Contact resistances between Crofer 22 APU and Crofer 22 H interconnect plates, Ni mesh and Ni-8YSZ anode interfaces were measured under an anode gas atmosphere (97%H 2 + 3%H 2 O) at 700 °C and 800 °C and current densities of 0 and 0.7 A/cm 2 for durations up to 3000 hours using the 4-point DC conductivity technique. Phase transformations within the steel samples close to the interface due to inter-diffusion of elements (Ni, Fe, Mn and Cr) were observed and analyzed. These phase transformations and the formation of oxide scales on steel as well as nickel mesh surface and grain boundaries do not seem to substantially affect the measured contact resistance with time.

In this work a methanol steam reforming (MSR) reactor has been operated thermally coupled to a high temperature polymer electrolyte fuel cell stack (HT-PEMFC) utilizing its waste heat. The operating temperature of the coupled system was 180 °C which is significantly lower than the conventional operating temperature of the MSR process which is around 250 °C. A newly designed heat exchanger reformer has been developed by VTT (Technical Research Center of Finland LTD) and was equipped with commercially available CuO/ZnO/Al 2 O 3 (BASF RP-60) catalyst. The liquid cooled, 165 cm², 12-cell stack used for the measurements was supplied by Serenergy A/S. The off-heat from the electrochemical fuel cell reaction was transferred to the reforming reactor using triethylene glycol (TEG) as heat transfer fluid. The system was operated up to 0.4 A cm-2 generating an electrical power output of 427 W el. A total stack waste heat utilization of 86.4 % was achieved. It has been shown that it is possible to transfer sufficient heat from the fuel cell stack to the liquid circuit in order to provide the needed amount for vaporizing and reforming of the methanol-water-mixture. Furthermore a set of recommendations is given for future system design considerations.

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