Removal of carbon dioxide from the atmosphere as well as waste gas streams from industrial and power stations has become the present day's world-wide attraction for many reasons, the most important being the trapping of heat from the sun by CO₂ and hence disruption of global warming effect. Activated carbon and CMS samples were prepared from coal samples of different origin. The effects of the various process parameters to prepare CMS from various coals were studied. Pre-oxidation of the coal, activation using CO₂ and pore narrowing through coke deposition by benzene cracking were the major process parameters used to prepare the CMS in this work. The CO₂ adsorption capacity of the samples was studied using gravimetric as well as volumetric methods. The adsorption capacity Of CO₂ on the CMS samples prepared was found to be 1.6 mmol/g of the adsorbent with an uptake ratio at equilibrium adsorption for CO₂/CH₄, >> 20. The morphology of the pore structure of the samples was studied using the Scanning Electron Microscope (SEM). The N₂ adsorption on the samples at liquid N₂ temperature was found to be very poor and hence surface area measurement was done using CO₂ adsorption data. The BET surface area thus calculated was found to be 20% less than the DA surface area calculated.