Carbon dioxide pressure swing adsorption process using modified alumina adsorbents

A pressure swing adsorption process for absorbing CO.sub.2 from a water-containing gaseous mixture having a first CO.sub.2 partial pressure comprising

• introducing the water-containing gaseous mixture into a reactor maintained at a selected temperature ranging from 100.degree. C. and 500.degree. C., which contains an alumina adsorbent formed by depositing a solution of a compound comprising a cation selected from an alkali metal, an alkaline earth metal or ammonium and an anion selected from an hydroxide, a carbonate, a bicarbonate, an acetate, a phosphate, a nitrate or an organic acid salt having a pH of 3.0 or more onto alumina and heating the alumina to a temperature ranging from 100.degree. C. and 600.degree. C., to adsorb CO.sub.2 to provide a CO.sub.2 laden alumina adsorbent and a CO.sub.2 depleted gaseous mixture and
• contacting the CO.sub.2 laden adsorbent residing in the reactor maintained at the selected temperature ranging from 100.degree. C. and 500.degree. C., with a weakly adsorbing purge fluid having a second CO.sub.2 partial pressure which is lower than the first CO.sub.2 partial pressure to desorb CO.sub.2 from the CO.sub.2 laden alumina adsorbent.