Abstract: The invention relates to a method for a low-temperature air separation in which an air separation unit is used comprising a first rectification column and a second rectification column. The first rectification column is operated at a first pressure level, and the second rectification column is operated at a second pressure level below the first pressure level. Fluid which is oxygen-enriched compared to atmospheric air is drawn from the first rectification column in the form of one or more first material flows. At least one fraction of the fluid which has been drawn from the first rectification column in the form of the one or more first material flows is heated in a heat exchanger; a fraction of the fluid which has been heated in the heat exchanger is compressed using a compressor and is returned to the first rectification column.

Abstract: The invention relates to a method for a low-temperature air separation in which an air separation unit is used comprising a first rectification column and a second rectification column. The first rectification column is operated at a first pressure level, and the second rectification column is operated at a second pressure level below the first pressure level. Fluid which is oxygen-enriched compared to atmospheric air is drawn from the first rectification column in the form of one or more first material flows. At least one fraction of the fluid which has been drawn from the first rectification column in the form of the one or more first material flows is heated in a heat exchanger; a fraction of the fluid which has been heated in the heat exchanger is compressed using a compressor and is returned to the first rectification column.

Abstract: The plant is used for producing oxygen by cryogenic air separation. The plant has a high-pressure column, a low-pressure column and a main condenser. An argon-elimination column is in fluid connection with an intermediate point of the low-pressure column and is connected to an argon-elimination column head condenser. An auxiliary column has a sump region, into which gas is introduced from the argon-elimination column head condenser. The head of the auxiliary column is connected to a return flow liquid line, in order to introduce a liquid stream from the high-pressure column or the head condenser. The liquid stream has an oxygen content which is at least equal to that of air. At least one part of the crude liquid oxygen from the sump of the high-pressure column is fed to the auxiliary column at a first intermediate point.

Abstract: A method and plant for discharging components that are less volatile than oxygen from an air separation plant that contains a main heat exchanger a side condenser and a two-column distillation column system for nitrogen-oxygen separation. The side condenser is constructed as a condenser-evaporator and is arranged in a vessel. A part of the feed air is cooled in the main heat exchanger and liquefied at least in part in the side condenser. A first oxygen fraction is withdrawn in the liquid state from the low-pressure column, introduced into the vessel of the side condenser and in part vaporized. A purge stream is taken off from the bottom of the vessel in the liquid state and discharged or withdrawn as end product. The vessel has a mass transfer section above the side condenser, which mass transfer section corresponds to more than one theoretical plate and fewer than 10 theoretical plates.

Abstract: The plant is used for producing oxygen by cryogenic air separation. The plant has a high-pressure column, a low-pressure column and a main condenser. An argon-elimination column is in fluid connection with an intermediate point of the low-pressure column and is connected to an argon-elimination column head condenser. An auxiliary column has a sump region, into which gas is introduced from the argon-elimination column head condenser. The head of the auxiliary column is connected to a return flow liquid line, in order to introduce a liquid stream from the high-pressure column or the head condenser. The liquid stream has an oxygen content which is at least equal to that of air. At least one part of the crude liquid oxygen from the sump of the high-pressure column is fed to the auxiliary column at a first intermediate point.

Abstract: A method and device to produce oxygen by the low-temperature separation of air at variable energy consumption. A distillation column system comprises a high-pressure column, a low-pressure column and a main condenser, a secondary condenser and a supplementary condenser. Gaseous nitrogen from the high-pressure column is liquefied in the main condenser in indirect heat exchange with an intermediate liquid from the low-pressure column. A first liquid oxygen stream from the bottom of the low-pressure column is evaporated in the secondary condenser in indirect heat exchange with feed air to obtain a gaseous oxygen product. The supplementary condenser serves as a bottom heating device for the low-pressure column and is heated by means of a first nitrogen stream from the distillation column system, which nitrogen stream was compressed previously in a cold compressor.

Abstract: A method and plant for discharging components that are less volatile than oxygen from an air separation plant that contains a main heat exchanger a side condenser and a two-column distillation column system for nitrogen-oxygen separation. The side condenser is constructed as a condenser-evaporator and is arranged in a vessel. A part of the feed air is cooled in the main heat exchanger and liquefied at least in part in the side condenser. A first oxygen fraction is withdrawn in the liquid state from the low-pressure column, introduced into the vessel of the side condenser and in part vaporized. A purge stream is taken off from the bottom of the vessel in the liquid state and discharged or withdrawn as end product. The vessel has a mass transfer section above the side condenser, which mass transfer section corresponds to more than one theoretical plate and fewer than 10 theoretical plates.

Abstract: A method and device to produce oxygen by the low-temperature separation of air at variable energy consumption. A distillation column system comprises a high-pressure column, a low-pressure column and a main condenser, a secondary condenser and a supplementary condenser. Gaseous nitrogen from the high-pressure column is liquefied in the main condenser in indirect heat exchange with an intermediate liquid from the low-pressure column. A first liquid oxygen stream from the bottom of the low-pressure column is evaporated in the secondary condenser in indirect heat exchange with feed air to obtain a gaseous oxygen product. The supplementary condenser serves as a bottom heating device for the low-pressure column and is heated by means of a first nitrogen stream from the distillation column system, which nitrogen stream was compressed previously in a cold compressor.