What question did this study set out to answer?

To evaluate the effectiveness of the Liquid Amines Carbon dioxide Removal (LACR) system for CO2 scrubbing in spacecraft environments.

May 9, 2026Open Access

A Capillary Fluidic CO2 Scrubber for Spacecraft: the Liquid Amine Carbon Dioxide Removal Assembly

Key Points

To evaluate the effectiveness of the Liquid Amines Carbon dioxide Removal (LACR) system for CO2 scrubbing in spacecraft environments.
Demonstrated the LACR system via ground tests focusing on its closed loop operation.
Utilized thin capillary film technology to absorb CO2 and regenerate sorbents.
Compared performance metrics against current solid sorbent systems.
The LACR system achieved over 2x reductions in size, mass, and power consumption compared to existing technologies.
The system efficiently absorbed and regenerated CO2 from cabin air using low maintenance and power.
Quantitative performance metrics were collected and analyzed during operational tests.

Abstract

Reliable air revitalization systems are in the critical path of the human exploration of space. The current state of the art regenerable solid sorbent CO2 removal systems have provided decades of service in low-earth orbit. However, certain novel technologies are rapidly developing that purport attractive and essential features for deep space missions: i.e., quiet, reliable, and continuous operation with lower-power, lower-volume, and lower-maintenance expectations. The recently successful ISS flight demonstration of the Capisorb Visible System (CVS) has increased awareness and confidence in the potential application of massively parallelized open-channel capillary fluidic devices and surfaces to perform the largely passive wet CO2 scrubbing air revitalization function. Such approaches have been exploited aboard submarines employing 'falling films' for decades with high-affinity amine liquid sorbents (MEA, DGA, etc.), a feat that could be replicated in re-formatted fashion in the microgravity environment of orbiting or coast spacecraft. The Liquid Amines Carbon dioxide Removal (LACR) system is a simple closed loop cycle with a flow-through 'thin capillary film' contactor that reacts with and absorbs CO2 directly from the cabin air. The sorbent is then drawn into a second capillary fluidic device where vacuum pressures and elevated temperatures reverse the reaction and degas the liquid, venting, re-routing, or storing the CO2 for subsequent processing. A single pump returns the regenerated sorbent to the contactor for continuous cabin air conditioning. The key components of the LACR system include a Porous-sheet Contactor (absorber), Capillary Conduit Degasser and Separator (desorber), and Capillary Condensing Heat eXchanger (CCHX). The design and function of these devices are reported along with quantitative performance characteristics of loop operation collected during ground tests. Scale-up of the system for a crew of four suggests significant (>2x) reductions in system size, mass, power, and consumables over the current state of the art.

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