To scrub climate-warming CO2 from the atmosphere, researchers in the U.K. are developing artificial trees that could make cap-and-trade systems more efficient.
What researchers are calling artificial trees, actually towers filled with various materials that adsorb carbon dioxide from the air, could play a major role in reducing climate change -- if they prove profitable.
"This is an industry still in its infancy," said Billy Gridley of Global Research Technologies, LLC, the company creating the C02-scrubbing towers. "This will eventually rival the size of today's energy markets."
GRT's artificial tree is based on an environmentally friendly resin, originally developed by Klaus Lackner, a professor at Columbia University in New York. The alkaline resin reacts with acidic carbon dioxide, holding it in place. After one hour exposed to the air, the resin is completely saturated with CO2.
Dry resin soaks up the CO2. Adding water releases the CO2, which is then captured and stored. Drying the resin again restores its abilities, a cycle that can be repeated indefinitely.
Over 24 hours Gridley estimates an artificial tree, containing about 32,800 feet of resin, will harvest about one ton of CO2 each day.
When the first artificial tree is ready, two to three years from now, it will cost about $150 for each ton, Gridley estimates. When the technology is fully mature, the price will be as low as $20.
GRT plans to sell the purified CO2 to a range of buyers. Oil and natural gas companies are probably the biggest customers for the artificial trees. Petroleum companies pump CO2 underground to raise the pressure and force oil to the surface. Greenhouses could pump in extra C02 to help plants grow. Fizzy soda drinks and sanding auto parts also require concentrated CO2.
All of these customers currently get CO2 by truck or by pipeline, most of which originates in Texas. The advantage of the artificial trees is that they can be placed next to whatever factory needs CO2 without having to ship it in.
Another use for the artificial trees would be in the cap-and-trade carbon credit system. The idea is that companies that produce CO2 would pay another company, like GRT, to get rid of it. The most likely place to put the C02 is in the salt-lined caverns that once held oil, a process known as carbon sequestration.
Wherever the CO2 is placed, at least it is out of the atmosphere, said David Keith, a professor at the University of Calgary in Canada, who developed his own artificial, C02-catching towers years ago and is working to refine his models. Keith, GRT, and other organizations aren't trying to profit from climate change; they are looking to prevent or at least slow it.
"Nobody doubts that this is doable," said Keith. "It's a matter of doing it at cost, and right now it's still unclear how that can be done."