Patent ID: 9459043
Filing Date: 2016-10-04
CPC Classification: F25J

Claim Text:
1. A method for producing carbon monoxide by cryogenic distillation using an installation comprising a system of distillation columns fed with a mixture of at least hydrogen and carbon monoxide as the main components and at least part of the time nitrogen, the method comprising the steps of: measuring a nitrogen content of the mixture or of a fluid from which the mixture is derived; separating the mixture in a system of distillation columns comprising a denitrogenation column configured to produce a nitrogen-rich flow and a carbon monoxide-rich flow; withdrawing the carbon monoxide-rich flow from the system of distillation columns to serve as the product; and introducing a nitrogen-rich fluid from a supplemental nitrogen source upstream of and/or into the denitrogenation column if the nitrogen content of the mixture or of a fluid from which the mixture is derived falls below a given threshold based on a value in which operation of the denitrogenation column would deteriorate, wherein the supplemental nitrogen source is different than the mixture source.