Direct air capture plant turning CO2 into baking soda

Erasing emissions – Turning CO2 into baking soda

Image credit: Climeworks AG.

If we want to save the planet it’s probably not going to be enough just to reduce emissions. A lot of damage has already been done and to avoid the long-term consequences we need to deal with the CO2 that’s already in the atmosphere. Planting trees is one way of doing this, a potentially more efficient way to accomplish this is direct air capture plants.

What is direct air capture?

Direct air capture is a technology that basically sucks CO2 emissions out of the air and removes them from the atmosphere. A typical direct air capture plant is covered in giant fans that suck in air which then is transported through filters that chemically separate the CO2 from the air. The filters are then heated which captures the CO2 and cleans the filter. The CO2 that’s been captured can either be used for products or be liquified and stored indefinitely in basaltic rock.

It’s a very promising technique but direct air capture has a major flaw – the cost. It costs approximately $600 dollars to capture one ton of CO2. Climate models predict that we need to capture 10 billion tons of CO2 yearly by 2050. Let me write out the price tag of that for you: $6’000’000’000’000, that’s 6 trillion dollars per year.

The solution – Turn CO2 into baking soda

A recent study published by researchers at Lehigh University in Pennsylvania proves that a newly developed material could reduce costs greatly by basically turning CO2 into baking soda. It works in a similar way to the filters currently used in direct air capture plants but by incorporating copper in them the researchers tripled the efficiency.

According to the study they absorb up to three times more CO2 and the researchers believe that the material can be produced in bulk rapidly. It would undoubtedly make it cheaper to capture carbon and the cost-cutting does not end here.

Storing the captured carbon is expensive and requires a lot of energy. The current method heats the filters, pressurizes the carbon, and then liquefies it. The researchers discovered that they instead could simply expose the materials to seawater. The seawater starts a reaction that turns the captured carbon into sodium bicarbonate, also known as baking soda. Storing sodium bicarbonate would be a lot simpler as well and in the end, it could potentially cut the cost from $600 to below $100 per ton.

Big, but unproven potential

Even if we are still talking about an enormous cost for all of the carbon we need to capture, $100 is an important line to cross. Basically, $100 seems to be the limit for what private companies are prepared to pay for captured carbon. If the technique can be as efficient as the research report shows it has huge potential.

The technology is still unproven in the field but the researchers are currently working hard on getting large-scale testing outside the lab up and running. Hopefully, the new materials will prove to be as efficient as the inventors believe and offer a big part of the solution to global warming.