From Synthetic Trees to Carbon Sponges: an interview with Scientist Klaus Lackner

March 18, 2008 |

It's not very often that a middle school science project results in a technology that could help avert a climate crisis. But when eighth-grader Claire Lackner wanted to prove that carbon dioxide could be cheaply captured from the air, something clicked for her father, Klaus Lackner, a scientist at Columbia University. Since then Lackner has succeeded in scaling up that science project to a level that might might allow humankind to pull carbon dioxide out of the air.

Last year he unveiled the world's first successful demonstration of air capture technology. His device, which he calls an "air extractor," can sop up carbon dioxide from the atmosphere like a sponge. Unlike carbon capture and sequestration devices, which act on the emissions of the power plant into which they are built, Lackner's air extractors can be placed anywhere, and act on carbon dioxide levels in the atmosphere as a whole.


lackner AC.jpg

An artist's rendering of an "air extraction" prototype being developed by Global Research Technologies and Klaus Lackner from Columbia University.

Many people who follow climate debates have seen photos of futuristic power plants that capture the carbon dioxide and pump it into the ground for storage, which some scientists say can reduce the emissions of those plants by 80 - 90 percent. How is "air capture" technology different carbon capture and storage?

With air capture, it doesn't matter where you take the carbon dioxide out -- you can collect carbon dioxide from everybody anywhere. You can emit emissions in New York and I can capture it in Australia. In the long term, this allows you to actually get carbon dioxide levels back down.

Would you store the carbon dioxide once you capture it?

Carbon dioxide capture can deliver the carbon dioxide for any sequestration method. The challenge is capture, not storage.

There are many good places to store carbon dioxide underground, but probably not enough to do it at a full scale. I'm focused on making carbonate rock out of carbon dioxide, which would neutralize it. This is what nature eventually does anyway. Our goal is to take a process that takes 100,000 years and compress it into 30 minutes.

synthetic trees.jpg

A computer-generated image of Lackner's "synthetic trees."

How did you first become interested in air capture technology?

My daughter Claire's school science fair project in 1999 helped me quantify a few things I had been wondering about air capture. She wanted to see if she could scrub carbon dioxide out of the air. So we went to the pet store, bought at aquarium pump, and bubbled air through a solution of calcium hydroxide and sodium hydroxide, and let it bubble all through the night. In the morning she poured acid in and measured the amount carbon dioxide that would come off. It turned out she'd collected about half the carbon dioxide that had passed through the pump.

From there, you went on to develop the first successful air capture prototype. Is this something that's ready to be commercialized?

We developed a pre-prototype that shows that all the pieces of this system work. Within two to four years it should be ready to be commercialized. The first time around it's always too expensive, but every time you do it, it gets a little cheaper. I think in the long term, the cost of capturing carbon dioxide from air will not be terribly different from conventional flue gas scrubbing, about $30 per ton of carbon dioxide, which corresponds to about 25 cents on the gallon.

That's almost nothing.

Even if I'm wrong, and its $50, that's not a terrible number. But Global Research Technologies won't hit even that first time around.

Some people worry that carbon capture and storage, and thus air capture too, will discourage our society from moving to clean energy alternatives.

Fossil fuels are not running out anytime soon, and if we were to turn all of them into carbon dioxide, we'll have a climate catastrophe. We may run out of oil and gas; you can be skeptical of that. But we won't run out of coal. We either abandon fossil fuels immediately -- within the next 50 years -- or figure out a way to do CCS.

Some people believe that to fix global warming, we have to completely change our lifestyles. But tying lifestyle changes to the carbon dioxide debate will make you fail in both. We can have a long discussion about whether people should change their lifestyles, but if you try to solve the problem this way, people will say, "Go fly a kite, we're not interested." But if I say, "You don't have to change your lifestyle, just give me 25 cents per gallon," I think I can get away with that.

So you don't foresee us moving away from fossil fuels so long as they're available.

There is this slogan that Shell has been using lately: "The Stone Age didn't end because we ran out of stones." My corollary is: "We use far more stones today than the Stone Age ever did."

One hundred years from now I could imagine that we won't think of ourselves as a fossil fuel burning country, but we'll still be consuming it at a higher rate because it's cheap and readily available. If oil does run out, then we'll move to coal and synthetic fuels.

The discussion of synthetic fuels is something that's new to me, and to the public. How do they relate to air capture?

Air capture can be used to make synthetic fuels out of renewable energy, water, and carbon dioxide. The energy is used to remove the oxygen from the water and the carbon dioxide, and to create a synthetic fuel that, when it is consumed, regenerates the water and the carbon dioxide. In order for this cycle to work, one needs air capture to recapture the carbon dioxide that has been emitted at the point of consumption.

There's such a small amount of US Federal R&D money that goes into energy research. Have you spoken to the Federal Government or members of congress about supporting this?

Yes. Through the Earth Institute we've put together a CCS task force to make that point. Energy is really a place where more technology is absolutely necessary. The challenge here is about how to have the right public policies to make it happen.

There aren't that many large scale sources of energy could be tapped at the scale the world needs them. Hydro will never be enough, and neither will wind. Solar, nuclear, and fossil could be enough, but they all have flaws. If we don't place big bets on all three, we could find ourselves with none of them working, and we'll have energy crisis of unprecedented proportions.


Thanks for this article, we need to keep this in front of the public and keep pushing to get these things built...
I linked to the article on my website
xanga kingofallclergy

By ed on 2008 11 07

Thanks for this interview!

There's also now an NPR interview online for those who want to hear more from Prof. Lackner-

Stephen Miller

By stephen miller on 2008 06 10