The objective of this research is to synthesize the microporous activated carbon and test its applicability for CO2 gas capture. In this study, coconut shell-based and commercial activated carbon is used as the solid adsorbent. Based on the findings, it shows that the gas adsorption capacity is correlated to the total surface area of the materials. In addition, reduction in the adsorption capacity with respect to temperature proves that the physisorption process is dominant. Higher carbon dioxide (CO2) adsorption capacity in comparison to nitrogen (N2) capacity contributes to higher CO 2/N2 selectivity, and confirms its applicability in the post-combustion process. Utilization of abundance agricultural wastes and one-step physical activation process is attractive as it promotes a cleaner pathway for activated carbon production, and simultaneously, reduces the total operating cost. Copyright © 2014 Trans Tech Publications Ltd, Switzerland.