A small to mid-scale liquefied natural gas production system and method is provided. The disclosed liquefied natural gas production system employs at least one heat exchanger, three turbine/expanders and at least three refrigerant compression stages. The expansion ratio of one turbine/expander is appreciably lower than the expansion ratio of the other turbine/expanders such that the temperature of the exhaust stream from the turbine/expander with the lower expansion ratio is above the critical point temperature of the compressed natural gas containing feed stream but colder than about −15° C. The present system and method may be configured using either a single nitrogen-based expansion refrigerant circuit or two separate refrigerant circuits wherein the turbine/expander with the lowest expansion ratio is contained within a separate refrigeration circuit from the other two turbine/expanders with the higher expansion ratios.

A system for processing liquified natural gas can include: a natural gas feed; a cold box; one or more natural gas cooling components; and a storage tank configured to store a refrigerant, wherein the one or more natural gas cooling components and the storage tank are located within the cold box. The cold box can be a methane cold box and the refrigerant can be propane, ethane, or ethylene. The system can also include a propane refrigerant cycle and/or an ethylene refrigerant cycle. Refrigerant stored in the methane cold box can be used to replenish refrigerant lost in the propane/ethylene cycles. The cold box can be an ethylene cold box of the ethylene refrigerant cycle. Propane can be stored in the ethylene cold box. A second storage tank can be located within a methane cold box and store ethane or ethylene.

A system and method for cooling, purifying and liquifying a feed gas stream uses liquid nitrogen for cooling the system. After cooling the system, the warmed nitrogen is vented as a vapor. The system and method include a water condenser, a first and second cooler and a liquifier and production of at least first and second contaminant streams. Optionally, the system includes a compressor or blower and/or a separator.

Provided herein are systems and methods for utilizing a natural gas letdown generator at a natural gas regulating station. The system utilizes the gas letdown generator to generate electricity by converting high pressure inlet gas to low pressure outlet gas, which in turn creates low temperature outlet gas. Electricity generated can power a data center. Heat may be transferred, using a heat exchanger, from dielectric fluid of the data center to the natural gas prior to entering the gas letdown generator. Heat may be further transferred, using a second heat exchanger, from the dielectric fluid to the natural gas at the output of the gas letdown generator. The heat exchange may substantially cool the dielectric fluid for transmission to the data center and may heat the low temperature outlet gas for transmission to an end user.

A system includes a heat exchanger including a first inlet for receiving a first pressurized gas stream and a first outlet for outputting a chilled gas stream produced by the heat exchanger cooling the first pressurized gas stream. The system also includes a turbo expander connected to the first outlet of the heat exchanger for receiving the chilled gas stream from the heat exchanger and producing a partially liquified gas stream, the partially liquified gas stream comprising vapors and LNG. The system further includes at least one separator connected to the turbo expander, wherein the partially liquified gas stream is fed into the at least one separator, and the at least one separator separates the vapors from the LNG.

A plant and process are used to liquefy and purify a high pressure ethane feed stream. The plant includes a cascaded refrigeration system that refrigerates the ethane feed stream. The refrigeration system includes a propylene circuit, an ethylene circuit and a mixed refrigerant circuit. The mixed refrigerant circuit includes a refrigerant that includes ethane and methane. The plant includes a demethanizer that is configured to remove methane and other natural gas liquids from the refrigerated ethane stream.

A method is disclosed for start-up of a system for liquefying a feed gas stream comprising natural gas. The system has a feed gas compression and expansion loop, and a refrigerant system comprising a primary cooling loop and a sub-cooling loop. The feed gas compression and expansion loop is started up. The refrigerant system is pressurized. Circulation in the primary cooling loop is started and established. Circulation in the sub-cooling loop is started and established. A flow rate of the feed gas stream and circulation rates of the primary cooling loop and the sub-cooling loop are ramped up.

Facility and method for hydrogen refrigeration, comprising a hydrogen circuit to be cooled, comprising:—a first and a second set of heat exchanger(s) arranged in series for exchanging heat with the hydrogen circuit to be cooled;—a first cooling device for exchanging heat with the first set of heat exchanger(s) comprising a refrigerator that operates a refrigeration cycle of a first cycle gas;—a second cooling device for exchanging heat with the second set of heat exchanger(s) comprising a refrigerator that operates a refrigeration cycle of a second cycle gas having a molar mass of less than 3 g/mol, the refrigerator of the second cooling device comprising, arranged in series in a cycle circuit: at least one centrifugal compressor, a cooling member, an expansion member and a member for reheating the second expanded cycle gas;—a system for mixing at least one additional component having a molar mass greater than 50 g/mol with the second cycle gas before it enters the at least one centrifugal compressor and a member for purifying the mixture at the outlet of the at least one compressor configured to remove the at least one additional component up to a determined residual content and located upstream of the first set of heat exchanger(s).

The present application includes a plant for treating gas, particularly natural gas, supplied by a transmission network. The plant includes a gas inlet connected to the transmission network, a portion of the plant that decompresses, to a predefined outlet pressure, a first fraction of the gas from the inlet, and supplies the decompressed gas at a first outlet. The plant also includes another portion that liquifies a second fraction of the gas from the inlet and supplies the liquefied gas at a second outlet. The portion that carries out the decompressing includes a valve for throttling the first gas fraction, a heat exchanger establishing a thermal exchange relationship between the decompressing portion placed downstream the throttle valve and the portion that liquifies and supplies the gas, another heat exchanger establishing a thermal exchange relationship between the plant portions placed downstream the first heat exchanger and upstream the throttle valve. The portion that liquifies and supplies also includes a valve for throttling the second gas fraction that is downstream the first heat exchanger.

A method for recovering associated gaseous hydrocarbons from a well for producing liquid hydrocarbons, the method comprising (i) providing gaseous hydrocarbons from a hydrocarbon well; (ii) providing a cryogenic liquid from an air separation unit or an associated nitrogen liquefaction facility within proximity of the hydrocarbon well; (iii) liquefying the gaseous hydrocarbons at a hydrocarbon liquefaction facility within proximity to the hydrocarbon well to thereby produce a liquefied hydrocarbon gas, where heat associated with the gaseous hydrocarbons is transferred to the cryogenic liquid; and (iv) transferring the liquefied hydrocarbon gas to an air separation unit or nitrogen liquefaction facility.