Adsorption of pure carbon dioxide and methane on dry coal from the sulcis coal province (SW Sardinia, Italy)

Abstract Enhanced coalbed methane recovery (ECBM) increases the recovery of the methane present in a coal seam by injecting CO 2 at high pressure. It is attractive from two perspectives, the valuable methane recovered and the storage of the greenhouse gas CO 2 for geological times. In the framework of a feasibility study for the Sulcis Coal Province in Italy, the adsorption of pure CO 2 and CH 4 on dry coal has been measured at 45 and 60°C, using a magnetic suspension balance with in situ density measurement. The results show that the CO 2 adsorption isotherms on coal are similar to those for other standard adsorbents such as silica gel and activated carbon. From the excess adsorption isotherms, the absolute adsorption is calculated using the assumption of constant volume of the adsorbed phase. As expected, CO 2 get adsorbed more than CH 4 in all cases. The Sulcis coal can uptake CO 2 at the reservoir conditions in an amount of about 10% of its mass. © 2006 American Institute of Chemical Engineers Environ Prog, 2006