Embodiments of the present invention provide a process for liquefaction of a natural gas. The process includes cooling the natural gas with a first refrigerant provided by a first cooling system and cooling the natural gas with a second refrigerant provided by a second cooling system. The second cooling system is a single phase cooling system. The first and second cooling systems operate independently from each other. The second refrigerant is cooled with the first refrigerant so that the cooling capacity of the second refrigerant and the second cooling system is increased.

A system and method for producing liquefied natural gas are provided. The method may include compressing a process stream containing natural gas in a compression assembly to produce a compressed process stream. The method may also include removing non-hydrocarbons from the compressed process stream in a separator, and cooling the compressed process stream with a cooling assembly to thereby produce a cooled, compressed process stream containing natural gas in a supercritical state. The method may further include expanding a first portion and a second portion of the natural gas from the cooled, compressed process stream in a first expansion element and a second expansion element to generate a first refrigeration stream and a second refrigeration stream, respectively. The method may further include cooling the natural gas in the cooled, compressed process stream to a supercritical state with the first and second refrigeration streams to thereby produce the liquefied natural gas.

Disclosed is a method of retrofitting a full-scale LNG plant to enhance the LNG production capacity of the LNG plant and a method for operating such a retrofit plant. A small scale LNG plant having a capacity less than 2 MTPA can be integrated with a main LNG plant having a capacity of at least 4 MTPA such that end flash gas and boil off gas from the main LNG plant can be liquefied by the small scale LNG plant as incremental LNG. It has been found that the production capacity of the integrated system can be improved by increasing the temperature of the gas stream exiting the main cryogenic heat exchanger of the main LNG plant between 5 C. and 30 C. as compared with the design temperature.

A system and method for producing liquefied natural gas are provided. The method may include compressing a process stream containing natural gas in a compression assembly to produce a compressed process stream. The method may also include removing non-hydrocarbons from the compressed process stream in a separator, and cooling the compressed process stream with a cooling assembly to thereby produce a cooled, compressed process stream containing natural gas in a supercritical state. The method may further include expanding a first portion and a second portion of the natural gas from the cooled, compressed process stream in a first expansion element and a second expansion element to generate a first refrigeration stream and a second refrigeration stream, respectively. The method may further include cooling the natural gas in the cooled, compressed process stream to a supercritical state with the first and second refrigeration streams to thereby produce the liquefied natural gas.

A liquid air energy storage system comprises an air liquefier, a liquid air storage facility for storing the liquefied air, and a power recovery unit coupled to the liquid air storage facility. The air liquefier comprises an air input, an adsorption air purification unit for purifying the input air, and a cold box for liquefying the purified air. The power recovery unit comprise a pump for pressurizing the liquefied air from the liquid air storage facility; an evaporator for transforming the high-pressure liquefied air into high-pressure gaseous air; an expansion turbine capable of being driven by the high-pressure gaseous air; a generator for generating electricity from the expansion turbine; and an exhaust for exhausting low-pressure gaseous air from the expansion turbine. The exhaust is coupled to the adsorption air purification unit such that at least a portion of the low-pressure gaseous air exhausted from the expansion turbine is usable to regenerate the adsorption air purification unit.

A system and method for producing liquefied natural gas are provided. The method may include compressing a process stream containing natural gas in a compression assembly to produce a compressed process stream. The method may also include removing non-hydrocarbons from the compressed process stream in a separator, and cooling the compressed process stream with a cooling assembly to thereby produce a cooled, compressed process stream containing natural gas in a supercritical state. The method may further include expanding a first portion and a second portion of the natural gas from the cooled, compressed process stream in a first expansion element and a second expansion element to generate a first refrigeration stream and a second refrigeration stream, respectively. The method may further include cooling the natural gas in the cooled, compressed process stream to a supercritical state with the first and second refrigeration streams to thereby produce the liquefied natural gas.

The invention relates to a method for storing and recovering energy, according to which a condensed air product (LAIR) is formed in an energy storage period, and in an energy recovery period, a pressure flow is formed and is expanded to produce energy using at least part of the condensed air product (LAIR) without a supply of heat from an external heat source. The method comprises inter alia, for the formation of the condensed air product (LAIR): the compression of air (AIR) in an air conditioning unit (10), at least by means of an adiabatically operated compressor device (12); the formation of a first and a second sub-flow downstream of the adiabatically driven compressor device (12), said flows being formed from the air (AIR) that has been compressed in said device and the guiding of the first and second sub-flows in parallel through a first thermal store (131) and through a second thermal store (132), in which stores heat produced during the compression of the air (AIR) is at least partially stored. For the formation of the pressure flow, a vaporized product (HPAIR) is produced inter alia from at least one part of the condensed air product (LAIR). During the energy-producing expansion process, the pressure flow is guided through a first expansion device (61) and a second expansion device (62) and is thus expanded in each device. Heat stored in the first heat store device (131) is transferred to the pressure flow upstream of the first expansion device (61) and heat stored in the second heat store device (132) is transferred to the pressure flow upstream of the second expansion device (62). The invention also relates to an installation (100).

A LNG liquefaction plant system includes concurrent power production, wherein the refrigeration content of the refrigerant or SMR is used to liquefy and sub-cool a natural gas stream in a cold box or cryogenic exchanger. For concurrent power production, the system uses waste heat from refrigerant compression to vaporize and superheat a waste heat working fluid that in turn drives a compressor for refrigerant compression. The refrigerant may be an external SMR or an internal LNG refrigerant working fluid expanded and compressed by a twin compander arrangement.

A method for energy storage and recovery is based on the liquid air energy storage (LAES) operated at the pressure relationship such that the pressure of discharge air is greater than the charge air to provide a high round-trip efficiency. External cold source and cold thermal energy storage are used in a LAES to achieve a decrease in the LAES capital costs. A demand for a supplemental cold energy provided by external sources may be minimized. These features alone or in combination may result in reduced power demand required for cooling.

The invention relates to a method for storing and recovering energy, wherein an air liquefaction product (LAIR) is formed during an energy storage period, and a fluid pressure flow (12) is formed during an energy recovery period using at least one part of the air liquefaction product (LAIR) and is expanded for operation in at least one energy recovery device (14, 17). The air liquefaction product (LAIR) is obtained as a liquid medium during the energy storage period by compressing air in an air conditioning device (3), said compression being operated while supplying energy, in particular while supplying a current (9), optionally stored in a cold state, and fed to an evaporator unit (7). The air liquefaction product (LAIR) is expanded for operation as a fluid pressure flow (12) in the at least one energy recovery device (14, 17) during the energy recovery period after a pressure increase. The aim of the invention is to provide a solution with which even existing gas and steam power plants or open gas turbines are to be equipped with an energy storage capability. This is achieved in that the fluid pressure flow (12), in particular an air flow, is expanded in a first energy recovery device (14) and conducted through a recuperator device (13), in particular a heat boiler, upstream of said first energy recovery device (14), and thermal energy which has been decoupled from a flue gas flow (23) fed to the recuperator device (13) is coupled into the fluid pressure flow (12) in said heating tank. The flue gas flow (23) is fed to the recuperator device (13) from a fuel-fired second energy recovery device (17), in particular a gas turbine.