Air Capture Technology Quickly Advances
October 1st, 2008Posted by: Roger Pielke, Jr.
From the University of Calgary, this news release:
In research conducted at the U of C, Keith and a team of researchers showed it is possible to reduce carbon dioxide (CO2) – the main greenhouse gas that contributes to global warming – using a relatively simple machine that can capture the trace amount of CO2 present in the air at any place on the planet.
“At first thought, capturing CO2 from the air where it’s at a concentration of 0.04 per cent seems absurd, when we are just starting to do cost-effective capture at power plants where CO2 produced is at a concentration of more than 10 per cent,” says Keith, Canada Research Chair in Energy and Environment.
“But the thermodynamics suggests that air capture might only be a bit harder than capturing CO2 from power plants. We are trying to turn that theory into engineering reality.”
The research is significant because air capture technology is the only way to capture CO2 emissions from transportation sources such as vehicles and airplanes. These so-called diffuse sources represent more than half of the greenhouse gases emitted on Earth. . .
“A company could, in principle, contract with an oilsands plant near Fort McMurray to remove CO2 from the air and could build its air capture plant wherever it’s cheapest – China, for example – and the same amount of CO2 would be removed,” Keith says.
Keith and his team showed they could capture CO2 directly from the air with less than 100 kilowatt-hours of electricity per tonne of carbon dioxide. Their custom-built tower was able to capture the equivalent of about 20 tonnes per year of CO2 on a single square metre of scrubbing material – the average amount of emissions that one person produces each year in the North American-wide economy.
“This means that if you used electricity from a coal-fired power plant, for every unit of electricity you used to operate the capture machine, you’d be capturing 10 times as much CO2 as the power plant emitted making that much electricity,” Keith says.
The U of C team has devised a new way to apply a chemical process derived from the pulp and paper industry cut the energy cost of air capture in half, and has filed two provisional patents on their end-to-end air capture system.
See that highlighted part above? It says that the capture part of air capture techonolgy might add as little as 11% to the cost of coal-generated electricity. Surely there are additional costs, and there are issues with sequestration and recycling. However, the progress in air capture technology in recent years on what are relatively modest research, development, and deployment budgets should give some optimism that this technology may have a role to play — a major role — in climate mitigation. Given the trends in global emissions, one would think that air capture would have a big fan club. Interestingly, it has a lot of vocal opponents.
October 1st, 2008 at 2:19 pm
[...] Roger Pielke, jr., cross posted from his blog, [...]
October 1st, 2008 at 3:21 pm
Hi Roger,
You write, “It says that the capture part of air capture techonolgy might add as little as 11% to the cost of coal-generated electricity. ”
That’s not what it says. What it says is confusing, because of the word “cost” being thrown in. But what it says is that 10 percent of the energy that the electrical power plant puts out would be needed to capture the CO2 from the ambient air.
So it’s a discussion of the energy used. It doesn’t say anything about what the cost would be (i.e., it doesn’t say what the capital costs of their tower would be for a given size, or what the operating costs would be, beyond the power to run the device).
Don’t get me wrong…it’s interesting. (It’s also a bit difficult to believe, especially the part about, “But the thermodynamics suggests that air capture might only be a bit harder than capturing CO2 from power plants.”) It’s the sort of idea where I think some sort of technology prize or prizes would be good.
Mark
P.S. Note that at 100 kWh per tonne (metric ton) of CO2 captured, at an electrical cost of $0.10 per kWh, that’s $10 per tonne of CO2. Given current worldwide emissions of approximately 31 billion tonnes of CO2 per year, that would be an electrical cost of $310 billion per year to capture all the CO2. (Of course, this says nothing about the annualized capital cost, or the other operating and maintenance costs.) But that annual electrical cost represents about 0.5 percent of the world GDP.
It’s simple calculations like that which reveal what nonsense the Stern Report really was. According to the Stern Report, people 100-200 years from now would be spending 5+% of their GDP to deal with problems of global warming. Why wouldn’t they instead spend a fraction of that amount to simply suck the CO2 down to pre-industrial levels (or whatever level above pre-industrial levels that seemed most convenient)?
October 1st, 2008 at 7:19 pm
Roger,
I may be misunderstanding something, but this research appears to refer only to the physical and chemical *capture process* and ignores the financial and energy cost of recovering the chemicals and separating out the CO2 (which itself obviously has some lower bounds). On top of that there is the issue of actually storing the CO2 somewhere. If air capture could approach the cost of other methods of reducing CO2 emissions then I’d be all for it – and I certainly don’t object to ongoing research – but it still seems a long way off, and I don’t think the results so far justify too much excitement. You will recall that even David Keith himself criticised one of your earlier plugs of his work.
October 2nd, 2008 at 10:21 am
James Annan’s comments remind me to go back to a previous post about the economics of ambient air capture of CO2:
http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/000789some_simple_economic.html
In that post, the estimated cost of ambient CO2 capture was $200 – $500 per ton of CO2. That cost is (obviously) significantly higher than the electricity-only cost of $10 per ton of CO2 that I calculated above.
Also, as James Annan noted, that cost may be only for electricity to remove the CO2 from the ambient air. It may not include the regeneration electricity (to separate the CO2 from the sorbent), and almost certainly doesn’t cover the cost to stick the CO2 underground.
Let’s say that this development has lowered the total cost from $200 – $500 per ton of CO2, to $150 – $400 per ton of CO2 (i.e., about at 25 percent decrease in total cost). That still is pretty darn expensive.
Since humans emit about 30 billion tons, at $150 – $400 per ton, that would be $4.5 – $12 trillion per year to remove everything we emit. With a world GDP of about $55 trillion (market exhange rate), that’s 8 – 22 percent of world GDP, just to remove all the CO2 we emit.
No way the world is going to do that.
P.S. However, my point about FUTURE actions still is valid. Suppose the world population in 2100 is 10 billion, and the world per-capita GDP is 10 times higher than at present. (Note: I think it will actually be closer to ***1000 times*** higher than at present.)
If the population is 10 billion (compared to 6.5 billion at present), and the per-capita GDP is 10 times higher, and the cost per ton of ambient air CO2 capture stays the same (it will probably go down, that will bring the cost as a percentage of GDP down by a factor of approximately 15.
Therefore, instead of the 8 – 22 percent of GDP we’re talking about today, the cost would be 8/15 to 22/15…or 0.5 percent to 1.5 percent of GDP. (Of course, that’s for removing 30 billion tons of CO2 per year. If the people of 2100 want to actually start lowering atmospheric CO2 concentrations, the cost would depend on the rate they wanted to lower emissions.)
So the Stern report’s conclusion that damages from CO2 will be greater than 5 percent of world GDP throughout the 2100-2200 time period is almost certainly wrong. (Note that this does not even cover adaptation measures such as slowing the rate at which Greenland and Antarctic glacies reach the sea, or developing portable storm surge protection systems for coastal protection.)
October 2nd, 2008 at 7:24 pm
Mark Bahner (4) — On the appropriate DoE web page it states they are researching CO2 storage deep underground and expect to be able to do this for $22 per tonne of CO2. Now if one could just estimate the cost of removing the CO2 from the sorbant, call it S, the operating cost per tonne of CO2 sequestered would be quite close to
$10 + $ 20 + S
and then whatever capital costs are required.
Here is the chemical reaction:
2NaOH + CO2 → Na2CO3 + H2O
from
http://en.wikipedia.org/wiki/Sodium_hydroxide
and I don’t know how eassy it is to reverse this reaction. Maybe it would be better simply to bury the resulting sodium carbonate?
October 3rd, 2008 at 3:47 pm
More information is found in the comments by Dunn and Dietz on
http://www.futurepundit.com/archives/005592.html
The additional cost for this method is about $43 per tonne for a total of around $75 per tonne of carbon dioxide; $275 per tonne of carbon. That’s about twice the cost of deep burial of biochar.
October 3rd, 2008 at 4:41 pm
Long time lurker..
thanks Roger for sticking with Prometheus.. the posts are always stimulating, enlightening and helpful ..
I’m continually astonished by the thin participation of commenters here .. is this simply continued ostracization for your lack of conformity to AGW/CC orthodoxy? .. has your reeducation been scheduled yet?
this CO2 capture R&D seems very promising especially if it is true that the device need not be co-located with the power plant or CO2 emissions source .. If I understand all of this, I might locate the device atop the targeted underground sequestration/storage location ..
any event – Keep up the good work on this blog..thank you ..
October 3rd, 2008 at 6:32 pm
Here is an idea using olivine to capture, permanently, the CO2:
ftp://ftp.geog.uu.nl/pub/posters/2008/Let_the_earth_help_us_to_save_the_earth-Schuiling_June2008.pdf
The cost estimate appear to be less than the cost of burying biochar.