ADVERTISEMENT

Can CO2 Be Captured and Sold?

A Canadian researcher hopes to prove that by running CO2 through pulverized rock, he can both capture the greenhouse gas and sell the resulting carbonate
cement plant



flickr/KaCey97007

A researcher is about to test a technology that he says could be a breakthrough for curbing greenhouse gas emissions from coal plants, natural gas generators and other industrial facilities.

Canadian professor Guy Mercier's answer to curbing fossil fuel emissions is literally set in stone. With $300,000 in new grant money from Carbon Management Canada, a network of academic centers, he plans to run gas emitted from a Holcim cement plant through pulverized concrete and rock.

If everything goes to plan, the resulting chemical reaction will capture 80 percent of the carbon dioxide from the tested gas stream at a lower cost than other capture methods.

In theory, the cost of capturing CO2 could head to zero, since the resulting magnesium carbonate formed from chemical reactions between cement plant emissions and rock can be sold at a profit to the wastewater and steel-making industries, Mercier said.

"This can be applied anywhere there's a huge amount of CO2 emitted from smokestacks," said Mercier, an environmental technology professor at the Institut National de la Recherche Scientifique, part of the University of Quebec. He is working with researchers from the University of Calgary and the University of Melbourne on the project.

Tweaking the rock mixture would allow the work to be applied to coal, he said.

Mercier's work fits into a growing industry focus on carbon capture and utilization, or using captured CO2 for commercial products, rather than storing it underground, where the gas holds no economic value. Earlier this year, the carbon capture industry added a "U" to the title of an annual CCS conference in Pittsburgh, making it the carbon capture, utilization and sequestration conference.

Use it; don't lose it
That "U" typically means enhanced oil recovery, but there is a growing interest in alternative funding options, such as using captured CO2 for algae production or pulp and paper processing. The firm Skyonic, for example, announced a deal earlier this year to capture carbon dioxide from a cement plant and turn the gas into baking soda, hydrocholoric acid and other products.

While some experts think these solutions are impractical for wide-scale use, others say there is a need for additional tests capturing carbon dioxide from cement, one of the highest-emitting industries.

Mercier's work comes as Nature Climate Change published a perspective piece Sunday, "Last Chance for Carbon Capture Storage," saying governments need to either increase their commitment to carbon capture technology or "accept its failure and recognize that continued expansion of power generation from burning fossil fuels is a severe threat." Carbon capture has never been proved at scale in the power sector but is considered the chief way to control heat-trapping emissions from coal, gas and other fossil fuels.

Mercier said he chose a cement plant to test his patented technology for the simple reason that Quebec does not have coal-fired power plants. It also holds a large number of abandoned mines with adequate rock supplies, he said.

He will blend magnesium and calcium-rich rocks with concrete, turn them into a powder, and place the pulverized mix into a reaction chamber attached to the emission stream from the Holcim plant, about an hour from Montreal.

Trapping the carbon in rock
Once the CO2-rich flue gas hits the pulverized rocks, the resulting chemical reaction produces a solid of magnesium carbonate. That solid then can be sold to wastewater operators for water treatment, and to the steel industry, which can use it during the manufacturing process, said Mercier.

The chemical reactor "is like a small plant within the big plant," he said.

The initial field test at the cement plant -- which will begin in late 2013 and run for a year -- will be small, on less than 1 percent of the plant's emissions. That will require about 1.5 tons of rock, Mercier said.

According to his economic modeling, the rough cost of capture will be $35 per ton of CO2, a figure that is at least half the cost of other capture methods, such as amine scrubbing. The cost of retrofitting an old coal plant with capture equipment, for example, could in theory run to more than $100 per ton.

With the potential sale of magnesium carbonate, the cost could flip into a net financial gain, said Mercier.

Some carbon capture experts are skeptical, however. Howard Herzog, a senior research engineer at the Massachusetts Institute of Technology, said "it's hard to believe this could be a major breakthrough."

"It could be a niche market," he said.

The idea of forming carbonates has been examined before, and rejected by some because of the magnitude of rock that would be needed to capture CO2 at commercial scale, he said. It also is tricky to perfect the chemical reactions and ensure they move fast enough, he said.

If the reactions are not efficient, the cost would rise significantly, he said. Many high-emitting sources also may not have appropriate rock available to do similar work, according to Herzog.

"This is officially bollocks (baloney). There are always mass transfer and cost issues that overwhelm even pilot scale projects and the costs becomes exceedingly high quickly," added Julio Friedmann, a CCS expert at U.S. Department of Energy's Lawrence Livermore National Laboratory.

Will future research be funded?
Mercier acknowledged the difficulties but said he had tweaked the combinations of metals in his chemical reactor to address prior problems. He has been working for more than two and a half years on finding the right types of rocks with the right combination of minerals to react efficiently with emissions from burned fossil fuels, he said.

In a report last year, the Global CCS Institute found that technologies reusing captured CO2 could play a role in controlling emissions in some markets, even if their global potential for controlling the greenhouse gas is small.

Regardless of whether Mercier's test works, it signals Canada's importance with research on capturing CO2, considering global financial cutbacks in the energy industry, another U.S.-based analyst said. The country is building what could be the world's first large-scale, integrated demonstration of carbon capture and sequestration technology on an existing coal plant at SaskPower's Boundary Dam Power Station in Saskatchewan.

That project took a step forward yesterday with SaskPower's announcement of the signing of an agreement with oil giant Cenovus, which agreed to purchase all of the captured CO2 from Boundary Dam for use in enhanced oil recovery operations near Weyburn. SaskPower said the project -- which would capture and store one million tons of metric CO2 annually from a coal plant -- was on track to become operational in April 2014.

Similarly, Canada has been aggressive in funding research like Mercier's and carbon capture research on oil sands operations via national funds and a $2 billion money pot from Alberta, said the analyst. Mercier's grant came as part of a $3.75 million distribution last month from Carbon Management Canada on various carbon control technologies.

The bulk of global carbon capture funding, though, came several years ago, when national climate change legislation was in play in both the United States and Canada. The $2 billion pot in Alberta is funding several commercial-scale projects that are close to construction, but no similar scale of money has come forth since then.

Richard Adamson, managing director at Carbon Management Canada, said the Albertan and Canadian governments supplied $50 million in funding two years ago, but it is uncertain whether similar amounts will be forthcoming.

As for Mercier, the scale-up of his project from less than 1 percent of the cement plant's gas to a commercial level will depend more on money than on technological success, he said.

"A lot will depend on how badly companies need magnesium carbonate," he said.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Holiday Sale

Give a Gift &
Get a Gift - Free!

Give a 1 year subscription as low as $14.99

Subscribe Now! >

X

Email this Article

X