The present disclosure relates to systems and methods that provide power generation using predominantly CO.sub.2 as a working fluid. In particular, the present disclosure provides for the use of a portion of the heat of compression from a CO.sub.2 compressor as the additive heating necessary to increase the overall efficiency of a power production system and method.

The present invention relates to a cryogenic air separation process that provides high pressure oxygen for an oxy-fired combustion of a fuel (e.g., a carbonaceous fuel). The air separation process can be directly integrated into a closed cycle power production process utilizing a working fluid, such as CO.sub.2. Beneficially, the air separation process can eliminate the need for inter-cooling between air compression stages and rather provide for recycling the adiabatic heat of compression into a process step in further methods wherein an additional heat supply is beneficial.

The present disclosure relates to systems and methods that provide power generation using predominantly CO.sub.2 as a working fluid. In particular, the present disclosure provides for the use of a portion of the heat of compression from a CO.sub.2 compressor as the additive heating necessary to increase the overall efficiency of a power production system and method.

The present disclosure relates to systems and methods useful for power production. In particular, a power production cycle utilizing CO.sub.2 as a working fluid may be configured for simultaneous hydrogen production. Beneficially, substantially all carbon arising from combustion in power production and hydrogen production is captured in the form of carbon dioxide. Further, produced hydrogen (optionally mixed with nitrogen received from an air separation unit) can be input as fuel in a gas turbine combined cycle unit for additional power production therein without any atmospheric CO.sub.2 discharge.

The present disclosure relates to systems and methods useful for power production. In particular, a power production cycle utilizing CO.sub.2 as a working fluid may be combined with a second cycle wherein a compressed CO.sub.2 stream from the power production cycle can be heated and expanded to produce additional power and to provide additional heating to the power production cycle.

Disclosed is a device for refrigerating or liquefying a fluid such as natural gas or hydrogen, comprising a fluid circuit that is to be cooled and has an upstream end for connection to a source of gaseous fluid as well as a downstream end for connection to a member for collecting the cooled or liquefied fluid, the device comprising a heat exchanger assembly in heat exchange with the fluid circuit to be cooled, the device comprising a refrigerator in heat exchange with at least a portion of the exchanger assembly, the refrigerator being of the type that has a cycle for refrigerating a cycle gas containing at least one of: helium, hydrogen, nitrogen or neon; said refrigerator comprising in series in a cycle circuit: a mechanism for compressing the cycle gas, at least one member for cooling the cycle gas, a mechanism for expanding the cycle gas, and at least one member for reheating the expanded cycle gas, wherein the compression mechanism comprises a plurality of compression stages in series composed of a centrifugal compressor assembly, the compression stages being mounted on a set of shafts that are rotationally driven by a motor assembly, the at least one member for cooling the cycle gas comprising at least one heat exchanger at the outlet of at least one compression stage in heat exchange with the cycle circuit, said heat exchanger being cooled by a heat transfer fluid, characterized in that the compression mechanism comprises at least two compression stages that are arranged successively in series and do not include any member for cooling the cycle gas such as a heat exchanger therebetween.

The present disclosure relates to systems and methods useful for power production. In particular, a power production cycle utilizing CO.sub.2 as a working fluid may be configured for simultaneous hydrogen production. Beneficially, substantially all carbon arising from combustion in power production and hydrogen production is captured in the form of carbon dioxide. Further, produced hydrogen (optionally mixed with nitrogen received from an air separation unit) can be input as fuel in a gas turbine combined cycle unit for additional power production therein without any atmospheric CO.sub.2 discharge.

Disclosed is a device for liquefying a fluid, comprising a fluid circuit to be cooled, the device comprising a heat exchanger assembly in heat exchange with the fluid circuit to be cooled, at least one first cooling system in heat exchange with at least a portion of the heat exchanger assembly, the first cooling system being a refrigerator having a cycle for refrigerating a cycle gas mainly comprising helium, said refrigerator comprising in series in a cycle circuit: a mechanism for compressing the cycle gas, at least one member for cooling the cycle gas, a mechanism for expanding the cycle gas, and at least one member for reheating the expanded cycle gas, wherein the compression mechanism includes at least four compression stages in series composed of a centrifugal compressor assembly, the compression stages being mounted on shafts that are rotationally driven by a motor assembly, the expansion mechanism comprising at least three expansion stages in series composed of a set of centripetal turbines, the at least one member for cooling the cycle gas being configured to cool the cycle gas at the outlet of at least one of the turbines, and wherein at least one of the turbines is coupled to the same shaft as at least one compression stage so as to feed the mechanical work produced during the expansion to the compression stage.

Disclosed is a device for refrigerating or liquefying a fluid such as natural gas or hydrogen, comprising a circuit for fluid that is to be cooled and has an upstream end for connection to a source of gaseous fluid and a downstream end for connection to a member for collecting the cooled or liquefied fluid, the device comprising a heat exchanger assembly in heat exchange with the circuit of fluid to be cooled, the device comprising a refrigerator in heat exchange with at least a portion of the heat exchanger assembly, the refrigerator being of the type that has a cycle for refrigerating a cycle gas containing at least one of: helium, hydrogen, nitrogen or neon; said refrigerator comprising, arranged in series in a cycle circuit: a mechanism for compressing the cycle gas, at least one member for coding the cycle gas, a mechanism for expanding the cycle gas, and at least one member for reheating the expanded cycle gas, wherein the compression mechanism comprises a plurality of compression stages in series composed of a centrifugal compressor assembly, the compression stages being mounted on a set of shafts rotated by an assembly of one or more motors, the at least one member for cooling the cycle gas comprising at least one heat exchanger arranged at the outlet of at least one compression stage in heat exchange with the cycle circuit, said heat exchanger being cooled by a heat-transfer fluid, characterized in that the compression mechanism comprises at least two compression stages that are arranged successively in series and do not include any member for cooling the cycle gas such as a heat exchanger therebetween.

Disclosed is a device for refrigerating or liquefying a fluid such as natural gas or hydrogen, comprising a fluid circuit that is to be cooled and has an upstream end for connection to a source of gaseous fluid as well as a downstream end for connection to a member for collecting the cooled or liquefied fluid, the device comprising a heat exchanger assembly in heat exchange with the fluid circuit to be cooled, the device comprising a refrigerator in heat exchange with at least a portion of the exchanger assembly, the refrigerator being of the type that has a cycle for refrigerating a cycle gas containing at least one of: helium, hydrogen, nitrogen or neon; said refrigerator comprising in series in a cycle circuit: a mechanism for compressing the cycle gas, at least one member for cooling the cycle gas, a mechanism for expanding the cycle gas, and at least one member for reheating the expanded cycle gas, wherein the compression mechanism comprises a plurality of compression stages in series composed of a centrifugal compressor assembly, the compression stages being mounted on a set of shafts that are rotationally driven by a motor assembly, the at least one member for cooling the cycle gas comprising at least one heat exchanger at the outlet of at least one compression stage in heat exchange with the cycle circuit, said heat exchanger being cooled by a heat transfer fluid, characterized in that the compression mechanism comprises at least two compression stages that are arranged successively in series and do not include any member for cooling the cycle gas such as a heat exchanger therebetween.