Abstract: In a method for separating a mixture containing carbon dioxide, the mixture is cooled in a heat exchanger and partially condensed and a first liquid is separated from the mixture in a first system operating at low temperature comprising at least one first phase separator and a gas from the first system is treated in a membrane system to produce a permeate and a non-permeate, the gas from the first system being divided into two portions, a first portion being sent to the membrane system without being heated and a second portion being heated to at least an intermediate temperature of the heat exchanger and then sent to the membrane system without being cooled.

Abstract: An approach for separating a gaseous mixture includes a multi-stage membrane system in which a rubbery membrane is operated at a low temperature. Various streams are cooled and heated in a multi-fluid heat exchanger. In specific configurations, the multi-fluid heat exchanger is cooled by using no fluids other than fluids derived from the permeate and/or residue generated in the first membrane stage.

Abstract: A method and system for purification of helium and CO2 from a stream containing at least Helium, CO2, nitrogen or methane uses a combination of cryogenic, membrane and adsorption technologies.

Abstract: A process for producing biomethane by scrubbing a biogas feed stream includes introducing the feed gas stream into a pretreatment unit wherein a CO2-depleted gas stream is partially separated from a CO2 stream and an oxygen stream and is compressed to a pressure P1 above 25 bar abs. Subjecting the CO2-depleted gas stream to cryogenic separation in a distillation column to separate a nitrogen stream and produce a CH4-enriched stream, the distillation column comprising n plates, n being an integer between 8 and 100. Recovering a pressurized CH4-enriched stream by pumping the CO2-depleted gas stream to a pressure P2 above 25 bar absolute.

Abstract: A process for purifying a feed gas including methane and heavy hydrocarbons, including: step a): cooling the feed gas in a heat exchanger; step b): introducing the resulting into a first phase separator to produce a liquid stream depleted in methane and enriched in heavy hydrocarbons and a gas stream; step c): separating the gas stream in a membrane from which a methane-enriched permeate stream and a partially condensed residue stream exit; step d): introducing the residue stream from step c) into a second phase separator vessel in order to produce a liquid stream and a gas stream; step e): introducing at least one portion of the gas stream resulting from step d) into a JT expansion means; and step f): heating at least one portion of the expanded stream in the heat exchanger used in step a) counter-current to the feed stream in order to cool the latter.

Abstract: A process for purifying a natural gas feed gas stream including methane and hydrocarbons, including step a): cooling the feed gas stream; step b): introducing the cooled stream into a first phase separator vessel in order to produce a liquid stream and a gas stream; step c): separating the gas stream resulting from step b) in a membrane unit from which a methane-enriched permeate stream and one partially condensed residue stream enriched in hydrocarbons exit; step d): introducing the residue stream resulting from step c) into a second phase separator vessel to produce a liquid stream and a gas stream; step e): introducing at least one portion of the liquid stream resulting from step d) into a JT expansion means; step f): heating at least one portion of the expanded by introduction into the heat exchanger used in step a) counter-current to the feed stream.

Abstract: A process for producing biomethane by scrubbing a biogas feed stream including introducing a feed gas stream into a pretreatment unit wherein the gas stream is partially separated from a CO2 stream and an oxygen stream, thereby producing a CO2-depleted gas stream, which is compressed, thereby producing a pressurized CO2-depleted gas stream; separating the pressurized CO2-depleted gas stream by cryogenic separation by introducing the pressurized CO2-depleted gas stream into a distillation column thereby producing a nitrogen stream and a CH4-enriched stream, recovering a pressurized CH4-enriched stream by pumping the CH4-enriched stream; wherein the separation of the CO2 stream and the oxygen stream from the feed gas stream is performed by a unit comprising at least two separating membrane stages in order that the CO2-depleted gas stream comprises between 0.3 mol % and 2 mol % of CO2.

Abstract: A feed containing methane and nitrogen gas is processed in a three-stage membrane system, each stage of which is selective for methane over nitrogen. The methane enriched permeate from the first stage is removed as product gas. The methane-depleted residue from the second stage is purified in second and third cascaded stages to provide second and third permeates and second and third residues. The third stage permeate is recycled to the feed.

Abstract: An approach for separating a gaseous mixture includes a multi-stage membrane system in which a rubbery membrane is operated at a low temperature. Various streams are cooled and heated in a multi-fluid heat exchanger. In specific configurations, the multi-fluid heat exchanger is cooled by using no fluids other than fluids derived from the permeate and/or residue generated in the first membrane stage.

Abstract: A process for purifying a gaseous feed stream of natural gas including methane, CO2 and heavy hydrocarbons including step a): cooling the gaseous feed stream in a heat exchanger; step b): introducing the cooled stream into a phase-separating chamber to produce a liquid stream depleted in methane and enriched in heavy hydrocarbons and a gaseous stream; step c): separating the gaseous stream obtained from step b) in a first membrane producing at least one CO2-enriched permeate stream and a residual stream enriched in methane; step d): introducing the residual stream obtained from step c) into a phase-separator to produce a liquid stream and a gaseous stream; step e): heating the gaseous stream obtained from step d) by introducing it into the heat exchanger used in step a) counter-currentwise with the feed stream thereby producing a gaseous stream depleted in CO2 and enriched in methane.

Abstract: A process for producing biomethane by scrubbing a biogas feed stream includes introducing the feed gas stream into a pretreatment unit wherein a CO2-depleted gas stream is partially separated from a CO2 stream and an oxygen stream and is compressed to a pressure P1 above 25 bar abs. Subjecting the CO2-depleted gas stream to cryogenic separation in a distillation column to separate a nitrogen stream and produce a CH4-enriched stream, the distillation column comprising n plates, n being an integer between 8 and 100. Recovering a pressurized CH4-enriched stream by pumping the CO2-depleted gas stream to a pressure P2 above 25 bar absolute.

Abstract: A process for producing biomethane by scrubbing a biogas feed stream, including introducing a feed gas stream into a pretreatment unit thereby partially separating a CO2 stream and an oxygen stream and producing a CO2-depleted gas stream which is then compressed to a pressure P1 above 25 bar abs; introducing the CO2-depleted gas stream to cryogenic separation in a distillation column to separate a nitrogen stream, the distillation column having n plates, n being an integer between 8 and 100; recovering a pressurized CH4-enriched stream by pumping the CO2-depleted gas stream) at a pressure P2 above 25 bar, wherein, when the molar concentration of nitrogen of the CO2-depleted gas stream is less than a predetermined threshold, nitrogen is injected prior to introduction into the distillation column, in order that the stream introduced into said column has a molar concentration of nitrogen at least equal to said predetermined threshold.

Abstract: A method of separating hydrocarbons containing three or more carbon atoms from an off-gas stream is provided. This method includes separating a light ends stream from a fractionator, thereby producing a stream rich in hydrocarbons containing three or more carbon atoms, and a stream lean in hydrocarbons containing three or more carbon atoms, separating the stream lean in hydrocarbons containing three or more carbon atoms in a membrane unit, thereby producing a permeate stream enriched in hydrocarbons containing three or more carbon atoms and a retentate stream, and separating the stream rich in hydrocarbons containing three or more carbon atoms in one or more separation columns, thereby producing one or more streams selected from the group consisting of a propylene stream, a propane stream, a butane stream, a light cat naptha stream, and a heavy cat naptha stream.

Abstract: A process for purifying a feed gas including methane and heavy hydrocarbons, including: step a): cooling the feed gas in a heat exchanger; step b): introducing the resulting into a first phase separator to produce a liquid stream depleted in methane and enriched in heavy hydrocarbons and a gas stream; step c): separating the gas stream in a membrane from which a methane-enriched permeate stream and a partially condensed residue stream exit; step d): introducing the residue stream from step c) into a second phase separator vessel in order to produce a liquid stream and a gas stream; step e): introducing at least one portion of the gas stream resulting from step d) into a JT expansion means; and step f): heating at least one portion of the expanded stream in the heat exchanger used in step a) counter-current to the feed stream in order to cool the latter.

Abstract: A process for purifying a natural gas feed gas stream including methane and hydrocarbons, including step a): cooling the feed gas stream; step b): introducing the cooled stream into a first phase separator vessel in order to produce a liquid stream and a gas stream; step c): separating the gas stream resulting from step b) in a membrane unit from which a methane-enriched permeate stream and one partially condensed residue stream enriched in hydrocarbons exit; step d): introducing the residue stream resulting from step c) into a second phase separator vessel to produce a liquid stream and a gas stream; step e): introducing at least one portion of the liquid stream resulting from step d) into a JT expansion means; step f): heating at least one portion of the expanded by introduction into the heat exchanger used in step a) counter-current to the feed stream.

Abstract: A method for cryogenically separating a natural gas supply stream into a gas containing the most volatile compounds of the supply stream, and a liquid product containing the heaviest compounds at least including the following. Introducing an at least partially condensed stream into an absorption column at an introduction stage in the lower part of said absorption column, thus producing, at the top, a gaseous stream that contains the most volatile compounds and, the bottom, a liquid product.

Abstract: A method of cryogenically separating a natural gas supply stream into a gas which contains the most volatile compounds of the supply stream, and a liquid product which contains the heaviest compounds of the supply stream, including the following steps: at least partially condensing a natural gas supply stream in a first heat exchanger system; introducing the liquid product into a fractionation column in order to obtain, in the bottom of the fractionation column, a liquid produce that contains the heaviest compounds of the supply stream and, at the top of the fractionation column, a distillate that is at least partially condensed; introducing, at a stage in the upper part of the absorption column, the gaseous phase of the condensed distillate as a supply stream for the absorption column; where the distillate is condensed in a bath-type vaporizer-condenser installed in a casing mounted on the fractionation column.

Abstract: A process for simultaneously producing treated natural gas and a propane-rich stream from a feed gas comprising methane, ethane and hydrocarbons having more than three carbon atoms.

Abstract: A process to produce at least carbon dioxide and carbon monoxide from a feed gas containing carbon dioxide, hydrogen and carbon monoxide; comprises separating at least part of the carbon dioxide from the compressed feed gas by partial condensation and/or distillation producing a carbon dioxide product and a carbon dioxide depleted stream, treating the carbon dioxide depleted stream in a treatment unit to produce a feed stream containing carbon monoxide and hydrogen, less rich in carbon dioxide than the carbon dioxide depleted stream and feeding at least part of the feed stream containing carbon monoxide and hydrogen to a separation unit operating at cryogenic temperatures to produce a carbon monoxide product.

Abstract: In a method for separating a mixture containing carbon dioxide, the mixture is cooled in a heat exchanger and partially condensed and a first liquid is separated from the mixture in a first system operating at low temperature comprising at least one first phase separator and a gas from the first system is treated in a membrane system to produce a permeate and a non-permeate, the gas from the first system being divided into two portions, a first portion being sent to the membrane system without being heated and a second portion being heated to at least an intermediate temperature of the heat exchanger and then sent to the membrane system without being cooled.