A method for producing power and argon is provided by providing a residual gas stream, purifying the residual gas stream in a front-end purification unit to remove carbon dioxide, thereby forming a purified residual gas stream, and introducing the purified residual gas stream to a cold box, wherein the purified residual gas stream is cooled and expanded within the cold box to produce power and then fed to a distillation column system for separation therein, thereby forming an argon-enriched stream and optionally a nitrogen-enriched stream and/or an oxygen-enriched stream, wherein the residual gas stream is sourced from a retentate stream of a cold membrane having oxygen, nitrogen, carbon dioxide, and argon.

Plant and method for producing hydrogen at cryogenic temperature, in particular liquefied hydrogen, comprising: an electrolyzer having an oxygen outlet and a hydrogen outlet; a hydrogen circuit to be cooled, comprising an upstream end connected to the hydrogen outlet and a downstream end to be connected to a member for collecting cooled and/or liquefied hydrogen, the plant also comprising a set of heat exchanger(s) in heat exchange with the hydrogen circuit to be cooled, the plant further comprising at least one cooling device in heat exchange with at least a portion of the set of heat exchanger(s), the hydrogen circuit to be cooled comprising a system for expanding the hydrogen stream and at least one hydrogen compressor upstream of the hydrogen stream expansion system, the hydrogen stream expansion system comprising at least one expansion turbine, wherein said at least one expansion turbine and said at least one compressor are coupled to the same rotating shaft to transfer expansion work from the pressurized hydrogen stream to the compressor in order to compress the hydrogen stream upstream of the turbine.

A system which integrates a power production system and an energy storage system represented by gas liquefaction systems is provided.

A method for controlling the refrigerant composition in a pre-cooled mixed refrigerant (PMR) cycle for LNG production includes obtaining a weather forecast temperature, measuring the concentration of each PMR component and measuring the ambient temperature. The method further includes calculating the optimum concentration of each PMR component for each of the measured and weather forecast temperatures and calculating the time period required to change appropriately each component concentration in transition from the ambient temperature to the weather forecast temperature; and comparing the measured and optimum concentration of each component in view of the calculated time period and direction of change in the component concentrations during the time period.

A method for liquid air and gas energy storage (LAGES) which integrates the processes of liquid air energy storage (LAES) and regasification of liquefied natural gas (LNG) at the import terminal through the exchange of thermal energy between the streams of air and natural gas (NG) in their gaseous and liquid states and includes harnessing the LNG as an intermediate heat carrier between the air streams being regasified and liquefied, recovering a compression heat from air liquefier for LNG regasification and utilizing a cold thermal energy of liquid air being regasified for reliquefaction of a part of send-out NG stream with its return to LNG terminal.

A system for liquefying production gas from a gas source containing a fluid having C1-C12 entrained gases includes a first phase separator for separating the C1-C12 gases from the fluid from the gas source. The first phase separator has an inlet in fluid communication with the gas source, a gas outlet and at least one alternative outlet. A first cryogenic liquefaction vessel has an inlet and an outlet. The inlet is in fluid communication with the gas outlet of the first phase separator. The first cryogenic liquefaction vessel cools the C1-C12 gases to liquefy the C3-C12 petroleum gases. A second phase separator is provided for separating the C3-C12 liquefied gases from the C1-C2 gases. The second phase separator has an inlet, a liquid outlet and a gas outlet. The inlet is in fluid communication with the outlet of the first cryogenic liquefaction vessel. At least one storage vessel is provided in fluid communication with the liquid outlet of the second phase separator for collection of the liquefied C3-C12 petroleum gases.

Apparatus, systems, and methods store energy by liquefying a gas such as air, for example, and then recover the energy by regasifying the cryogenic liquid and combusting or otherwise reacting the gas with a fuel to drive a heat engine. Carbon may be captured from the heat engine exhaust by using the cryogenic liquid to freeze carbon dioxide out of the exhaust. The process of liquefying the gas may be powered with electric power from the grid, for example, and the heat engine may be used to generate electricity. Hence, in effect these apparatus, systems, and methods may provide for storing electric power from the grid and then subsequently delivering it back to the grid.

A method for liquid air and gas energy storage (LAGES) which integrates the processes of liquid air energy storage (LAES) and regasification of liquefied natural gas (LNG) at the Floating Storage, Regasification and Power (FSRP) facilities through the exchange of thermal energy between the streams of air and natural gas (NG) in their gaseous and liquid states and includes recovering a compression heat from air liquefier and low-grade waste heat of power train for LNG regasification with use of an intermediate heat carrier between the air and LNG streams and utilizing a cold thermal energy of liquid air being regasified for increase in LAGES operation efficiency through using a semi-closed CO.sub.2 bottoming cycle.

A system for liquefying production gas from a gas source containing a fluid having C1-C12 entrained gases includes a first phase separator for separating the C1-C12 gases from the fluid from the gas source. The first phase separator has an inlet in fluid communication with the gas source, a gas outlet and at least one alternative outlet. A first cryogenic liquefaction vessel has an inlet and an outlet. The inlet is in fluid communication with the gas outlet of the first phase separator. The first cryogenic liquefaction vessel cools the C1-C12 gases to liquefy the C3-C12 petroleum gases. A second phase separator is provided for separating the C3-C12 liquefied gases from the C1-C2 gases. The second phase separator has an inlet, a liquid outlet and a gas outlet. The inlet is in fluid communication with the outlet of the first cryogenic liquefaction vessel. At least one storage vessel is provided in fluid communication with the liquid outlet of the second phase separator for collection of the liquefied C3-C12 petroleum gases.

A method for liquefying a feed gas stream. A refrigerant stream is cooled and expanded to produce an expanded, cooled refrigerant stream. Part or all of the expanded, cooled refrigerant stream is mixed with a make-up refrigerant stream in a separator, thereby condensing heavy hydrocarbon components from the make-up refrigerant stream and forming a gaseous expanded, cooled refrigerant stream. The gaseous expanded, cooled refrigerant stream passes through a heat exchanger zone to form a warm refrigerant stream. The feed gas stream is passed through the heat exchanger zone to cool at least part of the feed gas stream by indirect heat exchange with the expanded, cooled refrigerant stream, thereby forming a liquefied gas stream. The warm refrigerant stream is compressed to produce the compressed refrigerant stream.