Adsorption capacity of activated carbon for n-alkane VOCs

The volatile organic compounds (VOCs) in the indoor air come from many sources including building materials, furnishings, occupant activities and in some cases, the ventilation air. Granular activated carbons (GAC) have been increasingly used to remove these contaminants, particularly for small commercial buildings and those located in urban centers or near industrial plants where the quality of outdoor air may be worse than that of the indoor air. Tests were conducted to determine the efficiency of GAC in removing VOCs from the indoor air. Seven n-alkanes VOCs covering a wide range of molecular sizes were selected for these tests. They were pentane, hexane, heptane, octane, nonane, decane, and undecane. The breakthrough time and VOC mass adsorbed on GAC for these individual VOCs were obtained. It was found that the adsorption capacity of GAC decreases as the initial VOC concentration, C0, decreases.