Fast Startup, Fuel Flexible CPOX System for SOFC

A compact and portable SOFC, 1-3 kW, is an excellent choice to convert a hydrocarbon fuel source to electricity due to its high efficiency. Currently, SOFCs are optimized to run a single fuel source, and a fuel flexible reforming technique that can integrate with SOFC is needed to have the potential to utilize all different energy assets, including propane, methane, and biogas. Catalytic partial oxidation (CPOX) is particularly suitable for the fuel reforming need of a small SOFC because it eliminates heat-exchange at high temperature and offers a rapid startup for dynamic performance. The key to be a fuel flexible CPOX reformer is its ability to quickly and smoothly switch from one fuel to another, especially from high energy dense propane to low energy dense biogas with low methane concentration. Therefore, a compact CPOX assembly, and the ability to clean up biogas to make it usable, are critical factors technically and economically. Both Precision Combustion Inc. (PCI) and our academic partner have extensive experience and track records on catalysis, reforming, clean fuels, and biogas cleanup, for SOFC applications. We propose a CPOX design with PCI’s proprietary Microlith supported catalyst that will enable the CPOX to be fuel flexible and to integrate with SOFC. PCI has been developing CPOX over a dozen years, initially with liquid fuels, such as jet fuel and diesel, and recently expanding to propane. These CPOX designs are based on our short contact time, high surface area catalytic support on Microlith catalyst, patented and manufactured by PCI, which can reform fuels to syngas in millisecond timeframes. No water or steam is needed for the fuel reformation yet coking is avoided. The metallic Microlith support allows great thermal transfer and exceptionally good mixing with minimum pressure drop, which ensure short startup time and dynamic response. With these benefits of the Microlith reactor design, a compact CPOX reforming design will be achieved. It will run at lower reaction temperature than alternative CPOX catalysts, which will make integration with SOFC easy at improved efficiency. All these factors make our Microlith CPOX advantageous over other CPOX alternatives on fuel flexibility and integration with SOFC. Data from our recent compact propane CPOX design show it meets all Phase I requirements when operating on propane. A similar CPOX design as the propane one will be used to test methane and biogas to check the startup time, performance stability, cycle ability, volume and weight per kW, as well as compliance to MIL-SPEC-810 vibration levels. We expect our design will meet or exceed Phase I requirements with no or little modification.