Cold Box (Installation for producing carbon monoxide by cryogenic distillation)

An installation for producing carbon monoxide by cryogenic distillation comprising: a) a heat exchanger for cooling and partially condensing a gas mixture containing carbon monoxide, hydrogen and nitrogen to produce a cooled and partially condensed gas mixture; b) a separator for separating the cooled and partially condensed gas mixture to produce a hydrogen-enriched gas and a carbon monoxide-enriched liquid; c) means for conveying the cooled and partially condensed gas mixture from the heat exchanger to the separator; d) a stripping column and means for conveying at least part of the carbon monoxide-enriched liquid thereto; e) means for withdrawing a hydrogen-enriched gas from the top of the stripping column and means for withdrawing a hydrogen-free liquid from the bottom of the stripping column; and f) a distillation column, means for sending a stream of the hydrogen-free liquid to a first intermediate point of the distillation column, means for withdrawing a bottom liquid from the distillation column, means for withdrawing an overhead gas (RSD N2) from the distillation column and means for withdrawing an intermediate fluid at a second intermediate point of the distillation column, the second intermediate point being above the first intermediate point.