Cell performance and efficiency of tubular molten antimony (Sb) anode direct carbon solid oxide fuel cells (DC-SOFCs) was investigated with two different biomass carbon fuels. The 8 mol.% Y2O3 stabilized ZrO2 (YSZ) supported cells with La0.6Sr0.4Co0.2Fe0.8O3-10 mol.% Gd2O3 doped CeO2 (LSCF-10GDC) as the cathode were fabricated by slurry-casting, slurry-dipping and sintering processes. A relatively high power density of 196 and 304 mW cm(-2) was achieved at 750 and 800 degrees C, respectively. Two biomass carbon, cocoanut active charcoal (CAC) and pyrolysed corn starch (PCS), were used as the fuels for cell running at 750 and 800 degrees C and the exhausted gas consist was recorded. The proceedings of anode reactions were closely related to the fuel properties and working temperature and had an obvious influence on the cell running in turn. The fuel utilization and electrical efficiency of the special molten Sb anode cell was defined and calculated by the experimental data. The fuel utilization was above 50% but the electrical efficiency was below 34%, limited by the low Nernst voltage of the reaction of Sb oxidation, thick YSZ electrolyte used and significant heat generated by Sb2O3 reduction. (C) 2015 Elsevier Ltd. All rights reserved.