Development of a Membrane Based Gas-Liquid Separator for the Space Station Water Processor 2001-01-2357

The Water Processor developed for the International Space Station includes a high temperature catalytic reactor that utilizes oxygen gas to oxidize dissolved chemicals. The effluent from the reactor is a mixture of gases (O₂, CO₂, N₂) and hot water. Since the crew has requested that drinking water does not contain any free gas at body temperature (37.8 °C or 100 °F), a phase separator operating at elevated temperatures is required downstream of the catalytic reactor.

For this application, Hamilton Sundstrand Space Systems International (HSSSI) has developed a passive Gas Liquid Separator (GLS) that relies on a positive barrier - a membrane - to extract the free gas from the inlet two-phase mixture. The membrane selected is a hollow fiber hydrophobic asymmetric membrane with pore size in the ultra-filtration range.

This paper outlines the challenges in both design and operation that were overcome during the development of this device.