A team of researchers from the University of California, Los Angeles (UCLA) is developing a technology that captures carbon from the atmosphere in a process that mimics the formation of seashells on the ocean floor, a report by Fast Company explains.
Humanity faces an increasingly difficult task reducing the amount of carbon in our atmosphere in order to reverse the detrimental effects of climate change — human activity releases an estimated 37 billion metric tons of carbon dioxide annually.
Mimicking the ocean's natural CO2 extraction processes
Several startups are developing methods to take on the gargantuan task of removing carbon dioxide from the atmosphere, including the Bill Gates-backed Carbfix, which extracts the gas from the air and turns it into a solid form.
To develop a technology that could carry out a process required at such a large scale, the team from UCLA turned to the natural world for inspiration. Their concept, outlined in a paper published in ACS Sustainable Chemistry & Engineering, is called single-step carbon sequestration and storage, or sCS2 for short.
"To mitigate climate change, we need to remove carbon dioxide from the atmosphere at a level between 10 billion and 20 billion metric tons per year," senior author Gaurav Sant explained in a press release. "To fulfill a solution at that scale, we’ve got to draw inspiration from nature."
Due to the fact that the ocean and atmosphere are in a state of equilibrium, the ocean essentially acts as a sponge for the atmosphere's CO2. However, as it is already saturated it can't take any more. If CO2 is removed in large amounts from the ocean though, it will then suck more out of the atmosphere.
This is the main idea behind the UCLA scientists' new technology, which is aimed at speeding up the process of turning carbon dioxide into minerals in ocean water. In lab experiments, the team tested a prototype that pulls in seawater and creates limestone and magnesite, the same materials created by mollusks to form seashells.
The machine can either gather the seashell-like material for use on land, or it can release it back into the ocean. The seawater used in the machine flows back out to the ocean, where it will then absorb more carbon dioxide.
More efficient, permanent CO2 extraction
One of the great benefits of this method is that CO2 levels are 150 times more concentrated in seawater than they are in the air, meaning any method extracting CO2 from the ocean is more efficient. The sCS2 method also develops hydrogen as a byproduct, which could be used to help power the machine or sold as fuel for hydrogen-powered vehicles.
Turning CO2 into seashell-like materials is also a simple and efficient method for storing carbon dioxide — other methods that extract the gas from the air, often have to compress it to keep it in canisters.
"Durable, safe, and permanent storage is the premise of our solution," said first author Erika Callagon La Plante, a former UCLA assistant project scientist who is currently an assistant professor at the University of Texas at Arlington.
However, the team does caution that removing CO2 from the atmosphere is "first and foremost" an economic challenge, given the scale of the task. They say it would take approximately 1,800 of their sCS2 plants to remove 10 billion metric tons of carbon dioxide each year, costing trillions of dollars.
The research team's next step is to run real-world experiments so that they can improve their technology by collect data they couldn't acquire in the laboratory.