Wednesday, October 21, 2009

Air Capture Update – Is GRT’s Air Capture Device Viable?

Back in the July this blog wrote a detailed post about why the development of certain technological strategies to work in consort with emission reduction would be necessary to ward off significant climate change.

That post can be found here:

One of the more promising technologies was air capture, which involves capturing already emitted atmospheric CO2 instead of focusing on newly emitted CO2 for power plants. However, neither the system proposed by David Keith or Frank Zeman appeared to be cost effective and the system that Global Research Technologies (GRT) has proposed under the guidance of Klaus Lackner is still quite mysterious when it comes to the kinetics and costs.

Interestingly perhaps some light can now be shed on the GRT system in that in a recent interview with the Columbia University school newspaper, the Columbia Daily Spectator, (note that this interview has been recently taken down and appears to be no longer available) Mr. Lackner is reported to have said regarding the GRT device: “And even with current ‘dirty’ electricity, these machines are 80 percent efficient: Only 20 percent of what they sequester is cancelled out by their electricity use.”1 By knowing the efficiency of the device a cost per net ton of CO2 removed can be calculated. Also note that it is highly probable that Mr. Lackner misspoke in that statement in that the CO2 is not technically sequestered, but simply absorbed by the air capture device. This post is assuming that long-term sequestration of the absorbed CO2 typically within underground rock formations is not included in the efficiency calculation.

First, it is appropriate to assume that the current electrical grid, which is comprised of a balanced mix of electricity sources, is being used to power the device. As is typical 2007 grid percentages will be utilized in the analysis, for 2008 and 2009 data are not accurate assessments due to the recession. In 2007 coal made up 48.97% of the grid and produces approximately 1 ton of CO2 per MW-h generated;2 natural gas made up 20.08% of the grid and produces approximately 0.4 tons of CO2 per MW-h generated (when burned at maximum efficiency);2 petroleum made up 1.58% of the grid and produces approximately 0.75 tons of CO2 per MW-h;2 the rest of the grid can be assumed to be made up of trace/zero emission sources (nuclear, hydroelectric, wind, biomass and solar). Taking these elements into account it can be determined that electricity provided from the grid on average will produce 0.8594 kW-h of electricity/lb of CO2 emitted into the atmosphere. Knowing that the efficiency of the system is 80% the total amount of kW-h of electricity required to capture 1 gross ton of CO2 can be calculated at 0.17188 kW-h/lb of CO2.

Second, assume the same price on electricity per kW-h as was previously assumed in the sequestering post (9.1 cents). Knowing the system capture energy requirement, efficiency and the cost of electricity, a cost per ton of CO2 can be calculated → 0.091 dollars/kW-h * 0.17188 kW-h/lb of CO2 captured * 2000 lb/ton = $31.28 per gross ton CO2 captured. Of course that value is only the gross value, efficiency must be inserted into the equation to calculate the net value of $39.10 per net ton of CO2 capture. Based on these calculations it appears that GRT’s device is much better than the devices proposed by both David Keith and Frank Zeman.

However, although it seems better there are a variety of issues that remain regarding this value. First, just from a physics standpoint the above calculation seems very suspect. If accurate the GRT system only requires about 60 kJ to capture 1 mole of CO2. Without actual scientific documentation, heck even with it, it is extremely difficult to take that value seriously. Also the calculated value is already significantly lower than the $100 per ton of CO2 value that is frequently cited by GRT for the operation of their device, which does not make any sense.3

Second, regarding the above issue, there still appear to be no scientific publications on the device that GRT proposes, thus there is no genuine information regarding its abilities and capacities outside of the sound-bite blurbs that GRT representatives, most notably Mr. Lackner, give to the press like the above efficiency number. This lack of empirical evidence regarding how efficient and effective the device is leads to continued questioning and concern about the actual abilities of the GRT device. If the resin used in the device is proprietary and prototypes have already been tested where efficiency numbers can be declared then it naturally seems suspicious that no publications regarding the device have surfaced, at least where one could find them through conventional means.

Third, there is still a lack of information pertaining to the amount of water used per net ton of CO2 absorbed. The water question is critical because as discussed in the sequestering post, it is highly probable that the world will face significant water shortages in the near future and having to use millions to billions of gallons of water in air capture for a reduction of just 1 ppm could very well sink air capture as a viable remediation technology. Based on the limited information regarding the functionality of the GRT absorption resin it definitely appears to require water to function properly; however, there is no information regarding how much is required.

Fourth, the passive transport system is an attribute of the GRT device that may cause serious viability problems. Based on press releases and discussions with the press,3 it appears that the device as it is currently structured can absorb 1 ton of CO2 per day or 365 tons of CO2 per year if average day capacity is maintained throughout the year. This value is dreadfully small, for it would require approximately 21,370,000 devices to remove only 1 ppm from the atmosphere in a given year. Although it is reasonable to assume that the absorption value will increase with scale-up it is unlikely that the overall value using passive transport will exceed an average of 3 tons per day (1095 tons per year or 7,123,334 devices for 1 ppm per year).

Currently initial capital construction costs are estimated at $200,0001 (which means it will probably end up costing more). In the future Mr. Lackner believes that these costs will scale down to $20,000,1 but that seems unlikely; realistically $100,000 is probably as cheap as these devices will go. Splitting the difference half at $200,000 and half at $100,000, it would currently cost 1.0685 trillion dollars [in just initial capital costs not including maintenance or operational costs (note that operational costs are the real killer)] to construct the number of devices necessary to achieve a 1 ppm per year reduction at a 3 tons of CO2 per day absorption rate.

Overall it seems highly unlikely that anyone or government would invest such capital in a device that generated such small returns, especially without any viable long-term market for the capture CO2 (as discussed in the sequestering post). Mr. Lackner likes to use automobile production as an example to justify his future cost-estimates and the will of the public to invest in air capture, but such reasoning is seriously flawed because of the aforementioned lack of a long-term market for captured CO2. It is troubling that Mr. Lackner believes that the soft drink, oil and sanding equipment industries will provide viable markets that will be able purchase gigatons of CO2 annually.

Therefore, an active transport system needs to be utilized, even though such an addition would increase energy required to absorb CO2, which would increase the cost to absorb CO2, but such a cost increase is necessary if significant climate change is to be avoided. Recall that the primary advantage of air capture over simply planting trees is speed, an attribute the GRT system does not maximize. Without an active transport system, which literally sucks air into the system, it almost seems more rational to simply plant a bunch of trees than bother building an air capture network.

The more information available the better when it comes to evaluating where the government and private investors should put their money. Air capture might be the only real hope for humanity when it comes to avoid detrimental climate change. Unfortunately there appear to be a significant number of problems with the system proposed by GRT even despite the lack of available information. Note that the technical literature section of their website is still coming soon.

1. Columbia Newspaper Article; [Although the article no longer appears to be available a copy of text was made before it was taken down and is posted below]

2. “Electric Power Industry 2007: Year in Review.” Table ES1. Summary Statistics for the United States, 1996 through 2007. Energy Information Administration. May 2008.

3. Various Press-Releases and News Articles from GRT Wesite:


Columbia geophysics professor Klaus Lackner is building a device that can take carbon right out of the air. The machine, which is often described as looking like “a goal-post with Venetian blinds,” counteracts climate change in the same way trees do: by collecting carbon to keep it out of the atmosphere. But his devices are 100 times better at it and could address climate change without disrupting infrastructure, industry, or productivity. Lackner claims that “with the best technology currently available, I can get about a ton a day, maybe a little more, with a unit that can fit in a standard shipping container.”

These air capture devices could also be set up anywhere—from Antarctica to the Sahara. It doesn’t matter because, as Lackner points out: “You can have a car in San Francisco producing CO2 and a collector in the desert of Australia taking it back. It’s all the same CO2.” Once the machines are set up and plugged in (they do require some electricity) they are essentially passive, just collecting carbon dioxide as air flows across their “blinds,” which are strips of a special material developed by Lackner and his colleagues for grabbing CO2. And even with current “dirty” electricity, these machines are 80 percent efficient: Only 20 percent of what they sequester is cancelled out by their electricity use.

After they collect the carbon, Lackner and his team can go in one of two directions. They can either incorporate the CO2 into stable carbonates and bury it in the ground, or they can combine it with water to make synthesis gas: the precursor to synthetic gasoline and oil. This solution is especially promising because it could create a closed cycle of energy in which carbon dioxide is captured and re-emitted with no net increase in harmful greenhouse gasses.

Of course, one machine tree isn’t enough. We would need a million of them to mitigate climate change and up to 10 million to return to pre-industrial carbon levels. Surprisingly, this is feasible. As with cars, building just one air capture device would be extremely expensive, but mass-producing them in a streamlined system is 10 times cheaper. “To put that in perspective,” Lackner says, “the world produced 73 million cars in 2006 … so several million air capture units is not unreasonable.” “And,” he adds, “we clearly have enough room to park 10 million cars.”

Lackner is currently raising money to construct a full-scale prototype of his air capture device, which he estimates will cost about $200,000. Though this seems a high price, Lackner is confident that it will eventually fall to car-level: about $20,000. “We could actually collect carbon without ruining the world economy or changing how things are done,” he says. “With 3 or 4 factories, we’d be in the game.”

The air capture industry could also scale up just as the automobile industry did—starting out with small niche markets and higher prices and then, as manufacturing becomes more efficient, lowering costs and expanding into wider and wider markets. There are, in fact, a number of industries, including soft drink production and sanding equipment manufacturing, that must purchase large quantities of concentrated carbon dioxide to produce their goods. “That gives us a leg up,” says Lackner. “We can start with a few tons of CO2 in one location, and as we gain experience we can build more units that are cheaper, and our potential market will get larger.”

Air capture is unlike other climate solutions in that it addresses the problem directly and won’t require an overhaul of infrastructure or policy. Switching to electric cars, for example, would require a completely new and highly convenient refueling system, and would have a huge impact on trade and trade relations. Because Lackner’s devices are modular and can be installed anywhere, they don’t require that we develop a new transportation system or change the way we do things. Also, air capture is an ideal fit for the cap-and-trade system already in place because it collects carbon in a precisely quantifiable way.

When asked about his efforts to generate political interest for his work, Lackner laughs, “Well, we’re talking about it right?” It takes time to convince people that a technology is real and viable, he says, and it takes time to convince people it has policy implications. “It [climate change] also has to hurt before people will act, and we could well be too late by that time.”

Still, Lackner sees a bright future for climate and energy research. “Business as usual manifestly does not work, but we desperately need the energy,” he says. “So to me, this is one of the most exciting fields to be involved in.” A solution to climate change is about more than just science—it’s about economics and politics as well. “This field will not succeed,” he says, “unless it combines the restraints of all fields into one way to think about the problem.”

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