excavated through the overburden. At the bottom of the first hole, a second hole is excavated into the bedrock. The storage tank is placed in the second hole with the top closure of the storage tank facing upward. The storage tank is set into the bedrock with a cement mixture. Pipe risers are extended into the storage tank through the first closure. The pipe risers extend up through the first hole and provide access to the storage tank.

A system and method for creating a subterranean storage facility at a location where there is underlying bedrock. A storage tank is provided that is formed from a cylindrical casing that is sealed with a top closure and a bottom closure. A first hole is excavated through the overburden. At the bottom of the first hole, a second hole is excavated into the bedrock. The storage tank is placed in the second hole with the top closure of the storage tank facing upward. The storage tank is set into the bedrock with a cement mixture. Pipe risers are extended into the storage tank through the first closure. The pipe risers extend up through the first hole and provide access to the storage tank.

A computerized method for management of a slurry injection well and the associated surface facility. The method utilizes real time and historical data of injection and slurry parameters in conjunction with computer simulations on a computer-modelled reservoir to predict well behavior during one or a series of injection events. The system determines optimized injection operation schedules, recommends and implements changes to an injection operation, including while in process such as through automated equipment control.

A computerized method for management of a slurry injection well and the associated surface facility. The method utilizes real time and historical data of injection and slurry parameters in conjunction with computer simulations on a computer-modelled reservoir to predict well behavior during one or a series of injection events. The system determines optimized injection operation schedules, recommends and implements changes to an injection operation, including while in process such as through automated equipment control.

A compressed air energy storage system may have an accumulator and a thermal storage subsystem having a cold storage chamber for containing a supply of granular heat transfer, a hot storage chamber and at least a first mixing chamber in the gas flow path and having an interior in which the compressed gas contacts the granular heat transfer particles at a mixing pressure that is greater than the cold storage pressure and the hot storage pressure and a conveying system operable to selectably move the granular heat transfer particles from the cold storage chamber, through the first mixing chamber and into the hot storage chamber, and vice versa.