Synthetic activated carbons for the removal of hydrogen cyanide from air

Copper containing and copper free synthetic activated carbons produced from porous sulfonated styrene/divinylbenzene resin were studied for assessing the removal efficiency of HCN vapors from air. The pore structures and surface chemistry of these activated carbons were analyzed through N2 physisorption at 77 K and X-ray photoelectron spectroscopy (XPS), respectively. Incorporation of copper into starting material significantly increased HCN breakthrough times, but decreased benzene breakthrough times. The surface area and pore volume of the adsorbents also decreased with incorporation of copper. Results of XPS analysis revealed partial or complete reduction of the starting divalent copper on the surface of the adsorbents confirmed by the lack of formation of (CN)2 during the adsorption of HCN. The performance of copper containing water vapor activated adsorbent was compared to the performance of ASC Whetlerite carbon.