An improved sorbent could make carbon capture and storage much more efficient and enable the development of new storage methods
Spotted: In order to mitigate the impacts of climate change, it is likely that we will need to scale up direct air capture (DAC) technology and carbon storage. In DAC, air is run through filters and sorbents to separate out the CO2. The filters are then heated to release the CO2, which is either stored underground or used in products such as building materials and fuels. As you might expect, this process often requires significant energy and incurs expense.
Now, new research from a team at Lehigh University, has found a way to make the DAC process more efficient. Most current DAC filtering processes use amine-based sorbents (materials derived from ammonia, which contains nitrogen). In this study, the researchers added copper to the amines, which allowed the sorbent to filter out three times as much CO2 as existing products – lowering costs and improving efficiency.
On top of the improved efficiency, the addition of copper meant that when the material came into contact with seawater, it converted the captured CO2 into a harmless alkaline material almost identical to baking soda. This opens up the possibility of storing captured CO2 in the ocean, which could allow DAC plants to be built in a much wider range of locations.
The researchers point out that there is still a long way to go before this technology is sustainable. For one thing, ammonia is derived from fossil fuels. Another concern is that no one knows what the effect would be of large volumes of baking soda entering the oceans each year. But despite these notes of caution, the research is an exciting development as countries explore the practicalities of deploying DAC technology.
There are currently just a handful of DAC facilities around the world, but the technology has an important role to play in the reduction of atmospheric CO2. Springwise has also spotted a method for turning atmospheric carbon into solid carbon, and a process for permanently storing CO2 in rocks deep underground.
Written By: Lisa Magloff