Full-scale Development of Novel Vapor Chambers for Heating and Cooling of Carbon Dioxide Adsorbent System

The Four-Bed Carbon Dioxide Scrubber (4BCO₂) is a next-generation CO₂ removal system developed to improve upon the legacy Carbon Dioxide Removal Assembly (CDRA) by efficiently removing carbon dioxide from the spacecraft cabin atmosphere. Unlike the CDRA, which vents the captured CO₂ as waste, the 4BCO₂ delivers a concentrated CO₂ stream suitable for downstream utilization. One key application is oxygen recovery via the Sabatier reactor, which converts CO₂ and hydrogen into water and methane. In earlier life support architectures, this CO₂ stream required a separate mechanical compressor to achieve the pressure levels necessary for Sabatier operation. To reduce system complexity, power consumption, and mass, the newly developed Air-Cooled Temperature Swing Adsorption Compressor (AC-TSAC) was introduced as a replacement for the mechanical compressor. The AC-TSAC combines adsorption-based CO₂ compression with integrated thermal swing regeneration to produce a pressurized CO₂ output, suitable for direct use in onboard processing systems. A critical challenge in the 4BCO₂ system is the efficient regeneration of zeolite sorbent beds, which must be heated from ambient (~20 °C) to over 220 °C despite the material’s low thermal conductivity (~0.13 W/m·K). To overcome this limitation, the sorbent beds have been redesigned to incorporate concentric vapor chambers—passive, two-phase thermal transport devices with high effective thermal conductivity and near-isothermal performance. This work presents the design, optimization, and fabrication of vapor chamber- integrated 4BCO₂ beds, including wick design, thermal modeling, and additive manufacturing approaches.