Abstract: Described herein is a method of and system for fractionating and liquefying a natural gas feed stream. The natural gas is first fractionated in a scrub column. The overhead vapor from the scrub column is cooled, condensed and divided to form a first, a second and at least one further stream of liquefied first overhead. The first stream of liquefied first overhead is returned to the scrub column as a reflux stream. The second stream of liquefied first overhead forms an LNG product. The further stream of liquefied first overhead is used to provide or generate reflux for a de-methanizer column used to fractionate the bottoms liquid from the scrub column.

Abstract: Embodiments of the present invention provide improved shell-side fluid distribution in coil wound heat exchanger system and methods therefor. The fluid distribution system includes a system having a plurality of distribution arms having inner and outer cavities and valves to control the flow of shell-side fluid to control radial temperature profiles in a coil wound heat exchanger having multiple bundles of tubes.

Abstract: 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is a method of removing refrigerant from a natural gas liquefaction system in which vaporized mixed refrigerant is withdrawn from the closed-loop refrigeration circuit and introduced into a distillation column so as to be separated into an overhead vapor enriched in methane and a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 Overhead vapor is withdrawn from the distillation column to form a methane enriched stream that is removed from the liquefaction system, and bottoms liquid is reintroduced from the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.

Abstract: A method for liquefying a natural gas feed stream and removing nitrogen therefrom, the method comprising passing a natural gas feed stream through a main heat exchanger to produce a first LNG stream, and separating a liquefied or partially liquefied natural gas stream in a distillation column to form nitrogen-rich vapor product, wherein a closed loop refrigeration system provides refrigeration to the main heat exchanger and to a condenser heat exchanger that provides reflux to the distillation column.

Abstract: A method and apparatus for liquefying a natural gas feed stream and removing nitrogen therefrom to produce a nitrogen-depleted LNG product, in which a natural gas feed stream is passed through main heat exchanger to produce a first LNG stream, which is separated to form a nitrogen-depleted LNG product and a recycle stream composed of nitrogen-enriched natural gas vapor, and in which the recycle stream is passed through main heat exchanger to produce a first LNG stream, separately from and in parallel with the natural gas feed stream, to produce a first at least partially liquefied nitrogen-enriched natural gas stream that is separated to provide a nitrogen-rich vapor product.

Abstract: A method and apparatus for liquefying a natural gas feed stream and removing nitrogen therefrom to produce a nitrogen-depleted LNG product, in which a natural gas feed stream is fed into the warm end of a main heat exchanger, cooled and at least partially liquefied, withdrawn from an intermediate location of the main heat exchanger and separated to form a nitrogen-enriched natural gas vapor stream and a nitrogen-depleted natural gas liquid stream, the liquid and vapor streams being reintroduced into an intermediate location of the main heat exchanger and further cooled in parallel to form a first LNG stream and a first at least partially liquefied nitrogen-enriched natural gas stream, respectively.

Abstract: Liquefaction using a closed loop refrigeration system, including compressing a gaseous refrigerant stream; cooling at least a portion of the compressed gaseous refrigerant stream in a first heat exchanger; expanding a first portion of the cooled, compressed gaseous refrigerant stream from the first heat exchanger to provide a first expanded gaseous refrigerant stream; cooling and substantially liquefying a feed gas stream to form a substantially liquefied feed gas stream in a second heat exchanger through indirect heat exchange against the first portion of the first expanded gaseous refrigerant stream; and further cooling a second portion of the cooled, compressed gaseous refrigerant stream from the first heat exchanger in a third heat exchanger by indirect heat exchange with a second portion of the first expanded gaseous refrigerant stream, wherein the first expanded gaseous refrigerant stream exiting the first expander is substantially vapor.

Abstract: A method and apparatus of removing heavy hydrocarbons from a natural gas feed stream, the method comprising using first and second hydrocarbon removal systems in series such that the first system processes the natural gas feed stream to produce a heavy hydrocarbon depleted natural gas stream and the second system processes at least a portion of the heavy hydrocarbon depleted natural gas stream from the first system to produce a natural gas stream lean in heavy hydrocarbons, wherein one of said systems is a adsorption system that comprises one or more beds of adsorbent for adsorbing and thereby removing heavy hydrocarbons from a heavy hydrocarbon containing natural gas, and the other of said systems is a gas-liquid separation system for separating a heavy hydrocarbon containing natural gas into a heavy hydrocarbon depleted natural gas vapor and a heavy hydrocarbon enriched liquid.

Abstract: A method and apparatus of removing heavy hydrocarbons from a natural gas feed stream, the method comprising using first and second hydrocarbon removal systems in series such that the first system processes the natural gas feed stream to produce a heavy hydrocarbon depleted natural gas stream and the second system processes at least a portion of the heavy hydrocarbon depleted natural gas stream from the first system to produce a natural gas stream lean in heavy hydrocarbons, wherein one of said systems is a adsorption system that comprises one or more beds of adsorbent for adsorbing and thereby removing heavy hydrocarbons from a heavy hydrocarbon containing natural gas, and the other of said systems is a gas-liquid separation system for separating a heavy hydrocarbon containing natural gas into a heavy hydrocarbon depleted natural gas vapor and a heavy hydrocarbon enriched liquid.

Abstract: A method for liquefaction using a closed loop refrigeration system, the method comprising the steps of (a) compressing a gaseous refrigerant stream in at least one compressor; (b) cooling the compressed gaseous refrigerant stream in a first heat exchanger; (c) expanding at least a first portion of the cooled, compressed gaseous refrigerant stream from the first heat exchanger in a first expander to provide a first expanded gaseous refrigerant stream; and (d) cooling and substantially liquefying a feed gas stream to form a substantially liquefied feed gas stream in a second heat exchanger through indirect heat exchange against at least a first portion of the first expanded gaseous refrigerant stream from the first expander, wherein the first expanded gaseous refrigerant stream exiting the first expander is substantially vapor.

Abstract: A gas liquefaction process, especially for producing LNG, maintains product flow rate and temperature by controlling the refrigeration so that variation to reduce any difference between actual and required product temperatures is initiated before variation of the product flow rate to reduce any difference between actual and required flow rates.

Abstract: A system and method for removal of a contaminant comprising removing a liquefied portion of a refrigerant stream comprising nitrogen from a reverse Brayton cycle refrigerant system, introducing the liquefied refrigerant stream into a contaminant removal column as a reflux stream removing a contaminant stream from the bottom of the contaminant removal column, removing a vapor stream enriched in nitrogen from the top of the contaminant removal column, and introducing the vapor stream enriched in nitrogen back into the reverse Brayton cycle refrigerant system.

Abstract: A system and method for liquefying a natural gas stream, the method including the steps of providing a dehydrated natural gas stream for liquefaction, pre-cooling the dehydrated natural gas stream in a pre-cooling apparatus, where the pre-cooling is performed by using a pre-coolant that consists essentially of a hydroflorocarbon (HFC) refrigerant, further cooling the pre-cooled dehydrated natural gas stream in a main heat exchanger through indirect heat exchange against a vaporized hydrocarbon mixed refrigerant coolant to produce a liquefied natural gas product stream, where the mixed refrigerant coolant comprises ethane, methane, nitrogen, and less than or equal to 3 mol % of propane.

Abstract: A natural gas liquefaction system, the system comprising a first precooling refrigeration system that accepts at least a natural gas feed stream, a second precooling refrigeration system that accepts at least a first refrigerant stream; and a cryogenic heat exchanger fluidly connected to the first precooling refrigeration system and the second precooling refrigeration system that accepts the natural gas feed stream from the first precooling refrigeration system and the first refrigerant stream from the second precooling refrigeration system to liquefy the natural gas feed stream, where the second precooling refrigeration system accepts only stream(s) having a composition different from the stream(s) accepted by the first precooling refrigeration system.

Abstract: A method for liquefaction using a closed loop refrigeration system, the method comprising the steps of (a) compressing a gaseous refrigerant stream in at least one compressor; (b) cooling the compressed gaseous refrigerant stream in a first heat exchanger; (c) expanding at least a first portion of the cooled, compressed gaseous refrigerant stream from the first heat exchanger in a first expander to provide a first expanded gaseous refrigerant stream; and (d) cooling and substantially liquefying a feed gas stream to form a substantially liquefied feed gas stream in a second heat exchanger through indirect heat exchange against at least a first portion of the first expanded gaseous refrigerant stream from the first expander, wherein the first expanded gaseous refrigerant stream exiting the first expander is substantially vapor.

Abstract: The separation of methane from an admixture (110) with ethane and higher hydrocarbons, especially natural gas, using a scrub column (114), in which the admixture is separated into a methane-rich overhead (116) that is partially condensed (122) to provide reflux to the column (114) and liquid methane-depleted bottoms liquid (126), is improved by providing additional reflux (136) derived from an ethane enriched stream (130) from fractionation (128) of the bottoms liquid. Preferably, absorber liquid (140) from the fractionation (128) also is introduced into the scrub column. The vapor fraction (120) remaining after partial condensation can be liquefied (122) to provide LNG product (124).

Abstract: Processes are provided for the denitrogenation of a crude LNG stream. A crude LNG stream is expanded and then cooled in a thermosyphon reboiler. The resultant crude LNG stream is introduced into a nitrogen rejection column, wherein the nitrogen content of the LNG is reduced as the liquid flows down the column. A nitrogen-enriched vapor stream is withdrawn from the top of the column, and a first, and optionally a second, nitrogen-diminished liquid stream is withdrawn from the bottom of the column. The first stream may be recovered as a LNG product, and the second stream is passed through the thermosyphon reboiler, cooling the crude LNG stream, while partially vaporizing the second stream. The vaporized second stream is reinjected into the column at a level above the level of withdrawal of the second nitrogen-diminished bottoms LNG stream to provide column boilup. Alternatively, the thermosyphon reboiler is placed within the column.

Abstract: A gas liquefaction process, especially for producing LNG, maintains product flow rate and temperature by controlling the refrigeration so that variation to reduce any difference between actual and required product temperatures is initiated before variation of the product flow rate to reduce any difference between actual and required flow rates.

Abstract: The present invention relates to a process and apparatus for producing crude helium, liquefied natural gas product, and synthesis gas from natural gas. A natural gas comprising helium and methane is cooled to produce cooled natural gas. At least a portion of the helium and methane from the cooled natural gas is separated into a vapor comprising helium, from which crude helium is derived, and a liquid comprising methane. At least a portion of the methane from this liquid is separated into a vapor, which is reacted to produce synthesis gas, and a liquid, from which liquefied natural gas is derived. Additional heat exchange and separation steps may be included.

Abstract: Natural gas is liquefied in a hybrid liquefaction cycle in which the gas feed is precooled using vaporizing liquefied refrigerant gas; liquefied using vaporizing mixed refrigerant comprising ethylene and at least one other refrigerant selected from hydrocarbons and halocarbons; and subcooled using a work expanded pressurized gaseous refrigerant stream. Preferably, the liquefied refrigerant gas used for precooling is propane, the mixed refrigerant does not contain ethane or nitrogen and the pressurized gaseous refrigerant is nitrogen.