Highly Efficient Closed-Loop CO2 Removal System for Deep-Space ECLSS

Abstract

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 was previously developed at the University of Puerto Rico-Mayaguez (UPRM) under a NASA funded project (NNX08BA48A) for space craft cabin atmosphere revitalization, which also resulted in a U.S. patent US 9,623,364 B1. The Sr-SAPO-34 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 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.

We have successfully demonstrated that the Sr-exchanged SAPO-34 sorbent can effectively remove CO2 from spacecraft cabin atmosphere and 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 are scaling up the sorbent production and developing the valve-less sorbent system. The results from the STTR project will be presented at the meeting.

Description

Ambalavanan Jayaraman, TDA Research, Inc., USA
Margarita Dubovik, TDA Research, Inc., USA
Sarah Devoss, TDA Research, Inc., USA
Arturo Hernandez-Maldonado, University of Puerto Rico - Mayaguez (UPRM), Puerto Rico
Bethzaely Fernandez-Reyes, University of Puerto Rico - Mayaguez (UPRM), Puerto Rico
Silvana Urcia-Romero, University of Puerto Rico - Mayaguez (UPRM), Puerto Rico
Paola A. Baldaguez-Medina, University of Puerto Rico - Mayaguez (UPRM), Puerto Rico
Carlos E. Galiano-Haddock, University of Puerto Rico - Mayaguez (UPRM), Puerto Rico
ICES302: Physio-chemical Life Support - Air Revitalization Systems - Technology and Process Development
The 49th International Conference on Environmental Systems was held in Boston, Massachusetts, USA on 07 July 2019 through 11 July 2019.

Keywords

Cabin air revitalization, Closed loop, Deep space missions

Citation