A Study on the Thermal Extraction of H₂O(s) From Lunar Regolith Simulant Using Concentrated Solar Thermal Technology

This research aimed to determine the feasibility of using concentrated solar thermal (CST) technology to extract H2O from ice deposits on the lunar surface. The permanently shadowed regions (PSRs) of the Moon, believed to contain H2O(s), served as the primary target for this investigation. CST technology, supplemented by an indirect solar receiver (ISR) for enhanced heat transfer, was employed to explore sublimation processes. Initial studies examined H2O(v) transport through Lunar Mare Simulant (LMS-1) and Lunar Highland Simulant (LHS-1), leading to a diffusion model critical for developing in-situ resource utilization (ISRU) technologies.

A specialized Concentrated Lunar and Rapid Kinetics (CLARK) reactor was designed to replicate lunar surface conditions, enabling experiments on simulant packed beds under concentrated irradiation from a high-flux solar simulator (HFSS). The experiments explored key factors, including the use of a copper ISR, variations in packing density, and different irradiation levels, to study their impacts on sublimation efficiency. The inclusion of the ISR was shown to enhance sublimation rates significantly by improving heat transfer within the packed bed.

Preliminary transient computational models simulated heat and mass transfer phenomena, offering valuable insights for system optimization. X-ray tomography scans provided detailed packed bed models, enabling future studies of reflective and absorptive properties and flow dynamics through Monte Carlo and lattice Boltzmann simulations.

This work establishes the viability of CST technology for extracting H2O(v) from lunar regolith simulants and provides a strong foundation for future research into lunar H2O extraction, a critical step toward sustainable space exploration.