With the world struggling to reduce carbon emissions, several companies have focused instead of removing carbon dioxide directly from the atmosphere.
According to the IEA, 18 direct air capture plants are operating worldwide, capturing 0.01 Mt CO2/year. They are developing a state-of-the-art DAC plant in the US that could capture 1 Mt CO2/year. This capacity is tiny when you compare it to the needed CO2 captured to reach Net zero emissions by 2050, which is almost 60 Mt CO2/year by 2030.
Switzerland’s Climeworks is one of the best-known direct air capture companies. It has two plants in Iceland, Orca and Mammoth. Mammoth is still under construction and expected to be finished in a year or two, which by then could remove 36,000 tonnes of CO2, nine times more than the existing Orca plant. The captured carbon is mixed with water and injected underground, where the chemical reaction will turn it into rock.
However, the IEA says the target is achievable by deploying large-scale plants that could refine the technology and reduce the cost to make it feasible.
The BBC reports that the UK is building power plants with a carbon capture feature as part of its government’s commitment to decarbonising electricity production by 2035. The UK emitted 425 million tons of CO2 in 2021, falling by 50% since 1990. However, the amount of CO2 captured from these plants is minimal. None of the three proposed carbon capture plants can remove more than 2 million tonnes a year and falls short of the government target to remove between 20 to 30 million tonnes of CO2 per year by 2030.
Carbon capture technology has been around for decades, and many are mainly attached to industrial plants – like power stations, oil and gas processing, and fertiliser production that emits enormous amounts of carbon dioxide. The carbon dioxide captured is either reused or stored permanently underground.
A Global CCS Institute report says that in September 2022, there are 30 carbon capture facilities worldwide.
The cost of carbon capture technology can be very costly. Catherine Raw of energy company SSE told the BBC that building a gas power station with carbon capture technology would almost double the cost.
Direct air capture (DAC), as it suggests, are technologies that directly suck carbon dioxide from the atmosphere, as opposed to carbon capture attached to industrial plants or from flue gas. For example, captured carbon dioxide can be reused in food processing or combined with hydrogen to produce synthetic fuels.
A New Direct Air Capture that sucks three times more CO2
The BBC reports on a new DAC approach discovered by researchers that could suck in three times more carbon and cost cheaper than the current methods. One of the big obstacles to DAC technology is its cost because it consumes a lot of power for the amount of CO2 it captures. Experts say that the new method could also accelerate the deployment of carbon capture, which could help achieve the net zero targets.
The findings of their research are published in the Science Advances journal.
Because CO2 is relatively diluted in the atmosphere at 400 parts per million in the air, it is challenging to capture it and will require big machines that also use a lot of power to absorb and discharge carbon dioxide, researchers say.
The new approach uses off-the-shelf resins and other chemicals and promises far greater efficiency and lower cost.
Researchers have borrowed an approach used for applications in water and “tweaked” existing materials to remove CO2 from the air. The resulting new hybrid absorbing material can capture three times more CO2 than existing substances (McGrath, 2023).
The study’s lead author Prof Arup SenGupta from Lehigh University in the US, says, “To my knowledge, there is no absorbing material which, even at 100,000 ppm, shows the capacity we get it in direct air capture of 400 ppm” (McGrath, 2023). Currently, current carbon capture methods can only absorb 100,000 CO2 parts per million. This new approach can capture three times more CO2.
“This simple ability to capture CO2 at a high quantity, in a small volume of material, is a unique aspect of our work” (McGrath, 2023).
Dr SenGupta believes that removing CO2 directly from the atmosphere is critical in limiting global temperature rises. He also advocates for the technology to be available in developing countries like Bangladesh, Barbados, and the Maldives, to end their suffering and use the technology to fight climate change.
Read more about the research “Direct air capture (DAC) and sequestration of CO2: Dramatic effect of coordinated Cu(II) onto a chelating weak base ion exchanger” by clicking the link in the “Sources” section below.
McGrath, M. (2023, March 9). Climate change: New idea for sucking up CO2 from air shows promise. BBC. Retrieved from https://www.bbc.com/news/science-environment-64886116
Chen, H., Dong, H., Shi, Z., & SenGupta, A. (2023, March 8). Direct air capture (DAC) and sequestration of CO2: Dramatic effect of coordinated Cu(II) onto a chelating weak base ion exchanger. Science Advances. Retrieved from https://www.science.org/doi/10.1126/sciadv.adg1956
Fisher, J. (2023, February 28). Carbon capture: What is it and how does it fight climate change? BBC. Retrieved from https://www.bbc.com/news/science-environment-64723497
Direct Air Capture. (2022, September). IEA. Retrieved from https://www.iea.org/reports/direct-air-capture
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