A system for renewable energy storage, providing integral synthesis of heat source cryo-fuel and heat sink refrigerant for distributed electric generation and motor vehicle prime movers and refrigerant liquefiers. Fuel synthesis is by gasification and anaerobic digestion of organic feedstock with heat recovery to drive thermo-chemical reactor and air and fuel liquefiers.

A system and method for cooling and liquefying a gas in a heat exchanger that includes compressing and cooling a mixed refrigerant using first and last compression and cooling cycles so that high pressure liquid and vapor streams are formed. The high pressure liquid and vapor streams are cooled in the heat exchanger and then expanded so that a primary refrigeration stream is provided in the heat exchanger. The mixed refrigerant is cooled and equilibrated between the first and last compression and cooling cycles so that a pre-cool liquid stream is formed and subcooled in the heat exchanger. The stream is then expanded and passed through the heat exchanger as a pre-cool refrigeration stream. A stream of gas is passed through the heat exchanger in countercurrent heat exchange with the primary refrigeration stream and the pre-cool refrigeration stream so that the gas is cooled. A resulting vapor stream from the primary refrigeration stream passage and a two-phase stream from the pre-cool refrigeration stream passage exit the warm end of the exchanger and are combined and undergo a simultaneous heat and mass transfer operation prior to the first compression and cooling cycle so that a reduced temperature vapor stream is provided to the first stage compressor so as to lower power consumption by the system. Additionally, the warm end of the cooling curve is nearly closed further reducing power consumption. Heavy components of the refrigerant are also kept out of the cold end of the process, reducing the possibility of refrigerant freezing, as well as facilitating a refrigerant management scheme.

A system for renewable energy storage, providing integral synthesis of heat source cryo-fuel and heat sink refrigerant for distributed electric generation and motor vehicle prime movers and refrigerant liquefiers. Fuel synthesis is by gasification and anaerobic digestion of organic feedstock with heat recovery to drive thermo-chemical reactor and air and fuel liquefiers.

A method for separating air by cryogenic distillation in a system of columns comprising a first column and a second column operating at a lower pressure than the first column, comprising the steps of compressing all of the feed air in a first compressor to a first output pressure of at least 1 bar greater than the pressure of the first column, sending a first portion of the air under the first output pressure to the second compressor, and compressing the air to a second output pressure, cooling and condensing at least a portion of the air under the second output pressure in a heat exchanger, withdrawal of a liquid from a column of the system of columns, pressurising the liquid and evaporating the liquid by heat exchange in the heat exchanger, and pressure reduction of a portion of the compressed air to a second output pressure, at least partially evaporating said air in the heat exchanger, optionally additional heating of said air in the heat exchanger, and sending at least a portion of this air to the second compressor.

A system and method for separating air in an air separation plant is provided. The disclosed systems and methods divert a portion of the compressed, purified air stream to a bypass system configured to selectively produce a higher pressure compressed output stream or a lower pressure compressed output stream. The higher pressure and/or lower pressure compressed output streams are cooled in a main heat exchanger by indirect heat transfer with a plurality of product streams from the air separation plant and then rectified in the distillation column system. A second portion of the compressed, purified air stream is partially cooled in the main heat exchanger and expanding in a turbo-expander to produce power and an exhaust stream which is directed to the distillation column system of the air separation plant where it imparts additional refrigeration generated by the expansion of the compressed air stream in the turbo-expander.

A method for operating a heat exchanger, in which a first operating mode is carried out in first time periods, and a second operating mode is carried out in second time periods that alternate with the first time periods; in the first operating mode a first fluid flow is formed at a first temperature, is fed into the heat exchanger in a first region at the first temperature, and is partially or completely cooled in the heat exchanger; in the first operating mode a second fluid flow is formed at a second temperature, is fed into the heat exchanger in a second region at the second temperature, and is partially or completely heated in the heat exchanger; and in the second operating mode the feeding of the first fluid flow and of the second fluid flow into the heat exchanger is partially or completely halted.

The present invention relates to cryogenic energy storage systems for storing using high-grade heat-of-compression. The system includes a liquefaction sub-system (100) and thermal energy storage device (300). The liquefaction sub-system (100) includes a first compressor (102), a first, second and third heat exchanger (104, 116, 112) and second compressor (114). The first and second heat exchangers (104, 116) are configured to transfer the high-grade heat of compression from the first and second compressors (102, 114) respectively to the thermal energy storage device (300). The third heat exchanger (112) is configured to recuperate the low-grade heat of compression from the second compressor (114) back into the second compressor (114) enabling the second compressor (114) to generate high-grade heat of compression. Further systems use compressors (124) and expanders (122). Further systems include power recovery sub-systems (400). The present disclosure also relates to methods of heat-of-compression storage in cryogenic energy storage systems.

A proposed method provides a highly efficient fueled power output augmentation of the liquid air energy storage (LAES) through its integration with the semi-closed CO.sub.2 bottoming cycle. It combines the production of liquid air in air liquefier during LAES charge using excessive power from the grid and an effective recovery of stored air for production of on-demand power in the fueled supercharged reciprocating internal combustion engine (ICE) and associated expanders of the power block during LAES discharge. A cold thermal energy of liquid air being re-gasified is recovered for cryogenic capturing most of CO.sub.2 emissions from the facility exhaust with following use of the captured CO.sub.2 in the semi-closed bottoming cycle, resulting in enhancement of total LAES facility discharge power output and suppressing the thermal NOx formation in the ICE.

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 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.