Within the closed-system environment of the International Space Station (ISS), sufficient removal of carbon dioxide (CO?) is vital for life support efforts. Ideally, the removed CO? would also serve a purpose within the station. The Air-Cooled Temperature Swing Adsorption Compressor (AC-TSAC) is one such novel system that captures CO? from the ISS cabin air using a sorbent material. The CO? is then released from the sorbent material when heated up, which also works to compress the released gas. This high-pressure CO? can then be delivered to other systems within the ISS, such as a Sabatier reactor. The release of CO? recharges the sorbent material, allowing the sorbent to begin the adsorption cycle anew. The AC-TSAC operates with two beds, operating in offset cycles such that there is uninterrupted CO? adsorption and delivery. These beds need a high degree of thermal control, first to heat up to release the CO? and pressurize, and second to cool down rapidly to restart the adsorption cycle. This swing of temperatures needs to be uniform throughout the bed to ensure optimal efficiency of the AC-TSAC sorbent bed. Typical sorbent materials, such as zeolite, have notoriously poor heat transfer characteristics, so a thermal control system must be well integrated into the bed while taking up as little size, weight, and power (SWaP) as possible. Under a NASA Phase II SBIR Program, ACT has developed and compared four potential vapor chamber designs for the AC-TSAC, improving on initial Phase I Designs and adapting the technology to operate within the AC-TSAC's adsorption/compression cycle. The design process is discussed in depth, alongside modeling results describing the temperature profile of the AC-TSAC sorbent bed. The vapor chamber designs were compared based on achieving better temperature uniformity in the sorbent bed, higher average temperatures, and manufacturability.
Seber et al. (Sun,) studied this question.