Spacecraft Atmosphere Carbon Dioxide (CO<sub>2</sub>) Capture via Deposition

mechanical and fluid systems
Spacecraft Atmosphere Carbon Dioxide (CO2) Capture via Deposition (TOP2-291)
Next-generation CO2 Deposition (CDep) system
Overview
The goal of NASA is to return humans to the surface of the moon, then journey to Mars and even beyond. In order to accomplish this ambitious goal, robust life support systems are required to operate without reliance on a resupply. The current air revitalization system on the International Space Station (ISS), the Carbon Dioxide Removal Assembly (CDRA), utilizes sorbent-based, Temperature Swing Adsorption (TSA) technology. NASA Ames has developed a reliable successor to the state-of-the-art cabin atmosphere CO2 removal system. This novel patent-pending innovation takes advantages of the condensation/deposition temperature differences of air components to selectively deposit carbon dioxide from the atmosphere. CO2 deposition, or CDep, is highly reliable as it has no expendable materials, no vacuum is required, and needs minimal moving parts. CDep also potentially eliminates the need for a separate storage system to deliver pressurized, pure CO2 to an Oxygen generation system, such as the Sabatier processor currently on the ISS.

The Technology
Spacecraft Atmosphere Carbon Dioxide (CO2) Capture via Deposition is an air revitalization architecture that utilizes the different physical phase-change properties of International Space Station (ISS) cabin-like constituents (nitrogen, oxygen, carbon dioxide, water vapor, and various trace contaminants) to selectively separate constituents of interest, such as carbon dioxide and trace contaminants. As the main target constituent is CO2, which does not condense in atmospheric conditions, this architecture is referred to as CO2 deposition, or CDep. The technology addresses future CO2 removal and life support system needs using a completely different technical approach than currently employed on the ISS. Instead of using a sorbent, this technology utilizes cooling to directly freeze CO2 out of the atmosphere. Specifically, it involves forcing a phase change of CO2 from the cabin atmosphere by solidifying it onto a cold surface. The technology for spacecraft atmosphere CO2 capture uses sequential heat exchangers to cool airflow from the spacecraft atmosphere, and uses deposition coolers that can operate in a deposition mode, in which CO2 from the airflow is deposited to generate said CO2 depleted air, and a sublimation mode in which deposited CO2 is sublimated into CO2 gas. The system can alternately cycle between the deposition mode and the sublimation mode. A deposition system can also remove humidity in addition to CO2 via a multi-stage process, and can also significantly assist in controlling the trace contaminants.
Schematic of the subscale CO2 Deposition System
Benefits
  • Simpler construction and operation and also incorporates an additional method of thermal efficiency, reducing the power requirement of the overall system
  • Can be scaled up for increased throughput for any number of crew members
  • Simple startup, unaffected by any length of dormancy
  • Selectable cooling sources to optimize power efficiency for specified application
  • The cooling source and any additional cooling and/or deposition/sublimation stages that may be used, can also be similarly precisely controlled for pre-cooling and/or deposition and/or sublimation by a suitable controller(s)
  • Can measure a variety of parameters in the cooler or elsewhere in the system, such as temperature, pressure, flow rate, humidity, dewpoint, CO2 concentration, power consumption, electrical current flow, electrical voltage, and so on at different locations
  • Increased reliability and reduced need for system maintenance; including increased CO2 capture efficiency, and reduction of other air quality systems such as trace contaminant removal and humidity capture systems

Applications
  • Manned deep space exploration missions
  • Lunar base and orbiter missions
  • Scrubbers for industrial flue gas
  • Flue gas treatment industry
  • Power-plant combustion industry
  • Manufacturers of scrubbers for submarines and related systems
  • Terrestrial CO2 removal systems
  • CO2 removal system for direct air capture
Technology Details

mechanical and fluid systems
TOP2-291
ARC-18445-1
Stay up to date, follow NASA's Technology Transfer Program on:
facebook twitter linkedin youtube
Facebook Logo Twitter Logo Linkedin Logo Youtube Logo