Effects of discharge mode and fuel treating temperature on the fuel utilization of direct carbon solid oxide fuel cell

Direct carbon solid oxide fuel cells (DC-SOFCs) with the novel perovskite La _0.3 Sr _0.7 Fe _0.7 Ti _0.3 O _3–δ (LSFT) electrodes are evaluated by using biochar derived from some one-time toothpicks made of wood as fuel in different discharging modes. The constant current (CC) mode and constant resistance (CR) mode are compared with same fuel cell configuration and fuel loading. The results show that the fuel discharged in CR mode possesses larger fuel utilization (39.7%) than that in CC mode (34.5%). The biochar fuels obtained from the wood pyrolysis in Ar atmosphere for 1 h at 400 °C, 500 °C, 600 °C and 700 °C present the efficiencies of fuel utilization are 26.3%, 34.1%, 38.6% and 39.6%, respectively. A special discharging mode is employed in this paper for DC-SOFC to test cell performance and improve fuel utilization simultaneously as well.