University of Calgary researchers are attempting to scrub carbon dioxide out of thin air, using new technology that could help Alberta's oil and gas sector and other industries reduce their greenhouse gas emissions.
In the first large-scale experiment of its kind, the researchers have built a six-metre-high tower on the U of C campus that's designed to chemically capture carbon dioxide directly out of "free" or ambient air.
Research team leader David Keith says if the technology works at a reasonable cost, it could lead to industrial-sized facilities in Alberta and elsewhere in the world that scrub CO2 out of the air and pump it underground.
That would keep the greenhouse gas out of atmosphere where it's accumulating and heating up the planet.
|Mike Sturk, Business Edge|
|David Keith, bottom right, and his research team of Kenton Heidel, bottom centre, Leif Menezes, on ladder, and Joshua Stolaroff, top, stand ready at the CO2 capture tower.|
"We're trying this experiment on a much bigger scale than anybody else has tried," says Keith, the U of C's Canada research chair in energy and the environment, and a professor of chemical and petroleum engineering and economics.
The big advantage of direct air-CO2 capture technology "is that you can effectively capture CO2 from any part of the world economy with equal ease, because CO2 is well mixed in the air," he says.
Keith is an internationally recognized expert on carbon dioxide capture and storage, who was recruited last year by the U of C's Institute for Sustainable Energy, Environment and Economy from Carnegie Mellon University in Pittsburgh.
"I think it's an incredibly good idea, certainly worth pursuing," says Mike Singleton, director of technology, planning and integration at Suncor Energy.
Singleton, who stressed he was giving his personal view and not speaking on behalf of Suncor, said the technology would provide the oil and gas industry with another way to reduce its overall greenhouse gas emissions without having to cut back emissions at individual oil sands plants and refineries.
Instead, emissions could be captured directly from the air and pumped underground into geological reservoirs for "sequestration" or permanent storage.
The challenge will be to make the technology cheaper than current methods of managing carbon dioxide emissions, Singleton says.
It is expensive to capture anything but the purest gas stream of CO2 at individual industrial plants, he says.
Another problem is that most plants in Alberta with sizable greenhouse gas emissions - such as large coal-fired power plants west of Edmonton - are distant from geological storage sites.
That means a costly new pipeline network will be needed to transport the gas.
Right now it is more affordable for many companies to reduce their greenhouse gas emissions by buying emission-reduction credits from other companies whose operations keep CO2 out of the atmosphere.
Epcor Inc. announced last month it is buying 60,000 tonnes of CO2 credits from a southern Alberta gas plant to offset greenhouse gas emissions produced by Epcor's coal-fired Genesee 3 power plant west of Edmonton.
The Edmonton-based utility is buying the credits from Taylor NGL Ltd. Partnership, which is injecting CO2 recovered from its Turin sour gas-processing plant near Lethbridge into a depleted natural gas reservoir.
Epcor has bought 60,000 tonnes of credits this year and has an option to buy 70,000 tonnes a year through 2012.
"Epcor believes we can achieve made-in-Canada solutions to climate change, and this project shows the potential of geological sequestration," says Whitney Rockley, the company's director of environment and analytics.
Researcher Keith notes that facilities capable of capturing CO2 directly from the air wouldn't need to be located near an industrial plant that emits greenhouse gases.
"You could put this sort of facility anywhere," he says. "You put it in a place where CO2 disposal costs are cheap, and where you have access to an energy source that is going to drive this system because it takes energy to capture CO2 from the air."
Pulling carbon dioxide out of thin air is also expensive.
However, direct air-CO2 capture may be able to compete with technologies for reducing CO2 emissions from vehicles and other small or mobile sources, where costs are much higher than for capturing CO2 at individual industrial plants, Keith says.
"It looks like this technology might be more cost-effective than putting hydrogen fuel cells in our cars."
For their experiment, being funded mostly by the Canada Foundation for Innovation, Keith and his team built a tall tower in the high bay laboratory of the U of C's CCIT (Calgary Centre for Innovative Technology) building.
The tower is equipped with a chemical scrubber that removes CO2 from Calgary's air using a spray of sodium hydroxide solution.
The chemistry employed in the experiment is very similar to that used in the pulp and paper industry, and the technique has worked on a much smaller scale in the laboratory, Keith says.
Based on the physics and chemical engineering involved, "there's no question it is possible to do it. The question is: Can we do it at a reasonable cost?" Other scientists think the technology is worth pursuing.
One of Keith's research collaborators in the United States, Columbia University physicist Klaus Lackner, has proposed building synthetic "trees" that would chemically draw CO2 out of the air, like plants do through photosynthesis.
One synthetic tree would remove 90,000 tonnes of CO2 per year - equivalent to taking 15,000 cars off the road.
"Whichever way we look at it, I think sequestration will play a role in the future," Singleton says.
(Mark Lowey is a freelance writer in Calgary, the editor of EnviroLine and a communications consultant with the Institute for Sustainable Energy, Environment and Economy.)