Carbon Dioxide to Baking Soda: A Second Take on the Concept

The University of Calgary is working on a tower that will capture carbon dioxide in the air, rather than through a smokestack, with a chemical formula that seems to have some momentum.

There is a lot more CO2 floating around the atmosphere than coming out of smokestacks. Many people emitting CO2 also can’t or won’t pay for scrubbers. Thus, this could be a way to capture the billions of light and occasional polluters out there, assuming someone is willing to pay for the devices.

Climate scientist David Keith and his team showed they could capture CO2 directly from the air with less than 100 kilowatt hours of electricity per ton of carbon dioxide with the tower. The tower also was able to capture the equivalent of about 20 tons per year of CO2 on a single square metre of scrubbing material.

What’s the secret? The tower is coated with sodium hydroxide. CO2 comes in contact with it, a chemical reaction (with a little electricity helping) takes place and the harmful gases are captured so they can be sequestered. It’s similar to how a catalytic converter works in your engines.

Sodium hydroxide is also the secret ingredient in a CO2 capture device made by Skyonic. (see original article on Skyonic here. What do you know? I wrote it.) Skyonic mixes the two chemicals and comes out with sodium bicarbonate, or baking soda, and other byproducts. It is running trials in Texas. Skyonic, though, is selling its device to utilties.

Personally, I think these gas-to-solid systems will dominate carbon capture. It’s more efficient to shuttle the gas, in a gas or liquid form, into underground caverns, but that faces a huge uphill battle politically. Trying to turn CO2 into fuel is going to be tough. That leaves mineralization. Another company to watch: Carbon Sciences, which turns CO2 into calcium carbonates.