Fusion Science and Technology / Volume 56 / Number 1 / July 2009 / Pages 173-178
Tritium, Safety, and Environment / Eighteenth Topical Meeting on the Technology of Fusion Energy (Part 1)
For the purpose of developing a cryogenic pressure swing adsorption (PSA) system, we have been studying the breakthrough behavior of hydrogen isotopes with synthetic zeolite packed-beds under conditions specified for designing a PSA process. Previously, we have reported that overshooting breakthrough curves of tracer D2 in H2 were obtained from experiments of exchange-adsorption carried out after replenishing a packed-bed column with H2 from its outlet, following evacuation for a given period. The overshooting behavior is considered due to the enrichment of the heavier component D2 not only in the adsorption process but also in the evacuation process. In the next work, we have examined the effects of priming flow rates and evacuation periods on the overshooting behavior, using synthetic zeolites 5A and 13X packed-bed columns. In this paper, it is reported that the overshooting profile depends on the conditions of evacuation but not sensitively on the mass flow rates in replenishing process. The overshooting is advantageous for the adsorption process, because of improvement of the breakthrough time. Since the replenishing period is shortened proportionally to the priming flow late, the insensitive dependence of the overshooting on the priming flow rate is favorable to the PSA process, resulting in saving the time for replenishing process.