Integrating a Pd-Ag membrane for hydrogen purification and recirculation in a direct ammonia fueled SOFC-PEMFC system

This study introduces a novel hybrid system combining direct ammonia-fueled SOFC and PEMFC, incorporating a Pd-Ag membrane for efficient H2 purification and recirculation at the PEMFC anode. The membrane effectively separates H2 and N2 with low energy consumption compared to conventional methods, ensuring a steady H2 supply to the PEMFC. The N2 byproduct also offers supplementary revenue potential. A thermodynamic model based on experimental data is developed for the Pd-Ag membrane, and multi-objective optimization is employed to enhance both system efficiency and economic performance. Results show that with H2 recirculation, the system achieves an electrical efficiency of 67.2%, representing a 4.65% improvement over conventional SOFCPEMFC setups. Economic analysis estimates an additional annual profit of $309,000 from N2 recovery, with a payback period of 2.55 years. This research contributes to advancing ammonia-fueled system by introducing a highly efficient and economically viable solution for power generation systems.