Development Status of a Low-Power CO2 Removal and Compression System for Closed-Loop Air Revitalization 2008-01-2095

The “low power-CO₂ removal (LPCOR) system” is an advanced air revitalization system that is under development at NASA Ames Research Center. The LPCOR utilizes the fundamental design features of the ‘four bed molecular sieve’ (4BMS) CO₂ removal technology of the International Space Station (ISS). LPCOR improves power efficiency by replacing the desiccant beds of the 4BMS with a membrane dryer and a state-of-the-art, structured adsorbent device that collectively require 25% of the thermal energy required by the 4BMS desiccant beds for regeneration. Compared to the 4BMS technology, it has the added functionality to deliver pure, compressed CO₂ for oxygen recovery. The CO₂ removal and recovery functions are performed in a two-stage adsorption compressor. CO₂ is removed from the cabin air and partially compressed in the first stage. The second stage performs further compression and delivers the compressed CO₂ to a reduction unit such as a Sabatier reactor for oxygen recovery. This paper describes the development status of the LPCOR system, including the breadboard experiments to determine the performance parameters of the full-scale LPCOR drying components for an optimized process. Development and validation of the laboratory test platform for LPCOR, the cabin air simulator (CAS), to generate air at simulated temperature, humidity, and ventilation rates of a space cabin is also discussed.