A method for turndown of a liquefied natural gas (LNG) plant, the plant including a liquefaction unit arranged in a flow path of the plant, includes removing LNG from a first location in the flow path downstream of the liquefaction unit; vaporizing the removed LNG, or heating the removed LNG so that the removed LNG is transformed to gas phase; and re-admitting the vaporized or transformed LNG to the flow path at a second location upstream of the liquefaction unit. A corresponding LNG plant is also provided.

Power recovery sub-systems, cryogenic energy storage systems, and methods of capturing, storing, and re-using thermal energy are disclosed.

A method to recover hydrocarbonfractions from refineries gas streams involves a pre-cooled heat refinery fuel gas stream mixed with a pre-cooled and expanded supply of natural gas stream in an inline mixer to condense and recover at least C.sub.3.sup.+ fractions upstream of a fractionator. The temperature of the gas stream entering the fractionator may be monitored downstream of the in-line mixer. The pre-cooled stream of high pressure natural gas is sufficiently cooled by flowing through a gas expander that, when mixed with the pre-cooled refinery fuel gas, the resulting temperature causes condensation of heavier hydrocarbon fractions before entering the fractionator. A further cooled, pressure expanded natural gas reflux stream is temperature controlled to maintain fractionator overhead temperature. The fractionator bottoms temperature may be controlled by a circulating reboiler stream.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a single heat exchanger, multiple gas-liquid separators, multiple expander/compressor sets, and a rectifier attached to a liquid product drum.

The present invention relates to a refrigerant composition comprising neon and hydrogen. The present invention further relates to the use of the refrigerant composition in liquefying gaseous substances such as hydrogen or helium.

Provided are mixed refrigerant systems and methods and, more particularly, to a mixed refrigerant system and methods that provides greater efficiency and reduced power consumption.

Described herein is a method of removing refrigerant from a natural gas liquefaction system in which vaporized mixed refrigerant is withdrawn from the closed-loop refrigeration circuit and introduced into a distillation column so as to be separated into an overhead vapor enriched in methane and a bottoms liquid enriched in heavier components. Overhead vapor is withdrawn from the distillation column to form a methane enriched stream that is removed from the liquefaction system, and bottoms liquid is reintroduced from the distillation column into the closed-loop refrigeration circuit. Also described are methods of altering the rate of production in a natural gas liquefaction system in which refrigerant is removed as described above, and a natural gas liquefaction systems in which such methods can be carried out.

Embodiments provide a method for preventing shutdowns in LNG facilities by removing heavy hydrocarbons from the inlet gas supply. According to an embodiment, there is provided an LNG facility treating pipeline quality natural gas that is contaminated with lubrication oil and low concentrations of heavy hydrocarbons. Due to contamination, the behavior of the pipeline quality natural gas is not properly predicted by thermodynamic modeling. In an embodiment, heavy hydrocarbons are removed by a drain system in a heat exchanger. In an embodiment, heavy hydrocarbons are removed by a treatment bed.

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.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a single heat exchanger, multiple gas-liquid separators, multiple expander/compressor sets, and a rectifier attached to a liquid product drum.