Biogas upgrading by pressure swing adsorption using zeolite 4A. Effect of purge on process performance

•Zeolite 4A was investigated as a cheaper adsorbent to perform biogas upgrading by pressure swing adsorption.•Experimental data of adsorption equilibrium, single gas diffusion, binary breakthrough curves and PSA experiment are presented.•The PSA performance in a 6-step cycle, indicated that in purge step duration and flowrate can control the bio-methane purity but at the expense of reducing bio-methane recovery.