Cascade Distillation System – A water recovery system for deep space missions



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44th International Conference on Environmental Systems


Honeywell Aerospace has developed a distillation technology to process wastewater streams in microgravity environments for recovering potable water. The wastewater processing Cascade Distillation System (CDS) utilizes an innovative and proven multi-stage thermodynamic process to produce purified water. The Cascade Distiller (CD) is the core component of the CDS technology. The CD is a Centrifugal Vacuum Distiller (CVD) that processes wastewater as a feed source and purifies it to near potable water. Some volatile substances escape to the purified water. With minimum post processing, the water can be restored as potable for human consumption. The CD was tested at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) with a greater than 90% recovery rate during a technology comparison test. The results were compared with two other technologies. All three systems were challenged with two pretreated test solutions, each intended to represent a feasible wastewater generated in a deep space environment. An expert panel assembled by NASA down-selected the CDS as one of the technologies for further development. NASA internally developed the Vapor Compression Distiller (VCD) technology, which has reached Technology Readiness Level (TRL) 9. The VCD has paved the way for future development of wastewater recovery technologies by identifying critical requirements. However, the VCD has limited distillation capacity when compared to the CD. Currently, Honeywell Aerospace has an Indefinite Delivery, Indefinite Quantity (IDIQ) contract with NASA for further development of the CD.


Tucson, Arizona
The 44th International Conference on Environmental Systems was held in Tuscon, Arizona, USA on 13 July 2014 through 17 July 2014.
Vipul Patel, Honeywell International, USA
Henry Au, Honeywell International, USA
Sarah Shull, NASA Johnson Space Center, USA
Miriam J. Sargusingh, NASA Johnson Space Center, USA
Michael Callahan, NASA Johnson Space Center, USA