a method for adsorbing and oxidizing voc &# 39 ; s in the same bed , thus reducing the size of or even eliminating the need for a catalytic or thermal oxidation unit at the end of the system . in this system , a catalyst is intimately interspersed with the adsorbent material . the catalyst oxidizes voc &# 39 ; s released during desorption when it reaches the ` light off temperature ,` that is , the catalyst temperature necessary for oxidation to begin . as voc &# 39 ; s are desorbed , they are combusted by the catalyst in the same bed and also by their combustion , heat the bed to aid in the desorption of voc &# 39 ; s elsewhere in the bed .