Adsorption equilibrium of benzaldehyde and benzyl alcohol onto polymeric resin from supercritical CO2

A frontal chromatographic technique was used to measure the adsorption isotherms of benzaldehyde and benzyl alcohol onto a polymeric resin in supercritical CO2 (scCO(2)). The effect of temperature and pressure (density) on adsorption behavior was investigated. It was observed that benzyl alcohol has stronger adsorption than benzaldehyde. The desorption of benzaldehyde using scCO(2) from the polymeric resin adsorbent was studied under the same temperature and pressure ranges. The local equilibrium theory was found to reasonably predict the desorption profiles. A phenomenological statistical thermodynamic model combined with classic Peng-Robinson equations of state was used to correlate the adsorption equilibrium isotherms of the solutes from scCO(2). This theoretical model with three parameters is able to describe the adsorption behavior over wide temperature and pressure ranges.