Desulfurization activity of metal oxides blended into walnut shell based activated carbons

BACKGROUNDWalnut shell, a nutshell waste, was used to prepare activated carbons (AC) for desulfurization. Titanium ore (TO), TiO2 or Fe2O3 was blended into the resulting carbonized powders, which were extruded into cylinders and activated under CO2 atmosphere. The desulfurization activity of samples was evaluated in a fixed bed under a simulated gaseous mixture from coal combustion. RESULTSWalnut shell can be used to prepare activated carbons (AC) for desulfurization, giving an AC surface area of 401.2m(2)g(-1). When TO, TiO2 or Fe2O3 were added into the AC, the surface area of ACTO2, ACT2 and ACF2 increased to 937.1, 661.8 and 791.0m(2)g(-1). Ti and Fe in TO are changed into anatase TiO2 and Fe2O3 in ACTOx, and TiO2 and Fe2O3 exist in ACTx and ACFx, respectively. The optimum additive dosage of ACTOx, ACTx and ACFx is 2%. The breakthrough sulfur capacity of ACT2 is higher than that of ACTO2 and ACF2, but other ACTOx is better than ACTx and ACFx, indicating that TiO2 and Fe2O3 have synergistic effects in ACTOx. CONCLUSIONPore structure and metal oxides are the main factors which influence the desulfurization performance of catalysts. (c) 2013 Society of Chemical Industry