A process for capturing carbon-dioxide from a gas stream, said process comprising the following steps: a) providing a support, wherein said support is a silica-alumina support; b) impregnating potassium carbonate (K 2 CO 3) on said support to form an adsorbent comprising potassium carbonate (K 2 CO 3) impregnated support; c) stabilizing the temperature inside an adsorber and a desorber by circulating the adsorbent without injecting the carbon-dioxide (CO 2) and water-vapor/steam (H 2 O) in the adsorber and the desorber; d) activating said adsorbent in said adsorber by passing one of water-vapor and the gas stream comprising water-vapor at a temperature ranging from 40°C to 80°C, at a pressure ranging from 1 bar to 2 bar, and for a time period ranging from 1 minute to 20 minutes to form an activated adsorbent with active adsorption sites having reduced energies; e) passing said gas stream through said adsorber containing said activated adsorbent to enable adsorption of the carbon-dioxide from said gas stream on said activated adsorbent at a temperature ranging from 40°C to 90°C and at a pressure ranging from 1 bar to 2 bar to form a carbon-dioxide laden adsorbent; f) transferring said carbon-dioxide laden adsorbent to said desorber; and g) passing a carbon-dioxide deficient stream through said desorber for at least partially desorbing the carbon-dioxide from said carbon-dioxide laden adsorbent at a temperature ranging from 110°C to 200°C and at a pressure ranging from 1 bar to 2 bar to obtain a partially regenerated adsorbent, wherein said carbon-dioxide deficient stream is at least one selected from the group consisting of nitrogen, carbon-dioxide, and water-vapor; and h) returning said partially regenerated adsorbent to said adsorber for adsorbing the carbon-dioxide from said gas stream; wherein the process of impregnation in step b) is carried out in the following steps: i. treating said support at a temperature in the range of 550° C. to 1100° C. to obtain a treated support; ii. adding said treated support into a fluid medium comprising K 2 CO 3 in the range of 5 wt % to 60 wt % using an incipient wet impregnation method at a temperature in the range of 20° C. to 50° C.; and iii. allowing K 2 CO 3 to disperse on said treated support for a time period in the range of 10 min to 20 min to form the adsorbent followed by drying at a temperature in the range of 100° C. to 150° C. for at a time period in the range of 10 hours to 12 hours. a) providing a support, wherein said support is a silica-alumina support; b) impregnating potassium carbonate (K 2 CO 3) on said support to form an adsorbent comprising potassium carbonate (K 2 CO 3) impregnated support; c) stabilizing the temperature inside an adsorber and a desorber by circulating the adsorbent without injecting the carbon-dioxide (CO 2) and water-vapor/steam (H 2 O) in the adsorber and the desorber; d) activating said adsorbent in said adsorber by passing one of water-vapor and the gas stream comprising water-vapor at a temperature ranging from 40°C to 80°C, at a pressure ranging from 1 bar to 2 bar, and for a time period ranging from 1 minute to 20 minutes to form an activated adsorbent with active adsorption sites having reduced energies; e) passing said gas stream through said adsorber containing said activated adsorbent to enable adsorption of the carbon-dioxide from said gas stream on said activated adsorbent at a temperature ranging from 40°C to 90°C and at a pressure ranging from 1 bar to 2 bar to form a carbon-dioxide laden adsorbent; f) transferring said carbon-dioxide laden adsorbent to said desorber; and g) passing a carbon-dioxide deficient stream through said desorber for at least partially desorbing the carbon-dioxide from said carbon-dioxide laden adsorbent at a temperature ranging from 110°C to 200°C and at a pressure ranging from 1 bar to 2 bar to obtain a partially regenerated adsorbent, wherein said carbon-dioxide deficient stream is at least one selected from the group consisting of nitrogen, carbon-dioxide, and water-vapor; and h) returning said partially regenerated adsorbent to said adsorber for adsorbing the carbon-dioxide from said gas stream; i. treating said support at a temperature in the range of 550° C. to 1100° C. to obtain a treated support; ii. adding said treated support into a fluid medium comprising K 2 CO 3 in the range of 5 wt % to 60 wt % using an incipient wet impregnation method at a temperature in the range of 20° C. to 50° C.; and iii. allowing K 2 CO 3 to disperse on said treated support for a time period in the range of 10 min to 20 min to form the adsorbent followed by drying at a temperature in the range of 100° C. to 150° C. for at a time period in the range of 10 hours to 12 hours.