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

BACKGROUND Walnut shell, a nutshell waste, was used to prepare activated carbons ( AC ) for desulfurization. Titanium ore ( TO ), TiO 2 or Fe 2 O 3 was blended into the resulting carbonized powders, which were extruded into cylinders and activated under CO 2 atmosphere. The desulfurization activity of samples was evaluated in a fixed bed under a simulated gaseous mixture from coal combustion. RESULTS Walnut shell can be used to prepare activated carbons ( AC ) for desulfurization, giving an AC surface area of 401.2 m 2  g −1 . When TO , TiO 2 or Fe 2 O 3 were added into the AC , the surface area of ACTO2 , ACT2 and ACF2 increased to 937.1, 661.8 and 791.0 m 2  g −1 . Ti and Fe in TO are changed into anatase TiO 2 and Fe 2 O 3 in ACTO x , and TiO 2 and Fe 2 O 3 exist in ACT x and ACF x , respectively. The optimum additive dosage of ACTO x , ACT x and ACF x is 2%. The breakthrough sulfur capacity of ACT2 is higher than that of ACTO2 and ACF2, but other ACTO x is better than ACT x and ACF x , indicating that TiO 2 and Fe 2 O 3 have synergistic effects in ACTO x . CONCLUSION Pore structure and metal oxides are the main factors which influence the desulfurization performance of catalysts. © 2013 Society of Chemical Industry