Performance of a palladium membrane reactor using an Ni catalyst for fusion fuel impurities processing

The palladium membrane reactor (PMR) provides a means to recover hydrogen isotopes from impurities expected to be present in fusion reactor exhaust. This recovery is based on reactions such as water-gas shift and steam reforming for which conversion is equilibrium limited. By including a selectively permeable membrane such as PdAg in the catalyst bed, hydrogen isotopes can be removed from the reacting environment, thus promoting the reaction to complete conversion. Such a device has been built and operated at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory. ork was performed as part of the Annex IV collaboration between the US Department of Energy-TSTA and the Japan Atomic Energy Research Institute-Tritium Processing Laboratory. For the reactions listed above, earlier study with this unit has shown that hydrogen single-pass recoveries approaching 100% can be achieved. It was also determined that a nickel catalyst is a feasible choice for use with a PMR appropriate for fusion fuel impurities processing. The purpose of this study was to assess systematically the performance of the PMR using a nickel catalyst over a range of temperatures, feed compositions and flow rates. Reactions which were studied are the water-gas shift reaction and steam reforming.