| abstract |
A cryogenic process for the production of oxygen using an air separation unit comprising a double column, said double column comprising a high pressure column (9) and a low pressure column (11) comprising the steps of : sending compressed, cooled and purified air (6) to the high pressure column in gaseou form, sending oxygen enriched (19) fluid from the bottom of the high pressure column to the low pressure column, removing nitrogen enriched gas (25) from the top of the high pressure column, sending a first portion of nitrogen (23) enriched gas to a lower reboiler (29) in the low pressure column following compression in a cold compressor (27), sending a second portion of nitrogen enriched gas to an upper reboiler (21) in the low pressure column, sending nitrogen enriched liquid (22, 51) from at least one, of the first and second reboilers to at least one of the high pressure column and the low pressure column, expanding a stream of nitrogen enriched gas (37) from the high pressure column in an expander (39) following a warming step, driving the col compressor using a motor and producing oxygen rich gas (45) Ofrom the low ressure column. |