CO purification process

Claim 1

A process for the preparation of high purity CO from a CO 2 -free gaseous stream containing at least about 25% volume CO and also containing H 2 comprising a. countercurrently contacting the gaseous stream with a liquid aqueous absorbent solution containing dissolved therein as copper ammonium C 1-2 acylate from 10 to 18 pbw copper in an amount equivalent to from about 0.2 to about 2.0 gallons of absorbent solution per ft 3 (26.7 - 267 l/m 3 ) of CO in the gaseous stream at a CO partial pressure of at least about 30 psia (2.1 kg/cm 2 ) , by which CO reacts with the copper compound to form a stable water-soluble complex, small amounts of H 2 and other gases are absorbed into the absorbent solution and the non-absorbed and non-complexed components of the gaseous stream are separated from the absorbent solution; b. while maintaining the absorbent solution above its decomplexing pressure, countercurrently contacting the absorbent solution with a stream of purified gaseous CO, as defined hereinbelow, by which the absorbed gases are desorbed and separated from the absorbent solution; c. regenerating the absorbent solution from step (b) by reducing the pressure thereon to a level at which the CO is decomplexed and purified gaseous CO is separated from the absorbent solution; d. recycling purified gaseous CO to step (b) of the process in an amount equivalent to from about 0.03 to about 0.5 ft 3 of CO per ft 3 of total gaseous CO product separated in step (c); and e. recycling regenerated absorbent solution to step (a) of the process.