Next Big Future: CO2 capture from the Air for Fuel or Storage
GoatGuy
· 11 months ago
Very interesting proposals.
The NaOH version seems to suffer from enormous water requirements. To get a ton of CO2, it would take about 3,000 tons of air. A thousand tons of recirculated NaOH might be required at the misting heads ... that takes power. Dessicating the NaOH/Ca(OH)2 is very thermodynamically unfavorable ... taking more energy. Without doing a complete analysis, it seems unlikely to me that such a system could sequester CO2 without requiring an amount of power equal to, or greater than the amount of power generaged by the carbon that was oxidized to CO2 to begin with!
The CaO cycle is great fun - CaO of course comes from roasting CaCO3 ... which releases about 44% of its original mass as CO2 - so that has to be initially sequestered. But its not really a problem, because the CaO acts as a CO2 sponge, which can be "squeezed out" by application of high heat (re-roasting). Over and over again. I'm sure there would be all sorts of vortex-n-tube nonlinear (nonlaminar) flow losses, so pumping an appreciable amount of air past a bunch of hot calcium oxide nuggets ... looks a bit kooky to me. I guess it would work, but again ... 3,000 tons of air would be required to pass through all those tubes - during the hot part of the day - in order that the CO2 could be stripped. That's a lot of air.
The zeolite (or specialized polymer) method ... seems just as implausible. They're all flummoxed by the same reality: air having "only" 385 parts per million of CO2, being scrubbed optimistically to 185 parts (half) ... represents a LOT of air to scrub per ton of CO2 recovered. Somehow, I just don't see making millions of these processors (to recover millions of tons of CO2 per day, hardly a dent at all in global CO2-from-fossil-fuel production) all over the deserts or other parts of the world ... when we can't presently conceive of making an equal area of power PRODUCING (and thus CO2 mitigating) systems in the same deserts, today!
Well, AES has to keep its researchers in business. Let's just get on with mandating that our societies are going to CHANGE from burning fossil fuels to alternative energy sources, all of them renewable. After all, just like the transformation from hand tools, to power tools, and now to battery-powered tools ... we make changes. The change from fossil fuels to electrical systems ... is really nothing more than a commitment of society itself to make the change. Harder than, but no less achievable as all of the world ('cept a few) changing to the metric system.
GoatGuy
KarlSchroeder
· 10 months ago
I wrote a piece for WorldChanging.com about this last June (http://www.worldchanging.com/archives//008126.html). The key is use a system that moves a very large amount of air by passive means. My little SuperSCAF design is a hybrid of solar towers with the NaOH concept; it assumes the crudest technology and seems to come up with numbers that work. As a heat source such a tower could use something like a Hyperion nuclear battery (though that device in particular does not run hot enough). The entire system should be a net producer of power while moving truly prodigious amounts of air through it.
The reaction to this idea was generally hostile. Most people concerned with climate change have adopted the position that atmospheric scrubbing is an attempt to prop up fossil fuels--so the reaction is often *extremely* hostile. However, if you look at what would be involved in mitigating climate change strictly through emissions reductions (as George Monbiot does in his book HEAT) it quickly becomes obvious that emissions reductions by themselves are simply not going to work. We have to be actively removing the existing CO2 while not adding more. I hope that proposals such as these scrubbers are not science fiction, because if they are, we're screwed.
ajmoneykey
· 3 months ago
i got to questions im doing a sciencefair project 1st i wanna know it stores it in a liquid form right 2nd does anyone know how to test a chemecal (CO2) if it can be used as an energy source or fuel it would be great if someone could email me with some answers and a few links ajmoneykey@gmail.com
zachman1094
· 2 months ago
This is a very good idea. If taking the carbon we scrub from the flue's of coal and other energy plants we can solve two problems at once; we can slow down or even stop our pollution of the atmosphere and we can also create a fuel from this. This isn't a long term solution since the sources that the CO2 is coming from aren't renewable, but it's a very good short term solution until we have the technology to create a long term solution.
All Comments
The NaOH version seems to suffer from enormous water requirements. To get a ton of CO2, it would take about 3,000 tons of air. A thousand tons of recirculated NaOH might be required at the misting heads ... that takes power. Dessicating the NaOH/Ca(OH)2 is very thermodynamically unfavorable ... taking more energy. Without doing a complete analysis, it seems unlikely to me that such a system could sequester CO2 without requiring an amount of power equal to, or greater than the amount of power generaged by the carbon that was oxidized to CO2 to begin with!
The CaO cycle is great fun - CaO of course comes from roasting CaCO3 ... which releases about 44% of its original mass as CO2 - so that has to be initially sequestered. But its not really a problem, because the CaO acts as a CO2 sponge, which can be "squeezed out" by application of high heat (re-roasting). Over and over again. I'm sure there would be all sorts of vortex-n-tube nonlinear (nonlaminar) flow losses, so pumping an appreciable amount of air past a bunch of hot calcium oxide nuggets ... looks a bit kooky to me. I guess it would work, but again ... 3,000 tons of air would be required to pass through all those tubes - during the hot part of the day - in order that the CO2 could be stripped. That's a lot of air.
The zeolite (or specialized polymer) method ... seems just as implausible. They're all flummoxed by the same reality: air having "only" 385 parts per million of CO2, being scrubbed optimistically to 185 parts (half) ... represents a LOT of air to scrub per ton of CO2 recovered. Somehow, I just don't see making millions of these processors (to recover millions of tons of CO2 per day, hardly a dent at all in global CO2-from-fossil-fuel production) all over the deserts or other parts of the world ... when we can't presently conceive of making an equal area of power PRODUCING (and thus CO2 mitigating) systems in the same deserts, today!
Well, AES has to keep its researchers in business. Let's just get on with mandating that our societies are going to CHANGE from burning fossil fuels to alternative energy sources, all of them renewable. After all, just like the transformation from hand tools, to power tools, and now to battery-powered tools ... we make changes. The change from fossil fuels to electrical systems ... is really nothing more than a commitment of society itself to make the change. Harder than, but no less achievable as all of the world ('cept a few) changing to the metric system.
GoatGuy
The reaction to this idea was generally hostile. Most people concerned with climate change have adopted the position that atmospheric scrubbing is an attempt to prop up fossil fuels--so the reaction is often *extremely* hostile. However, if you look at what would be involved in mitigating climate change strictly through emissions reductions (as George Monbiot does in his book HEAT) it quickly becomes obvious that emissions reductions by themselves are simply not going to work. We have to be actively removing the existing CO2 while not adding more. I hope that proposals such as these scrubbers are not science fiction, because if they are, we're screwed.