Abstract: The invention provides a process for removing gaseous contaminants from a feed gas stream which comprises methane and gaseous contaminants, the process comprising: 1) providing the feed gas stream (1); 2) cooling the feed gas stream to a temperature at which liquid phase contaminant is formed as well as a methane enriched gaseous phase,—3) separating the two phases obtained in step 2) by means of a gas/liquid separator (4); and 4) subjecting the methane enriched gaseous phase obtained in step 3) to a distillation treatment in a distillation section (10) thereby obtaining a bottom stream (12) rich in liquid phase contaminant and lean in methane, and a top stream (11) rich in methane and lean in gaseous contaminant. The invention further concerns a device for carrying out the present process, the purified gas stream, and a process for liquefying a feed gas stream.

Abstract: The invention relates to a process for producing a helium-enriched vapor stream, a methane-enriched vapor stream, and a liquid stream enriched in hydrocarbons heavier than methane from a pressurized, multicomponent, multiphase stream comprising methane (C1), helium (He) and hydrocarbons heavier than methane (C2+). The process includes cooling the multiphase stream to produce at least one vapor stream enriched in helium and at least one liquid stream, withdrawing at least a portion of the at least one vapor stream as a helium-enriched product stream, passing at least a portion of the at least one liquid stream to a demethanizer, withdrawing from the demethanizer a vapor enriched in methane (C1), and withdrawing from the demethanizer a liquid enriched in hydrocarbons heavier than methane (C2+).

Abstract: A process and an apparatus are disclosed for recovering ethane, ethylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The stream is cooled, expanded to lower pressure, and supplied to a first fractionation tower at a mid-column feed position. A distillation liquid stream is withdrawn from the first fractionation tower below the feed position of the expanded stream, heated, and directed into a second fractionation tower that produces an overhead vapor stream and a bottom liquid stream. The overhead vapor stream is cooled to condense it, with a portion of the condensed stream directed to the second fractionation tower as its top feed and the remainder directed to the first fractionation tower at a lower column feed position. The bottom liquid stream from the second fractionation tower is cooled and directed to the first fractionation tower as its top feed.

Abstract: The present invention provides a process for producing purified gas from a feed gas stream comprising methane and gaseous contaminants, the process comprising the steps of: 1) providing the feed gas stream; 2) cooling the feed gas stream to a temperature at which at least part of the feed gas stream is present in the liquid phase; 3) separating the cooled feed gas stream by means of cryogenic distillation into a bottom stream rich in contaminants and lean in methane, and into a top stream rich in methane and lean in gaseous contaminants, in which the bottom stream contains between 0.5 and 15% of the methane present in the feed gas stream; 4) cooling the stream rich in methane to a temperature at which solid and/or liquid phase contaminants are formed; 5) introducing the cooled stream of step 4) into a gas/liquid/solids separation vessel, and 6) removing from the gas/liquid/solids separation vessel the purified gas and a stream rich in contaminants.

Abstract: A process and an apparatus for liquefying a portion of a natural gas stream are disclosed. The natural gas stream is cooled under pressure and divided into a first stream and a second stream. The first stream is cooled, expanded to an intermediate pressure, and supplied to a lower feed point on a distillation column. The second stream is expanded to the intermediate pressure and divided into two portions. One portion is cooled and then supplied to a mid-column feed point on the distillation column; the other portion is used to cool the first stream. The bottom product from this distillation column preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas, so that the overhead vapor from the distillation column contains essentially only methane and lighter components.

Abstract: A process to reduce emissions discharged from a natural gas processing system wherein the processing system includes a glycol dehydrator for absorbing water, moisture and absorbable hydrocarbons, a reboiler for heating water rich glycol, a still column in communication with the reboiler and a reflux condenser. The process includes the steps of directing vapors and gases from the still column and reflux condenser to a condenser in order to condense vapors to liquid. The gases and liquids from the condenser are directed to a condensate separator in order to separate by gravity. Non-condensible vapors and water from the condensate separator are delivered to a vaporization chamber immersed in the reboiler. Water is re-vaporized into steam and permitted to mix with non-condensible vapors in the vaporization chamber. The steam and non-condensible vapors are inducted into a combustion zone in a firetube in the reboiler. The hydrocarbons in the vapors are combusted in the firetube.

Abstract: A method of natural gas liquefaction may include cooling a gaseous NG process stream to form a liquid NG process stream. The method may further include directing the first tail gas stream out of a plant at a first pressure and directing a second tail gas stream out of the plant at a second pressure. An additional method of natural gas liquefaction may include separating CO2 from a liquid NG process stream and processing the CO2 to provide a CO2 product stream. Another method of natural gas liquefaction may include combining a marginal gaseous NG process stream with a secondary substantially pure NG stream to provide an improved gaseous NG process stream. Additionally, a NG liquefaction plant may include a first tail gas outlet, and at least a second tail gas outlet, the at least a second tail gas outlet separate from the first tail gas outlet.

Abstract: A process and an apparatus are disclosed for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The stream is cooled and divided into first and second streams. The first stream is further cooled to condense substantially all of it and divided into first and second portions. The first and second portions are expanded to the fractionation tower pressure and supplied to the fractionation tower at upper mid-column feed positions, with the expanded second portion being heated before it enters the tower. The second stream is expanded to the tower pressure and supplied to the column at a mid-column feed position.

Abstract: A process for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream is disclosed. The stream is cooled and divided into first and second streams. The first stream is further cooled to condense substantially all of it and is thereafter expanded to the fractionation tower pressure, heated, and supplied to the fractionation tower at an upper mid-column feed position. The second stream is expanded to the tower pressure and is then supplied to the column at a mid-column feed position. A distillation vapor stream is withdrawn from the column above the feed point of the second stream and is then directed into heat exchange relation with the expanded cooled first stream and the tower overhead vapor stream to cool the distillation vapor stream and condense at least a part of it, forming a condensed stream. At least a portion of the condensed stream is directed to the fractionation tower as its top feed.

Abstract: A process and an apparatus are disclosed for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The stream is cooled and divided into first and second streams. The first stream is further cooled to condense substantially all of it and is thereafter expanded to the fractionation tower pressure and supplied to the fractionation tower at an upper mid-column feed position. The second stream is expanded to the tower pressure and supplied to the column at a mid-column feed position. A distillation vapor stream is withdrawn from the column above the feed point of the first stream, combined with a portion of the tower overhead vapor stream, compressed to higher pressure, and directed into heat exchange relation with the remaining tower overhead vapor stream to cool the compressed combined vapor stream and condense at least a part of it, forming a condensed stream.

Abstract: The method provides liquefaction of a natural gas by carrying out the following stages: cooling the natural gas, feeding the cooled natural gas into a fractionating column so as to separate a methane-rich gas phase and a liquid phase rich in compounds heavier than ethane, and liquefying the methane-rich stream so as to obtain the liquid natural gas. According to the invention, the operating conditions in the fractionating column are so selected that said liquid phase comprises a molar proportion of methane ranging between 10% and 150% of the molar proportion of ethane.

Abstract: Processes for the separation of a hydrocarbon-containing feed streams are described herein.

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 semi-closed loop system for producing liquefied natural gas (LNG) that combines certain advantages of closed-loop systems with certain advantages of open-loop systems to provide a more efficient and effective hybrid system. In the semi-closed loop system, the final methane refrigeration cycle provides significant cooling of the natural gas stream via indirect heat transfer, as opposed to expansion-type cooling. A minor portion of the LNG product from the methane refrigeration cycle is used as make-up refrigerant in the methane refrigeration cycle. A pressurized portion of the refrigerant from the methane refrigeration cycle is employed as fuel gas. Excess refrigerant from the methane refrigeration cycle can be recombined with the processed natural gas stream, rather than flared.

Abstract: A process and an apparatus are disclosed for a compact processing assembly to remove carbon dioxide from a hydrocarbon gas stream. The gas stream is cooled, expanded to intermediate pressure, and fed to the top of a mass transfer means. A distillation liquid stream from the mass transfer means is heated in a first heat and mass transfer means to strip out its volatile components and form a bottom liquid product. A distillation vapor stream from the mass transfer means is combined with any vapor in the expanded cooled gas stream, and the combined vapor stream is cooled in a second heat and mass transfer means to partially condense it, forming a condensed stream that is fed to the top of the mass transfer means. A portion of the bottom liquid product is subcooled, expanded to lower pressure, and used to cool the combined vapor stream.

Abstract: An ethane recovery process utilizing multiple reflux streams is provided. Feed gas is cooled, partially condensed, and separated into a first liquid stream and a first vapor stream. First liquid stream is expanded and sent to a demethanizer. First vapor stream is split into a first and a second separator vapor streams. First separator vapor stream is expanded and sent to demethanizer. Second separator vapor stream is partially condensed and is separated into a reflux separator liquid stream, which is sent to demethanizer, and a reflux separator vapor stream, which is condensed and sent to demethanizer. Demethanizer produces a tower bottom stream containing a substantial amount of ethane and heavier components, and a tower overhead stream containing a substantial amount of remaining lighter components and forms a residue gas stream. A portion of residue gas stream is cooled, condensed, and sent to the demethanizer tower as top reflux stream.

Abstract: A method and apparatus for cooling and separating a hydrocarbon stream such as natural gas. The method comprises providing a hydrocarbon stream, cooling the hydrocarbon stream (10) to provide a partially liquefied hydrocarbon stream, passing at least a fraction of the partially liquefied hydrocarbon stream into a distillation column through a first inlet, providing a lower feed stream, providing a refrigerant circuit comprising at least a refrigerant stream, heating the lower feed stream against the refrigerant stream to provide a heated lower feed stream and a cooled refrigerant stream, passing the heated lower feed stream into the distillation column through a second inlet lower than the first inlet, and separating the partially liquefied hydrocarbon stream in the distillation column to provide at least a first overhead gaseous stream and a first bottom liquid stream.

Abstract: Improved processes for the separation of olefins from paraffins, such as propylene from propane are provided. Two product splitters are used in parallel to separate propylene from propane. One of the product splitters operates at a lower pressure, while the second product splitter operates at a higher pressure. The use of the two splitters in parallel provides a process for recovery of a high purity propylene product with lower energy consumption compared to prior art processes.

Abstract: A process and an apparatus are disclosed for a compact processing assembly to recover ethane, ethylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The gas stream is cooled and divided into first and second streams. The first stream is further cooled, expanded to lower pressure, and supplied as a feed between two absorbing means. The second stream is expanded to lower pressure and supplied as a bottom feed to the lower absorbing means. A distillation liquid stream from the bottom of the lower absorbing means is heated in a heat and mass transfer means to strip out its volatile components. A distillation vapor stream from the top of the heat and mass transfer means is cooled by a distillation vapor stream from the top of the upper absorbing means, thereby forming a condensed stream that is supplied as a top feed to the upper absorbing means.

Abstract: A process and an apparatus are disclosed for a compact processing assembly to recover ethane, ethylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The gas stream is cooled and divided into first and second streams. The first stream is further cooled, expanded to lower pressure, heated, and its liquid fraction is supplied as a first top feed to an absorbing means. The second stream is expanded to lower pressure and supplied as a bottom feed to the absorbing means. A distillation vapor stream from the absorbing means is combined with the vapor fraction of the first stream, then cooled by the expanded first stream to form a condensed stream that is supplied as a second top feed to the absorbing means. A distillation liquid stream from the bottom of the absorbing means is heated in a heat and mass transfer means to strip out its volatile components.

Abstract: A process for the recovery of heavier hydrocarbons from a liquefied natural gas (LNG) stream and a hydrocarbon gas stream is disclosed. The LNG feed stream is heated to vaporize at least part of it, then expanded and supplied to a fractionation column at a first mid-column feed position. The gas stream is expanded and cooled, then supplied to the column at a second mid-column feed position. A distillation vapor stream is withdrawn from the fractionation column below the mid-column feed positions and directed in heat exchange relation with the LNG feed stream, cooling the distillation vapor stream as it supplies at least part of the heating of the LNG feed stream. The distillation vapor stream is cooled sufficiently to condense at least a part of it, forming a first condensed stream. At least a portion of the first condensed stream is directed to the fractionation column at an upper mid-column feed position.

Abstract: A process for the recovery of heavier hydrocarbons from a liquefied natural gas (LNG) stream and a hydrocarbon gas stream is disclosed. The LNG feed stream is heated to vaporize at least part of it, then expanded and supplied to a fractionation column at a first mid-column feed position. The gas stream is expanded and cooled, then supplied to the column at a second mid-column feed position. A distillation vapor stream is withdrawn from the fractionation column below the mid-column feed positions and directed in heat exchange relation with the LNG feed stream, cooling the distillation vapor stream as it supplies at least part of the heating of the LNG feed stream. The distillation vapor stream is cooled sufficiently to condense at least a part of it, forming a condensed stream. At least a portion of the condensed stream is directed to the fractionation column as its top feed.

Abstract: A process and an apparatus are disclosed for a compact processing assembly to recover propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The gas stream is cooled, expanded to lower pressure, and fed to an absorbing means. A first distillation liquid stream from the absorbing means is fed to a mass transfer means. A first distillation vapor stream from the mass transfer means is cooled to partially condense it, forming a residual vapor stream and a condensed stream. The condensed stream is supplied as the top feed to the absorbing means. A second distillation vapor stream from the absorbing means is heated by cooling the first distillation vapor stream, combined with the residual vapor stream, and heated by cooling the gas stream. A second distillation liquid stream from the mass transfer means is heated in a heat and mass transfer means to strip out its volatile components.

Abstract: A method of separating off an N2-rich fraction from a liquefied hydrocarbon-rich fraction is described, in particular from liquefied natural gas, wherein the liquefied hydrocarbon-rich fraction, after its liquefaction and subcooling, is fed to a stripping column which serves for separating off the N2-rich fraction. According to the invention, a first substream of the liquefied hydrocarbon-rich fraction (2, 2?) is applied to the stripping column (S) as reflux, whereas a second substream of the liquefied hydrocarbon-rich fraction (3, 3?) is fed to the bottom of the stripping column (S), wherein the second substream of the liquefied hydrocarbon-rich fraction (3, 3?) has a higher temperature than the first substream of the liquefied hydrocarbon-rich fraction (2, 2?).

Abstract: An ethane recovery process utilizing multiple reflux streams is provided. Feed gas is cooled, partially condensed, and separated into a first liquid stream and a first vapor stream. First liquid stream is expanded and sent to a demethanizer. First vapor stream is split into a first and a second separator vapor streams. First separator vapor stream is expanded and sent to demethanizer. Second separator vapor stream is partially condensed and is separated into a reflux separator liquid stream, which is sent to demethanizer, and a reflux separator vapor stream, which is condensed and sent to demethanizer. Demethanizer produces a tower bottom stream containing a substantial amount of ethane and heavier components, and a tower overhead stream containing a substantial amount of remaining lighter components and forms a residue gas stream. A portion of residue gas stream is cooled, condensed, and sent to the demethanizer tower as top reflux stream.

Abstract: A process and an apparatus are disclosed for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream in a compact processing assembly. The gas stream is cooled and divided into first and second streams. The first stream is further cooled to condense substantially all of it and is thereafter expanded to lower pressure and supplied as a feed between first and second absorbing means inside the processing assembly. The second stream is expanded to lower pressure and supplied as the bottom feed to the second absorbing means. A distillation vapor stream is collected from the upper region of the first absorbing means and directed into one or more heat exchange means inside the processing assembly to heat it while cooling the gas stream and the first stream. The heated distillation vapor stream is compressed to higher pressure and divided into a volatile residue gas fraction and a compressed recycle stream.

Abstract: A process and an apparatus are disclosed for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream in a compact processing assembly. The gas stream is cooled and divided into first and second streams. The first stream is further cooled to condense substantially all of it and is thereafter expanded to lower pressure and supplied as the top feed to an absorbing means inside the processing assembly. The second stream is also expanded to lower pressure and supplied as the bottom feed to the absorbing means. A distillation vapor stream is collected from the upper region of the absorbing means and directed into one or more heat exchange means inside the processing assembly to heat it while cooling the gas stream and the first stream.

Abstract: An apparatus and process for the separation of refrigerant mixtures is provided. The apparatus includes a first distillation column, a first condenser, and a first collection vessel. The apparatus also includes a sorter vessel that includes a sorter agent, wherein the sorter vessel is fluidly connected to the first distillation column.

Abstract: The invention provides a method and system for the separation of a mixture containing H2, hydrocarbon, and C02. The generated mixture (3) is introduced into a distillation column (2) having a side stream to generate a top stream comprising H2 (21), a middle (volatility) stream comprising hydrocarbon (30); and a bottom stream comprising C02 (32). In a preferred embodiment, the mixture further comprises N2 which is obtained in the top stream (21). In a most preferred embodiment, the H2 and the N2 are present in a molar ratio of 3H2:1N2. The generated H2 and N2 may be used for the synthesis of ammonia. Thus, the invention also proves a method and system for the generation of ammonia.

Abstract: A method and device for the cryogenic separation of a methane-rich flow is provided.

Abstract: A method for cooling natural gas with a refrigerant, one non-limiting embodiment which includes: (A) compressing and cooling the refrigerant to a first pressure to form a compressed refrigerant; (B) splitting the compressed refrigerant into a first stream and a second stream both at the first pressure; (C) cooling the first stream to form a cooled first stream; (D) expanding the cooled first stream to a first expansion pressure to form an expanded first stream; (E) compressing the second stream to a second pressure higher than the first pressure, forming a higher pressure second stream; (F) cooling the higher pressure second stream to form a cooled second stream; (G) expanding the cooled second stream to a second expansion pressure to form an expanded second stream; and, (H) Cooling the natural gas with the expanded first stream and expanded second stream, forming a cooled natural gas stream.

Abstract: The process of treating imported heating grade source LNG to form engine fuel grade LNG, and/or produce power.

Abstract: Disclosed is a method and apparatus for adjusting heating value of natural gas, wherein components having high heating value are separated from natural gas consisting of various hydrocarbon components to reduce heating value of natural gas supplied to the markets. The method includes heating liquefied natural gas (LNG), separating the LNG heated and partially gasified into a gaseous component having low heating value and a liquid component having high heating value.

Abstract: Apparatus for condensing hydrocarbons, such as but not limited to butane and propane, from a stream of natural gas includes as its primary components a pre-cooler assembly, a chiller assembly, a refrigerant compressor/condenser assembly, and separator assembly. In the pre-cooler assembly warm gas entering the apparatus is cooled by counter-current flow heat exchange with cooled natural gas exiting the apparatus. The chiller assembly of the apparatus the hydrocarbon stream is cooled in co-current flow heat exchange with a first refrigerant tube, carrying a first refrigerant which is itself cooled in co-current heat exchange with a second refrigerant tube disposed in coaxial relationship with the first refrigerant tube. Both first and second refrigerant tubes are disposed in coaxial relationship with an outer jacket conveying the gas stream through the chiller assembly. Condensed hydrocarbons are separated from the gas stream in the separator assembly.

Abstract: A natural gas liquid plant includes a separator (103) that receives a cooled low pressure feed gas (4), wherein the separator (103) is coupled to an absorber (108) and a demethanizer (110). Refrigeration duty of the absorber (108) and demethanizer (110) are provided at least in part by expansion of a liquid portion of the cooled low pressure feed gas (4) and an expansion of a liquid absorber bottom product (19), wherein ethane recovery is at least 85 mol % and propane recovery is at least 99 mol %. Contemplated configurations are especially advantageous as upgrades to existing plants with low pressure feed gas where high ethane recovery is desirable.

Abstract: A method for separating one or more C2+ hydrocarbons from a mixed phase hydrocarbon stream such as partly vapourised liquefied natural gas, the method at least comprising the steps of: (a) supplying a mixed phase hydrocarbon feed stream (10) to a first gas/liquid separator (12); (b) separating the hydrocarbon feed stream (10) in the first gas/liquid separator (12) into a first gaseous stream (20) from a first outlet (23) and at least one C2+ liquid stream (30); (c) passing the first gaseous stream (20) through a compressor (14) to provide a compressed stream (60); and (d) cooling the compressed stream (60) in one or more heat exchangers (16) to provide an at least partly condensed hydrocarbon product stream (70); wherein a second gaseous stream (40) is added to a stream (20, 60, 70) downstream of the first outlet (23).

Abstract: A process for removing gaseous contaminants from a feed gas stream that comprises a gaseous product and gaseous contaminants, comprising: providing the feed gas stream, cooling the feed gas stream to a temperature at which liquid phase contaminant is formed as well as a gaseous phase rich in gaseous product, separating the two phases by means of a gas/liquid separator, and introducing the gaseous phase rich in gaseous product into a cryogenic separation device that comprises a freezing zone and a distillation zone positioned below the freezing zone, and removing from the cryogenic separation device a bottom stream rich in liquid phase contaminant and lean in gaseous product, and a top stream rich in gaseous product and lean in gaseous contaminant. The invention further includes a device for carrying out the present process, the purified gas stream, and a process for liquefying a feed gas stream.

Abstract: The present invention concerns a process for recovering lower carbon olefins from MTO or DTO product gas. Said process primarily comprises the product gas compressing, pre-deethanizing, demethanizing and ethylene recovering apparatus, depropanizing column, ethylene rectification column, propylene rectification column and the like. In addition, the process of the present invention needs no independent ethylene cooling system, and the ethylene recovery rate may achieve 99.5%.

Abstract: An apparatus for reducing the energy consumption of a distillation column is disclosed. The apparatus draws off an intermediate vapor stream from the rectification section of the distillation column, where the vapor stream is compressed and used to reboil a portion of the bottoms stream. The compressed vapor stream transfers energy to the bottoms stream, thereby condensing a portion of the vapor stream while vaporizing the bottoms stream.

Abstract: A hybrid gas separation membrane/cryogenic distillation method and system produces high purity gaseous methane from a gas mixture containing a majority of methane and a minority of nitrogen.

Abstract: In a method of treating a hydrocarbon stream, such as a natural gas stream, a partly condensed feed stream (10) is supplied to a first gas/liquid separator (2), where it is separated into a gaseous stream (20) and a liquid stream (30). The liquid stream (30) is expanded and fed (40) into a second gas/liquid separator (3), and the gaseous stream (20) is split into at least two sub-streams (50, 70). A first sub-stream (50) of the at least two sub-streams is expanded, thereby obtaining an at least partially condensed first sub-stream (60), and subsequently fed (60) into the second gas/liquid separator (3). A second sub-stream (70) of the at least two sub-streams is cooled against a cold stream (120), thereby obtaining an at least partially condensed second sub-stream (90, 90a), which is fed (90, 90a) into the second gas/liquid separator (3) from which a gaseous stream (130) and a liquid stream (100, 100a) are removed.

Abstract: The subject of the invention is a method for treating a natural gas containing ethane, comprising the following stages: (a) extraction of at least one part of the ethane from the natural gas; (b) reforming of at least one part of the extracted ethane into a synthesis gas; (c) methanation of the synthesis gas into a methane-rich gas; and (d) mixing of the methane-rich gas with the natural gas. Installation for implementing this method.

Abstract: A process of extraction of natural gas liquids from a liquefied natural gas stream is disclosed.

Abstract: Contemplated NGL plants include a feed gas bypass circuit through which a portion of the feed gas is provided downstream to a vapor portion of the feed gas to thereby increase turbo expander inlet temperature and demethanizer temperature. Contemplated configurations are especially advantageous for feed gases with relatively high carbon dioxide content as they entirely avoid carbon dioxide freezing in the demethanizer, provide additional power production by the turboexpander, and recover C2+ components to levels of at least 80% while achieving a low carbon dioxide content in the NGL product.

Abstract: A process and an apparatus for liquefying a portion of a natural gas stream are disclosed. The natural gas stream is cooled under pressure and divided into a first stream and a second stream. The first stream is cooled, expanded to an intermediate pressure, and supplied to a lower feed point on a distillation column. The second stream is expanded to the intermediate pressure and divided into two portions. One portion is cooled and then supplied to a mid-column feed point on the distillation column; the other portion is used to cool the first stream. The bottom product from this distillation column preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas, so that the overhead vapor from the distillation column contains essentially only methane and lighter components.

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: Contemplated plants and methods for NGL recovery from feed gases having a carbon dioxide content equal or greater than about 2% employ temperature control configurations that allow high-level and flexible recovery of ethane and heavier components while avoiding freezing of the carbon dioxide in the process. Where the feed gas has a significant fraction of C3+ components and moderate carbon dioxide content, a single column configuration with an intermediate reflux condenser may be used, while two-column configurations may be used for feed gases with high carbon dioxide content and relatively low C3+ component concentration.

Abstract: Contemplated methods and configurations use a cooled ethane and CO2-containing feed gas that is expanded in a first turbo-expander and subsequently heat-exchanged to allow for relatively high expander inlet temperatures to a second turbo expander. Consequently, the relatively warm demethanizer feed from the second expander effectively removes CO2 from the ethane product and prevents carbon dioxide freezing in the demethanizer, while another portion of the heat-exchanged and expanded feed gas is further chilled and reduced in pressure to form a lean reflux for high ethane recovery.

Abstract: A process and apparatus for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbons from a liquefied natural gas (LNG) stream is disclosed. The LNG feed stream is divided into two portions. The first portion is supplied to a fractionation column at an upper mid-column feed point. The second portion is directed in heat exchange relation with a warmer distillation stream rising from the fractionation stages of the column, whereby this portion of the LNG feed stream is partially vaporized and the distillation stream is totally condensed. The condensed distillation stream is divided into a “lean” LNG product stream and a reflux stream, whereupon the reflux stream is supplied to the column at a top column feed position. The partially vaporized portion of the LNG feed stream is separated into vapor and liquid streams which are thereafter supplied to the column at lower mid-column feed positions.

Abstract: An LNG facility employing an optimized heavies removal system. The optimized heavies removal system can comprise at least one distillation column and at least two separate heat exchangers. The heat exchangers can be operable to heat a liquid stream withdrawn from a distillation column to thereby provide predominantly vapor and/or liquid streams that can be reintroduced into the column.