CO2–N2 separation performance of a simple Skarstrom type pressure vacuum swing adsorption (PVSA) cycle is compared with a heavy reflux cycle with a potassium exchanged X zeolite adsorbent. Contrary to literature reports, the performance of the Skarstrom cycle has been found to be better under different PVSA process conditions. The best CO2 purity achieved was 92 mol % at a recovery as high as 80% from a feed consisting of 15 mol % CO2 in N2 and under an excellent feed throughput of 790 LSTP/h/kg. The power consumption in the Skarstrom cycle is also found to be lower than in the heavy reflux cycle.