The day where life on the Moon is possible is getting closer and closer. Research by the University of Glasgow postdoctoral student, Beth Lomax, has demonstrated that oxygen can be extracted from lunar soil.
The oxygen from simulated lunar soil, or regolith, was almost entirely extracted — leaving a mixture of metal alloys. Both this metal and the oxygen could be used by future Moon inhabitants.
Samples of actual lunar soil were used to determine that lunar regolith is made of 40 to 45 percent oxygen by weight, making it the soil's most available element.
How did the team extract the oxygen?
Lomax's Ph.D. work, supported by the European Space Agency (ESA), involved the process of placing the powdered regolith in a mesh-lined container along with molten calcium chloride salt, which served as an electrolyte heated to 950 degrees Celcius.
Congrats to @UofGChem PhD student Beth Lomax, whose research is featured on the @esa 'Space in Images' page today! Her work on extracting oxygen from lunar soil could be helpful for future moon colonisation missions. 🌙 https://t.co/VeHQ8H0Wxupic.twitter.com/4UzimVpcd5— University of Glasgow (@UofGlasgow) October 9, 2019
At this temperature, the regolith remains solid.
The process took 50 hours, saw 96% of the oxygen extracted, and involved a current passing through the regolith. This caused the oxygen to be extracted and to migrate across the salt and to an anode.
The first 15 hours alone saw 75% of all the oxygen extracted.
Lomax said this about the process: "The processing was performed using a method called molten salt electrolysis. This is the first example of direct powder-to-powder processing of solid lunar regolith simulant that can extract virtually all the oxygen. Alternative methods of lunar oxygen extraction achieve significantly lower yields, or require the regolith to be melted with extreme temperatures of more than 1600°C."
Adding to this, Lomax said: "This work is based on the FCC process—from the initials of its Cambridge-based inventors—which has been scaled up by a UK company called Metalysis for commercial metal and alloy production."
She ended with, "This research provides a proof-of-concept that we can extract and utilise all the oxygen from lunar regolith, leaving a potentially useful metallic by-product."
This before-and-after image shows simulated lunar soil, or 'regolith', having almost all the oxygen extracted from it, leaving behing metal alloys. In this way, both oxygen and metals would be available to future #Moon settlers 👉 https://t.co/rO9C8jOAfT#ForwardToTheMoonpic.twitter.com/B8lZBIQRjq— ESA (@esa) October 9, 2019
Why is this discovery so important?
"This oxygen is an extremely valuable resource, but it is chemically bound in the material as oxides in the form of minerals or glass and is therefore unavailable for immediate use," said Lomax.
Even though the research is not finished quite yet, it's certainly a step in the right direction for future life in space.
"We are working with Metalysis and ESA to translate this industrial process to the lunar context, and the results so far are very promising," said Mark Symes, Lomax's Ph.D. supervisor at the University of Glasgow.
Furthermore, James Carpenter, ESA's lunar strategy officer commented that "This process would give lunar settlers access to oxygen for fuel and life support, as well as a wide range of metal alloys for in-situ manufacturing—the exact feedstock available, would depend on where on the Moon they land."
The research was published in September in Science Direct.