A method and a device for producing an air product based on cryogenic rectification; after being cooled by a main heat exchanger, raw material air and nitrogen compressed by means of a compressor are sent to a rectification system for low temperature separation. In the rectification system, products such as oxygen and nitrogen are obtained by means of low temperature separation, and oxygen-enriched liquid air is obtained at or near the bottom of a rectification tower. The oxygen-enriched liquid air or liquid-state air in the rectification system is sent out after being raised to a target pressure by means of a low temperature liquid air pump; air products of various pressures can be produced by means of selecting low temperature liquid air pumps with different lifts or by connecting in series different amounts of low temperature liquid air pumps. The present method can avoid the need to arrange additional air compressors, entirely changing the method for producing medium and high pressure air products in a nitrogen circulation process, and importantly can reduce production costs significantly whilst having greater flexibility. In addition, the present method can increase the oxygen extraction rate of an apparatus, thereby improving the energy efficiency level.

A compression unit for supplying high and low pressure services to a plant including a single driver associated with two driver shaft-ends projecting apart from the driver, a first driver shaft end and a second driver shaft end, a first unit being operatively connected to the first driver shaft-end and a second unit being operatively connected to the second driver shaft-end.

The invention relates to a process for cryogenic fractionation of air using an air fractionation plant comprising a rectification column system comprising a high-pressure column operated at a pressure level of 9 to 14.5 bar, a low-pressure column operated at a pressure level of 2 to 5 bar, and an argon column. It is envisaged that a recirculating stream is formed using the second tops gas or a portion thereof, which is heated, compressed, cooled again, and after partial or complete liquefaction or in the unliquefied state is introduced partially or completely, or in fractions, into the first rectification column and/or into the second rectification column. The present invention also relates to a corresponding system.

A method and plant for the cryogenic separation of air, the plant having an air compressor, a heat exchanger and a distillation column system having a low-pressure column at a first pressure and a high-pressure column at a second pressure. Feed air is compressed in the air compressor to a third pressure at least 2 bar above the second pressure A first fraction of compressed feed air is cooled in the heat exchanger and expanded in a first expansion turbine. A second fraction is cooled in the heat exchanger and expanded in a second expansion turbine A third fraction is compressed to a fourth pressure, cooled in the heat exchanger and then expanded. The third fraction is compressed to the fourth pressure in sequence in a recompressor, a hot first turbine booster and a second turbine booster. A dense fluid expander is used to expand the third fraction.

A method for obtaining one or more air products by means of an air separation unit comprising a first booster, a second booster, a first decompression machine, and a rectification column system which has a high-pressure column operated at a first pressure level and a low-pressure column operated at a second pressure level below the first pressure level. All of the air supplied to the rectification column system is first compressed to a third pressure level, which lies at least 3 bar above the first pressure level, as a feed air quantity. A first fraction of the feed air quantity is supplied to a first booster at the third pressure level and at a temperature level of −140 to −70 ° C. and is compressed to a fourth pressure level using the first booster.

A method and the apparatus for the cryogenic separation of air in an air separation plant which has a main air compressor, a main heat exchanger and a distillation column system with a high-pressure column and a low-pressure column. All of the feed air is compressed in the main air compressor to a first air pressure which is at least 3 bar higher than the operating pressure of the high-pressure column. A first part of the compressed total air flow, as first air flow at the first air pressure, is cooled and liquefied or pseudo-liquefied in the main heat exchanger, then expanded and introduced into the distillation column system. A second part of the compressed total air flow, as second air flow, is post-compressed in an air post-compressor to a second air pressure and at least part is further compressed in a first turbine-driven post-compressor to a third air pressure.

The present disclosure relates to systems and methods useful for power production. In particular, a power production cycle utilizing CO.sub.2 as a working fluid may be combined with a second cycle wherein a compressed CO.sub.2 stream from the power production cycle can be heated and expanded to produce additional power and to provide additional heating to the power production cycle.

A method and the apparatus for obtaining a compressed gas product by means of cryogenic separation of air in a distillation column system which has a high-pressure column and a low-pressure column. All of the feed air is compressed in a main air compressor to a first pressure which is at least 4 bar higher than the operating pressure of the high-pressure column. A first partial flow of the feed air compressed in the main air compressor is cooled to an intermediate temperature in a main heat exchanger and is expanded so as to perform work in a first air turbine. At least a first part of the first partial flow expanded so as to perform work is introduced into the distillation column system.

The present invention discloses a cryogenic rectification process-based method for producing an air product, and an air separation system. By adding an air product outlet line and a liquid air booster pump to an existing cryogenic rectification process apparatus, the existing rectification apparatus is used to prepare oxygen-enriched liquid air by pressurizing, cooling and liquefying feed air; and moreover, a high-pressure or ultra-high-pressure air product can be prepared according to customer requirements by adjusting the ratio of the feed air to the oxygen-enriched liquid air, and pressurizing the mixture to a target pressure by the liquid air booster pump before being vaporized via heat exchange with a gas or liquid product produced by rectification through a heat exchange apparatus. According to the present invention, when gas or liquid products of oxygen and nitrogen are produced by means of rectification, a high-pressure or ultra-high-pressure air product can be provided according to customer requirements, and there is no need to provide an additional air compressor or passively increase the discharge pressure of the air booster, so that the production costs are greatly reduced and the energy efficiency level is improved. The method of the present invention can also improve the stability of devices, especially when a small amount of high-pressure/ultra-high-pressure air product needs to be produced.

A method and a device for producing an air product based on cryogenic rectification; after being cooled by a main heat exchanger, raw material air and nitrogen compressed by means of a compressor are sent to a rectification system for low temperature separation. In the rectification system, products such as oxygen and nitrogen are obtained by means of low temperature separation, and oxygen-enriched liquid air is obtained at or near the bottom of a rectification tower. The oxygen-enriched liquid air or liquid-state air in the rectification system is sent out after being raised to a target pressure by means of a low temperature liquid air pump; air products of various pressures can be produced by means of selecting low temperature liquid air pumps with different lifts or by connecting in series different amounts of low temperature liquid air pumps. The present method can avoid the need to arrange additional air compressors, entirely changing the method for producing medium and high pressure air products in a nitrogen circulation process, and importantly can reduce production costs significantly whilst having greater flexibility. In addition, the present method can increase the oxygen extraction rate of an apparatus, thereby improving the energy efficiency level.