Used 33 TPD Argon Recovery and 17 TPD Nitrogen Recovery Plant. The feed gas is designed as the tail gas from Hydrogen Recovery Unit in Ammonia Plant. The feed gas is cooled down to cryogenic temp in the plate-fined type of heat exchangers against separation products. In the argon recovery column the feed is separated into a CH4 fraction, a N2 fraction and a N2-Ar fraction. The N2-Ar fraction leaving as liquid side stream from the argon recovery column is fed into the argon purification column. The argon recovery process is operated by a nitrogen cycle.