CARBON CAPTURE UNIT: The Mountaineer power plant near
New Haven, W.Va., uses chilled ammonia technology to grab carbon
dioxide from the coal-fired power plant's flue gas for subsequent storage underground.
Image: Courtesy of American Electric Power
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Over the next five years at least half a million tons of carbon dioxide will be injected into rock deep underneath the Mountaineer power plant near New Haven, W.Va. Although that is less than 0.00001 percent of global emissions of the greenhouse gas and less than 2 percent of the plant’s own CO2 output, the sequestration, which begins this week, marks the first commercial demonstration of the only available technological fix for the carbon problem of coal-fired power plants, one that many coal facilities around the world hope to emulate.
Coal accounts for roughly 50 percent of the electricity generated in the U.S. and as much as 75 percent of the electricity generated by American Electric Power, says Nick Akins, executive vice president of generation at the utility, which owns Mountaineer. The plant can pump out 1,300 megawatts of electricity, making it one of the single largest coal-fired power plants in the U.S. and a leading source of CO2 emissions. (The top emitters of global warming pollution—China and the U.S.—burn nearly four billion tons of the dirty black rock a year.)
As a result, everyone from coal companies to environmental groups have identified carbon capture and storage, or CCS, as critical in enabling significant and rapid cuts in greenhouse gases. But there have been only a handful of demonstrations of the technology to capture the gas and, outside of using CO2 to pump more oil out of the ground, even fewer attempts to store it.
To capture CO2 from its smokestacks, Mountaineer will employ so-called chilled ammonia technology, which relies on ammonium carbonate chemistry to pull CO2 out of the exhaust gases. (The other two basic capture technologies either burn coal in pure oxygen to produce a CO2-rich emissions stream or siphon off the CO2 made during the gasification of coal.) Mountaineer takes the captured CO2 and compresses it to at least 2,000 pounds per square inch, liquefying it and pumping it roughly 8,000 feet down into the ground. That deep, the liquid CO2 flows through the porous rock formations, adhering to the tiny spaces, slowly spreading out over time and, ultimately, chemically reacting with rock or brine. “We’re not going into a salt cavern; we’re not going into an underground river. We’re going into microscopic holes,” explains geologist Susan Hovorka of the University of Texas at Austin, referring to CCS in general. “Add it up, and it’s a large volume.”
In fact, the Department of Energy estimates that the U.S. has the geologic room for 3.9 trillion tons of CO2 underground, more than enough for the 3.2 billion tons emitted every year by large industrial sources.
The two geologic formations below Mountaineer are the Rose Run Sandstone and Copper Ridge Dolomite, which run underneath layers of relatively impermeable rock that will keep the CO2 trapped. “Part of our project is to kind of take those through their paces and get an idea of their acceptance of CO2,” says Gary Spitznogle, a CCS engineering manager at American
Electric Power. After all, a similar effort in Ohio revealed that formations there stored less CO2 than expected. The company will monitor the CO2 via three specially drilled wells, in addition to the two wells for pumping the CO2 down in the first place.
The process of capturing and storing carbon dioxide may be simple chemistry and geology, but it has significant industrial costs. American Electric Power alone will pay $73 million for just the capture technology at Mountaineer and has asked for $334 million in federal stimulus—half the total cost, the company says—to scale up the project to nab roughly 20 percent of the plant’s emissions in future years.
Despite the steep price of CCS, Mountaineer is not alone. In the U.S., utilities are planning multibillion-dollar power plants that will incorporate CCS; by 2011 Alabama Power may outsequester Mountaineer and bury 150,000 tons of CO2 from its Plant Barry in the Citronelle Oil Field. Abroad, China has several test facilities funded in part by Australia, and in Iceland an international consortium of researchers will pump CO2 into underground basalt where it will react to form a carbonate mineral.
But even if CO2 is permanently locked away in rock, other environmental problems surrounding coal remain. The technology does nothing to remedy the impacts of coal mining, particularly mountaintop removal, or residual toxic fly ash, among other issues. Moreover, although the Environmental Protection Agency has begun to craft rules to regulate the CO2-injection wells, it is still unclear who owns the pore space resource as well as who assumes liability in the event of an accident, such as a sudden, geyserlike release of the gas.
Nevertheless, given looming regulation on emissions, utilities are anticipating extensive CCS installation in just the next few decades. “Our first full scale would be around 2015, and by 2025 we would have a pretty considerable amount constructed on large coal units,” Spitznogle says.
That means one thing: higher electricity prices. In May 2007 the Department of Energy estimated that capturing 90 percent of the CO2 with amine scrubbers would make electricity at a cost of more than $114 per megawatt-hour, compared with just $63 per megawatt-hour without CO2 capture. For the consumer, the extra cost would amount to about $0.04 per kilowatt-hour— a necessary price, perhaps, for less of the warming gas in the atmosphere.
This story will appear in the November 2009 print issue.
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21 Comments
Add CommentOne problem that is not addressed in sequestering is that for every Carbon atom 2 atoms of Oxygen are also locked up forever. Does this not cause reduction in oxygen levels in the atmosphere? Photosynthesis not only removes Carbon but also release oxygen. So is sequestering actually solving a problem or creating another one?
Reply | Report Abuse | Link to thisSuch CCS technology has one major drawback : It does nothing to eliminate the CO2 already released into the air by power plants and other sources and that will go on causing climate change far into the future. This is where any subsidies must include technology to sequester atmospheric CO2. Check out www.eprida.com to see how a small group of dedicated scientists have already cracked the problem economically...
Reply | Report Abuse | Link to thisSince mass produced nuclear is about $20 a megawatt hour and releases no mercury arsenic particles radiation or CO2 into the air, why are we bothering with this nonsense. Whoops forgot its all those campaign donations from Big Coal to benefit our corrupt politicians.
Reply | Report Abuse | Link to thisOxygen loss is really not a problem. The oxygen coming out of photosynthesis is ultimately the result of combining CO2 and water. As far as plants are concerned globally, there is an infinite supply of water, and there is going to be plenty of CO2 regardless of how much is sequestered, especially since no one is aiming to pull the level down below pre-industrial, when everything seemed to have enough oxygen...
Reply | Report Abuse | Link to thisPlus, when the plants die, the CO2 is gassed right back out, usually by the organisms that decompose them. Which is why "plant more trees" is not the answer.
And while I agree with eco-steve, sequestering atmospheric CO2 is beyond a tall order at any significantly effective scale. It's ultimately a perfect solution if it can be implemented, though.
Technologly speaking,it is possible to eliminate the concentration of CO2 in the atmosphere significantly,but it will cause another problem ignored by scientist.It will definitely change the balance between the amount of O2 and CO2.Let's see.
Reply | Report Abuse | Link to thisTechonologly speaking,it is possible to decrease the concentration o f CO2 in the atmosphere .But it will of course give rise to the unbalanced level betweenCO2 and O2.We human beings need the Oxygen.Let's just see it!
Reply | Report Abuse | Link to thissethdayal I think you are neglecting to figure in the 9 - 15 billion dollar price tag of nuclear plant construction into your economics. Not to mention nuclear is not "clean", and it sends us down another path where the developed world operates under a double standard we would not apply to the rest of the world. Do you want to tell hostile regimes nuclear is the answer to their economic development?
Reply | Report Abuse | Link to thisMy concern is that I see very little difference in burying our pollution vs. emmitting it into the air. 100 years ago as we started to become industrialized I'm quite sure everyone thought the sky could handle whatever we put into it. It wasn't until people in our industrialized cities started dying that we realized there might be a downside. Now, less than 150 years later the other shoe has dropped. What happens in another 150 years when the environmental impacts of CCS become more clear? It seems to be the current challenge of scrubbing the atmosphere will be easy by compairison to remediating our aquifers and bedrock.
Google Westinghouse China AP1000 you'll see Westinghouse sold China four 1.2 Gigawatt nukes for $5.5 billion. Construction started a few months ago. I presume they intended to make money.
Reply | Report Abuse | Link to thisWestinghouse claims that for $1000 a kilowatt, they can mass produce and build nukes under a one time national regulatory environmental and safety license, ie no teams of 300 attorneys, billions in graft to corrupt officials and politicians, and endless environmental hearings on every project.
Ontario Hydro recently received a $7 billion bid from Areva for a 3.3 gigawatts one time build of nukes. Areva committed to $24 billion for all costs including fuel to run the reactors for 60 years. That's less than 2 cents a kwh.
If CCS makes dirty electricity more expensive, it will hasten the arrival of the day when wind and solar are at grid parity. (I'd imagine that in many areas they'll already be there by 2015, but it can't hurt.) I'd call that a benefit, not a drawback.
Reply | Report Abuse | Link to thisAs unpopular as the concept is, I feel that the only solution, in the short and long run is conservation. I live in a temperate climate and my house is all electric. We use on average about 800 KWH per month. I have no doubt that we could cut that usage by at least 30% without causing too much discomfort. Most of you out there use a lot more than 800 KWH per month and could easily reduce by at least 25%. There should be tax incentives for this approach. We should learn to conserve until coal is replaced and the new habits will allow us to better use the more expensive energy from carbon free sources. With electric cars as the goal of the future conservation is going to become even more important. Those electrons to charge those batteries to run those cars have to come from somewhere, and for the near future we will still be using coal. Lifestyle changes will be coming for all of us and we might as well get used to the idea. We simply cannot continue to rip up mountains to get dirty coal out and continue to deal with the environmental mess that coal causes.
Reply | Report Abuse | Link to thisAny of you folk out there read about coal ash and uranium residues in it poisoning ground water in the Punjab: http://www.guardian.co.uk/world/2009/aug/30/india-punjab-children-uranium-pollution/print
Reply | Report Abuse | Link to thisRegarding sequestration read this:
http://www.newscientist.com/article/mg20327273.800-climate-change-may-trigger-earthquakes-and-volcanoes.html?page=2
On Page 2: Bury Carbon and set off a quake.
Lower population of face extinction, honestly its too late now.
I'm not a fan of CCS for many of the reasons other commenters have mentioned. And to back up my thoughts, I ran some calculations based on ACTUAL reports on the numbers behinds CCS, and they just dont make sense! For instance, it takes a huge amount of energy to capture and pump the CO2. Where do you think that energy comes from: mostly COAL. So CCS reduces a plant's output by up to 25%, and that 25% has to be made up on the grid by other coal burning plants without CCS. You can see my whole analysis here. Please tell me if you can find any loopholes in my argument:
Reply | Report Abuse | Link to thishttp://blog.mapawatt.com/2009/03/13/carbon-capture-and-storage/
The real truth of the matter is that we are going to pay a whole lot of extra money to capture and pump CO2 into the ground when it is totally unnecessary to begin with. If everyone will recall, CO2 is not a pollutant to begin with. It is the product of respiration and complete combustion. Plants need it to grow and give off O2, the perfect God given cycle. And if everyone will also recall, CO2 is approximately 350 parts per million in the atmosphere which is way less than 1% and has been PROVEN to be even higher in the past. Warming trends drive CO2 not the other way around!!!!
Reply | Report Abuse | Link to thisStan,
Reply | Report Abuse | Link to thisIn naturally occurring cycles, you might be right that warming drives CO2, but what we have is an unnatural cycle. CO2 isn't a pollutant, sure. Have you ever heard of water poisoning? It's when you're body absorbs too much water and you die. Water, the most essential element to life. Too much of anything is a bad thing. And right now, we are unnaturally putting too much CO2 in the atmosphere. Let's move past these elementary arguments.
The right and economical way to sequester carbon is through increased photosynthesis. The biomass can be charred and put back in ground as fertilizer. Liquid and gas products of charring (pyrolysis) are net energy gain. All other methods use fossil or other energy.
Reply | Report Abuse | Link to thisWouldn't sequestering cause earthquakes?
Reply | Report Abuse | Link to thisWouldn't it be better (and cheaper) to run the flue gases through columns of water with algae? Each pass would remove 20-40% of the CO2 (depends on the species that is used) and 86% of the NO (which is a worse greenhouse gas than CO2) and possibly the particulates. The algae can then be used for fertilizer, animal feed, and/or run through the Mcgyan process and converted to fuel.
I agree with you. Permanently removing 5,000 tons a day of CO2 from the atmosphere or maybe someday removing 3.5 million tons of CO2 from the atmosphere will also permanently remove a lot of Oxygen from our air. Reducing the amount of oxygen will cause problems. It would probably cause the ozone layer to disappear at a faster rate, and reduce the amount of water we have,leading to
Reply | Report Abuse | Link to thiswater shortages and droughts.These experiments can cause massive damage to the environment.
How do you know removing thousands of tons or even millions of tons each day of Oxygen from our air is a safe thing to do? There should be an environmental impact study on the future effects this experiment will have on the environment. Oxygen is essential for life, it is important to think about it before we permanantly remove thousands, possibly millions of tons of it each day.
Reply | Report Abuse | Link to thisHow do you know removing thousands of tons or even millions of tons each day of Oxygen from our air is a safe thing to do? There should be an environmental impact study on the future effects this experiment will have on the environment. Oxygen is essential for life, it is important to think about it before we permanantly remove thousands, possibly millions of tons of it each day.
Reply | Report Abuse | Link to thisI agree. Oxygen is essential for life, but these big companies want to permanently remove 5,000 tons of CO2 or someday more than 3.5 million tons of CO2 from our air and that seems like a lot of Oxygen will get removed in the process, it sounds like a foolish experiment that will only make our environmental problems worse, actually accelerate the rate of environmental damage.
Reply | Report Abuse | Link to thisNuclear energy may seem clean to you, but nobody has come up with a reasonable, affordable safe way to dispose of the radioactive waste,and to guard the waste for the next couple thousand years. I like clean energy but nuclear energy is probably the most hazardous and dangerous way of generating energy.
Reply | Report Abuse | Link to this