Abstract: A method for separating a mixture containing at least nitrogen and methane by cryogenic distillation in a first column operating in a first pressure and a second column operating at a second pressure lower than the first pressure, the mixture being separated in the first column to form a gas enriched in nitrogen and a liquid enriched in methane, at least a portion of the gas enriched in nitrogen being at least partially condensed in a heat exchanger and returned to the first column, the gas enriched in nitrogen is sent into the heat exchanger by the bottom, ascends in a first series of passages of the exchanger and condenses therein at least partially, the liquid formed descending in these passages of the first series and exiting by the bottom of the exchanger.

Abstract: A method for separating a mixture containing at least nitrogen and methane by cryogenic distillation in a first column operating in a first pressure and a second column operating at a second pressure lower than the first pressure, the mixture being separated in the first column to form a gas enriched in nitrogen and a liquid enriched in methane, at least a portion of the gas enriched in nitrogen being at least partially condensed in a heat exchanger and returned to the first column, the gas enriched in nitrogen is sent into the heat exchanger by the bottom, ascends in a first series of passages of the exchanger and condenses therein at least partially, the liquid formed descending in these passages of the first series and exiting by the bottom of the exchanger.

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: In a method for producing a series of at least a first and a second plate-fin heat exchangers, several elongate fluid distribution tanks are installed on the matrix unit, each tank capping just some of the openings assigned to the first fluid and to the second fluid, each tank having its axis in the direction of stacking and each being connected to a pipe so that the number of openings assigned to the first fluid differs from the number of openings assigned to the first fluid, and for preference, the number of openings assigned to the second fluid differs from the number of openings assigned to the second fluid for the at least first and second exchangers of the series.

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 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 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: In a method for producing a series of at least a first and a second plate and fin heat exchanger, each having at least one fluid distribution tank capping at least some of the openings of the matrix unit and which is connected to a pipe, the tank is partitioned into several compartments using at least one partition, so as to distribute the number of openings assigned to a first fluid and to a second fluid, the partition being designed to divide the tank into several compartments which are each connected to a pipe for the passage of the first fluid or of the second fluid and which each communicate with a number of openings that varies according to the configuration adopted by the at least one partition, for the exchanger of the series.

Abstract: In a method for producing a series of at least a first and a second plate and fin heat exchanger, each having at least one fluid distribution tank capping at least some of the openings of the matrix unit and which is connected to a pipe, the tank is partitioned into several compartments using at least one partition, so as to distribute the number of openings assigned to a first fluid and to a second fluid, the partition being designed to divide the said tank into several compartments which are each connected to a pipe for the passage of the first fluid or of the second fluid and which each communicate with a number of openings that varies according to the configuration adopted by the at least one partition, for the exchanger of the series.

Abstract: In a method for producing a series of at least a first and a second plate-fin heat exchangers, several elongate fluid distribution tanks are installed on the matrix unit, each tank capping just some of the openings assigned to the first fluid and to the second fluid, each tank having its axis in the direction of stacking and each being connected to a pipe so that the number of openings assigned to the first fluid differs from the number of openings assigned to the first fluid, and for preference, the number of openings assigned to the second fluid differs from the number of openings assigned to the second fluid for the at least first and second exchangers of the series.

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.