Adsorption equilibrium and kinetics of gasoline vapors onto carbon-based adsorbents

Adsorption equilibrium and kinetics of gasoline vapors onto two types of carbon-based adsorbents have been experimentally investigated. The adsorbents used in this study are activated carbon (AC) of type Maxsorb III and a felt-type activated carbon fiber that is known commercially as ACF-1500. The experiments have been conducted at assorted adsorbent temperatures between (20 and 60) degrees C by using a thermogravimetric analyzer (TGA) unit which has an accuracy of +/- 0.1 mu g for the vapor uptake, and the results are logged continuously. The Dubinin-Radushkevich (D-R) equation is found to be suitable to correlate the adsorption isotherms, and the Fickian diffusion model is used to represent the adsorption kinetics. The results show that although the Maxsorb III/gasoline pair has more than twice the uptake of the ACF-1500/gasoline pair at equilibrium conditions the latter has about a 10-fold improvement in the diffusion time constant.