Abstract: A method for operating an air separation plant having a distillation column system, a heat exchanger, and an adsorber, wherein, in a first time period, a first operating mode is carried out and, in a second time period following the first time period, a second operating mode is carried out. In a third time period between the second time period and the first time period, a third operating mode is carried out, in which third operating mode compressed air is at least partially freed of water and carbon dioxide in the adsorber and at least part of said compressed air is cooled in the heat exchanger, an air product is removed from the distillation column system and at least part of said air product is heated in the heat exchanger.

Abstract: A method for operating a heat exchanger, in which a first operating mode is carried out in first time periods, and a second operating mode is carried out in second time periods that alternate with the first time periods; in the first operating mode a first fluid flow is formed at a first temperature level, is fed into the heat exchanger in a first region at the first temperature level, and is partially or completely cooled in the heat exchanger; in the first operating mode a second fluid flow is formed at a second temperature level, is fed into the heat exchanger in a second region at the second temperature level, and is partially or completely heated in the heat exchanger. A corresponding arrangement and a system with such an arrangement are also covered by the present invention.

Abstract: A method for operating a heat exchanger, in which a first operating mode is carried out in first time periods, and a second operating mode is carried out in second time periods that alternate with the first time periods; in the first operating mode a first fluid flow is formed at a first temperature, is fed into the heat exchanger in a first region at the first temperature, and is partially or completely cooled in the heat exchanger; in the first operating mode a second fluid flow is formed at a second temperature, is fed into the heat exchanger in a second region at the second temperature, and is partially or completely heated in the heat exchanger; and in the second operating mode the feeding of the first fluid flow and of the second fluid flow into the heat exchanger is partially or completely halted.

Abstract: A method for obtaining an air product from an air separation plant having a distillation column system and a tank system. The tank system includes a first tank and a second tank. Cryogenic liquid is withdrawn from the distillation column system, stored in the tank system, and used as the air product. The cryogenic liquid is supplied to the first tank and withdrawn from the second tank during a first period, and is supplied to the second tank and withdrawn from the first tank during a second period. The tank system has a third tank to which cryogenic liquid withdrawn from the first tank and the second tank is transferred unheated. The air product is withdrawn from the third tank in liquid state, vaporized and discharged. Alternatively, the cryogenic liquid can be withdrawn from the third tank and stored in the liquid state in a fourth tank.

Abstract: A method for obtaining an air product from an air separation plant having a distillation column system and a tank system. The tank system includes a first tank and a second tank. Cryogenic liquid is withdrawn from the distillation column system, stored in the tank system, and used as the air product. The cryogenic liquid is supplied to the first tank and withdrawn from the second tank during a first period, and is supplied to the second tank and withdrawn from the first tank during a second period. The tank system has a third tank to which cryogenic liquid withdrawn from the first tank and the second tank is transferred unheated. The air product is withdrawn from the third tank in liquid state, vaporized and discharged. Alternatively, the cryogenic liquid can be withdrawn from the third tank and stored in the liquid state in a fourth tank.

Abstract: The invention relates to a process and apparatus for producing nitrogen by low-temperature fractionation of air in a rectification system which has a high-pressure column (4) and a low-pressure column (5). Feed air (1, 3) is introduced into the high-pressure column (4). An oxygen-containing liquid fraction (11) is removed from the high-pressure column (4) and fed into the low-pressure column (5). Gaseous nitrogen (18) is extracted from the low-pressure column (5) above a mass transfer section (25), which has at least one theoretical or practical plate, and is at least partially condensed in a top condenser (17) by indirect heat exchange with a refrigerant (13). High-purity nitrogen is removed from the low-pressure column below the mass transfer section (25), and is obtained as a nitrogen product (26, 27, 30). The process and apparatus have a refrigeration-supply system, in which a refrigeration fluid (31) flows.

Abstract: The invention relates to a process and apparatus for producing nitrogen by low-temperature fractionation of air in a rectification system which has a high-pressure column (4) and a low-pressure column (5). Feed air (1, 3) is introduced into the high-pressure column (4). An oxygen-containing liquid fraction (11) is removed from the high-pressure column (4) and fed into the low-pressure column (5). Gaseous nitrogen (18) is extracted from the low-pressure column (5) above a mass transfer section (25), which has at least one theoretical or practical plate, and is at least partially condensed in a top condenser (17) by indirect heat exchange with a refrigerant (13). High-purity nitrogen is removed from the low-pressure column below the mass transfer section (25), and is obtained as a nitrogen product (26, 27, 30). The process and apparatus have a refrigeration-supply system, in which a refrigeration fluid (31) flows.

Abstract: Krypton and/or xenon are extracted from a krypton-xenon concentrate by means of distillation, for example, a krypton-xenon concentrate obtained from a low-temperature air separation unit. To remove fluorine- and/or chlorine-containing contaminants, especially fluorocarbons, CF.sub.4 and/or SF.sub.6, the krypton-xenon concentrate, a krypton stream and/or a xenon stream are purified in a solid sorbent that contains phyllosilicates.