A precool heat exchanger system receives a stream of first cryogenic fluid for warming a second cryogenic fluid. A first splitter receives and divides a first cryogenic fluid stream into a motive stream and a secondary cooling stream. An ejector receives the motive stream. An expansion device receives and expands the secondary cooling stream and directs at least a portion of it to the precool heat exchanger system so that a second cryogenic fluid is cooled. First cryogenic fluid from the precool heat exchanger is directed into the ejector suction port and the pressure therein is reduced. A primary separation device divides a first cryogenic fluid mixed phase stream from the ejector into a first cryogenic fluid vapor stream and a liquid recycle stream that exit the primary separation device. A recycle pump directs first cryogenic fluid to the first splitter.

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

A system and method for power generation and CO.sub.2 sequestration include a fuel cell system configured to generate power using natural gas (NG), a container configured to store liquid natural gas (LNG), and a fluid processor configured to convert LNG received from the container into NG and to convert exhaust output from the fuel cell system to dry ice by transferring heat between and the LNG and the exhaust.

A system and method for cryogenic purification of a hydrogen, nitrogen, methane and argon containing feed stream to produce a methane free, hydrogen and nitrogen containing synthesis gas and a methane rich fuel gas, as well as to recover an argon product stream, excess hydrogen, and excess nitrogen is provided. The disclosed system and method are particularly useful as an integrated cryogenic purifier in an ammonia synthesis process in an ammonia plant. The excess nitrogen is a nitrogen stream substantially free of methane and hydrogen that can be used in other parts of the plant, recovered as a gaseous nitrogen product and/or liquefied to produce a liquid nitrogen product.

A system and method for cryogenic purification of a hydrogen, nitrogen, methane and argon containing feed stream to produce a methane free, hydrogen and nitrogen containing synthesis gas and a methane rich fuel gas, as well as to recover an argon product stream, excess hydrogen, and excess nitrogen is provided. The disclosed system and method are particularly useful as an integrated cryogenic purifier in an ammonia synthesis process in an ammonia plant. The excess nitrogen is a nitrogen stream substantially free of methane and hydrogen that can be used in other parts of the plant, recovered as a gaseous nitrogen product and/or liquefied to produce a liquid nitrogen product.

A system and method for cryogenic purification of a hydrogen, nitrogen, methane and argon containing feed stream to produce a methane free, hydrogen and nitrogen containing synthesis gas and a methane rich fuel gas, as well as to recover an argon product stream, excess hydrogen, and excess nitrogen is provided. The disclosed system and method are particularly useful as an integrated cryogenic purifier in an ammonia synthesis process in an ammonia plant. The excess nitrogen is a nitrogen stream substantially free of methane and hydrogen that can be used in other parts of the plant, recovered as a gaseous nitrogen product and/or liquefied to produce a liquid nitrogen product.

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.

Method for the liquefaction of nitrogen using the recovery of cold energy deriving from the evaporation of liquefied natural gas comprising the steps of: sending a flow of nitrogen (100) to be liquefied to a precooler (101); sending a flow (107) of nitrogen gas exiting said precooler (101) to a heat exchanger (108) of the high pressure recirculation compressor; sending a flow (114) of nitrogen exiting said heat exchanger (108) to a high pressure recirculation compressor (115, 117); sending a flow (120) of nitrogen exiting said compressor (115, 117) to a liquefaction heat exchanger (121); sending to said liquefaction heat exchanger (121) a flow (123) of natural gas, countercurrent to the flow (120) exiting said compressor (115, 117); sending a flow (126, 150) of nitrogen exiting said liquefaction heat exchanger (121) to said heat exchanger (108) countercurrent to said flow (107) of nitrogen gas and to said flow (114) of nitrogen; sending a flow (151, 152) of nitrogen exiting said heat exchanger (108) to said precooler (101) countercurrent to said flow of nitrogen (100) to be liquefied; sending the flow (126, 130) of nitrogen exiting said liquefaction heat exchanger (121) to an expander (131); sending the flow of nitrogen exiting said expander (131) to a medium pressure separator (112) that delivers an exiting flow (132) of nitrogen.

An apparatus and process for removal of heavy hydrocarbons (e.g., hydrocarbons that include five or more carbons such as pentane and hexane, etc.) from a feed (e.g., a feed comprised of methane and impurities) can include a scrub column and a stabilizer column arranged so that a portion of a first stream output from the stabilizer column is fed to the scrubber column to function as a reflux stream. Embodiments are provided in which the scrub column produces a stream comprising mostly methane (e.g. over 85 mole percent methane) and reduced heavy hydrocarbons so that reduced operational costs and improved operational flexibility can be realized in downstream natural gas liquefaction operations.

Systems and methods for pre-cooling a natural gas stream to a liquefaction plant. A system may include a compressor configured to receive a first natural gas stream at a first pressure and produce a second natural gas stream at a second pressure; an exchanger to cool the second natural gas stream; and an expander to receive the cooled natural gas stream and expand the cooled natural gas stream to produce a chilled natural gas stream. The refrigeration content of the refrigerant is used to liquefy and sub-cool the natural gas stream to produce liquefied natural gas in a cold box or cryogenic exchanger. The refrigerant may be an external gas or an internal refrigerant working fluid expanded and compressed in a twin compander arrangement and compressed by a refrigerant compressor, or an external single mixed refrigerant working fluid compressed by a refrigerant compressor and expanded thru a JT valve.