Demonstration of a Closed-Loop CO2 Removal System for Deep-Space ECLSS



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2020 International Conference on Environmental Systems


In current International Space Station (ISS) and other low orbit missions, the metabolically generated CO2 is removed from the cabin air via adsorption and vented into space, resulting in a net loss of O2. However, a closed-loop cabin Atmosphere Revitalization System (ARS) is crucial to NASA’s mission architectures for future long duration human space exploration to the Moon and Mars and other deep space missions.

TDA Research, Inc. (TDA) is developing a highly efficient CO2 removal system for closed-loop space craft cabin air re-vitalization during deep space missions. The key to TDA’s system is a strontium exchanged silico-alumino-phosphate (Sr-SAPO-34) zeolite that selectively adsorbs CO2 from cabin air; the sorbent is then regenerated under temperature swing (120°C) to deliver high-pressure gas (~15 psia) in closed-loop operation. This sorbent can be regenerated at a much lower temperature than the 5A zeolite (currently used in ISS), which provides significant energy savings. TDA’s system uses a valve-less design, eliminating the sorbent attrition problems that have plagued traditional fixed bed sorbent systems. The system delivers a continuous flow of CO2, allowing uninterrupted steady-state operation of the downstream processes that produce propellants and/or life support consumables; this greatly reduces the overall system size and complexity.

Previously, we have successfully demonstrated that the Sr-exchanged SAPO-34 sorbent can effectively remove CO2 from spacecraft cabin atmosphere and that the sorbent maintains its working capacity over 200 cycles in fixed bed tests, elevating the TRL to 3. In a current STTR Phase II project, we scaled up the sorbent production and are now integrating the sorbent into a valve-less sorbent system. Test results from the demonstration of the Sr-SAPO-34 in a closed loop CO2 removal system (which will elevate the TRL to 5) will be presented at the meeting.


Ambalavanan Jayaraman, TDA Research, Inc., US
Margarita Dubovik, TDA Research, Inc., US
Matthew Cates, TDA Research, Inc., US
Nathan Roszel, TDA Research, Inc., US
Christopher Marotta, TDA Research, Inc., US
Arturo Hernandez-Maldonado, University of Puerto Rico at Mayaguez, PR
ICES302: Physio-chemical Life Support- Air Revitalization Systems -Technology and Process Development
The proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.


Air revitalization, CO2 removal system, closed-loop