Carbon capture — commonly thought of as the use of technology to remove carbon dioxide from the air — is a hotly debated topic.
Though the U.S. Department of Energy just committed $131 million to various carbon capture projects, opponents claim that focus on carbon capture distracts from other, more effective strategies for combating our warming planet.
Now, an MIT research team may have found a way to make everybody happy: by removing carbon dioxide from the world’s oceans.
In a new paper published in the journal Energy & Environmental Science, six MIT engineers have detailed a comprehensive plan for cleansing seawater of carbon dioxide.
The process utilizes two asymmetrical electrochemical cells consisting of silver and bismuth electrodes. The first cell releases protons into the water that converts to carbon dioxide that is then collected by a vacuum. The second cell then returns the seawater to a more basic state before releasing it back into the ocean, free from carbon dioxide.
The researchers say the process has “a relatively low energy consumption” and “high electron efficiency.” It’s also expected to cost less than comparable air-based carbon capture technologies. After capture, the isolated carbon dioxide could be stored under the seafloor or used on land to make fuels, chemicals, or even products.
Removing carbon dioxide from the world’s oceans is more important than ever, as they absorb 50 times more carbon than the atmosphere and 20 times more than all the world’s plants and soil combined.
According to the International Atomic Energy Agency, 26% of the carbon dioxide produced by human activity is absorbed by the ocean, and high carbon dioxide concentration has caused widespread ocean acidification. The more acidic oceans become, the harder it is for coral and other species to build their shells and exoskeletons, leading to disrupted ecosystems and less marine life.
The researchers behind the new carbon capture technology note that carbon dioxide in seawater is more than 100 times more concentrated than it is in the air but that a focus on water-based carbon capture has been lacking.
“The total amount of CO2 emissions partitioning into the oceans rivals that retained by the atmosphere,” the researchers write, “and thus effective means for its removal could augment the other negative emissions technologies to reduce the environmental burden imposed by this greenhouse gas.”
The technology proposed by the new research, which is expected to be demonstration-ready in two years, has the potential to change the face of carbon capture.
Currently, the nonprofit Food & Water Watch says the idea of carbon capture amounts to “pie-in-the-sky greenwashing technologies” that will “only prolong the fossil fuel industry.”
But the deployment of large-scale, energy-efficient, ocean-based carbon capture could turn be a powerful tool for creating a healthier planet.
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