Binary gas mixtures can be completely separated via dual-reflux pressure swing adsorption (DR-PSA) process, where pressure of the column to which the feed gas is supplied and the kind of gas employed for pressure swing determine different configurations. DR-PSA studies have been predominantly confined to the configurations that use heavy gas for pressure swing. For such configurations, we formerly reported an equilibrium theory-based optimum design approach that defined a complete separation region and a selection criterion to enable the choice of suitable configuration. In this Article, same design strategy is applied to the less studied DR-PSA configurations, those utilizing light gas for pressure swing. Unique understanding of the separation behavior of such configurations is achieved and presented. After discussing the impact of process variables on design constraints, a systematic analysis of key parameters defining the process performance with respect to the ratio of high to low operating pressures is finally reported.