Nano-sized carbon hollow spheres for abatement of ethylene

In this paper, the ethylene adsorption capacities of the nano-sized carbon hollow spheres (CNB) and active carbon (AC), the Pd (PdCl2) impregnated CNB or AC (Pd/CNB, Pd/AC) and heat treatment under various conditions, were studied at different ethylene concentrations from 64 to 1060 ppm. The results indicated that AC had a good ethylene adsorption capacity at high ethylene concentration. Pd impregnation decreased the ethylene adsorption capacity of AC. Heat treatment and H, activation could increase the ethylene adsorption capacity, but also lowered than AC itself. CNB had lower ethylene adsorption capacity than AC, but heat treatment and H-2 activation could increase its ethylene adsorption capacity markedly. With activating condition from heat treatment in N-2 at 300 degrees C to activation in H-2/N-2 at 100 degrees C, to activation in H-2 at 200 degrees C, and to activation in H-2 at 300 degrees C, the ethylene adsorption capacity of Pd/CNB was increased regularly. At low ethylene concentration, viz., 64 ppm, the ethylene adsorption quantities (q(a)) by Pd/CNB activated in H-2 at 200 or 300 degrees C were higher than any other adsorbents. So, activated in H-2 atmosphere at higher than 100 degrees C, Pd/CNB is particularly advantaged for adsorbing low concentration of ethylene. Amongst all the adsorbents used, Pd/CNB activated in H-2 atmosphere at 300 degrees C for 2 h has the highest ethylene adsorption capacity at lower concentration than 125 ppm. In addition, all the CNB, Pd/CNB, AC, and Pd/AC samples can be easily regenerated in airflow for more than 3 h.