CARBON CAPTURE: Are there better ways of capturing the CO2 billowing from fossil fuel-fired power plants' smokestacks? ARPA-E aims to find out.
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WASHINGTON—Every second, our bodies capture carbon dioxide in our tissues, transport it via the blood, and dump it in the lungs from where it is exhaled. This unconscious process is yet another way humans contribute to the accumulation of the greenhouse gas in the atmosphere—albeit in a minuscule volume compared with burning fossil fuels. The key to this metabolic process is an enzyme called carbonic anhydrase and it's efficiency at capturing and releasing CO2 is what human engineers want to mimic at the power plant scale.
Research engineer Harry Cordatos and his colleagues at United Technologies Corp. (UTC) are working on just such a system—and have garnered funding from the U.S. Department of Energy's new ARPA-E program. After all, UTC subsidiary Hamilton Sundstrand has been making CO2 capture units for the space program since the 1960s with different technology. But carbonic anhydrase "captures 600 molecules every second," Cordatos said at the ARPA-E summit in Washington, D.C., last week. "To take this enzyme out of the body is challenging. Our bodies continuously regenerate the enzyme because it degrades."
So Cordatos and UTC's idea is not to use the enzyme itself, but to master its chemistry and "use it in the unnatural environment of power plant flue gas," Cordatos said. The key appears to be a single zinc atom that sits at the core of the enzyme, which resembles a pyramid in structure. That structure allows the carbonic anhydrase to grip the CO2 "not too loose and not too tight," Cordatos explained, which is critical for efficiently capturing and then releasing the greenhouse gas.
UTC is not alone in this pursuit. In the ARPA-E program alone, four of the 37 funded developing technologies concerned researching more energy-efficient ways to capture the CO2 in a fossil fuel–fired power plant's flue gas. Chemist David Moore at Lehigh University in Bethlehem, Pa., employs electricity itself to charge absorbent materials for CO2 capture. Nalco Co., is developing an "electrochemical platform" to do the job. And physicist Olgica Bakajin of Hayward, Calif.–based Porifera, Inc., plans to use membranes composed of carbon nanotubes to separate CO2 from the other gases—using carbon to capture carbon.
"We need to develop the technologies that enable us to use our fossil fuels in a clean way," Secretary of Energy Steven Chu told ScientificAmerican.com at the conference. "This is something you don't solve in five years, 10 years. It will take a half century to get our carbon emissions down to where we need to go to protect the climate." At the same time, the U.S. will require a steady supply of electricity which, today, means coal burning or nuclear power, Chu said.
Some companies, however, are working on turning a fossil fuel–fired power plant's CO2 emissions into something useful, like cement. Calera bubbles the flue gas from the Moss Landing power plant on the California coast through seawater to produce an aggregate from carbonate, the same mineral sea creatures use to build their shells, perhaps more familiar as chalk. "They are producing hundreds if not thousands of tons today," said venture capitalist Vinod Khosla at the ARPA-E summit, an early investor in the technology. "It's a way to capture carbon at zero price because it's a product you can sell. It turns CO2 from a problem to a feed stock."
UTC, for its part, is developing a membrane system based on the chemistry of carbonic anhydrase that, although not zero cost, saves 30 percent of the energy that would be needed to capture carbon with amines or other known chemistries. "Liquid amines react rather slowly with CO2—sluggish kinetics," Cordatos noted.
Perhaps that's why Southern Co., has announced it will no longer fund a proposed project to use such amines to capture CO2 at a coal-fired power plant in Alabama, despite securing $295 million from the federal government to do so (or roughly 100 times what UTC received). "It is expensive," Doug May, vice president of energy and climate change at The Dow Chemical Co., which develops such amine-based technology, told ScientificAmerican.com at the conference. "It's not where it needs to be."
Adds Timothy Brown, a spokesman for France-based Alstom Power, which developed this amine-based capture technology for power plants. "We believe Congress should pass comprehensive climate legislation to establish the certainty needed to maintain the growing momentum for this technology, given its proven ability to mitigate CO2 emissions and create jobs."
Nor has it proved easy to find storage for the CO2 once captured. Although injection into deep rock formations has proceeded without difficulty at a pilot project at the Mountaineer coal-fired power plant in West Virginia—3,000 metric tons have been stored so far, says Gary Spitznogle of American Electric Power, which owns the facility—public opposition halted a similar government-funded project in Ohio.
Nevertheless, either carbon capture and storage will have to be developed and deployed or low-emission electricity sources, such as wind, solar and nuclear power, will have to grow significantly. "Eighty percent [of human greenhouse gas emissions] come from coal, oil and natural gas, which provide 80 percent of the world's energy supply," observed White House Office of Science and Technology Policy advisor John Holdren during remarks at the ARPA-E summit. "That tells you about how much of the energy system needs to be transformed."
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14 Comments
Add CommentWest Virginia's pilot project on cleaning up CO2 is one of the biggest shams and scams in the history of that inprovished state. The coal powered power plants there put 500 billion metric tons of CO1 and CO2 and other deadly chemicles into the air, water, and land every day. How proficient is a plant that can only clean 3000 metric tons of CO2 out of the air a week? These plants are overly expensive, take decads to bring up to operating proficiency and are poorly built and inadequate in cleaning up anything. Take the money you are waisting on these pieces of garbage storage plants and put it toward building clean geothermal or clean nuclear that uses spent nuclear fuel to produce energy.
Reply | Report Abuse | Link to thisJames,
Reply | Report Abuse | Link to thisyou may want to check your data again or maybe typo because 500 billion metric tons/day seems an awful lot for West Virginia alone.
Does anyone know exactly how harry cordatas at the united technologies corps. plans to store the CO2? I mean what form is it stored as....gas?
Reply | Report Abuse | Link to thisI think Vinod Khosla's support of the cement producing carbon recycling is the smartest in this article. It not only provides away to recycle the carbon...but to turn it into something useful, which will no doubt be both a useful, lucrative, but also attractive business for intelligent innovative engineers.
The calera comment caught my eye...as always the way to get ride of waste is to make it a product....
Reply | Report Abuse | Link to thisspent the last hour scouring the web and all i see is alot of questions about byproducts(acids) and them not addressing it...too bad...they've had a pilot(test) plant running for years...you would think they would have addressed all the output from the process...pros and cons.....
A company called Carbon Sciences currently has an enzymatic system that can be put directly into the smoke stack and convert CO2 into methanol and subsequently gasoline. Seems rather amazing, if true.
Reply | Report Abuse | Link to thisDavid, you are way off the mark, if you think CO2 in human expired breath contributes at all to the even a miniscule increase in the concentration of green house gases. This would only be true if humans ate coal, natural gas, or petroleum. We do not. We eat food which is usually grown in the troposphere, that is the air at the lowest part of the atmosphere. When plants, the food that humans eat (and the food for the animals that we eat) grows, then by the process of photosynthesis, CO2, H2O and light energy are used to fix the carbon into the plants. People and animals eat the carbohydrates and protiens from the plants and we eat animals that eat only these plants. That is how and where from that humans get carbon into their bodies. When we exhale CO2, then the carbon we exhale is carbon that was originally (and very recently) come from the atmosphere, the troposphere.
Reply | Report Abuse | Link to thisSo, human expiration is at worst carbon neutral and does not contribute to the increase in the greenhouse gas, CO2.
Now, you may argue that the original source for Carbon found in coal, petroleum, or natural gas also came from plants that took it out of the atmosphere. This is correct. The difference is that fossil carbon has been locked under the ground and has not contributed to any level of CO2 in the atmosphere for circa 300 million years. When humans extract this fossil carbon and burn it to obtain the chemical energy it contains. Then CO2 is a direct waste product from burning and the carbon in that CO2 has not seen the light of day in again, nearly 300 million years. It is estimated that humans are very close to or have already surpassed the consumption of half of the fossil carbon reserves that are to be found. Humans did this in ~160 years. SOme the contribution to the increase in atmospheric CO2 rest very heavily on fossil fuel burning. Humans have also degraded soils and reduce the amount of organic carboon that they contained once, before agriculture. Humn breathing HAS NOT increased atmospheric CO2!
Look at the production and use of biochar for carbon sequestration. Reduction in atmospheric CO2 will require "fixing" or sequestering approximately 2.12 BILLION tons of pure Carbon for every ppm (part per million) of CO2 that is removed from the atmosphere.
Reply | Report Abuse | Link to thisCapturing CO2 emissions headed into the atmosphere as flue gas and converting this CO2 into a "fixed", non-gaseous form is an energy intensive process. Consequently, it is also economically unviable. No one processes waste. That's why it's called "waste". If it had economic value, then it would have been exploited already. CO2 in flue gas is waste!
Biochar is charcoal. It is made by the conversion of plant biomass into charcoal through a chemical process called pyrolysis, which is essentially heating in an oxygen deprived environment. Biochar is generally 85-95% pure Carbon and it contains 50-70% of the original carbon from the biomass feedstock that it is made from.
Biochar has two primary benefits. 1) As a soil amendment it has been shown to improve fertility in soils and once charcoal (biochar) has been put into the soil, it stays there unchanged for a very long time (it has a half-life in soil that is estimated at several millennia). So, 2) This means that biochar is an excellent carbon sequestration medium.
Plants remove CO2 directly from the atmosphere when they grow. Converting plants into charcoal and using that charcoal in soil will remove CO2 from the atmosphere and sequester it for thousands of years, out of the atmosphere, plus it will provided the added benefit of improving soil fertility and productivity.
Biochar can be an economically viable product! The energy required to make it is supplied by the biomass feedstock as well. The equipment to make it cleanly is very simple and inexpensive to operate. Available feedstock for its production includes all of the ~26 BILLION tons of agricultural biomass that is handled each year worldwide and which does not go directly into food products.
Skbarry,
Reply | Report Abuse | Link to thisI agree, biochar can contribute A LOT to reduce GHG in the atmosphere. Some interesting links:
A very interesting and full-of-resources article on biochar written by Thomas Blakeslee, President of The Clearlight Foundation: www.clrlight.org/Biochar.htm
BBC released this excelent anthropological video on Terra Preta. Superb!!! http://video.google.com/videoplay?docid=8993313723654914866
CNN: http://www.cnn.com/2009/TECH/science/03/30/biochar.warming.energy/index.html
BBC: http://video.google.com/videoplay?docid=8993313723654914866 http://www.bbc.co.uk/science/horizon/2002/eldorado.shtml
http://www.biochar.org/joomla/index.php?option=com_content&task=blogcategory&id=5&Itemid=8
Nature: http://www.nature.com/nature/journal/v442/n7103/full/442624a.html
Time: http://www.time.com/time/magazine/article/0,9171,1864279,00.html
Natgeo: http://ngm.nationalgeographic.com/2008/09/soil/mann-text
Sciam: http://www.sciam.com/article.cfm?id=pyrolyisis-terra-preta-could-eliminate-garbage-generate-oil-carbon-sequestration
and a paper on slash and biochar VS slash and burn: http://www.biochar.org/joomla/images/stories/SteinerPhDSummary.pdf
An excellent resource is The International Biochar Initiative
http://www.biochar-international.org/
New Book: Biochar for Environmental Management published by Earthscan. Press release:
http://www.earthscan.co.uk/Portals/0/pdfs/Biochar_Press_Release.pdf
Senator / Secretary of Interior Ken Salazar has done the most to nurse this biofuels system in his Biochar provisions in the 07 & 08 farm bill,
http://www.biochar-international.org/newinformationevents/newlegislation.html
US Congretional Research Service: "Biochar: Examination of an Emerging Concept to Mitigate Climate Change"
http://assets.opencrs.com/rpts/R40186_20090203.pdf
* Environmental Health Perspectives: "Biochar: Carbon Mitigation from the Ground up"
http://www.ehponline.org/members/2009/117-2/EHP117pa70PDF.PDF
* International Biochar Initiative: "How much carbon can biochar systems offsetand when?"
http://www.biochar-international.org/images/final_carbon.pdf
Biochar data base;
http://terrapreta.bioenergylists.org/?q=node
NASA's Dr. James Hansen Global warming solutions paper and letter to the G-8 conference, placing Biochar / Land management the central technology for carbon negative energy systems.
http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf
UNCCD Submission to Climate Change/UNFCCC AWG-LCA 5
"Account carbon contained in soils and the importance of biochar (charcoal) in replenishing soil carbon pools, restoring soil fertility and enhancing the sequestration of CO2."
http://www.unccd.int/publicinfo/AWGLCA5/menu.php
This new Congressional Research Service report (by analyst Kelsi Bracmort) is the best short summary I have seen so far - both technical and policy oriented.
http://assets.opencrs.com/rpts/R40186_20090203.pdf
How to cook biochar at home: http://www.youtube.com/watch?v=nzmpWR6JUZQ
Skbarry,
Reply | Report Abuse | Link to thisI agree biochar can contribute A LOT to reduce GHG in the atmosphere. Some interesting links:
A very interesting and full-of-resources article on biochar written by Thomas Blakeslee, President of The Clearlight Foundation: www.clrlight.org/Biochar.htm
BBC released this excelent anthropological video on Terra Preta. Superb!!! http://video.google.com/videoplay?docid=8993313723654914866
CNN: http://www.cnn.com/2009/TECH/science/03/30/biochar.warming.energy/index.html
BBC: http://video.google.com/videoplay?docid=8993313723654914866 http://www.bbc.co.uk/science/horizon/2002/eldorado.shtml
http://www.biochar.org/joomla/index.php?option=com_content&task=blogcategory&id=5&Itemid=8
Nature: http://www.nature.com/nature/journal/v442/n7103/full/442624a.html
Time: http://www.time.com/time/magazine/article/0,9171,1864279,00.html
Natgeo: http://ngm.nationalgeographic.com/2008/09/soil/mann-text
Sciam: http://www.sciam.com/article.cfm?id=pyrolyisis-terra-preta-could-eliminate-garbage-generate-oil-carbon-sequestration
and a paper on slash and biochar VS slash and burn: http://www.biochar.org/joomla/images/stories/SteinerPhDSummary.pdf
An excellent resource is The International Biochar Initiative
http://www.biochar-international.org/
New Book: Biochar for Environmental Management published by Earthscan. Press release:
http://www.earthscan.co.uk/Portals/0/pdfs/Biochar_Press_Release.pdf
Senator / Secretary of Interior Ken Salazar has done the most to nurse this biofuels system in his Biochar provisions in the 07 & 08 farm bill,
http://www.biochar-international.org/newinformationevents/newlegislation.html
US Congretional Research Service: "Biochar: Examination of an Emerging Concept to Mitigate Climate Change"
http://assets.opencrs.com/rpts/R40186_20090203.pdf
* Environmental Health Perspectives: "Biochar: Carbon Mitigation from the Ground up"
http://www.ehponline.org/members/2009/117-2/EHP117pa70PDF.PDF
* International Biochar Initiative: "How much carbon can biochar systems offset—and when?"
http://www.biochar-international.org/images/final_carbon.pdf
Biochar data base;
http://terrapreta.bioenergylists.org/?q=node
NASA's Dr. James Hansen Global warming solutions paper and letter to the G-8 conference, placing Biochar / Land management the central technology for carbon negative energy systems.
http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf
UNCCD Submission to Climate Change/UNFCCC AWG-LCA 5
"Account carbon contained in soils and the imp:
Assuming we can capture and sequester the carbon dioxide, how much will it cost in terms of money and energy?
Reply | Report Abuse | Link to thisWhat will it cost, again in terms of money and energy, to clean - that is remove from the biosphere - the mercury, arsenicals, and other toxic products of burning coal?
And how much will it cost to remediate the mines?
If coal is so great, why is West Virginia so poor?
On Dec. 22, 2008, a flood in the retention pond at the Kingston Plant poured 1 Billion Gallons of a toxic soup into the Clinch and Tennessee Rivers, and covered 300 acres.
Reply | Report Abuse | Link to thisThe price tag of the experimental CCS subsystem being bolted onto the Mountaineer plant in W. Virginia looks like $143 million for a 20 MW subsystem. That's a price tag of $7.15 Million per MW. PV Solar is cheaper - $6.00 per MW without subsidies. Solar, obviously, doesn't work at night. CCS however, is estimated to require 25% or more of the energy produced by a plant - think about it, you're capturing, compressing, piping the carbon dioxide. That ain't free. So the costs are about $10 million per gw, plus the cost of building the coal plant, the costs of mining, processing, and transporting the coal, cleaning up other combustion products, remediating the mines.
T. Boone Pickens estimates the cost of wind power to $2.0 billion per gw. Even if it's capacity factor is 20% it's cheaper than coal with CCS.
Why try to capture carbon from coal when it IS captured and buried already? This is surely like trying to invent the perpetual motion machine.
Reply | Report Abuse | Link to thisThere is no future for coal as it contains little methane and therefore hydrogen for extraction for a hydrogen-based economy. Perhaps the only utility is as a strategic reserve in case it should one day be needed to fight off a glaciation?
Collecting fullerenes from the tons of smokestack C02 could provide the raw material to manufacture many things, (nano electronics to skyscrapers).
Reply | Report Abuse | Link to thisJust another example of hidden corporate welfare for the fossil fuel industry. Southern Company is getting $295 million to mitigate their pollution. Externalize costs, internalize profits.
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