In-situ production of silicon carbide (SiC) from Lunar and Martian regolith

S.K. Nithya Srimurugan, S. Sathyan
Indian Institute of Technology Madras,

Keywords: In-situ resource utilisation, regolith, silicon carbide


Expeditions into space aim to establish sustainable and enduring exploration of the moon in the near future. This ambitious goal requires a diverse array of technologies for resource extraction from lunar regolith. Given the challenges of planetary surface exploration, including the absence of timely resupply missions, these technologies must minimize reliance on secondary raw materials such as reagents, binders, and electrolytes. In the current landscape of space exploration, lunar regolith, characterized by its composition of various metal oxides, serves as a pivotal raw material. Research efforts till date predominantly focus on additive manufacturing (AM) techniques for processing lunar soil, facilitating the fabrication of intricately shaped parts with a degree of autonomy during production. Moreover, investigations have explored the creation of ferrosilicon alloy for lunar structure construction, the production of ceramic glasses from lunar regolith, and the development of silicon solar cells by entities like Blue Origin for lunar electrical power generation. Notably, process technologies like carbothermal reduction and molten regolith electrolysis have demonstrated efficacy in extracting oxygen from lunar and Martian regolith, marking significant strides toward sustainable resource utilization in extraterrestrial environments. Our research is driven by the potential of extracting silicon carbide (SiC) from loose regolith powder by carbothermal reduction process using methane as the carbonaceous source. Silicon, abundant on both the Moon and Mars in the form of silicon dioxide, serves as the primary precursor for SiC. Methane will be available as a by-product of the Sabatier reaction which is used for processing carbon dioxide in the ISS. Successful implementation of this process could unlock a myriad of manufacturing opportunities, from abrasives and cutting tools to telescopes, high-power semiconductor devices, and radiation-resistant components, all achieved without the need for consumables from Earth, thereby advancing sustainable manufacturing practices. In this study, Lunar and Martian regolith simulants such as LHS-1, LMS-1 and MGS-1 (Exolith Labs, USA) are used. Then the simulants are sieved to a desired particle size of less than 53 microns to enhance the surface area available for reduction by methane. The regolith simulant powders are spread into a pocket of dimensions 5mm x 5mm x 0.3mm milled on a graphite substrate. The graphite substrate is then placed inside a tubular furnace and heated upto 1200℃ with a heating rate of 5℃/min. Then, methane gas is passed inside the tube at 1200℃ for 15 mins. The flowrate of methane is maintained at 12.5 sccm. Then the reduced samples along with the graphite substrate are characterized by X-Ray diffraction to investigate the formation of SiC. The diffraction peaks are dominated by graphite which is inherent because of the substrate. By zooming the XRD plot in the region from 30° to 40°, it is observed that there is a faint peak visible at 35.66° (2θ) which corresponds to the presence of β- SiC. Future efforts are ongoing to extract SiC from the reduced samples and to have high pure SiC crystals which can be used in manufacturing abrasives, optics and electronic devices.