Reactivation of spent beaded activated carbon for decreasing irreversible adsorption

Reactivation was used to restore the porosity and VOC adsorption capacity of spent beaded activated carbon (BAC) and adsorption/regeneration cycles were used to evaluate changes in the formation of heel during reuse. Reactivation in N₂ and CO₂ were studied with varying water concentrations, and the reactivated samples were analyzed for five adsorption/regeneration cycles using a simulated, industrial VOC gas stream containing nine organic compounds. Weight loss during reactivation was between 22 and 78% due to removal of strongly adsorbed organic compounds (heel) and partial oxidation of the adsorbent. Compared to the virgin material, reactivated BAC had ≤ 40% more surface area and 20% more micropore volume. Compared to virgin BAC, cumulative heel was > 10% lower for carbon reactivated with 10 g H₂O I g BAC in CO₂ or N₂. The results suggests approaches for industrial reactivation of spent BAC adsorbents, helping to minimize operating cost and need for disposal of spent carbon adsorbents and to ultimately improve methods for VOC emissions control. This is an abstract of a paper presented at the AWMA's 107th Annual Conference & Exhibition (Long Beach, CA 6/24-27/2014).