Solid Oxide Electrolysis Based Lunar PSR Ice Processing System for Propellant Hydrogen and Oxygen Production

In-Situ Resource Utilization (ISRU) of ice from the permanently shadowed regions (PSRs) on the lunar surface presents an opportunity to produce liquid hydrogen (H2) and oxygen (O2) propellant fuels for cislunar transport and exploration of more remote areas of the solar system. OxEon Energy and the Colorado School of Mines (Mines) have teamed to integrate OxEon�s high-temperature solid-oxide electrolysis (SOXE) stack technology with an effective and reliable balance-of-plant (BOP) that produces separated H2 and O2 streams from recovered lunar ice. OxEon�s SOXE stack technology is used in the MOXIE (Mars Oxygen ISRU Experiment) system that demonstrated O2 production from atmospheric CO2 on Mars in 2021. In a Tipping Point partnership with NASA, OxEon and Mines modeled tradeoffs between efficiency, reliability, and system portability to design a thermally integrated SOXE BOP system. Extensive analysis of initial system models mapped the operating envelope and informed the design of a lab-scale demonstration unit. Fabrication and testing of a 2.5kWe SOXE stack and its associated BOP is approaching completion. Testing in a cryo-vacuum chamber at Mines to simulate the lunar environment will be completed in 2021. Results of system testing in a lunar-relevant environment will be presented. The integrated breadboard system is designed to produce 1.8kg/day of H2 with a system specific power target of 46kWh/kg H2. Initial SOXE stack tests have demonstrated electrochemical compression of the O2 product stream, which will reduce the work and size of the post-processing equipment required to liquify and store LOx . Results from operating the lab-scale system will be used to refine system models and inform a technoeconomic analysis of the system. The improved models and technoeconomic analysis will address the value of scaling up via modular systems versus a single full-scale system for actual lunar PSR application.