When I tell molecular biophysicist Deane Little that I'm extremely skeptical about carbon capture and sequestration, he looks up from the solar-powered chemical reactor he's just set up in the window and responds, "We are, too."
For Little and his colleagues at New Sky Energy, successfully capturing carbon from the air doesn't involve a giant fake tree or pumping huge amounts of CO2 into the ground. Instead, they've developed a chemical system that elegantly turns CO2 and salt solution into valuable products.
Little, who is New Sky's CEO and chief scientific officer, walks me through their technological process in a sunny conference room in downtown Boulder, Colo., where the company is based. He explains that he first learned how to capture carbon using sodium hydroxide, also known as caustic soda, when he was working on the biodegradation of chlorinated solvents at Oak Ridge National Laboratory. Caustic soda, a major industrial chemical, can fix an impressive amount of CO2. It's broadly used in industrial manufacturing, including paper, soaps and detergents.
Unfortunately, producing sodium hydroxide is both energy intensive and creates chlorine gas as a byproduct. You might know this highly toxic, volatile stuff from its use as a poison during World War I. Yeah. Bad. Little decided to search for an alternative sustainable process and, with less than $50 worth of materials from a local hardware store, he built a prototype reactor that could take water, a salt solution, as well as atmospheric CO2 and, with an electric charge, turn it into an acid, a base, hydrogen and oxygen. Then, in a second step, base reacts with CO2 to form safe carbonates such as baking soda or limestone.
"No one else can do what we propose to do," says New Sky's executive vice president for business development Mark Ashford. Anyone else using conventional chemistry would have to make nearly a ton of chlorine gas every time they convert a ton of CO2.
Unlike chlorine gas, the carbonate byproducts from their system are extremely valuable. We not only eat baking soda, but calcium carbonate can also be used in building materials. The need to mine salt for this could pose a problem, except that new desalination efforts mean opportunities to collect and use unwanted salt. The electrical charges will come from solar panels or other renewable energy sources.
"We're moving up in prototypes," chief technical officer Joe Kosmoski adds, showing me one of them, which looks like two 12-inch square tiles in a sandwich. Now the plan is to scale the reactors up physically and then out, he says, similar to the way batteries are scaled by stacking electrodes.
"Not to sound like a jerk," I say to the guys, "but why hasn't anyone else done this before?" Little chuckles and tells me I'm definitely not the first person to ask. Knowledgeable scientists realized that one could use base to capture CO2, he says, but the nasty chlorine remained a hurdle and dealing with that is difficult and expensive. In addition, Kosmoski points out, there was less pressure to reduce CO2 in the past and not much incentive to switch from the established production methods.
Currently New Sky is setting up a large pilot project in the Fresno area. The project is funded by a water agency that sells irrigation water to farms and one of the partners is a desalination plant. Using a reactor that could fill a tractor trailer, New Sky aims to prove that their system can desalinate water, precipitate the sodium sulfate salt, and end up with clean water and useful products that are worth more than the water's value. In five or six years, the company would like to be forming partnerships to make brand new products with the carbonates, such bricks.
I watch as Little hooks the reactor to a solar panel. Sure enough, the salt solution flowing from a glass vase through the reactor comes out into brightly colored acid and base in a matter of moments. Closing the carbon loop never looked so bright.
Photo: New Sky Energy's reactor produces acid and base using a charge from the solar panel at left. Credit: Deane Little.