Development Testing of High-Pressure Cathode Feed Water Electrolysis Cell Stacks for Microgravity Environments

Abstract

The International Space Station (ISS) requires advanced life support to reduce logistic resupply requirements as the Space Shuttle retires from service. Additionally, as humans endeavor to explore the moon and Mars, advanced vehicles and extraterrestrial bases will rely on life-support systems that feature in situ resource utilization to minimize launch weight and enhance mission capability. A goal is the development of advanced systems that meet the requirements of both mission scenarios to reduce development costs and potentially improve life support redundancy by deploying common modules. A high-pressure oxygengenerating system can provide a recharge capability for the high-pressure oxygen storage tanks on board the ISS independently of the soon to be retired Space Shuttle as well as offer a pathway for advanced life-support equipment for future manned-space exploration missions. Giner Electrochemical Systems, LLC (GES), along with subcontractor Hamilton Sundstrand (HS), worked with NASA Marshall Space Flight Center on an SBIR Phase I effort (NNX10CF27P) to successfully advance oxygen output pressure to 3,600 psig, enhance computer modeling capabilities to better understand high-differential-pressure, cathodefeed electrolysis, and work collaboratively to identify materials and methodologies that demonstrate promise for high-differential-pressure applications. At the heart of the Phase I program was an ambitious parametric test matrix in which pressure was varied between ambient and 3,600 psid, and temperature was varied between 40°C and 80°C. GES employed an electrolyzer housed in a pressurized dome, whereas HS extended the capabilities of its high-differential-pressure oxygen generator stack to reach 3,600 psid. Nomenclature ASF= Amps/ft 2 EVA = extravehicular activity GES = Giner Electrochemical Systems, LLC HDP = high pressure differential HHV = higher heating value HPOGA = high-pressure oxygen-generating assembly HS = Hamilton Sundstrand Corporation 1 Principal Engineer, Engineering and Manufacturing, 89 Rumford Ave./MS94, and AIAA Member.

Variation of Two-Phase Species Distribution inside a Unitized Regenerative Fuel Cell during an Electrolytic Cell Mode

“…Liquid water is supplied by the oxygen electrode side or hydrogen electrode side, which were two common ways of hydroelectricity electrolysis cell. 7 The bubbles formed in liquid water in the cell are often driven by the liquid flowing at a high velocity to discharge the cell. 8,9 Visualization studies in the microgravity environment showed that the generated gas formed bubbles in liquid water, and the bubbles were not easy to leave from the electrode surface and discharge the cell in the microgravity environment.…”

“…Russia has applied this technology to the space station to provide life support for three astronauts. Liquid water is supplied by the oxygen electrode side or hydrogen electrode side, which were two common ways of hydroelectricity electrolysis cell . The bubbles formed in liquid water in the cell are often driven by the liquid flowing at a high velocity to discharge the cell. , Visualization studies in the microgravity environment showed that the generated gas formed bubbles in liquid water, and the bubbles were not easy to leave from the electrode surface and discharge the cell in the microgravity environment. ,, With the aim of solving this problem, a newly designed cell structure of the proton exchange membrane electrolytic cell using a porous media membrane had been developed, which enabled water to be transported to the cell inlet in the form of liquid and then entered the cell channel in the form of gas under the action of membrane, and then diffused to the oxygen electrode side to participate in electrochemical reactions. , In the process of gas transmission, the supply of water vapor was mainly controlled by the rate of the electrochemical reaction on the oxygen electrode side, so it was not necessary to use a high-pressure pump to press liquid water into the cell to participate in the reaction.…”

Exergy Efficiency Promotion for the System of CO2 Hydrogenation to Methanol in Habitable Confined Space

“…It is of great importance to keep the interior atmosphere in a habitable condition at all times (Carey et al, 1983). Water electrolysis is currently used in the HCS to provide oxygen for crews in longperiod missions (Schmitt et al, 2011). However, it produces hydrogen as a by-product.…”