CYCLIC ADSORPTION AND DESORPTION OF METHANE AND CARBON DIOXIDE ON COCONUT SHELL ACTIVATED CARBON

Natural gas can be stored as an adsorbed phase in porous materials and is referred to as ANG. The use of adsorbent materials in a storage vessel for storing natural gas, at relatively low pressure (3.5-4 MPa) and at room temperature, is a possibility for making natural gas vehicles competitive with other types of vehicle. For adsorbent materials, activated carbon is the most commonly used and effective modified adsorbent support because of its high specific surface area and pore volume among these materials. In this work, investigation on cyclic adsorption and desorption of methane and carbon dioxide by using coconut shell activated carbon (CSAC) was carried out in a stainless steel packed bed column with an inside diameter of 10.2 mm at atmospheric pressure and room temperature. The effects of methane as a desorbent in binary adsorption system were also scrutinized. The properties of the CSAC was characterized by SAA, and FE-SEM. The results indicated that the proper desorption time by using methane as a desorbent should be one hour. Moreover, carbon dioxide is more strongly adsorb on the CSAC than methane, so methane roll-up can be observed in the binary adsorption system.