Marine carbon removal technology that turns carbon dioxide in seawater into 'stone' for permanent storage

A team of scientists led by Professor Dong-Yeun Koh and Professor T. Alan Hatton from the Massachusetts Institute of Technology have developed an innovative electrochemical technology for removing carbon dioxide from seawater and converting it into a stable mineral form for long-term storage. This method, known as electrochemical dissolved ocean carbon removal (e-DOC), could potentially enable the ocean to absorb even more carbon dioxide from the atmosphere, acting as a natural countermeasure to climate change.

The research, published in Advanced Energy Materials, addresses the challenge of mineral scaling, which has previously hindered the effectiveness of conventional carbon removal technologies. By employing a hollow fiber electrode assembly (HFEA) - a structure composed of bundled, hollow, thread-like electrodes - the researchers were able to prevent mineral buildup directly on the electrode surface.

Instead, minerals form outside the electrodes, while hydrogen bubbles generated during the reaction naturally clean the surfaces, ensuring the system remains functional for extended periods.

During laboratory tests using Jeju lava seawater, the e-DOC system operated continuously for over 120 hours, successfully removing 80-90% of dissolved inorganic carbon and cutting electricity consumption by as much as 54% compared to existing technologies. As a bonus, the process also produced high-purity hydrogen and magnesium hydroxide, materials with various industrial applications. The modular design of the device makes it adaptable for installation on ships, offshore facilities, and other marine industrial settings.

According to Professor Koh, "This technology converts carbon dioxide dissolved in seawater into a mineral form that does not return to the atmosphere, enabling permanent storage and helping the ocean continuously absorb new carbon dioxide." The team hopes that this breakthrough will accelerate the commercialization of marine carbon removal technologies, contributing to the global effort to achieve carbon neutrality and combat climate change.