A groundbreaking discovery has emerged from a singular electrochemical process that holds the potential to significantly reduce emissions in the most challenging-to-decarbonize industries, such as steel and cement. Researchers at MIT are at the forefront of global efforts to combat greenhouse gas emissions, focusing on carbon capture technologies to tackle the most resistant industrial emitters.
Industries like steel, cement, and chemical manufacturing pose unique decarbonization challenges due to their heavy reliance on carbon and fossil fuels in their operations. The development of technologies capable of capturing and reusing carbon emissions within their production processes could lead to a substantial reduction in emissions from these “hard-to-abate” sectors.
Presently, existing experimental technologies capture and convert carbon dioxide through two separate energy-intensive processes. The MIT team is pioneering a more efficient, integrated system that could potentially run on renewable energy sources, enabling both the capture and conversion of carbon dioxide from concentrated industrial sources.
The latest findings on carbon capture and conversion, published in the journal ACS Catalysis on September 5, shed light on the mechanism behind capturing and converting carbon dioxide through a single electrochemical process. This process involves using an electrode to attract carbon dioxide released from a sorbent and convert it into a reduced, reusable form.
While similar demonstrations have been reported in the past, the MIT team’s research uncovered the crucial factor driving the electrochemical reaction: the partial pressure of carbon dioxide. In simple terms, the more pure carbon dioxide that contacts the electrode, the more effectively it can capture and convert the molecule. Understanding this key driver, often referred to as the “active species,” provides valuable insights for optimizing similar electrochemical systems for efficient carbon capture and conversion in an integrated process.
These electrochemical systems are well-suited for highly concentrated emissions generated by industrial processes, especially those lacking obvious renewable alternatives. As study author Betar Gallant, the Class of 1922 Career Development Associate Professor at MIT, explains, “We can and should switch to renewables for electricity production. But deeply decarbonizing industries like cement or steel production is challenging and will take a longer time.”
The MIT team’s concept revolves around an electrode that can be integrated into existing carbon-capture chambers. When a voltage is applied to the electrode, it enables the conversion of carbon dioxide into a usable product using protons from water, thus making the sorbent available to bind more carbon dioxide. This integrated system could potentially operate entirely on renewable electricity, eliminating the need for fossil-fuel-derived steam.
Gallant emphasizes that this technology is not about carbon removal but rather recycling carbon dioxide multiple times within existing industrial processes, thereby reducing associated emissions. The long-term vision includes using electrochemical systems to facilitate mineralization and permanent storage of CO2—a genuine carbon removal technology.
The research involved a team of MIT co-authors, including lead author and postdoc Graham Leverick, graduate student Elizabeth Bernhardt, and collaborators from Sunway University in Malaysia, Aisyah Illyani Ismail, Jun Hui Law, Arif Arifutzzaman, and Mohamed Kheireddine Aroua.
Carbon-capture technologies play a critical role in capturing emissions from power plants and manufacturing facilities, diverting them into chambers filled with capture solutions. These solutions chemically bind with carbon dioxide, producing a stable form that can be separated from other flue gas components. High temperatures are then used to release the captured carbon dioxide, which can be stored, mineralized, or further converted into chemicals or fuels.
Gallant notes that while carbon capture is a well-established technology, it requires large installations, is expensive, and consumes significant energy. The aim is to develop more modular and flexible technologies that can adapt to diverse sources of carbon dioxide, with electrochemical systems presenting a promising avenue for progress in this direction.