Adsorption and mass transfer characteristics of pentane and cyclopentane by various adsorbents

Experiments have been conducted to investigate gas-phase adsorption charact eristics of pentane and cyclopentane by activated carbon fiber (ACF), extru ded activated carbon (GAC), granular activated carbon (GAC), activated alum ina and molecular sieve. Pentane and cyclopentane are currently regarded as excellent replacements for CFC-11, a foaming agent used extensively in the soft and rigid polyurethane foam industries. Adsorption performances of pe ntane and cyclopentane were characterized by the equilibrium adsorption cap acity, time to reach equilibrium and desorption efficiency of exhausted ads orbent. A simple thermal treatment process with proper operating temperatur e and treatment duration was found to be effective for pretreatment of fres h adsorbents and regeneration of exhausted ones. Adsorption isotherms of th e empirical Freundlich and Jossens types were observed to represent quite w ell the present equilibrium adsorption. A mass transfer model based on the pseudo steady state squared driving force was adopted to describe the mass transfer process of the pentane and cyclopentane adsorption.