The later is rarely used for the VOC emission control because, it involves a less-reversible
chemical bonding of the adsorbate (pollutant) and the adsorbing solid ( packing) and is
relatively expensive. Physical adsorption uses the Van der Waals force, giving the
advantage of reversibility and regeneration due to the weaker bonding of the gas and
adsorbent material. The adsorbed material can be either recovered or incinerated.
Regeneration is usually accomplished by heating or extraction/displacement.
Activated carbon is a commonly used adsorbent.