Abstract: A process for separation of carbon dioxide that is present in a gas mixture by pressure-modulated adsorption (PSA) that comprises at least the following stages is described: a) Bringing said mixture that is to be purified into contact with at least one adsorbent that is formed by a porous carbon material that comprises at least 70% by weight of carbon, whereby said material has a specific surface area that is larger than 1,500 m2/g, a micropore volume of between 0.5 and 2 cm3/g of adsorbent and between 0.5 and 0.8 cm3/cm3 of adsorbent, b) The adsorption of carbon dioxide on said adsorbent at a total pressure P1, c) The desorption of at least a portion of CO2 that is adsorbed in said stage b) so as to produce a CO2-enriched stream at a total pressure P2 that is less than P1.