Process for purifying a gas mixture

摘要

A process is described for purifying a gas mixture which is essentially composed of hydrogen and which contains, e.g., carbon monoxide, methane and argon as impurities, by scrubbing with liquid nitrogen in a scrubbing column composed of two sections. In order to be able to further process, simply and without high capital expenditure, the residual gases formed in the scrubber which contain, in particular, CO, argon and CH4, it is proposed that the liquid nitrogen is added in an amount which is sufficient to almost completely scrub out the carbon monoxide and that a carbon monoxide-enriched portion of the scrubbing liquid is taken off between the upper and lower sections, the amount taken off being measured in such a way that the residual amount of scrubbing medium remaining in the lower section of the scrubbing column is sufficient to scrub the methane out of the gas mixture but to leave the majority of the carbon monoxide still in the gas mixture. <IMAGE>