Researchers at Stanford have developed a groundbreaking reactor that uses electricity instead of fossil fuels to generate the high temperatures needed for industrial processes. This innovation offers a cleaner, more efficient alternative to traditional methods, with the potential to significantly reduce carbon emissions.

Industrial activities in the United States account for about one-third of the nation’s carbon dioxide emissions, surpassing the combined emissions from all passenger vehicles, trucks, and airplanes. Decarbonizing this sector is essential for mitigating climate change, but it has proven to be a complex challenge.

To address this, Stanford Engineering has designed and demonstrated a new type of thermochemical reactor. Unlike conventional reactors that burn fossil fuels to generate heat, this electrified reactor uses magnetic induction—similar to the process used in induction stoves. The reactor is not only smaller and more cost-effective than existing fossil fuel technologies but also far more efficient. The findings were published on August 19 in the journal Joule.

“We’ve developed an electrified and scalable reactor infrastructure for thermochemical processes that features optimal heating and heat-transfer properties,” said Jonathan Fan, an associate professor of electrical engineering at Stanford and the senior author of the paper. “We’re essentially pushing reactor performance to its physical limits while using green electricity to power it.”

Heating with Induction

Traditional thermochemical reactors heat a fluid by burning fossil fuels, which then flows through pipes in the reactor, similar to how a boiler heats water in an old-fashioned radiator system. This method requires extensive infrastructure and often results in significant heat loss.

The new reactor, however, generates heat internally using magnetic induction. By exploiting the interactions between electric currents and magnetic fields, heat is created directly within the reactor, eliminating the need to transport heat through pipes. For example, by wrapping a wire around a steel rod and running an alternating current through it, an oscillating magnetic field is generated, inducing a current in the steel. Since steel is not a perfect conductor, some of that current converts to heat, effectively heating the entire piece from within.

Adapting induction heating for industrial use, however, requires more than just turning up the heat. Industrial reactors need to evenly generate and distribute heat in three-dimensional space and achieve much higher efficiency than a typical stovetop. To maximize efficiency, the researchers used high-frequency currents along with materials that are poor conductors of electricity.

The team, led by Juan Rivas-Davila, an associate professor of electrical engineering at Stanford and a co-author of the paper, developed new high-efficiency electronics to produce the required currents. These currents were then used to inductively heat a three-dimensional lattice made of a poorly conducting ceramic material at the core of the reactor. The lattice’s structure is crucial because it further lowers electrical conductivity while allowing for efficient heat transfer. The lattice can also be filled with catalysts—materials that need to be heated to trigger chemical reactions—resulting in a more compact and efficient reactor.

“You’re heating a large surface area structure that is right next to the catalyst, so the heat you’re generating gets to the catalyst very quickly to drive the chemical reactions,” Fan explained. “Plus, it simplifies everything. You’re not transferring heat from elsewhere and losing some along the way; there are no pipes going in and out of the reactor—you can fully insulate it. This is ideal from an energy management and cost point of view.”

Proving the Concept

The researchers successfully demonstrated the reactor’s capabilities by using it to power a chemical reaction known as the reverse water gas shift reaction, which converts captured carbon dioxide into a valuable gas that can be used to produce sustainable fuels. This reaction, which requires high heat, was powered by a new sustainable catalyst developed by Matthew Kanan, a professor of chemistry at Stanford and a co-author of the paper.

In the proof-of-concept demonstration, the reactor achieved over 85% efficiency, meaning it converted nearly all the electrical energy into usable heat. Additionally, the reactor created ideal conditions for the chemical reaction, with carbon dioxide being converted to usable gas at the predicted theoretical rate—a result that is often not achieved with new reactor designs.

This innovation represents a significant step forward in the quest to decarbonize industrial processes, offering a cleaner, more efficient way to generate the necessary heat while reducing reliance on fossil fuels.

By Impact Lab