Effects of activated carbon surface properties on the adsorption of volatile organic compounds

Physical and chemical properties of activated carbon (AC) were analyzed to investigate the effects of adsorbate properties on AC adsorption performance. Fixed-bed adsorption experiments were conducted with toluene, acetone, and xylene as adsorbates. From the results, the adsorption capacities of the three adsorbates had the following order: xylene > toluene > acetone. The correlation between experimental data and adsorbate properties was also analyzed. The results showed that different functional groups corresponding to the properties of adsorbates influenced the adsorptive properties of AC differently. The adsorption capacity of AC increased linearly as the molecular weight, dynamic diameter, boiling point, and density of the adsorbate increased. However, adsorption capacity decreased as the polarity index and vapor pressure of the adsorbate increased. For adsorption onto three types of AC, the adsorption energies of the three adsorbates had the following order: xylene > toluene > acetone.