MIT researchers have developed a new method for carbon capture by focusing on removing carbon dioxide from the world’s oceans. The process, detailed in a paper published in Energy & Environmental Science, involves two electrochemical cells with silver and bismuth electrodes.
The first cell releases protons into seawater, converting them to carbon dioxide, which is then collected by a vacuum. The second cell restores the seawater to a more basic state before releasing it back into the ocean, free from carbon dioxide. This method is reported to have a relatively low energy consumption and high electron efficiency, making it potentially more cost-effective than air-based carbon capture technologies.
The researchers highlight the importance of removing carbon dioxide from oceans, as they absorb 50 times more carbon than the atmosphere and 20 times more than all the world’s plants and soil combined. Ocean acidification caused by high carbon dioxide concentration is a growing concern, impacting marine life and disrupting ecosystems.
Currently, 26% of carbon dioxide produced by human activity is absorbed by the ocean, leading to widespread ocean acidification. The researchers emphasize that carbon dioxide concentration in seawater is over 100x more than in the air, underscoring the significance of water-based carbon capture.
The captured carbon dioxide could be stored under the seafloor or used on land to produce fuels, chemicals, or other products. The new technology, expected to be demonstration-ready by 2025, could provide an efficient and effective means for removing carbon dioxide from the oceans and contribute to reducing the environmental impact of this greenhouse gas.
The researchers argue that ocean-based carbon capture has been underemphasized compared to air-based approaches, and their innovative method seems to have the potential to be a significant tool in addressing climate change concerns.