METHOD AND APPARATUS FOR PRODUCING CARBON MONOXIDE BY CRYOGENIC DISTILLATION USING A DISTILLATION COLUMN SYSTEM SUPPLIED WITH A MIXTURE OF WHICH THE MAIN COMPONENTS ARE AT LEAST HYDROGEN AND CARBON MONOXIDE

摘要

(EN) In a method for producing carbon monoxide by cryogenic distillation using a system of distillation columns (5, 11) supplied with a mixture containing at least hydrogen and carbon monoxide as the main components thereof and, at least some of the time, nitrogen, wherein the mixture is separated in a column system including a denitrogenation column (11) to give a nitrogen-rich flow and a nitrogen-poor flow, and a carbon monoxide-rich flow is extracted from the column system for use as a product, characterised in that when the nitrogen content of the mixture falls below a predetermined threshold, nitrogen (17) from an external source other than the source of the mixture is fed in upstream of or in the denitrogenation column.