A CO2 Solution bioreactor, like the one shown in the diagram above, contains an enzyme-bonded packing material that interacts with a water solution pumped in from the top and smokestack emissions that enter and bubble up through the bottom. The carbon dioxide in the emissions stream is captured by the enzymes on the surface of the packing material and converted into bicarbonate ions. Cleaned-up air then escapes from the top while the bicarbonate solution exits the bottom. The bicarbonate, in a separate process, can be extracted from the solution and made into compounds, such as limestone, for use by industry.
CO2 Solution Inc.
A new process turns the greenhouse gas into useful materials.
A new way to capture carbon dioxide from smokestacks produces a raw material that can be sequestered underground or turned into substances such as baking soda, chalk, or limestone. CO2 Solution, of Quebec City, Canada, has already tested its process on a small municipal incinerator and an Alcoa aluminum smelter. Its scientists are now working with power-plant equipment giant Babcock and Wilcox on ways to adapt the technology to a coal-fired generating station.
The company has genetically engineered E. coli bacteria to produce an enzyme that converts carbon dioxide into bicarbonate. The enzyme sits at the core of a bioreactor technology that could be scaled up to capture carbon-dioxide emissions from power plants that run on fossil fuels--a timely development as political support grows for cap-and-trade schemes that assign a market value to carbon.
"So far we have a small prototype," says Sylvie Fradette, vice president of research and development at CO2 Solution. "Next we have to look at what's necessary for a very large prototype or pilot plant."
The enzyme, called carbonic anhydrase, ordinarily processes carbon dioxide produced in organisms. In E. coli it plays an essential role in metabolism. As a doctoral student in the 1990s, Fradette led a research team at the University of Laval that isolated the enzyme, immobilized it, and figured out how to reproduce it. After getting her Ph.D. in chemical engineering, she joined CO2 Solution in 1998. "We thought it would be interesting to use this enzyme to replicate what it already does so well in nature," Fradette says. "We found it was very efficient in doing the CO2 transformation."
There are many other ways of capturing carbon dioxide from industrial and power-plant flue stacks, but separation of the carbon-dioxide stream from other gases and pollutants makes most of these approaches energy intensive and therefore quite costly. Fradette says CO2 Solution's approach--which does not require separation of carbon dioxide from other gases--can be applied to any gaseous effluent that contains carbon dioxide, so it would be ideal for both conventional coal plants and newer "clean coal" facilities based on gasification.
The bioreactor is a long cylinder containing a packing material that acts as a solid support for the enzyme. The surface of this material has been chemically modified so that the enzymes attach securely. At the top of the cylinder, a water solution is pumped in and flows around the packing material, while gases from a smokestack enter the bottom of the cylinder and bubble up through the solution. The carbon dioxide is absorbed into the solution and then interacts with the enzymes, which convert the greenhouse gas into bicarbonate ions. To end the process, cleaned up air escapes from the top while the bicarbonate solution is extracted for further processing--either back into pure carbon dioxide for long-term geological storage or into a carbonate compound, such as limestone, that can be used by industry.
A New Jersey plant is planning to put ocean-floor carbon sequestration to the test.
The great carbon shortage of 2050
I always thought that when humanity learns to make building materials from carbon like plants do, the demand will eventually outstrip production and we'll go into a carbon shortage crisis where they'll begin mining coal and that sequestered CO2 for manufacturing use.
Re: The great carbon shortage of 2050
We already have that amazing building material. It is called timber. We just need to find a better way of producing and harvesting than the one we use now.
Re: The great carbon shortage of 2050
My jolly how the world leaders do not see that is beyond me. All this bull dust about emissions! One decent volcanic eruption will put all of humanity efforts of decades to a shame, do they not realize it? What fools! Yet deforestation continues I believe at a football field avery second! HOW LONG!!!??? This is the real problem and how easily fixed! But that will not put $$$$$$$$$$$$$$$$$ in politicians pockets! So do not expect correction soon! Any carbon trading is a pump for $ out of your pocket! Target of any power hungry poli.
Re: The great carbon shortage of 2050
<i>One decent volcanic eruption will put all of humanity efforts of decades to a shame, do they not realize it?</i>
They don't realize it, because it isn't true. CO2 emissions from fossil fuel combustion are much larger than emissions from volcanic sources, and CO2 levels are rising higher than they've been in at least tens of thousands of years (your putative 'decent' volcanic eruptions notwithstanding).
Re: The great carbon shortage of 2050
what about buildings out of carbon nanotubes
Re: The great carbon shortage of 2050
I wrote about this in an editorial on Nanotech-news that no one seems to have noticed.
CNT's are amazingly useful creations... CO2 from exhaust gas can be used as feedstock in conversion machinery at plants at small energy cost and locally derived CNT's in quantity can be stored, used in building construction, roads, etc.
The process is called recarbonization and produces
a viable solution to the excess CO2 problem.
Alan Shalleck
Nanoclarity LLC
www.nanoclarity.om
Tracks: path: a line or route along which something travels or moves
http://www.google.com/search?q=define%3Atrack&btnG=Search
Tracts:An area of land bounded by features as described for blocks, or by municipal or county boundaries
http://www.google.com/search?num=100&hl=en&q=define%3Atracts&btnG=Search
If you don't believe google, you HAVE to believe Monty Python.
FATHER: Don't like her?! What's wrong with her? She's beautiful,
she's rich, she's got huge... tracts of land.
http://www.sacred-texts.com/neu/mphg/mphg.htm
There is no need for capturing carbon. With a for the world little investment (compared to for instance investments in defence or agriculture subsidies) both world energy needs and climate problems can easily be solved. Read for instance http://www.greeninventions.net/wiki/Portal:Solar.
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
On Twitter
Become a Fan on Facebook
Subscribe to the Feed
hsfrey
13 Comments
Half a solution
Where do you get all the Calcium or other cation to combine with the bicarbonate? Make it from limestone? <g> You're going to need vast quantities to make a dent.
So, what cation is very common, easily isolated without a lot of energy, and which has an insoluble carbonate?
This sounds like half a solution to the problem. But not even that - you don't need the bugs - just dissolving CO2 in water gives bicarbonate.
Reply
kearns
30 Comments
Re: Half a solution
Yes, and sea creatures like coral convert dissolved C02 in the oceans into coral reefs. If you could speed up the process temporarily the oceans could conceivably clear the air of the excess CO2. Turning it off would be the problem, however. You could precipitate an ice age if too much CO2 was removed.
Reply
pfdietz
2 Comments
Re: Half a solution
It's my understanding that precipitation of calcium carbonate would actually cause a net release of CO2 from the ocean into the atmosphere. This is because the inorganic carbon in seawater is mostly in bicarbonate ions, so the reaction is Ca(+2) + 2 HCO3(-) --> CaCO3 + CO2 + H2O.
On a time scale of centuries, CO2 will be absorbed into the ocean by a process involving the dissolution of calcium carbonate, not its deposition. On a longer time scale, additional positive ions are added by weathering, and this ultimately leads to carbonate deposition.
Reply