University of Wisconsin-Madison (UW-Madison)

The University of Wisconsin - Madison will develop components for a hybrid distributed energy generation system that couples a pressurized solid oxide fuel cell (SOFC) with a premixed compression ignition (PCI) engine system. In the resulting system, gases that leave the fuel cell, which consumes about 75% of the fuel, are directed into the engine to be ignited by compression of the pistons. To achieve a targeted 70% electric efficiency, the SOFC system must operate near 75% fuel utilization. When operating at this high level of fuel utilization, however, the flame speed of the leftover fuel in the cell’s “tailgas” is too low to be used effectively in a conventional spark-ignited engine. The team will address this challenge by using a novel, PCI engine concept that adds an extra burst of spark-ignited natural gas, improving engine efficiency. The system will be analyzed in conjunction with a next generation, intermediate temperature (600°C to 800°C), metal-supported SOFC, but the final engine system will be designed to be suitable with any pressurized, intermediate temperature SOFC. With this universal capability, the final product will be an engine system that can “plug into” any intermediate temperature SOFC system. The team's design targets larger industrial applications, aiming for systems as large as 1MW.