Compact Water Electrolyzer for Low-Gravity Environments

An improved electrolyzer is needed by NASA for generating propellants in low-gravity environments using water or ice as the reactant. It is desired to minimize the mass and energy requirements for the electrolyzer system to lessen launch and operational requirements during gas generation. The operation of the electrolyzer system in a low-gravity environment also possess challenges to the flow of two-phase gas/liquid flows in the electrolyzer system. MicroCell Technologies proposes a Phase I program to develop and demonstrate a compact and energy efficient electrolyzer that may generate high-pressure hydrogen and oxygen gas. This pressurized gas is generated within the electrolyzer directly without compressors up to 2000 psig that may be used for post-processing the fuel and oxidant into cryogenic storage vessels. Our electrolyzer system generates this pressurized gas within a compact and energy efficient device of 1.1 kW/kg at a hydrogen production rate of 1.8 liters/hr (STP) with an efficiency of 85%.