Fusion Science and Technology / Volume 54 / Number 2 / August 2008 / Pages 607-610
Technical Paper / Process Applications
Pilot scale (0.5 kg) SAES St 909 methane cracking tests were conducted for potential tritium process applications. Up to 1400 hours tests were done at 700°C, 202.7 kPa (1520 torr) with a 0.03 sLPM feed of methane plus impurities, in a 20 vol% hydrogen, balance helium, stream. Carbon dioxide gettered by St 909 can be equated to an equivalent amount of methane gettered, but equating nitrogen to an equivalent amount of methane was nitrogen feed composition dependent. A decreased hydrogen feed increased methane getter rates while a 30°C drop in one furnace zone increased methane emissions by over a factor of 30. The impact of gettered nitrogen can be somewhat minimized if nitrogen feed to the bed has been stopped and sufficient time given to recover the methane cracking rate.