ANALYSIS OF ADSORPTION ENTROPIES OF HIGH-PRESSURE GAS-ADSORPTION DATA ON ACTIVATED CARBON

High-pressure adsorption data for methane, ethane, ethylene, propane, carbon dioxide, and nitrogen on activated carbon were analyzed to determine adsorption entropies. Thermal entropies associated with two phase and localized adsorbed phase models were evaluated. It was found that for each gas at a given temperature, thermal entropy for a localized adsorbed phase remained constant with coverage. However, thermal entropy corresponding to a mobile adsorbed phase varies with coverage. These results indicate the adsorbed phase is localized in nature. It was also found that thermal entropy of the adsorbed phase increases with temperature, which implies the adsorbed phase molar volumes increase with temperature. © 1990.