Using Thermoelectric Generators for Carbon-Free Fuels and Chemicals

Scientists at the University of British Columbia (UBC) have demonstrated a groundbreaking approach to carbon dioxide (CO₂) conversion using readily available thermoelectric generators. A proof-of-concept study revealed that even modest temperature differences can provide enough power to drive the transformation of CO₂ into valuable resources, paving the way for sustainable solutions in energy and resource management.  

This research not only stands to decarbonize Earth but also may eventually have applications on Mars. 

Thermoelectric generators create electricity by utilizing temperature differences between two surfaces. In a laboratory setup, the team connected one side of the generator to a hot plate and the other to an ice bath. When the temperature difference reached at least 40 °C, standard thermoelectric generators produced sufficient current to power an electrolyzer capable of converting CO₂ into carbon monoxide (CO). 

This technology, with further refinement, could be integrated into geothermal systems. Laboratory results suggest that the temperature gradient between hot geothermal pipes returning from underground and the cooler surface environment is adequate to drive thermoelectric generators, providing enough power for CO₂ conversion. 

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“The mission of my academic group at UBC is to decarbonize the planet,” explained Curtis Berlinguette, a professor of chemistry and chemical engineering at UBC. “We build electrochemical reactors that can decarbonize cement production, chemicals production and fuels production.” 

From an energy stance, electrochemical reactors offer a unique way to produce energy.  

“Our reactors use clean electricity to convert air into fuels,” Berlinquette said. “To do this, we need to capture CO₂ from air and concentrate it so we can feed our reactors with a pure stream of CO₂ in order to produce meaningful amounts of fuel.” 

What makes the UBC technology unique is that it integrates the capture and conversion steps, then bypasses the need for heat or vacuum that is required by all other technologies, he continued. 

“In this report, we show that thermoelectric generators, which are devices that convert heat into electricity, can also power our reactors," Berlinquette explained. “Thus, we show electricity generated from waste heat or geothermal heat—or the temperature gradients on Mars—to generate the voltages necessary to upgrade CO₂ into fuels."  

On to Mars? 

Space exploration nowadays is often foreshadowed with talk of reaching the planet Mars and further exploring it. However, in a 2023 Whitepaper, “Moon to Mars Architecture,” NASA indicated that one of the challenges in exploring Mars is the availability of fuel once any exploration team or equipment could make it there.  

Although the UBC researchers did not reference the NASA whitepaper, their research could potentially impact the duration of how long a crew or equipment could persist on a future Mars mission. In such a challenging environment, significant temperature gradients could be harnessed not only to produce energy using thermoelectric generators but also to convert the plentiful CO₂ in Mars’s atmosphere into essential resources to support a potential colony. 

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Part of the challenge in converting air into fuels here on Earth is that CO₂ exists in very dilute concentrations, Berlinquette said. “We were sitting in a group meeting thinking through how to solve this problem when someone said, ‘we should just go do this on Mars – the atmosphere there is almost entirely CO₂,’” he added. 

But what first seemed like a silly idea became a fun component of the project. “We set out to prove that ‘Mars air’ could be upgraded directly into fuels using our reactor, without the need to capture it like we do on Earth,” he continued. 

The proposed reactor could provide power to a colony on Mars or fuels for transportation, and even chemicals for conversion into useful plastics. 

For now, the UBC team is working to commercialize this technology for Earth applications through a start-up called Sora Fuel in Boston.

Jim Romeo is a technology writer in Chesapeake, Va.