METHOD AND DEVICE FOR SEPARATING A MIXTURE CONTAINING AT LEAST HYDROGEN, NITROGEN AND CARBON MONOXIDE BY CRYOGENIC DISTILLATION

摘要

The invention relates to a method for separating a mixture containing carbon monoxide, nitrogen and hydrogen by cryogenic distillation in a separation means system including a denitrification column (C4) and at least another column, that comprises separating the mixture in order to obtain a fluid enriched with carbon monoxide and containing nitrogen, separating the fluid in the denitrification column, pressurising the carbon monoxide flow from the column system in a compressor (V1, V2) up to a high pressure, a fraction (7) of the carbon monoxide flow being used as a product, expanding a variable amount (57) of the high-pressure carbon monoxide flow cooled in a valve (59) before supplying it to the vat of the denitrification column, and varying the flow expanded in the valve according to the re-boiling needs of the denitrification column