Performance analysis of a polymer electrolyte fuel cell supplied with bio-hydrogen from methane or syngas reforming

• Impact of simulated bio-hydrogen fuel on the performance of hydrogen fuel cell. • Identify the reversible and irreversible impacts of individual syngas contaminants. • Establish minimum levels of contaminants in bio-hydrogen as a fuel to fuel cells. • Use of conventional and acoustic emission metrology for performance diagnostics. Hydrogen fuel cells are increasingly being used as power sources for a range of applications in the domestic, automotive, and industrial sectors and the polymer electrolyte fuel cell (PEFC) has the broadest applicability. This calls for a commensurate supply of hydrogen fuel. Promising ways to produce sustainable, low carbon hydrogen is through the reforming of biogas or gasification of biomass or waste feedstock, followed by gas conditioning and CO 2 separation. However, the produced bio-hydrogen can still contain impurities from the original gas feedstock, like methane (CH 4 ), nitrogen (N 2 ), carbon monoxide (CO), and carbon dioxide (CO 2 ) carried from the thermochemical process. In this study, a low-temperature PEFC is operated with a simulated bio-hydrogen stream consisting of pure hydrogen, doped with different volume percentages of syngas contaminants. The corresponding electrochemical cell performance is reported. Polarisations indicate CO 2 and CH 4 contamination in hydrogen results in irreversible and reversible impacts, respectively, on the cell performance. CH 4 has been identified to be more of a dilution agent, while CO 2 poisoning has resulted in a chemical reaction inside the cell. Specifically, a 6 % reduction in cell performance was observed at 0.1 vol% of CO 2 , which increases to 18 % at 5 vol% of CO 2 . Besides, when pure hydrogen conditions are restored, the PEFC performance did not recover, indicating an irreversible impact on the cell. Electrochemical impedance spectroscopy measurements and durability studies corroborate the findings from polarisation analysis. Current density cycling is performed to highlight the effect of CO 2 contamination on successive polarisation cycles. Finally, acoustic emission (AE) based hydration diagnostics are performed for the first time on PEFCs, evaluating the impact of level of CO 2 contamination on the cell performance acoustically. This niche technique has been used to assess the water content in the cell, which is influenced by the contamination conditions and vice versa .