Influence of devolatilized gases composition from raw coal fuel in the lab scale DCFC (direct carbon fuel cell) system

摘要

The effect of thermal decomposition gases on anodic reaction has been investigated in the DCFC (direct carbon fuel cell). To demonstrate this phenomenon, of three raw coals and the corresponding coal chars were selected. Their electrochemical reactions were evaluated by open circuit voltage, current density, and maximum power density under the same conditions. From this evaluation, higher DCFC performance was achieved with the raw coal than with the coal char due to the additional reaction of the produced gases. At the high operating temperature of this system (over 500℃), the fuels undergo pyrolysis or partial gasification to release hydrogen or hydrocarbon as additional products that may affect the electrochemical reactions at the anode. The dominant effective generated gases observed in thermog-ravimetric analysis (TGA) experiments were H_2, CH_4, CO, and CO_2. These gases provided additional electrochemical potential for this system.