US 2011/0214453 A1 · PROCESS AND DEVICE FOR CRYOGENIC AIR FRACTIONATION

Abstract

The process and the device serve for cryogenic air fractionation, in particular for supplying an oxygen-enriched (product stream to an oxyfuel power plant. The distillation column system for nitrogen/oxygen separation has a high-pressure column (26) and a low-pressure column (32). The high-pressure column (26) and the low-pressure column (32) are thermally coupled via a condenser-evaporator (37). Feed air (1) is compressed in an air compressor (3), cooled at least in a first post-cooler (6) and purified in a purification device (22), cooled in a main heat exchanger (23a, 23b, 23c) and introduced at least in part (25, 29) into the high-pressure column (26). At least one liquid stream (33, 35) is introduced from the high-pressure column (26) into the low-pressure column (32). An oxygen-enriched product stream (41, 45, 46,47, 48) is taken off from the low-pressure column (32). A first nitrogen stream (63, 64, 65, 66) is withdrawn from the high-pressure column (26) and warmed to a temperature of at least 280 K (6). The warmed first nitrogen stream (67) is work-expanded (72) in a first warm expansion engine (68). The first nitrogen stream (70, 71) which is expanded in the first warm expansion engine (68) is work-expanded in a second warm expansion engine (72).

Claims16

Dependent claims

A process for cryogenic fractionation of air in a distillation column system for nitrogen-oxygen separation, which has a high-pressure column (26) and a low-pressure column (32), in which

the high-pressure column (26) and the low-pressure column (32) are thermally coupled via a condenser-evaporator (37),
feed air (1) is compressed in an air compressor (3), cooled at least in one first aftercooler (6) and cleaned in a cleaning apparatus (22), cooled in a main heat exchanger (23a, 23b, 23c) and at least partly introduced (25, 29) into the high-pressure column (26),
at least one liquid stream (32, 35) from the high-pressure column (26) is introduced into the low-pressure column (32),
an oxygen-enriched product stream (41, 45, 46, 47, 48) is withdrawn from the low-pressure column (32),
a first nitrogen stream (63, 64, 65, 66) from the high-pressure column (26) is drawn off and warmed (6) to a temperature of at least 280 K, and
the warmed first nitrogen stream (67) is expanded (72) to perform work in a first warm expansion machine (68), characterized in that
the first nitrogen stream (70, 71) expanded in the first warm expansion machine (68) is expanded to perform work in a second warm expansion machine (72).

4 more elements

An apparatus for cryogenic fractionation of air

comprising a distillation column system for nitrogen-oxygen separation which has a high-pressure column (26) and a low-pressure column (32),
the high-pressure column (26) and the low-pressure column (32) being thermally coupled via a condenser-evaporator (37),
comprising an air compressor (3) for compressing feed air (1), a first aftercooler (6) for cooling compressed feed air (4), a cleaning apparatus (22) for feed air, arranged downstream of the first aftercooler (6), a main heat exchanger (23a, 23b, 23c) for cooling cleaned feed air (23) and a main air line (25) for introducing cooled feed air into the high-pressure column (26),
comprising means for withdrawing at least one liquid stream (33, 35) from the high-pressure column (26) and introduction thereof into the low-pressure column (32),
comprising an oxygen product line for withdrawing an oxygen-enriched product stream (41, 45, 46, 47, 48) from the low-pressure column, comprising a first nitrogen line for withdrawing a first nitrogen stream (63) from the high-pressure column (26),
comprising means (6) for warming the first nitrogen stream (65, 66) to a temperature of at least 280 K and
comprising a first warm expansion machine (68) for work-performing expansion of the warmed first nitrogen stream (67), characterized by a second warm expansion machine (72) for work-performing expansion of the first nitrogen stream (70, 71) expanded in the first warm expansion machine (68).

4 more elements

Dependencies are inferred from the claim text.

Process and device for cryogenic air fractionation

Life of this patent

Process and device for cryogenic air fractionation

Life of this patent

Abstract

Claims16