Scientists find a way to soak up carbon pollution, turn it into baking soda and store it in the oceans

(CNN) Scientists have devised a way to suck the planet’s carbon pollution out of the air, turn it into sodium bicarbonate and store it in the oceans, according to a new paper.

The technique could be up to three times more efficient than current carbon capture technology, say the authors of the study, published Wednesday in the journal Science Advances.

Tackling the climate crisis means drastically reducing the burning of fossil fuels, which release pollution from the planet. But because humans have already pumped so much of this pollution into the atmosphere and are unlikely to reduce emissions sufficiently in the short term, scientists say we need to remove it from the air, too.

Nature does this – forests and oceans are valuable carbon sinks, for example – but not fast enough to keep up with the amounts humans are producing. So we’ve turned to technology.

One method is to capture carbon pollution directly at the source, for example from steel or cement factories.

But another way that this study focuses on is “direct air capture.” This involves sucking carbon pollution directly out of the atmosphere and then storing it, often by injecting it into the ground.

The problem with direct air trapping is that while carbon dioxide can be a very potent planet-warming gas, its concentrations are very small – it makes up about 0.04% of the air. This means that removing it directly from the air is challenging and expensive.

That’s a “significant hurdle,” Arup SenGupta, a professor at Lehigh University and a study author, told CNN.

Even the largest plants can only remove relatively small amounts, and each ton of carbon costs hundreds of dollars to remove.

According to the company, Climeworks’ direct air removal project in Iceland is the largest facility and can capture up to 4,000 tons of carbon dioxide per year. This corresponds to the carbon pollution produced by fewer than 800 cars over a year.

The new technique described in the study may help tackle these problems, SenGupta said.

The team has used copper to modify the absorbent material used for direct air trapping. The result is an absorbent “that can remove CO2 from the atmosphere in ultra-dilute concentration with a capacity two to three times greater than existing absorbents,” SenGupta said.

This material can be produced easily and cheaply and will help reduce the cost of direct air capture, he added.

Once the carbon dioxide is trapped, it can be converted into sodium bicarbonate – baking soda – using seawater and released into the sea in a small concentration.

The oceans “are infinite things,” SenGupta said. “If you put all the CO2 from the atmosphere that is emitted every day – or every year – into the ocean, the increase in concentration would be very, very small,” he said.

SenGupta’s idea is that direct air capture plants can be located offshore, giving them access to abundant seawater for the process.

Stuart Haszeldine, professor of carbon capture and storage at the University of Edinburgh, who was not involved in the study, told CNN that the chemistry was “new and elegant.”

The process is a modification of one we already know, he said, “which is easier to understand, scale up and develop than something completely new.”

But there may be regulatory hurdles to overcome. “The disposal of large tonnages of sodium bicarbonate into the sea can legally be defined as ‘dumping’, which is prohibited by international treaties,” Haszeldine said.

Others remain concerned about negative impacts on the oceans, which are already under pressure from climate change, pollution and other human activity.

Peter Styring, professor of chemical engineering and chemistry at the University of Sheffield, told CNN: “Unless you have a full ecotoxicity study, you don’t know what it’s going to do, even at small concentrations.”

Direct air capture also remains expensive and inefficient, Styring said. “This is a large-scale problem. Why would you capture from the atmosphere when you’ve gotten so much out of power plants and industrial plants? It just makes sense to go for the high concentrations first,” he said.

Some scientists have expressed concern that a focus on technology to remove carbon pollution could distract from policies to reduce fossil fuel burning or could give polluters permission to continue polluting.

But given the scale of the climate crisis, there is a big push from governments and international bodies to scale up this technology.

More research will be needed to understand how the method works at scale, Haszeldine said. But it’s promising, he added, saying “the world needs lots of this type of discovery.”

SenGupta said the technology is ready to be taken out of the lab and tested. “This is the time to go forward and do something in maybe two or three different places around the world. Let other people get involved, find mistakes, improve it, and then move on from there,” he said.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top
%d bloggers like this: