A new PSA process was developed and applied to the removal and enrichment of carbon dioxide from air-CO2 mixtures. This PSA process is constituted by a dual reflux policy and admission of the feed gas mixture at an intermediate axial position of the column. The influences of the feed inlet position and reflux ratio on process performance were experimentally investigated. For both parameters there is respectively an optimum value at which the process performance was relatively higher. At the optimal values it was possible to concentrate and remove the CO2 simultaneously beyond a factor of the pressure ratio P(a)/P(d), a situation unattainable in the conventional PSA in which the feed gas is supplied at the end of the column.