Off-the-shelf thermoelectric generators could enable CO2 conversion on Mars

Off-the-shelf thermoelectric generators could enable CO2 conversion on Mars

by Clarence Oxford

Los Angeles CA (SPX) Nov 08, 2024

Readily accessible thermoelectric generators (TEGs), operating with modest temperature differences, can drive CO2 conversion, according to new proof-of-concept research by chemists at the University of British Columbia (UBC).

This development suggests that temperature differentials across a variety of environments – from geothermal sites on Earth to Mars’s cold terrain – could support the conversion of CO2 into useful fuels and chemicals.

“The environment on Mars really got me interested in the long-term potential of this technology combination,” said Dr. Abhishek Soni, postdoctoral research fellow at UBC and lead author of the study published in ‘Device’.

“This is a harsh environment where large temperature differences could be leveraged to not only generate power with thermoelectric generators, but to convert the abundant CO2 in Mars’ atmosphere into useful products that could supply a colony.”

The TEGs used in the study generated electricity by spanning two temperatures, such as a hot plate and an ice bath. The team found that when the temperature difference between these surfaces reached at least 40 C, standard thermoelectric generators produced a steady current sufficient to power an electrolyzer for CO2 conversion into carbon monoxide (CO).

Closer to home, the technology has potential applications at geothermal facilities. “Our results in the lab indicate the temperature difference between hot geothermal pipes returning from underground and the relatively cooler surface temperature is enough for thermoelectric generators to power a convertor,” explained Dr. Soni.

On Mars, the application would involve greater extremes. To sustain human colonies, biodomes on Mars would need room-temperature environments. Thermoelectric generators attached to the outer surfaces of these biodomes could exploit the temperature gradient between the warm interior and the frigid Martian atmosphere to generate power, which would then drive CO2 conversion into valuable carbon-based products, such as fuels and plastics. Mars’s atmosphere consists of 95 percent carbon dioxide, with temperatures ranging from 20 C to -153 C.

“This paper shows a fun way to make carbon-neutral fuels and chemicals,” said Professor Curtis P. Berlinguette, principal investigator at UBC. “We’ll need plastic on Mars one day, and this technology shows one way we can make it there.”

The next phase of research will test the thermoelectric generators with the electrolyzer in real-world conditions here on Earth.

Research Report:Thermoelectric CO2RR electrolysis