Abstract: A gas separation system includes: a first gas separation membrane unit; a second gas separation membrane unit; a material gas feed line connected to a gas inlet port of the unit; a first compressor interposed to the line; a first connection line connecting a permeated gas discharge port of the unit and a gas inlet port of the unit; and a second connection line connecting a non-permeated gas discharge port of the unit and the line. The unit and unit each have a gas separation selectivity of 30 or greater. The CH4 recovery rate is 98% or higher. The CO2 content in non-permeated gas of the unit is 5 mol % or less. The flow rate of gas fed to the unit is 60% or less of the flow rate of material gas fed to the unit.

Abstract: A gas separation system includes: a first gas separation membrane unit; a second gas separation membrane unit; a material gas feed line connected to a gas inlet port of the unit; a first compressor interposed to the line; a first connection line connecting a permeated gas discharge port of the unit and a gas inlet port of the unit; and a second connection line connecting a non-permeated gas discharge port of the unit and the line. The unit and unit each have a gas separation selectivity of 30 or greater. The CH4 recovery rate is 98% or higher. The CO2 content in non-permeated gas of the unit is 5 mol % or less. The flow rate of gas fed to the unit is 60% or less of the flow rate of material gas fed to the unit.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: In a gas separation system, a retentate gas discharge port of a first unit U1 and a gas inlet port of a second unit U2 are connected by a retentate gas discharge line. A permeate gas discharge port of U1 and a gas inlet port of a third unit U3 are connected by a permeate gas discharge line. A feed gas mixture supply line is connected to a gas inlet port of U1. A permeate gas discharge port of U2 and the feed gas mixture supply line are connected by a permeate gas return line. A retentate gas discharge port of U3 and the feed gas mixture supply line are connected by a retentate gas return line. At least in operation, the gas permeability of U2 is higher than that of U3, and the gas selectivity of U3 is higher than that of U2.

Abstract: In a gas separation system, a retentate gas discharge port of a first unit U1 and a gas inlet port of a second unit U2 are connected by a retentate gas discharge line. A permeate gas discharge port of U1 and a gas inlet port of a third unit U3 are connected by a permeate gas discharge line. A feed gas mixture supply line is connected to a gas inlet port of U1. A permeate gas discharge port of U2 and the feed gas mixture supply line are connected by a permeate gas return line. A retentate gas discharge port of U3 and the feed gas mixture supply line are connected by a retentate gas return line. At least in operation, the gas permeability of U2 is higher than that of U3, and the gas selectivity of U3 is higher than that of U2.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A gas separation system includes: first, second, and third gas separation membrane units. A first retentate gas line connects a retentate gas discharge port of the first unit and gas inlet port of the second unit. A first permeate gas line connects a permeate gas discharge port of the first unit and gas inlet port of the third unit. A feed gas mixture supply line is connected to a gas inlet port of the first unit, and provided with first compression elements. The first permeate gas line is provided with second compression elements. The permeate gas discharge port of the second unit is connected by a second permeate gas line to the suction side of the first compression elements in the feed gas mixture supply line. A retentate gas discharge port of the third unit is connected by a third retentate gas line to the first retentate gas line.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A gas separation membrane module in which deformation of a tube sheet such as swelling and shrinkage can be prevented in gas separation. The gas separation membrane module includes a hollow fiber bundle provided by bundling multiple hollow fiber membranes, a module vessel in which the hollow fiber bundle is placed, and a tube sheet fixing the plurality of hollow fiber membranes at an end portion of hollow fiber bundle. The cross section of the tube sheet includes a hollow fiber membrane embedded portion in which the hollow fiber membranes are embedded and a solid portion in which no hollow fiber membrane is embedded, and the solid portion is located outside the hollow fiber membrane embedded portion. At least some of the hollow fiber membranes are wound with reinforcing fiber cloth at least within the hollow fiber membrane embedded portion.

Abstract: A gas separation system includes: first, second, and third gas separation membrane units. A first retentate gas line connects a retentate gas discharge port of the first unit and gas inlet port of the second unit. A first permeate gas line connects a permeate gas discharge port of the first unit and gas inlet port of the third unit. A feed gas mixture supply line is connected to a gas inlet port of the first unit, and provided with first compression elements. The first permeate gas line is provided with second compression elements. The permeate gas discharge port of the second unit is connected by a second permeate gas line to the suction side of the first compression elements in the feed gas mixture supply line. A retentate gas discharge port of the third unit is connected by a third retentate gas line to the first retentate gas line.

Abstract: A gas separation membrane module, comprising: a hollow fiber element having a hollow fiber bundle consisting of a number of hollow fiber membranes and a tube sheet provided at an end of the hollow fiber bundle for binding the hollow fiber membranes; a vessel having an opening through which the hollow fiber element is inserted or removed; a lid member having a gas outlet formed therein and attached to cover the opening of the vessel; and a perforated plate having a plurality of through holes for forming gas channels formed therein, the perforated plate being mounted between the tube sheet and the lid member, the gas separation membrane module performing gas separation by supplying mixed gas to the hollow fiber membranes.

Abstract: In a gas separation system, a retentate gas discharge port of a first unit U1 and a gas inlet port of a second unit U2 are connected by a retentate gas discharge line. A permeate gas discharge port of U1 and a gas inlet port of a third unit U3 are connected by a permeate gas discharge line. A feed gas mixture supply line is connected to a gas inlet port of U1. A permeate gas discharge port of U2 and the feed gas mixture supply line are connected by a permeate gas return line. A retentate gas discharge port of U3 and the feed gas mixture supply line are connected by a retentate gas return line. At least in operation, the gas permeability of U2 is higher than that of U3, and the gas selectivity of U3 is higher than that of U2.

Abstract: A gas separation membrane module in which deformation of a tube sheet such as swelling and shrinkage can be prevented in gas separation. The gas separation membrane module includes a hollow fiber bundle provided by bundling multiple hollow fiber membranes, a module vessel in which the hollow fiber bundle is placed, and a tube sheet fixing the plurality of hollow fiber membranes at an end portion of hollow fiber bundle. The cross section of the tube sheet includes a hollow fiber membrane embedded portion in which the hollow fiber membranes are embedded and a solid portion in which no hollow fiber membrane is embedded, and the solid potion is located outside the hollow fiber membrane embedded portion. At least some of the hollow fiber membranes are wound with reinforcing fiber cloth at least within the hollow fiber membrane embedded portion.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A gas separation membrane module, comprising: a hollow fiber element having a hollow fiber bundle consisting of a number of hollow fiber membranes and a tube sheet provided at an end of the hollow fiber bundle for binding the hollow fiber membranes; a vessel having an opening through which the hollow fiber element is inserted or removed; a lid member having a gas outlet formed therein and attached to cover the opening of the vessel; and a perforated plate having a plurality of through holes for forming gas channels formed therein, the perforated plate being mounted between the tube sheet and the lid member, the gas separation membrane module performing gas separation by supplying mixed gas to the hollow fiber membranes.

Abstract: There is provided a process for producing nitrogen-rich air by feeding a high temperature air at 150° C. or more to an air separation membrane module.

Abstract: A gas separation membrane module has a vessel housing a hollow fiber element including a hollow fiber bundle consisting of a number of hollow fiber membranes (1) and a tube sheet (2) holding one end of the hollow fiber bundle. The interior of the vessel is partitioned by the tube sheet (2) into two spaces consisting of a raw gas chamber and a permeate gas chamber. A high-pressure mixed gas is fed into the raw gas chamber where gas separation is carried out. The gas separation membrane module has a configuration where during operation, the tube sheet (2) is supported by means of a perforated plate (8) in the vessel by a pressure from the mixed gas fed to maintain airtightness between the two spaces and when the tube sheet (2) receives a pressure in the reverse direction to that applied during the operation of the gas separation membrane module, the tube sheet (2) is forced to move within the vessel by the pressure in the reverse direction, thereby losing airtightness between the two spaces.

Abstract: A gas separation membrane module has a vessel housing a hollow fiber element including a hollow fiber bundle consisting of a number of hollow fiber membranes (1) and a tube sheet (2) holding one end of the hollow fiber bundle. The interior of the vessel is partitioned by the tube sheet (2) into two spaces consisting of a raw gas chamber and a permeate gas chamber. A high-pressure mixed gas is fed into the raw gas chamber where gas separation is carried out. The gas separation membrane module has a configuration where during operation, the tube sheet (2) is supported by means of a perforated plate (8) in the vessel by a pressure from the mixed gas fed to maintain airtightness between the two spaces and when the tube sheet (2) receives a pressure in the reverse direction to that applied during the operation of the gas separation membrane module, the tube sheet (2) is forced to move within the vessel by the pressure in the reverse direction, thereby losing airtightness between the two spaces.