CLIMATE CHANGE CURE?: By running the flue gas from Moss Landing's mammoth smokestacks through ocean water, a new company can make cement from carbon dioxide pollution.
Image: COURTESY OF DYNEGY
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The turbines at Moss Landing power plant on the California coast burn through natural gas to pump out more than 1,000 megawatts of electric power. The 700-degree Fahrenheit (370-degree Celsius) fumes left over contain at least 30,000 parts per million of carbon dioxide (CO2)—the primary greenhouse gas responsible for global warming—along with other pollutants.
Today, this flue gas wafts up and out of the power plant's enormous smokestacks, but by simply bubbling it through the nearby seawater, a new California-based company called Calera says it can use more than 90 percent of that CO2 to make something useful: cement.
It's a twist that could make a polluting substance into a way to reduce greenhouse gases. Cement, which is mostly commonly composed of calcium silicates, requires heating limestone and other ingredients to 2,640 degrees F (1,450 degrees C) by burning fossil fuels and is the third largest source of greenhouse gas pollution in the U.S., according to the U.S. Environmental Protection Agency. Making one ton of cement results in the emission of roughly one ton of CO2—and in some cases much more.
While Calera's process of making calcium carbonate cement wouldn't eliminate all CO2 emissions, it would reverse that equation. "For every ton of cement we make, we are sequestering half a ton of CO2," says crystallographer Brent Constantz, founder of Calera. "We probably have the best carbon capture and storage technique there is by a long shot."
Carbon capture and storage has been identified by experts ranging from the U.N.'s Intergovernmental Panel on Climate Change to the leaders of the world's eight richest nations (G8) as crucial to the fight against climate change. The idea is to capture the CO2 and other greenhouse gases produced when burning fossil fuels, such as coal or natural gas, and then permanently store it, such as in deep-sea basalt formations.
Calera's process takes the idea a step forward by storing the CO2 in a useful product. The U.S. used more than 122 million metric tons of Portland cement in 2006, according to the Portland Cement Association (PCA), an industry group, and China used at least 800 million metric tons.
The Calera process essentially mimics marine cement, which is produced by coral when making their shells and reefs, taking the calcium and magnesium in seawater and using it to form carbonates at normal temperatures and pressures. "We are turning CO2 into carbonic acid and then making carbonate," Constantz says. "All we need is water and pollution."
The company employs spray dryers that utilize the heat in the flue gas to dry the slurry that results from mixing the water and pollution. "A gas-fired power plant is basically like attaching a jet engine to the ground," Constantz notes. "We use the waste heat of the flue gas. They're just shooting it up into the atmosphere anyway."
In essence, the company is making chalk, and that's the color of the resulting cement: snow white. Once dried, the Calera cement can be used as a replacement for the Portland cement that is typically blended with rock and other material to make the concrete in everything from roads to buildings. "We think since we're making the cement out of CO2, the more you use, the better," says Constantz, who formerly made medical cements. "Make that wall five feet thick, sequester CO2, and be cooler in summer, warmer in winter and more seismically stable. Or make a road twice as thick."
Of course, Calera isn't the only company pursuing this idea—just the most advanced. Carbon Sciences in Santa Barbara, Calif., plans to use flue gas and the water leftover after mining operations, so-called mine slime, which is often rich in magnesium and calcium, to create similar cements. Halifax, Nova Scotia–based Carbon Sense Solutions plans to accelerate the natural process of cement absorbing CO2 by exposing a fresh batch to flue gas. And a number of companies are working on reducing the energy needs of Portland cement making. The key will be ensuring that such specialty cements have the same properties and the same or lower cost than Portland cement, says Carbon Sciences president and CEO Derek McLeish.
But the companies may also find it challenging to get their cements approved by regulators and, more importantly, accepted by the building trade, says civil engineer Steven Kosmatka of the Portland Cement Association. "The construction industry is very conservative," he adds. "It took PCA about 25 years to get the standards changed to allow 5 percent limestone [in the Portland cement mix]. So things move kind of slowly."
Calera hopes to get over that hurdle quickly by first offering a blend of its carbon-storing cement and Portland cement, which would not initially store any extra greenhouse gases but would at least balance out the emissions from making the traditional mortar. "It's just a little better than carbon neutral," notes Constantz, who will make his case to the industry at large at the World of Concrete trade fair in February. "That alone is a huge step forward."
"Could you take this calcium carbonate and add it to Portland cement? You sure can," Kosmatka says. "Could you add it to the ready mix to replace some of the Portland cement? You probably can do that, too." That would help to rein in the greenhouse gas emissions from buildings—both from building them and powering them once they are built—that makes up 48 percent of U.S. global warming pollution.
Nor are there any limitations on the raw materials of the Calera cement: Seawater containing billions of tons of calcium and magnesium covers 70 percent of the planet and the 2,775 power plants in the U.S. alone pumped out 2.5 billion metric tons of CO2 in 2006. The process results in seawater that is stripped of calcium and magnesium—ideal for desalinization technologies—but safe to be dumped back into the ocean. And attaching the Calera process to the nation's more than 600 coal-fired power plants or even steel mills and other industrial sources is even more attractive as burning coal results in flue gas with as much as 150,000 parts per million of CO2.
But Calera is starting with the cleanest fossil fuel—natural gas. The company has set up a pilot plant at Moss Landing because California is soon to adopt regulations limiting the amount of CO2 power plants and other sources can emit, and natural gas is the primary fuel of power plants in that state. According to Constantz, some flue gas is already running through the company's process. "We are using emissions from gas-fired generation as our CO2 source at the pilot plant where we are making up to 10 tons a day," he says. "That material will be used for evaluations."
The California Department of Transportation (Caltrans) has expressed interest in testing the cement, and Dynegy, owner of the Moss Landing power plant, is also intrigued. Although no formal agreement has been struck, "their proposed technology for capturing CO2 from flue gases and turning it into a beneficial, marketable product sounds very interesting to us," Dynegy spokesman David Byford says. "There are very good technologies for capturing the emissions of other pollutants. The carbon issue is something we are just turning our attention to now, and so far it's been quite elusive."
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57 Comments
Add CommentThis sounds too good to be true. I mean where's the catch? Otherwise this is very exciting.
Reply | Report Abuse | Link to thisI've read/heard about the idea of sequestering to reduce greenhouse gas content. But every idea I've heard has had significant downsides. They could go out of control and have worse global impacts. Or they could require more energy. Or the application can't be scaled up from the lab.
This technique won't ever run rampant, seems to not require extra energy and is clearly scalable. And it produces something useful. And even if it can't bear as much load as traditional cement, you can still definitely use it for something.
And the wonderful thing is if America moves towards a system of trading carbon credits, these guys absorbing carbon will be very economically viable. Beautiful.
Not a very scientific article. Where is the other side of the chemistry? "Carbonate" is not a compound, it's an ion. For the productto be "limestone", there has to be another raw material to supply calcium and/or magnesium ions and they have to ride in on a compound that has some other negative ion. So there's a by-product. Chemistry 101a, first week.
Reply | Report Abuse | Link to thisThis is definitely something that should be explored, as its potential benefits are great, but a close eye must also be kept on its potentially negative effects on the marine environment. Calcium and magnesium are both critical to biological processes in all plants and animals. Although these elements are abundant in nature, we should pay special attention to the results of their removal from the sea.
Reply | Report Abuse | Link to thisVery true. When I was reading this article, that was the first thing I thought – what is the resultant effect on marine life going to be here? Although Ca and Mg are abundant, they are tied up an ionic form. From the amounts of ‘cement’ they are talking here, eventually thousands of metric tons of these important biological ions will be removed from the marine environment. They state that there are billions of tons of calcium and magnesium in the ocean, but please tell me how they plan to use even a tiny fraction of this? The detrimental effects on marine organisms will be localized. Removing such large quantities of important ions from any one area will have huge effects on the marine life living in that area. Furthermore, wouldn’t removing carbonate ions some how effect pH?
Reply | Report Abuse | Link to thisCO2 is a naturally occurring compound in the atmosphere.
Reply | Report Abuse | Link to thisWithout it plant life could not exist.
It seems that "pollutant" is a similar term to "weapons of mass destruction" in the campaign of FUD.
You miss the point. The industrial processes of six billion humans are returning to the atmosphere enormous quantities of CO2 that had been sequestered in fossil fuels, through natural processes, over hundreds of millions of years. That creates an imbalance.
Reply | Report Abuse | Link to thisI want to know more! It seems to me if it was as easy to produce a cement product as running exhaust through sea water that this would already be the preferred and economical way of producing cement . As to the environmental concerns, agreed there needs to be impact studies done. however there shouldn't be a problem as long as its situated someplace where there is a strong current continually rotating in and out sea water. Our even better no impact if as they said they used the water for desalinization.
Reply | Report Abuse | Link to thisI want to know more. It seems to me if it was as easy to produce a cement product as running exhaust through sea water that this would already be the preferred and economical way of producing cement . As to the environmental concerns, agreed there needs to be impact studies done. however there shouldn't be a problem as long as its situated someplace where there is a strong current continually rotating in and out sea water. Our even better no impact if as they said they used the water for desalinization.
Reply | Report Abuse | Link to thisThe article states that the process uses ocean water to neutralize carbonic acid. It appears to greatly underestimating the environmental impacts by stating that: "the process results in seawater that is stripped of calcium and magnesiumideal for desalinization technologiesbut safe to be dumped back into the ocean. " I question the safety of discharging massive amounts to acidified seawater to the oceans.
Reply | Report Abuse | Link to thisFor more information on the effects of ocean acidification, please refer to:
http://www.research.noaa.gov/research/2007/ocean_acidity.shtml
By using carbonic acid to neutralize ocean water and precipitate calcium carbonate, the resulting effluent would be more acidic than normal ocean water. Inadequate consideration is being given to the environmental effects. The statement "The process results in seawater that is stripped of calcium and magnesium—ideal for desalinization technologies—but safe to be dumped back into the ocean" is clearly incorrect, unless there is an additional step to raise the pH of the effluent. Ocean acidification is already a well-known environmental issue.
Reply | Report Abuse | Link to thisFor information on ocean acidification, see:
http://www.research.noaa.gov/research/2007/ocean_acidity.shtml
The whole piece is misleading.
Reply | Report Abuse | Link to thisThey're making chalk. Not cement.
Chalk is soluble calcium carbonate.
it has low mechanical strength.
It makes lousy aggregate for concrete.
The whole piece is misleading.
Reply | Report Abuse | Link to thisThey are making chalk, not cement.
Chalk makes lousy aggregate for concrete.
It is too soluble, and has low mechanical strength.
They don't say which anion they are releasing when they
turn that CO2 into a CO3 salt.
That could well be a worse problemthan the CO2
they're sequestering.
An alternative to using ocean water would be using brine from deep wells. Of course, this would depend upon the chemical composition of the brine. Reinjecting the brine (into other deep wells) would eliminate any potential environmental impacts on marine life.
Reply | Report Abuse | Link to thisEven if the precipitate has poor mechanical properties, it still might have economic value. For instance, it could potentially be substituted for gypsum in wallboard. Fibers could be added to the paste to increase the mechanical strength and reduce the cracking tendency.
Reply | Report Abuse | Link to thisThere is already a natural ecoysystem called a forest that sequesters carbon dioxide and produces many useful products including wood. Ther e is no way that this new process would make cement carbon neutral. The article seems heavy on hope and promises and light on objective criticism of this new process.
Reply | Report Abuse | Link to thisMy earlier comment was based on a too-hasty reading of the atricle. Sorry.
Reply | Report Abuse | Link to thisBut some calculations still make this idea seem problematical (somebody check my figures, please). Sea water contains 0.129% magnesium and 0.039% calcium, so a tonne of sea water would, at perfect efficiency, provide enough of the two metal ions to capture about 3.8 kg of CO2. A tonne of natural gas generates 2.75 tonnes of CO2 when burned, so it would take almost 800 tonnes of sea water to deal with the flue gas from one tonne of gas.
To put this in more familiar terms, to handle the flue gas from one standard hopper car of coal would take over 8 million gallons of sea water. The energy required to move that much sea water though any kind of absorption device must be pretty large. Maybe there's a nifty way to take advantage of tides.
The product, calcium and magnesium carbonates ARE IN NO WAY "cement"; the process, as described, can't work; it would result in even more acidification of the oceans than the natural uptake of CO2. The product would be chalk or powdered limestone; which could be turned into mortar (calcium oxide) by driving off the CO2 with heat, but then the CO2 would be back in the atmosphere. I can't imagine how this passed editorial review inj Scientific American?
Reply | Report Abuse | Link to thisI agree lenornst, but I would be concerned with harm caused to marine Life from the mechanical stress of processing the amounts of seawater needed to run this process.
Reply | Report Abuse | Link to this@UserName1, the carbonic acid is depleted in formation of the calcium and magnesium "carbonate" , the cement is the carbonic acid used upper. chemistry 101a, first week. If you remove the acid the water returns to neutral, if you return the water to neutral you can return it to supply
Reply | Report Abuse | Link to thisI^mz .... I = infinite ^ angle of mz = largest and smalles measurement programmed ga programming infinite global var; this works with a-z in science like earth = e3 = mc
Reply | Report Abuse | Link to thisVic213:
Reply | Report Abuse | Link to thisCO2 + H2O + Ca++ = CaCO3 + 2H++ This is the reaction, and it produces acid!
lenornst
Yes the result is acification of the sea water efflent, and you can't correct that without using an alkaline reagent. I wonder if there's another shoe to drop, out in the open ocean where no one could detect it. Sea water contains a fair amount of bicarbonate ion --- more than the amount of Mg + Ca. If the new acidity reacts with that, the sea water would release CO2 to the atmosphere. But I don't know if the pH works out right for that --- it can be calculated or an easy experiment.
Reply | Report Abuse | Link to thisTypical Greenie response. No matter what the solution or potential solution there is to a problem someone like username1 will respond with the anti solution. Nuclear is too dangerous, wind kills birds, solar upsets the bugs in the desert. What do these people want? Maybe a good nuclear war to wipe out the entire population. That's it! A nuclear war will solve the problem, no people, no polution. No one to enjoy the polution free world but at least username1 would be happy. Sooooo much angst. Someone needs a shrink.
Reply | Report Abuse | Link to thisI doubt that we'll make cement out of stack gas. I doubt that we can lift billions of people to another solar system any time soon. I also doubt that a "hydrogen economy" will be a significant part of the energy picture (maybe for over-the-road freight, buses or railroads) but that doesn't mean that all other ideas are equally suspect. I think that a combination of wind, solar and nuclear plus an upgraded power grid and plug-in hybrids might be good package but its counterproductive for the government to be picking winners; better to encourage competition.
Reply | Report Abuse | Link to thisThe commonly used inorganic cements such as Ordinary Portland cement and High Alumina Cement and the Phosphate Cements harden due to the formation in situ of a new species formed through the agency of water. Thus OPC and HAC form hydrates of Calcium Silicate or Calcium Aluminate and the growth and interlocking of the crystals of these hydrates results in the setting and hardening of the concrete. The phosphate cements are a little different because they are two part containing a base usually MgO and Phosphoric Acid or an acid Phosphate salt which react together to form a Magnesium Phosphate. The important point to note is that the reactive ingredients are confined within a restricted volume and that the hardening reaction takes place within that space. Calcium and Magnesium Carbonates are quite unreactive and do not form hydrates so it is therefore a little difficult to believe that bubbling flue gas through seawater would produce a reactive species suitable for cement. This is leaving aside the logistical problems of processing enough seawater to extract anysolid materials. So either the chemistry is quite different from conventional cements or it does not work as suggested in the article.
Reply | Report Abuse | Link to thisIs this the same process that was developed in the late 1980's by a researcher in the Engineering Department at James Cook University in Townsville Australia (as I recall) to make artificial reefs? This process involved immersing galvanised metal meshes in seawater and electrolysing the them. This resulted in the formation of Calcium/Magnesium Carbonates over the grids to form a sort of reinforced concrete structure. In other words the cementing material formed in situ and was not collected and formed separately into another structure . It would therefore be interesting to learn something more of the process reported in your article.
Incidentally Portland cement will absorb CO2 and return to Calcium Carbonate over time. One tonne of Portland cement at a typical CaO content of 65% will absorb just over 1/2 tonne of CO2. One cubic metre of concrete typically contains 200-400 kg of Portland Cement so eventually it will absorb between 100 and 200 kg of CO2. This process is very slow and its rate is determined by the diffusion of CO2 into the concrete. Naturally this is slow because CO2 has a low concentration in the atmosphere and the porosity of the concrete is also slow. Of course this will only return to the ground the CO2 originally in the Limestone and will not absorb the CO2 produced in burning the fuel to make the cement.
I agree with j.quasimodo, where are the details of the chemical reaction? What exactly are they using in the sea water? This sounds a little like improving gas mileage using sea water or cold fusion.
Reply | Report Abuse | Link to thisI may be misunderstanding this article, but I believe that the process creates calcium or magnesium carbonate, which can then be used as a low grade aggregate when mixed with cement and water to form concrete. I cannot see how bubbling CO2 through water containing salts of calcium or magnesium could produce cement. The essence of creating cement is to drive off CO2 by heating, not to add CO2.
Reply | Report Abuse | Link to thisSciAm has become a left wing reactionary mouthpiece that has little or nothing to do with science anymore. My family has subscribed to SciAm for over 100 years and I have issues from the year the write brothers flew that were handed down to me. Sadly when my print subscription runs out I will not renew. The editors are just to liberal in what they deem suitable for this magazine. This story and the "Fewer April Showers for U.S. Southwest as Climate Changes" story are prime examples.
Reply | Report Abuse | Link to thisBryan Albers
Brian, why do you keep spamming Scientific American with the same copy and paste comments?
Reply | Report Abuse | Link to thisThis is all fine and good, except the ocean is one of the carbon sinks that takes up atmospheric CO2 anyway...
Reply | Report Abuse | Link to thisIf CO2 is the biggest problem, bubbling it through the ocean is a terrible idea, and accomplishes nothing...
Anyone ever hear of equilibrium? Unless they have a means to return the pH of the sea water... Did i miss something?
There are many chemical routes to precipitate useful minerals from seawater, brine or bitterns including massive amounts of carbonate and TecEco my company are exploring several as we have for many years advocated the production of man made carbonate for use in building and construction as the solution to global warming.
Reply | Report Abuse | Link to thisIf Brent Constantz from Calera actually has a viable process up and running as reported by David Biello in Scientific American on August 7, 2008 then congratulations to him. It may not be the most efficient process and only time and money will reveal what is and I will talk more about that later. Its clear however that Calera and the people at Moss Landing power station are moving in the right direction. We just have to get politicians around the world understanding how important this direction is.
The magic bullet that will solve the global warming problem is going to be anthropogenic sequestration as I predicted back in 2001. Fred Pearce, the author who was writing about TecEcos Eco-Cement technology was correct when he said in the New Scientist on the 13th July 2002 There is a way to make our city streets as green as the Amazon rainforest. Almost every aspect of the built environment, from bridges to factories to tower blocks, and from roads to sea walls, could be turned into structures that soak up carbon dioxide - the main greenhouse gas behind global warming. All we need to do is change the way we make cement. (See http://www.tececo.com/media.php)
If we geomimic what trees and shellfish do by learning to use CO2 on a profitable commercial scale our modeling demonstrates that if only 40% - 50% of building and construction was man made carbonate phased in over a 15 year period then the problem of global warming would start to go away by about 2025. Its that simple.
Anthropogenic sequestration is not only potentially very profitable but safe. Every liter of seawater contains roughly 1.28 grams of magnesium and about .412 grams of calcium so there are massive amounts of the right cations required to make carbonate in the oceans. There are even greater concentrations in salt lakes, some underground waters and in bitterns and brines. Our calculations are that there are about 1.2 billion years worth given current sequestration needs in oceans alone which is damned close to an infinite supply when you . As the half life in the crust of magnesium is only about 60 million years there is basically a damn close to infinite supply. All we have to do is efficiently attach these cations to CO2.
Early process like the DOW and Geo-Processors processes cannot be very efficient because calcium hydroxide or lime has to be produced first. The Calera process sounds a lot more efficient in that it at least it is supposted to use so called waste energy from power stations that would otherwise go up the chimney to spray evaporate the carbonate rich water they produce. I say so called because waste energy is energy that is not used properly. The waste power station heat that is in steam should be utilized using Newcomen technology to generate more electricity because if this were done power stations could be almost twice as efficient. (See http://www.gaiaengineering.com/simple.newcomen.php)
What I have in mind is much more efficient as it uses very little energy at all and does not rely on evaporation or brute force to seperate water from what is dissolved in it. (See http://www.gaiaengineering.com/index.php)
If Calera want to add magnesium oxide or hydroxide produced as a by product from their process to Portland cement, any other hydraulic cement or geopolymer then they are going to have to talk to us as we have the US patent on this as well as patents in many other countries. Besides we also have the know how and experience of making blended cements using carbonates after all that is what our Eco-Cements are. If they want to use their carbonate as feedstock for making PC then they should also talk to us as we are well progressed in the development of the right sort of kiln technology.
The direction Calera are going in is the right direction. What is missing is recognition by politicians and big business that it is the right direction. Here in Australia we have no support from the coal industry who have been brainwashed by the oil industry into thinking that geosequestration is the only option. It is not the only option and besides, it cannot possible be safe. Whatever leakage you assume, and there must be some leakage, that leakage accumulates as more CO2 is pumped underground and eventually becomes more that can be sequestered.
Lets hope for the sake of all of us that governments wake up to this and start putting their R & D dollars and purchasing power behind anthropogenic sequestration.
There are many chemical routes to precipitate useful minerals from seawater, brine or bitterns including massive amounts of carbonate and TecEco my company are exploring several as we have for many years advocated the production of man made carbonate for use in building and construction as the solution to global warming.
Reply | Report Abuse | Link to thisIf Brent Constantz from Calera actually has a viable process up and running as reported by David Biello in Scientific American on August 7, 2008 then congratulations to him. It may not be the most efficient process and only time and money will reveal what is and I will talk more about that later. Its clear however that Calera and the people at Moss Landing power station are moving in the right direction. We just have to get politicians around the world understanding how important this direction is.
The magic bullet that will solve the global warming problem is going to be anthropogenic sequestration as I predicted back in 2001. Fred Pearce, the author who was writing about TecEco’s Eco-Cement technology was correct when he said in the New Scientist on the 13th July 2002 “There is a way to make our city streets as green as the Amazon rainforest. Almost every aspect of the built environment, from bridges to factories to tower blocks, and from roads to sea walls, could be turned into structures that soak up carbon dioxide - the main greenhouse gas behind global warming. All we need to do is change the way we make cement.” (See http://www.tececo.com/media.php)
If we geomimic what trees and shellfish do by learning to use CO2 on a profitable commercial scale our modeling demonstrates that if only 40% - 50% of building and construction was man made carbonate phased in over a 15 year period then the problem of global warming would start to go away by about 2025. It’s that simple.
Anthropogenic sequestration is not only potentially very profitable but safe. Every liter of seawater contains roughly 1.28 grams of magnesium and about .412 grams of calcium so there are massive amounts of the right cations required to make carbonate in the oceans. There are even greater concentrations in salt lakes, some underground waters and in bitterns and brines. Our calculations are that there are about 1.2 billion years worth given current sequestration needs in oceans alone which is damned close to an infinite supply when you . As the half life in the crust of magnesium is only about 60 million years there is basically a damn close to infinite supply. All we have to do is efficiently attach these cations to CO2.
Early process like the DOW and Geo-Processors processes cannot be very efficient because calcium hydroxide or lime has to be produced first. The Calera process sounds a lot more efficient in that it at least it is supposted to use so called waste energy from power stations that would otherwise go up the chimney to spray evaporate the carbonate rich water they produce. I say so called because waste energy is energy that is not used properly. The waste power station heat that is in steam should be utilized using Newcomen technology to generate more electricity because if this were done power stations could be almost twice as efficient. (See http://www.gaiaengineering.com/simple.newcomen.php)
What I have in mind is much more efficient as it uses very little energy at all and does not rely on evaporation or brute force to seperate water from what is dissolved in it. (See http://www.gaiaengineering.com/index.php)
If Calera want to add magnesium oxide or hydroxide produced as a by product from their process to Portland cement, any other hydraulic cement or geopolymer then they are going to have to talk to us as we have the US patent on this as well as patents in many other countries. Besides – we also have the know how and experience of making blended cements using carbonates – after all that is what our Eco-Cements are. If they want to use their carbonate as feedstock for making PC then they should also talk to us as we are well progressed in the development of the right sort of kiln technology.
The direction Calera are going in is the right direction. What is missing is recognition by politicians and big business that it is the right direction. Here in Australia we have no support from the coal industry who have been brainwashed by the oil industry into thinking that geosequestration is the only option. It is not the only option and besides, it cannot possible be safe. Whatever leakage you assume, and there must be some leakage, that leakage accumulates as more CO2 is pumped underground and eventually becomes more that can be sequestered.
Let’s hope for the sake of all of us that governments wake up to this and start putting their R & D dollars and purchasing power behind anthropogenic sequestration.
There are many chemical routes to precipitate useful minerals from seawater, brine or bitterns including massive amounts of carbonate and TecEco my company are exploring several as we have for many years advocated the production of man made carbonate for use in building and construction as the solution to global warming.
Reply | Report Abuse | Link to thisIf Brent Constantz from Calera actually has a viable process up and running as reported by David Biello in Scientific American on August 7, 2008 then congratulations to him. It may not be the most efficient process and only time and money will reveal what is and I will talk more about that later. Its clear however that Calera and the people at Moss Landing power station are moving in the right direction. We just have to get politicians around the world understanding how important this direction is.
The magic bullet that will solve the global warming problem is going to be anthropogenic sequestration as I predicted back in 2001. Fred Pearce, the author who was writing about TecEco’s Eco-Cement technology was correct when he said in the New Scientist on the 13th July 2002 “There is a way to make our city streets as green as the Amazon rainforest. Almost every aspect of the built environment, from bridges to factories to tower blocks, and from roads to sea walls, could be turned into structures that soak up carbon dioxide - the main greenhouse gas behind global warming. All we need to do is change the way we make cement.” (See http://www.tececo.com/media.php)
If we geomimic what trees and shellfish do by learning to use CO2 on a profitable commercial scale our modeling demonstrates that if only 40% - 50% of building and construction was man made carbonate phased in over a 15 year period then the problem of global warming would start to go away by about 2025. It’s that simple.
Anthropogenic sequestration is not only potentially very profitable but safe. Every liter of seawater contains roughly 1.28 grams of magnesium and about .412 grams of calcium so there are massive amounts of the right cations required to make carbonate in the oceans. There are even greater concentrations in salt lakes, some underground waters and in bitterns and brines. Our calculations are that there are about 1.2 billion years worth given current sequestration needs in oceans alone which is damned close to an infinite supply when you . As the half life in the crust of magnesium is only about 60 million years there is basically a damn close to infinite supply. All we have to do is efficiently attach these cations to CO2.
Early process like the DOW and Geo-Processors processes cannot be very efficient because calcium hydroxide or lime has to be produced first. The Calera process sounds a lot more efficient in that it at least it is supposted to use so called waste energy from power stations that would otherwise go up the chimney to spray evaporate the carbonate rich water they produce. I say so called because waste energy is energy that is not used properly. The waste power station heat that is in steam should be utilized using Newcomen technology to generate more electricity because if this were done power stations could be almost twice as efficient. (See http://www.gaiaengineering.com/simple.newcomen.php)
What I have in mind is much more efficient as it uses very little energy at all and does not rely on evaporation or brute force to seperate water from what is dissolved in it. (See http://www.gaiaengineering.com/index.php)
If Calera want to add magnesium oxide or hydroxide produced as a by product from their process to Portland cement, any other hydraulic cement or geopolymer then they are going to have to talk to us as we have the US patent on this as well as patents in many other countries. Besides – we also have the know how and experience of making blended cements using carbonates – after all that is what our Eco-Cements are. If they want to use their carbonate as feedstock for making PC then they should also talk to us as we are well progressed in the development of the right sort of kiln technology.
The direction Calera are going in is the right direction. What is missing is recognition by politicians and big business that it is the right direction. Here in Australia we have no support from the coal industry who have been brainwashed by the oil industry into thinking that geosequestration is the only option. It is not the only option and besides, it cannot possible be safe. Whatever leakage you assume, and there must be some leakage, that leakage accumulates as more CO2 is pumped underground and eventually becomes more that can be sequestered.
Let’s hope for the sake of all of us that governments wake up to this and start putting their R & D dollars and purchasing power behind anthropogenic sequestration.
There are several catches to the Calera process.
Reply | Report Abuse | Link to this(1) It requires energy to run the spray driers. The energy may be waste energy but there is still the opportunity cost of other potential uses for it.
(2) Seawater is denuded of Ca++ and Mg++
This is not so much of an issue as underground brines or bitterns could be used as sources of cations and besides, there is over 1.2 billion years years worth Ca++ and Mg++ in the oceans and the residence time of these ions is around 60 million years. i.e they will be recycled before they are used to any extent damaging to sea life.
What kind of pump is use to get the CO2 from the stack and who makes the pumps.What 's the name of the pump maker.
Reply | Report Abuse | Link to thisWhat kind of pump and what brand or name of the pump that is used
Reply | Report Abuse | Link to thisto pump the CO2 from the stack to where it is being used and what company makes the pump.
Sea Salt in cement causes 'concrete cancer', meaning constructions have to be demolished. This usually occurs even after washing sea-sand mixed into concrete. This could be a problem for CO2 sequestration in brine?
Reply | Report Abuse | Link to thisRemoving sodium chloride from brine is costly. NaCl in cement causes 'concrete cancer', requiring subsequent demolition. This could be a big headache for the proponents of this CO2 sequestration technique?
Reply | Report Abuse | Link to thisCalcium and magnesium are acid buffers. In the ocean they act like Tums to neutralize the recent bout of acid indigestion caused by the man made increase in C02 which precipitates from the atmosphere in the form of carbonic acid infused rain. Oceanographers have recently decried the loss of radiolaria diatoms and tiny mollusks which have shells made of calcium carbonate. The acidic sea water is dissolving their shells and killing them. These creatures are a large part of the bottom of the oceanic food chain. Use care.
Reply | Report Abuse | Link to thisSorry, carbolic acid like in soda pop.
Reply | Report Abuse | Link to this@j.quasimodo,
Reply | Report Abuse | Link to thisMy thoughts exactly. I got numbers of the same order of magnitude.
A more detailed discussion is on my blog:
http://energy-eng.blogspot.com/2008/11/comments-marine-cement-production.html
@j.quasimodo,
Reply | Report Abuse | Link to thisI agree. My calculations also give me numbers similar to what you get.
More on my blog: http://energy-eng.blogspot.com/2008/11/comments-marine-cement-production.html
it's has review many sites like gas for free,run your car on water etc.
Reply | Report Abuse | Link to thishttp://carwaterguide.blogspot.com
Agreed. Scary to think of the environmental impacts of removing these quatities of Ca and Mg ions locally to produce huge quantities of calcium carbonate cement for industrial applications. Trading one problem for another is not a viable solution. What happens when you dump little acid rain on Calcium Carbonate! I like the direction these guys are headed however. We need to come up with other sources of these ions and try to limit our tinkering with seawater chemistry in that regard. The mining operations are a good idea. Lots of excess Ca and Mg in tailings there.
Reply | Report Abuse | Link to this
Reply | Report Abuse | Link to thisThe Calera story sounds good - but upon close examination, and a reading of their patent, it is clear that it is a complete Greenwash.
Their patent application US 20090020044 (search under patent number at http://appft1.uspto.gov/netahtml/PTO/search-adv.html). The patent describes taking dolomite/dolomitic limestone and calcining it (releasing CO2) and then reacting this with seawater and CO2 to regenerate calcium/magnesium carbonate!!!
There is very little if any capture of CO2 by their process since the calcining step generates so much CO2, and there is CO2 generated from the processing operations - it is highly probable that the technology has a net positive carbon footprint.
Where is the biological process for capturing CO2? Calera is using decades old and very dirty and polluting chemistry for extracting magnesium/calcium from seawater - a very similar process was used by the magnesium factory which formerly occupied the Moss Landing site.
There is nothing Green about Calera's process - basically, they are burning/calcining limestone, and using it to make artificial limestone from seawater. All smoke and mirrors.
And, Calera's product is no cement - at best it is a poor mineral admixture. The patent shows that at a 20% replacement of Portland cement, the strength is only 50% (3000 psi) of that of 100% Portland cement - to get close to the strength development of Portland cement, the replacement level has to be reduced to 5%. Also, the drying shrinkage is doubled at 20% replacement of Portland cement.
Not only is Calera's product not a cement, but its addition to Portland cement is very deleterious - it greatly reduces strength and increases shrinkage - and almost certainly decreases long-term durability, corrosion resistance, freeze-thaw resistance, etc..
This is very disappointing - first Calera said that it had a 100% replacement for Portland cement that would capture 1 ton of CO2 per ton of cement (impossible, unless the cement is pure CO2!) - they then amended this to a 50% replacement for Portland cement and a carbon neutral cement. Now what - 5% replacement for Portland cement? Total Greenwash!
how about the waste material from acetylene industry, 92 percent calcium hydroxide. used only as a filler. upon reaction with air, the resulting solid has content similar to calcium carbonate. just by air drying.
Reply | Report Abuse | Link to thisCan calcium carbonate be considered a cement? Cement is calcined limestone, so I see this as only a concrete admixture (like aggregate). Surely it will decrease structural strength if percieved as a cement substitute.
Reply | Report Abuse | Link to thisThank you gwashtracker. I could tell something didn't smell right as I read the article.
Reply | Report Abuse | Link to thisI have been experimenting with Class C fly ash from our local Texas coal-fired power plants. Using that stuff as a replacement for Portland cement makes far, far more sense than Calera's greenwash baloney. The University of Montana has been, and is, paving the way for us ... just use the ash from the coal-fired power plant, mixed with water, instead of Portland cement. No "advances" needed, just simple process modification.
I like the idea of turning the final effluent into desalinated drinking water instead of dumping it back into the sea. Doing this, even as a demostration, would clearly identify all the byproducts.
Reply | Report Abuse | Link to thisfrom recent readings, i notice that one problem of the oceans absorbing CO2 is that they are becoming more acidic, and the tiny shellfish are not able to make their shells, removing important food from the food chain; coral reefs are disintegrating because of acidic ocean water plus other pollutants.
Reply | Report Abuse | Link to thisI wonder how this would compare (in terms of overall carbon sequestration efficiency and ecosystem impact) to simply dumping the alkaline materials this process needs directly into various bodies of salt water. (Though of course you would have to figure in the need to manufacture some other cement substitute.) To be clear, I don't pretend to know the answer; I merely would be much more comfortable if I knew such alternatives were also being thought about.
Reply | Report Abuse | Link to thisthe process is akin to sea water flue gas desulpharisation using and harvesting it.
Reply | Report Abuse | Link to thismay be more research is reqd.
i can add value based on 34 years of cement plant research and development experience in india if someone shows interest.
sea water .similar technologies are in vogue by ducon technologies of usa.
but energy reqd to precipitate the caco3 or evaporate in spray drier besides other contaminants is the major issue.
economically at this stage project will be a disaster and unles we develop microbial treatment for eating co3
Interested on this CO2 capture system subject. But find some "errors" in the article/news
Reply | Report Abuse | Link to thisThe capturing CO2 increases 30% fuel consumtion at power plant. then the reclaiming of CaCO3 will also require energy, and then obtained CaCO3 will agin require Fuel for pre-calcination and clinkarization in rotary kiln, and finally the sea water pH& marine minerals will decrease, how it will posible that CO2 emmission will reduce, any one can expalin?
Reply | Report Abuse | Link to thisCement from carbon dioxide.
Reply | Report Abuse | Link to this1. What is the latest data on this system?
2. How much energy is used in the system as a percentage of the power station output?
1. What is the latest data for the system?
Reply | Report Abuse | Link to this2. How much energy is used for the system as a percentage of power station output?
ananthraman: This is a couple of years late but we are trying to work with new concepts in concrete and would be interested in communicating.
Reply | Report Abuse | Link to thisWade Swicord
wade@vol.com