Implementation of Advanced Sorbents in a Pressure-Swing Carbon Dioxide Removal System

Date

2020-07-31

Journal Title

Journal ISSN

Volume Title

Publisher

2020 International Conference on Environmental Systems

Abstract

As the future ambitions of NASA have turned towards deep space missions, a search for an alternative to current carbon dioxide (CO2) removal systems, namely the Carbon Dioxide Removal Assembly (CDRA) on ISS, is underway. One promising area of research is the use of Metal Organic Frameworks (MOFs) to selectively capture CO2 due to the occurrence of open Lewis acidic coordination sites where CO2 can bind. Under contract with NASA/MSFC, an undergraduate-led team at Iowa State University synthesized and characterized samples of the magnesium-based MOF, Mg-MOF-74, and functionalized two different amine groups onto the base structure to study the adsorption potential of the MOF with the aforementioned modifications. Because of the low binding energy of the coordination sites, the MOFs could be quickly and easily saturated then purged of CO2. By incorporating MOF-packed beds into a vacuum pressure-swing system, the group studied the results of long-term CO2 exposure and pressure cycling. Cabin-feed air at 2650 ppm CO2 was flowed through the system and monitored until saturation occurred, at which point the packed beds were exposed to vacuum and desorbed, then purged using N2. Results showed an approximate 10% increase in weight when saturated, with the potential to mitigate several issues experienced by CDRA and for significant energy savings.

Description

Nevin Smalls, Iowa State University, USA
Bradley Willimack, Iowa State University, USA
Thomas Krohn, Iowa State University, USA
Tho Bui, Iowa State University, USA
Zachary Alston, Iowa State University, USA
James Alleman, University of Notre Dame, USA
Igor Slowing, Iowa State University, USA
Thomas Paskach, Iowa State University, USA
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.

Keywords

MOF's, CO2, life support systems

Citation