Plasma Abatement of Volatile Organic Compounds in Nitrogen and Carbon Dioxide Background Gases

Date

2024-07-21

Journal Title

Journal ISSN

Volume Title

Publisher

2024 International Conference on Environmnetal Systems

Abstract

Thermal conversion of crew waste to gases that can be vented from spacecraft for mass reduction has been investigated by NASA and others within the Trash-to-Gas program. One concern with operating thermal waste processors onboard spacecraft is the potential for contamination of cabin atmosphere with volatile organic compounds (VOCs) from gaseous reactor effluent. Recent efforts at Kennedy Space Center's Applied Chemistry Laboratory have developed and reported on a recirculating plasma gas system for the rapid reduction of VOCs. In this case, a direct-current thermal plasma was used to break down VOCs into simpler, and preferably more benign chemical species. Previous work reported the application of this system on gases with carbon dioxide as the background. Here the authors report the results of plasma VOC abatement with an improved recirculation system. The VOCs studied included a set in a nitrogen background (benzene, pentane, ethanol, and Freon 113) and a set in a carbon dioxide background (benzene, pentane, ethanol, and acetone). Each of these analyte species is included in NASA's Spacecraft Maximum Allowable Concentrations list. The plasma abatement system showed a greater than 99.999% reduction in VOC concentrations within 2 minutes of plasma treatment for the nitrogen background, and greater than 95% VOC reduction within 2 minutes for the carbon dioxide background. This is a significant improvement over what was reported previously. All analytes obeyed first-order rate kinetics in agreement with the previous work.

Description

Joel Olson, Bennett Aerospace, Inc., USA
Shayla Peak, Engineering Research and Consulting, Inc., USA
Ryan Gott, NASA Kennedy Space Center (KSC), USA
Maria Elizarraga, NASA Kennedy Space Center (KSC), USA
Kenneth Engeling, National Aeronautics and Space Administration (NASA), USA
Ray Pitts, NASA Kennedy Space Center (KSC), USA
ICES304: Physico-Chemical Life Support- Waste Management Systems- Technology and Process Development
The 53rd International Conference on Environmental Systems was held in Louisville, Kentucky, USA, on 21 July 2024 through 25 July 2024.

Keywords

Plasma, Volatile Organic Compounds, benzene, pentane, ethanol, acetone, Freon, abatement

Citation