The desorption behavior of various volatile organic compounds (VOCs: toluene, acetone, n-hexane, n-octane, methanol, ethanol, 2-propanol, and propylene glycol monomethyl ether) from activated carbon was measured in supercritical carbon dioxide (scCO2) using the fixed-bed method at 313–353 K and 10.0–15.0 MPa. The measured behavior strongly depended on the type of VOC, and the CO2 density and volatility of the VOCs were the primary factors influencing this behavior. The desorption behavior was correlated with a kinetic model that assumed material balances in the bulk and pore phases with local adsorption equilibria in the adsorbed phase. The fitting parameters determined using these correlations were reasonably explained by the CO2 density and properties of VOCs, and they provided quantitative information about the desorption phenomena in scCO2.
- Activated carbon
- Kinetic model
- Supercritical carbon dioxide
- Volatile organic compounds (VOCs)