Experimental Study of an SOFC Stack Operated With Autothermally Reformed Diesel Fuel

Abstract

A 500 W SOFC stack provided by Topsoe Fuel Cells A/S was run with reformed diesel fuel for 1,200 h. Diesel fuel used was Swedish Environmental Class 1 containing <10 ppm of sulfur. The fuel was reformed with an autothermal reformer (ATR). The reformer consisted of a mixing chamber and a reactor chamber containing a noble metal catalyst provided by SüdChemie. The reformer used the diesel fuel without any pre‐treatment such as sulfur adsorbent. The reformer unit was able to achieve high conversion of reactants with only ppm levels of higher hydrocarbons at the reformer outlet. Particulate emissions of the reformer were measured to be 30 μg m–3, a very low value even below daily exposure limits in ambient air set by the European Comission directives. The stack was first run with 3% humidified H2 + N2 fuel to obtain baseline performance and then switched to reformate. Diesel reformate was found not to induce significantly more long‐term degradation on the stack compared to hydrogen case. However, an initial degradation of about 20 mV cell–1 was observed during the first 150 h on diesel fuel reformate. This could be an indication of a poisoning mechanism taking place, but needs further research to be verified.

Strategies for Carbon and Sulfur Tolerant Solid Oxide Fuel Cell Materials, Incorporating Lessons from Heterogeneous Catalysis

“…As discussed above, some of these levels of sulfur may be too high for Ni/YSZ anodes, although there are examples of SOFC stacks being run on reformed ULSD without desulfurisation. A Topsøe SOFC stack was run on steam reformed ULSD (<10 ppm of S) for 1200 h. 113 After an initial 150 h period of rapid degradation, there was only 0.2%/1000 h voltage degradation over the rest of the test. Delphi tested a 5-cell stack with simulated reformate containing 2.5 ppm sulfur and also found a rapid initial degradation followed by stable performance, 114 indicating that SOFCs may be able to operate stably with ULSD reformate without desulfurisation, albeit with a performance drop caused by sulfur poisoning.…”

“…As discussed above, some of these levels of sulfur may be too high for Ni/YSZ anodes, although there are examples of SOFC stacks being run on reformed ULSD without desulfurisation. A Topsøe SOFC stack was run on steam reformed ULSD (<10 ppm of S) for 1200 h . After an initial 150 h period of rapid degradation, there was only 0.2%/1000 h voltage degradation over the rest of the test.…”

Brennstoffzellensysteme in der Luftfahrt

“…Nach [33] können bei der Herstellung auch Porenbildner verwendet werden, um die Porosität der Diffusionsschicht und der Elektrode gezielt einzustellen. Durch die größere Porosität lassen sich die Konzentrationsüberspannungen bei großen Stromdichten verringern [33].…”

“…Aufgrund der Konzentrationsabhängigkeit der elektrochemischen Reaktionen ändert sich die lokale Stromdichte entlang des Kanals; sie nimmt ab.Von Kulikovsky[32,33] wurde die lokale Stromdichte entlang eines Kathodenkanals beschrieben (Abb. Bei offener Zellspannung entspricht der Verlust einem Stromdichteäquivalent von etwa 5 mA cm − 2 [55].…”

A Compact, Self-Sustaining Fuel Cell Auxiliary Power Unit Operated on Diesel Fuel

“…Rautanen et al operated a 0.5 kW e SOFC stack in a furnace with diesel reformate from ATR during inline testing. Following an initial phase of degradation, the stack displayed stable electrochemical performance [19]. The combination of the diesel ATR and metal-based SOFC technology is also being developed at the Korea Advanced Institute of Science and Technology (KAIST) with the aim of implementing it in truck APUs [20].…”