A similar article linked at the GRT website from several weeks ago is shown below. Some material at the website http://www.grtaircapture.com/ has changed from the last time I looked. The last update is June 22, the same day as the CNN article.
I agree with a lot of what Lackner says, having investigated the potential for capture of CO2 from transportation and non power plant residential and commercial sources (there isn't any for the reasons he states). As for the business model he is now promoting, it seems to have morphed from air capture to remove the legacy CO2 to "let's see if we can keep this business going long enough with sales of CO2 for commercial use until we can get the government to underwrite the costs of air capture of CO2 that has no economic value which is almost all of it." No problem with that one either, especially in today's global economy. I am somewhat surprised at the claim that the energy costs are now about the same as those estimated for removal and sequestration of CO2 from pulverized coal-fired power plants. This implies that the new resin-based system (actually the resin used in water softeners) removes CO2 at a cost of less than $300/ton of CO2, about 3-5 times less than previous estimates. A more detailed side-by-side comparison is needed to convince me. $300/ton is also too expensive and I would note that the way in which costs for technologies decrease is not linear. That is, as the process becomes more and more efficient, the additional efficiency becomes harder and harder to achieve and at greater cost. Look at photovoltaic as an example. I also think that from a practical perspective, the CO2 that can be captured is probably less than 20% of the total, in that not only is it not possible to capture emissions from mobile sources, homes, businesses and factories including large industrial plants like petroleum refineries and steel mills, it probably will not be cost effective to capture CO2 from ANY sources other than coal-fired and natural gas fired power plants that don't produce a nearly 100% CO2 gas stream. As none of these exist today and will not exist in significant numbers for decades (read the latest climate change bill), CCS cannot contribute to stopping the warming for a long, long time. I also don't understand the comparison between the wind turbine and the air capture collector. They are designed for different purposes. Broecker also understates the magnitude of the scale of the number of units and the requisite time required to lower the atmospheric CO2 level. Remember that we are dealing with the "debt here," not the increase in the "debt," to make an economic comparison. To stabilize the atmospheric CO2 level would require the removal of about 15 billion tons of CO2 per year, that number increasing to 20 in a few decades if not sooner. Lowering the level would require removal of even greater quantities, unless human emissions are decreased from present day. But even a stabilization of emissions over the next 20-50 years (quite an accomplishment when you consider what we are facing) will not be enough. However, as part of a portfolio that includes source mitigation, energy efficiency, SRM and other other geo technologies along with policy mechanisms (taxes, cap and trade, treaties), air capture may be able to play a significant role in this century, but not for decades. The final statement that Lackner makes in the NYT article that the air emitted from the collector has the pre-industrial level of CO2 is unclear to me also. The air emitted should have close to 0 ppmv CO2 and the air next to the collector about that from 2009 as the air mixes very quickly close to the ground. The real problem with this and other systems proposed for the same purpose is not the danger of altering the atmospheric CO2 level. It's that due to the magnitude of the problem and the time scales, it won't in time. Still, I think this should be a MAJOR research area for DOE and other government energy agencies. The fact that only a handful of people are working on this now (GRT isn't hiring and I thought they closed down last year for a time) will make the development of practical scalable systems that much more unlikely. That's probably why there are geoengineering groups and not air capture groups. http://www.cnn.com/2009/TECH/science/06/22/synthetic.tree.climate.change.ccs/index.html 'Synthetic tree' claims to catch carbon in the air a.. Story Highlights b.. "Synthetic tree" would capture carbon dioxide in the air to reduce emissions c.. Trapped carbon would be compressed to liquid CO2 ready for sequestration d.. Technology is being developed by scientists at Columbia University in the U.S. e.. Broecker: "I think this is something that the world's going to have to have" updated 3:37 p.m. EDT, Mon June 22, 2009 By Hilary Whiteman CNN LONDON, England (CNN) -- Scientists in the United States are developing a "synthetic tree" capable of collecting carbon around 1,000 times faster than the real thing. A conceptual design of how the "synthetic tree" might look should they ever reach the stage of production. As the wind blows though plastic "leaves," the carbon is trapped in a chamber, compressed and stored as liquid carbon dioxide. The technology is similar to that used to capture carbon from flue stacks at coal-fired power plants, but the difference is that the "synthetic tree" can catch carbon anytime, anywhere. "Half of your emissions come from small, distributed sources where collection at the site is either impossible or impractical," said Professor Klaus Lackner, Ewing-Worzel Professor of Geophysics in the Department of Earth and Environmental Engineering at Columbia University. "We aim for applications like gasoline in cars or jet fuel in airplanes. We are going after CO2 that otherwise is nearly impossible to collect," he told CNN. While the idea of carbon-catchers may sound far-fetched, an early model has been built and Lackner is in the process of writing a proposal for consideration by the U.S. Department of Energy. He personally explained the concept in a 45-minute meeting with U.S. Energy Secretary Steven Chu last month at a three-day symposium on climate change in London. "He was there and I was there and he showed interest," Lackner told CNN. "That's exciting, but I don't particularly want to discuss this in a public forum because I think this gives me a little bit of an opportunity to tailor my proposals to the Department of Energy in a way that makes them more palatable." Lackner started working on the concept of an ambient carbon catcher in 1998. "I argued back then and I still argue that the reason this can be done, from a theoretical point of view, is that the CO2 in the air is actually surprisingly concentrated, therefore the device you need to collect CO2 is quite small." The "synthetic tree" looks more like a public convenience block than a hi-tech method of reducing carbon emissions, but Lackner told CNN it is highly efficient for its size when compared, for example, to a modern power-generating wind turbine. "If you give me one of those big windmills which have those big areas through which the rotor moves -- how much CO2 can I avoid? And if I had an equally sized CO2 collector -- how much CO2 can I collect? It turns out the collector is several hundred times better than the windmill." Is the "synthetic tree" an interesting alternative, or a scientific flight of fancy that's unlikely to happen? Sound Off below. Lackner told CNN that initial concerns over the cost of the technology were focused on the "front-end" carbon collector, including the sorbent used to catch the carbon dioxide in the air. But after years of research, Lackner told CNN he and his colleagues have developed a sorbent that is "close to the ideal," in that it uses a relatively small amount of energy to release the CO2 and is not prohibitively expensive. "By the time we make liquid CO2 we have spent approximately 50 kilojoules [of electricity] per mole of CO2." Compare that, Lackner said, to the average power plant in the U.S. which produces one mole of CO2 with every 230 kilojoules of electricity. "In other words, if we simply plugged our device in to the power grid to satisfy its energy needs, for every roughly 1000 kilograms [of carbon dioxide] we collected we would re-emit 200, so 800 we can chalk up as having been successful," he said. Lackner told CNN the biggest cost was at the "back-end" of the collector, primarily the technology used to release the CO2 from the sorbent. He said for that reason, on a cost-basis, the "synthetic tree" could not compete with modern coal-fired power plants that are designed to release fewer carbon emissions than their older predecessors. But he said when compared to the cost of retro-fitting an existing coal plant, the "synthetic tree" becomes more viable. "The bottom line is we have in this way the ability to deal with the problem at a cost which is somewhat higher than on a coal-fired power plant retro-fit, but not much higher." Besides, he said, the technology is not being developed as an alternative to the carbon capture and storage methods currently being tested for large-scale use on coal-fired power stations. He's targeting carbon that's already in the air. The concept of the "synethic tree" has caught the imagination of one of the first scientists to warn the world about global warming, Lackner's colleague at Columbia University, Newberry Professor of Earth and Environmental Sciences, Professor Wally Broecker. "I'm extremely excited about this. I think this is something that the world's going to have to have, unfortunately," Broecker told CNN from Madrid where he received a BBVA Foundation Frontiers of Knowledge Award for his work on the issue of climate change. Broecker told CNN most people still don't recognize the magnitude of the task the world faces in reducing global carbon emissions, and it was likely that one day urgent action would need to be taken, above and beyond the current measures being discussed. "We're probably not going to stop CO2 rising until it's double what it was near-1800 and maybe even more than that," he said. "I think we will find that the planet is too warm, ice is melting too fast... and we'll want to bring the CO2 back down again. The only way we can do that on a short timescale would be to pull it back out of the atmosphere." Broecker told CNN the units could stand in the middle of Australia, for example, and their presence wouldn't significantly disrupt the atmospheric distribution. "Each unit would take out a ton of CO2 a day -- which would be the amount of CO2 produced by 20 average automobiles in the U.S.A. And the cost of each unit would be about the cost of a Toyota. So that would mean if you added a five percent surcharge on automobile purchases that money could go to building units to remove the CO2 those vehicles are going to create." ----- Original Message ----- From: "Dan Whaley" <[email protected]> To: "geoengineering" <[email protected]> Sent: Friday, July 03, 2009 12:45 PM Subject: [geo] NY Times on Lackner Trees Bold claims that they are getting close to cost parity.... but 10 million collector for 10% of emissions? Puts the task we have in front of us in perspective for sure. http://greeninc.blogs.nytimes.com/2009/07/01/scrubbing-co2-with-synthetic-trees/?emc=eta1 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
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