Cycle Testing of AgZ-PAN and HZ-PAN

Idaho National Laboratory (INL) has been conducting, as part of the off-Gas Sigma Team, producing and testing sorbents for the selective capture of xenon and krypton from surrogate nuclear fuel recycling off-gas streams. AgZ-PAN and HZ-PAN, both developed and produced at INL, have shown promising results for the selective capture and separation of xenon and krypton, respectively. Previous testing of both sorbents has focused on saturation and initial breakthrough capacities across a variety of operating conditions. However, the sorbents can only be truly viable for use in a process if they have sufficient longevity through multiple adsorption/desorption cycles. This research, therefore, focused on putting both sorbents through as many thermal swing adsorption/desorption cycles as possible over the course of one year. The primary focus of cycling tests was on AgZ-PAN, which previously demonstrated possible loss of capacity after multiple cycles. While capacity was shown to be recoverable over the short term, the goal is to ensure effective long-term viability so it was placed through 100 cycles, the estimated equivalent of one year of operation. HZ-PAN had not shown any deleterious effects from cycling during previous testing. Additionally, due to the colder temperatures required for Kr capture, each cycle required considerably more time to complete, so this sorbent was subjected to 50 cycles. Both sorbents maintained their capacities throughout the series, indicating promising potential for long-term reliability.