A CO.sub.2 energy storage system includes a storage tank that stores a CO.sub.2 slurry, including dry ice and liquid CO.sub.2, at CO.sub.2 triple point temperature and pressure conditions. The storage system also includes a first pump coupled in flow communication with the storage tank. The first pump is configured to receive the CO.sub.2 slurry from the storage tank and to increase a pressure of the CO.sub.2 slurry to a pressure above the CO.sub.2 triple point pressure. The energy storage system further includes a contactor coupled in flow communication with the first pump. The contactor is configured to receive the high pressure CO.sub.2 slurry from the pump and to receive a first flow of gaseous CO.sub.2 at a pressure above the CO.sub.2 triple point pressure. The gaseous CO.sub.2 is contacted and then condensed by the melting dry ice in the slurry to generate liquid CO.sub.2

A plant for energy storage, comprises: a basin (2) for a work fluid having a critical temperature (T.sub.c) lower than 0?; a tank (3) configured to store the work fluid in at least partly liquid or super-critical phase with a storage temperature (T.sub.s) close to the critical temperature (T.sub.c); an expander (4); a compressor (5); an operating/drive machine (6) operatively connected to the expander (4) and to the compressor (5); a thermal store (8) operatively interposed between the compressor (5) and the tank (3) and between the tank (3) and the expander (4). The plant (1) is configured for actuating a Cyclic Thermodynamic Transformation (TTC) with the work fluid, first in a storage configuration and then in a discharge configuration. The thermal store (8), in the storage configuration, is configured for absorbing sensible heat and subsequently latent heat from the work fluid and, in the discharge configuration, it is configured for transferring latent heat and subsequently sensible heat to the work fluid.

An apparatus and process for liquid oxygen production can be configured to avoid use of a feed compressor and a recycle compressor. Embodiments can be configured for open loop operation so that a relatively low yield liquid oxygen recovery can be obtained from a feed output from an electrolyzer that is comprised mostly of oxygen (e.g. at least 80 volume percent oxygen, between 80 vol % and 100 vol % oxygen, etc.). The relatively low yield liquid oxygen recovery can be surprisingly provided to permit an advantageous recovery of oxygen to limit waste oxygen that may ultimately be vented while also minimizing equipment and power requirements for the liquid oxygen recovery.

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 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.

A transportable apparatus for production of liquefied natural gas (LNG) having include a housing, a natural gas feed inlet, a heat exchanger, a phase separator, a liquid outlet disposed on the cold end of the heat exchanger, an LNG product outlet disposed on the cold end of the heat exchanger, a first refrigeration supply, a second refrigeration supply, and wherein the heat exchanger, the phase separator, the first expansion valve, the first refrigeration supply, and the second refrigeration supply are all disposed within the housing. The first refrigeration supply includes expansion of a portion of the LNG product, and the second refrigeration supply can include expansion of another portion of the LNG product or expansion and heat exchange with a supply of liquid nitrogen. The production of LNG is achieved without the external supply of electricity.

A method for the production of liquefied natural gas (LNG) without the use of externally provided electricity is provided The method may include the steps of: providing a transportable apparatus, wherein the transportable apparatus comprises a housing, a heat exchanger, a phase separator, a first refrigeration supply, and a second refrigeration supply, wherein the first refrigeration supply and the second refrigeration supply are configured to provide refrigeration within the heat exchanger; introducing a natural gas stream into the transportable apparatus at a first pressure under conditions effective for producing an LNG stream; withdrawing the LNG stream from the transportable apparatus; and withdrawing a warm natural gas stream from the transportable apparatus, wherein the warm natural gas stream is at a second pressure, wherein the second pressure is lower than the first pressure.

A method and installation for storing and recovering energy, according to which a condensed air product 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. For the formation of the condensed air product: the compression of air in an air conditioning unit, at least by means of at least one isothermally operated compressor device and the adsorptive cleaning of the air by means of at least one adsorptive cleaning device at a hyperbaric pressure level.

Liquid air energy storage (LAES) systems with increased efficiency and operating profit obtained through rational selection and configuration of the equipment used and optimization of the configuration/parameters of such equipment. In various embodiments, the LAES system is intended for operation preferably in an environmentally-friendly stand-alone regime with recovery of hot thermal energy extracted from compressed charging air and cold thermal energy extracted from discharged air.