Degradation-considered techno-economic analysis of ammonia solid oxide fuel cell recirculation system using electrochemical hydrogen compressor

The transition to renewable energy necessitates alternative fuels like green ammonia, which offers advantages in storage and transport over hydrogen. A solid oxide fuel cell (SOFC), particularly suited for ammonia due to its high operating temperature, exists in various configurations, including hybrid, cascade, and recirculation systems. However, increasing efficiency often leads to greater system complexity, requiring both energy and economic evaluations. Anode off-gas recirculation in SOFC systems typically relies on blowers or ejectors, but proton exchange membrane electrochemical hydrogen compressors (PEM-EHCs) provide potential benefits in control and hydrogen separation. This study investigates an ammonia-fed SOFC recirculation system utilizing PEM-EHCs, assessing electrical efficiency and cost. Experimental data from ammonia SOFC stacks and PEM-EHCs validate numerical models, which subsequently evaluate system performance and calculate the levelized cost of electricity (LCOE). Additionally, SOFC stack degradation scenarios undergo examination, exploring the reuse of end-of-life proton exchange membrane fuel cells (PEMFCs) as PEM-EHCs. The results indicate that PEM-EHCs serve as efficient alternatives to conventional blowers in ammonia-fed SOFC recirculation systems, enhancing both efficiency and cost-effectiveness. Furthermore, strategies for system operation under stack degradation present new research opportunities in advancing ammonia-fed SOFC technology.