Concept Development and Design of a Multi-fuel SOFC System using Ammonia and Natural Gas

Within the Fraunhofer wide flagship project "Ammonvektor" the Fraunhofer IKTS develops a 1kWel system near multi-fuel-NH3-H2-CH4 testing platform for stationary industrial and communal energy supply applications. The demonstrator will be able to use ammonia or hydrogen for highly efficient, CO2-free combined heat and power supply. It can also utilize the well-established energy carrier CH4 for purposes of gradually shifting from fossil fuels to renewable fuels, giving the flexibility to switch between the two fuels based on current needs. While system development and demonstrator setup is progressing, several pretests for ammonia have been carried out at stack and hotbox level, including the testing of full load 1kWel SOFC stack hotbox with varying stack internal ammonia cracking rates. The test results showed that the stack operation is stable and efficient with ammonia at elevated operation temperatures (830 °C). The results provide valuable data for the development of the system near multi-fuel demonstrator.

This work reports simulation results alongside experimental validation that underpin the demonstrator development and discusses their implications. A central focus is the simulation and design of the thermally coupled afterburner–cracker–reformer unit. Also, the current system-level demonstrator design will be outlined, with implementation and commissioning planned for the second half of 2026.