Incineration and condensation are
cost-effective only for moderate to high VOC concentrations.
Adsorption and absorption do not destroy VOCs but simply
transfer them to another medium. The humid gas stream can plug the condenser, and fill up the adsorption site of the adsorbent. None of these methods is cost-effective for gas streams with lowto moderate concentration and large numbers of compounds, as the recovery and reuse of the compounds is not economically feasible. Photocatalytic systems do not have the above mentioned problems and are cost effective for treating low concentration gas streams.