Marine-inspired technology could accelerate carbon capture from ships

The ocean has a hidden talent, honed over millennia: the ability to capture and store large amounts of carbon dioxide, a key driver of climate change. But the ocean's natural carbon capture cycle, which takes hundreds of thousands of years, can't keep up with the carbon emissions humans put out. The global shipping industry alone is responsible for about 3% of global CO2 emissions.₂ Emissions.

Now, a new technology inspired by the ocean itself offers a potential solution: Researchers at the University of Southern California and California Institute of Technology, working with startup Calcarea, have developed a device to directly capture carbon dioxide emissions from cargo ships and other diesel vessels that power the global shipping industry.

“Our technique mimics the ocean's natural carbon capture process, but at a much faster rate,” said William Berelson, the Paxson H. Offield Professor of Coastal Marine Systems in the USC Dornseis School of Letters and Science and one of the project's principal investigators.

“What nature would take years to do, our reactors accomplish in minutes,” Berelson told USC News at AltaSea, a public-private marine research institute headquartered in the Port of Los Angeles, one of the world's largest ports and the busiest in the United States.

Carbon Capture: Tams for the Oceans

The natural reaction in the ocean is similar to antacids such as Tums, a common household remedy.

Limestone, a type of calcium carbonate and the main ingredient in antacids, is plentiful on the ocean floor. Just like you take an acid-neutralizing pill when you have an upset stomach, the ocean uses limestone to neutralize excess CO2.₂ It is absorbed from the atmosphere. A by-product of this reaction is bicarbonate, a natural component of seawater.

The researchers' technology works in two reactors, named Ripple 1 and Ripple 2, which currently produce CO₂ It converts engine exhaust gases directly into a slightly bicarbonate-rich solution that can be safely pumped back into the ocean with minimal impact on the overall water chemistry. Essentially, the reactor makes the water slightly saltier than it would be naturally, with negligible impact on marine life.

From the lab to the sea

The reactor technology came about through rigorous development: Researchers developed a prototype, Ripple 1, at the University of Southern California's University Park campus to test carbon capture in seawater under strictly controlled conditions.

Promising results from these initial tests paved the way for the Ripple 2 reactor, an iteration of which is currently being tested at Alta Sea. All this time, USC scientists have made sure that Ripple's wastewater does not harm marine life.

“The beauty of this technology is its scalability,” says Berelson, who was recently awarded the USC Wrigley Institute for the Environment and Sustainability Faculty Innovation Award for his carbon capture research. “Our goal is to develop this technology into a commercially viable solution that can be easily integrated into existing shipping operations. With commercial-scale deployment across the shipping sector, we hope to significantly reduce global CO2 emissions.”₂ “Emissions”

“More than 90% of the products we use in our daily lives have been transported by ship at some point.₂ “As a society, we need to approach this problem with the understanding that we can't electrify every part of industry,” says Jess Adkins, founder and CEO of Calcarea and the Smits Professor of Geochemistry and Geoenvironmental Sciences at the California Institute of Technology.

“Shipping is a good example of an industry where electrification has not worked well. As a society we have to embrace renewable energy, but it's hard to imagine ships running on batteries,” he said.

The technology is already garnering attention in the shipping industry, with Calcarea recently announcing a partnership with Lomar Shipping’s corporate venture lab, lomarlabs, to commercialize and deploy an on-board carbon capture system.

“Our technology has lower energy demands, lower costs and lower infrastructure requirements than comparable alternatives for reducing emissions from ships,” Adkins said. “But to get our system adopted and used by industry, we need the cooperation of the shipowners and operators themselves. This cooperation will accelerate the testing and marine engineering required to put our system to use, ultimately reducing emissions.”