Patent ID: 6434973
Filing Date: 2002-08-20
Classification: F25J

Abstract:
Process for the production of a flow enriched in oxygen in a cryogenic distillation unit, which comprises the stages of:a) cooling a feed flow (1) comprising oxygen, nitrogen and argon and introducing this flow into a distillation unit comprising an auxiliary column (25) for separating a flow (29) comprising at least argon and oxygen and at least two other columns (9, 11); b) separating this flow by cryogenic distillation in the unit, in order to form fluids enriched in oxygen and in nitrogen (15, 33, 35); c) conveying the flow comprising at least argon and oxygen from one of the other columns to the auxiliary column, the auxiliary column operating substantially at the same pressure as the column (11) from which originates the flow comprising at least argon and oxygen, this pressure being between 2 and 10 bar absolute; d) withdrawing a flow enriched in oxygen (37), comprising at least 95 mol % of oxygen, from a column of the unit; e) withdrawing a flow enriched in argon (49) from the auxiliary column; characterized in that at least a portion of the flow enriched in argon (49) is discharged to the atmosphere and/or is used to regenerate reversible exchangers or adsorbent beds (4) and/or at least a portion of the flow enriched in argon is used as product, after being mixed with a gas enriched in nitrogen (47) from the unit and/or another unit.