Process for the recovery of nitrogen-rich gases from gases containing at least oxygen as other component

The present process is an improvement of an earlier process wherein a nitrogen enriched gas is obtained from a gas containing oxygen and possibly other components. In that process the feed gas is passed in a continuous flow cycle through an adsorber containing carbonaceous molecular sieve coke followed by evacuation of the adsorber, oxygen and possibly other gas components being adsorbed and the discharged nitrogen-enriched gas being collected until the continually rising oxygen contents thereof reaches a predetermined limit value whereupon the molecular sieve coke is desorbed of the residual gases prior to the next charging cycle. The present improvement is constituted by the feature that the flow of feed gas through the molecular sieve coke is effected at a continually increasing pressure until a terminal pressure of about 3 to 10 bar has been reached.