We can suck CO2 from the air and store it in the ocean as baking soda

Carbon dioxide captured from the atmosphere turns into baking soda and can be stored in oceans around the world. That’s thanks to a newly identified substance that researchers say could revolutionize the direct air capture (DAC) industry.

For years, carbon capture technology has focused on capturing CO2 from pollution sites before it enters the atmosphere. For example, from the chimneys of coal and steel plants.

Extracting carbon directly from air presents a much greater challenge, as atmospheric CO2 is much more diluted and extracting it requires more energy and materials. This means that his current DAC plant is expensive to operate, costing hundreds of dollars to extract one tonne of CO2 from the air.

Arup SenGupta and his colleagues at Lehigh University in Bethlehem, Pennsylvania, set out to develop new absorbing materials, called sorbents, that could pull more CO2 out of the air than current materials.

The researchers say that by modifying the existing amine solvent with a copper solution, they increased the carbon-trapping capacity of DAC by two to three times.

SenGupta said the new material could fundamentally increase the potential of DAC as an effective and commercially viable technology to mitigate climate change.

“This material can be produced in very high volumes and very quickly,” says SenGupta. “It should definitely improve the cost-effectiveness of the process.”

Dawid Hanak of Cranfield University in the UK says the research has the potential to “significantly reduce the cost of DAC”.

Captured CO2 can be converted to sodium bicarbonate or baking soda by adding seawater. The team suggests that this could be safely stored in the ocean, which represents an “infinite sink” for captured CO2.

Sengupta says releasing baking soda into the ocean won’t harm the ecosystem. Because sodium bicarbonate is alkaline, it could provide some benefits by reversing the acidification of the oceans that occurs when CO2 dissolves, he says. “Higher alkalinity also means higher bioactivity, which means more of his CO2 sequestration.”

Ultimately, DAC plants using this sorbent could be installed offshore, allowing countries with no potential for geological carbon storage to begin removing carbon from the atmosphere, says SenGupta. says.

The proposal is “elegant and clever chemistry,” says Stuart Haszeldine of the University of Edinburgh, UK. “[The] The ability to store CO2 directly in seawater is also very strong, as the very deep ocean has vast capacities of CO2 storage available for hundreds to thousands of years. ”

But he says more research is needed to understand how the material performs on an industrial scale after absorbing and releasing CO2 hundreds of times. There may also be legal barriers to discharging baking soda into the ocean, which could be classified as industrial waste.

According to the International Energy Agency, the use of carbon removal technologies must be rapidly expanded to limit global warming to 1.5°C. This should go from about 0.01 megatonnes per year today to about 60 million tonnes per year by 2030.

Myles Allen of the University of Oxford says that new sorbents may offer a technological breakthrough to improve the efficiency of DACs, but what the global market really needs to expand at this rapid pace is government energy companies. to force investment into

“I have consistently argued that the only way to get this to the scale we need is to make it a condition of the license to continue selling fossil fuels,” he says. “As soon as that happens, it will happen on a scale that is unimaginable today.”