Hybrid Direct Carbon Fuel Cell (HDCFC); from Theory and Laboratory Scale to Demonstration Plant

Traditional methods of generating power from coal involve combustion, where chemical energy is converted into electrical energy through a series of energy transformations. Even using state-of-the-art techniques in coal fired power stations, overall efficiencies of less than 40% are generally accepted as best practice. Due to the nature of the combustion process, usually further pre- or post-treatment of the feeding or flue gas is required to generate a clean, sequestration-ready carbon dioxide stream. These treatments are energy intensive and use parasitic energy from the process, reducing efficiency even further.Direct carbon fuel cell (DCFC) is an innovative technology that has ability to efficiently utilise coal to produce electricity with significantly reduced environmental green-house gas emissions. The DCFC replaces this inefficient pathway through direct electrical energy generation without combustion. Instead, the same reaction employed in a coal-fired power station is broken down into its component electrochemical half reactions using a fuel cell arrangement. Thermodynamically and kinetically its efficiency is much higher than a coal fired power station; i.e., thermodynamic efficiency is 100%, while practical efficiencies are ~80% (compare to efficiency of 40% in a state-of-the-art coal-fired power station). Since carbon dioxide is directly generated as the reaction product, the flue gas has the potential to be pure and sequestration ready carbon dioxide with little to no flue gas treatment required. Hybrid direct carbon fuel cell (HDCFC), which utilises both solid oxide fuel cell (SOFC) and molten carbonate fuel cell (MCFC) technologies, has significant advantages and shown better performance among other DCFC techniques on the small scale. This presentation will cover research outcomes from our laboratory including theory and technology development towards building a 10 kW DCFC demonstration plant.