Work

Demonstration of an Electrochemically-Driven Multi-Cell Stack Using Shorted Anion Exchange Membranes for Spacecraft Cabin Air Revitalization

Year: 2023

Type: conference-paper

Abstract: Cabin CO2 removal remains a major obstacle for long-duration, manned deep space missions. The incumbent CO2 removal technology for spacecraft air revitalization-Carbon Dioxide Removal Assembly (CDRA)-requires frequent and costly maintenance. Numerous potential substitutes are being considered, including solid and liquid sorbents as well as cryogenics. This work proposes an alternative CO2 removal technology harnessing the alkaline environment surrounding an anion exchange membrane to separate CO2 from air. The electrochemically-driven CO2 separator (EDCS) is a low-cost, compact device that has been experimentally demonstrated to continuously and effectively separate CO2 at various concentrations (400-5000 ppm) and moderate temperatures using only a small hydrogen stream to power separation. The only products from the EDCS are a CO2-depleted air stream and a CO2-concentrated stream contaminated with unreacted hydrogen and pure water. This paper reports the design and first demonstration of the multi-cell EDCS stack prototype using carbon-composite, or �shorted,� anion exchange membranes. A 100 cm2, 2-cell EDCS stack has been demonstrated successfully at more demanding conditions than required in spacecraft air revitalization. At ambient conditions (420 ppm, 30 oC), the 2-cell EDCS stack has been shown to capture 80% of incoming CO2 while consuming less than 1.8 H2 per CO2 (mol/mol). Furthermore, based on single-cell work at relevant conditions for spacecraft air revitalization, a 100 cm2, 136-cell stack (3. L, 13.6 kg) would be sufficient to remove CO2 for a six-person crew (6.24 kg/day) operating at a temperature of 40 oC; for comparison, an EDCS of this size would be less than 10% the volume and less than 20% of the mass of the desiccant/adsorbent beds of the CDRA on the International Space Station.

Source: International Conference on Environmental Systems (ICES)

DOI: 10.32865/2346/94717

Authors: Marco Colin Martinez, Stephanie Matz, Brian Setzler, Yushan Yan

Institution: University of Delaware

Language: English

Topic: Carbon Dioxide Capture Technologies

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Climate action, Responsible consumption and production

Open Access status: bronze

Funders: U.S. Department of Energy, Advanced Research Projects Agency - Energy, Advanced Research Projects Agency