Researchers look to refine carbon-capture
It’s a “make or break” decade for humanity’s addiction to fossil fuel.
Carbon-dioxide emissions created by the combustion of oil, coal and natural gas account for 90 per cent of human-caused CO2 emissions each year. Without a determined effort to curtail or contain those emissions, the global warming implications could be dire.
Here in Canada, where energy is a primary export, the federal government has yet to jump off the oil bandwagon. But along with the government of Alberta, it’s currently funding work by independent scientists to develop and refine technology that could reduce or eliminate the amount of carbon released in industrial processes such as power generation and gas processing.
Researchers are looking for ways to refine existing technology such as the carbon capture and storage (CCS) methods pioneered a decade ago in Weyburn, Sask. — piping CO2 from an industrial plant in North Dakota and then pumping the gas underground, hopefully for good, at Weyburn.
The whole world is watching that project — it could show that it’s possible to develop a quick, practical fix for CO2 emissions while developing cleaner energy systems.
Removing CO2 from industrial emissions — for example, trapping it in smokestack filters at a coalfired power plant and permanently burying it underground — isn’t a panacea, but it’s an important tool. Ultimately, more than one solution will be necessary.
For example, one research group funded by Carbon Management Canada is developing a method of crystallizing carbon dioxide into a frozen “hydrate.”
Another is looking at containing it in a fluid, sort of like CO2 bubbles in a can of soda, and pumping it underground to support oil recovery while achieving a sort of balance between the CO2 coming out and the CO2 going in. The carbon dioxide would add bulk to the fluid, or slurry, making it cheaper to use.
Several groups are doing vital work to refine existing carbon capture methods — for example, developing more discerning and durable tools that would go down into underground carbon wells and do long-term monitoring to make sure the wells are leak-proof.
Others are farther out on the frontier.
“The ultimate goal is the same, but you can arrive by a different vehicle, if you will. You can do quite a significant amount of game changing in these kinds of situations,” said Sushanta Mitra of University of Alberta.
Mitra is one of the lead researchers on a project that is looking at feeding nutrients to the colonies of microbes that live in underground coal seams so that they produce commercial volumes of methane, or natural gas. The advantage is that you don’t ever mine or burn the coal, which produces more CO2 than methane — and there’s a possibility that such a source of gas could be sustainable, unlike a natural gas well.
“You are reducing the net CO2 emission. There are some rough calculations that show we can have a potential of 25-per-cent reduction or more,” Mitra said. “We are not doing any re-engineering of the bugs. The bugs are all there. We can augment the process, make them more productive in some sense.”
But cutting back on oil, coal and gas consumption would work best to slow global warming.
Shahin Dashtgard of Simon Fraser University noted that it could be cost effective to deal with, and even profit from, CO2 emissions from large-scale industrial sites. But for a much larger number of smaller sites, cheap containment will be the answer.
A petroleum geologist, Dashtgard is working with a group looking to overcome the cost of long-distance piping of CO2 for industrial processing by converting the gas to a stable frozen “hydrate” suitable for storage in the small, shallow spent wells that are scattered throughout northern Alberta. It’s an innovative idea, and also a possible solution to the worldwide problem of cost-effective sequestering of smaller amounts of CO2.
“The long-term answer to CO2 sequestration is going to be just reducing the amount of CO2 that’s produced,” Dashtgard said.
“In the medium term ... if people aren’t injecting it underground and making money off of it, no one is going to do it unless they’re forced to.”