Abstract
Keywords
Fuel Cells, Poisoning, Impurities, Clean Energy, Alternative Fuel
Abstract
This paper covers our investigation into a decline in fuel cell performance resulting from hydrogen fuel containing impurities. The results of the investigation are summarized as follows:
1) Impurities that are estimated to be mixed in hydrogen fuel have been investigated. Specifically, clarification has been provided of the fuel gas composition and concentration of the fuel finally supplied to the fuel cell when the methanol reforming method, gasoline reforming method, or low purity hydrogen is utilized as the fuel storage supply method.
2) The existence of CO, formaldehyde, formic acid, hydrogen sulfide, sulfur dioxide and benzene poisonings have been pointed out, and their extents were evaluated and compared. The tolerable mixing concentration has been also investigated.
3) It has been shown that hydrogen sulfide and sulfur dioxide poisonings had peculiar properties.
Specifically, it has been made transparent that their poisoning effects were extremely strong, and the development of poisoning is slow compared with that of CO poisoning; further, their poisonings were not reversible.
4) The Pt-Ru type catalytic-electrode is widely expected to be utilized as a countermeasure for the CO poisoning. However, unexpectedly, it has been pointed out that a decline in electricity generation occurs when the Pt-Ru type catalytic-electrode is utilized for poisoning of formaldehyde, formic acid, hydrogen sulfide, sulfur dioxide and benzene, as compared with when the Pt type is utilized.
5) It has been confirmed that no poisoning behavior was found for methane.