Suck on this, CO2
by Jeremy Elton Jacquot, Los Angeles on 09.27.07
Much of the attention of late has been focused on finding new ways to scrub carbon dioxide from power plant stacks or to capture it and sequester it below ground. This, say some scientists, misses a crucial point: how to effectively - and, more importantly, cheaply - remove the carbon dioxide that is issued from millions of tailpipes and homes from the air.
Frank Zeman, an engineer at Columbia University, and his colleagues claim they may have just discovered such a solution. They report in a new study that employing the technology used by pulp and paper mills - industrial-scale "scrubbers" - could help draw down carbon dioxide from the atmosphere. The captured gas could then be stored by being pumped underground or into the ocean.
Zeman's process would work by moving air through a packing material-filled chamber where it would come into contact with a sodium hydroxide solution - a liquid that absorbs carbon dioxide. The resulting solution would be combined with lime to precipitate limestone - which could then be heated to release a form of carbon dioxide ready for storage (or, if some of Zeman's other ideas pan out, for transportation fuels).
The cost for all of this, however, wouldn't come cheap: a whopping $200 per metric ton of carbon dioxide captured. Zeman and David Keith, his co-author, estimate improvements in the technology could help cut into that price tag over time, especially since it is already being used in pulp and paper mills around the world.
It won't be easy, Zeman acknowledges. Since ambient air only contains about 380 ppm of carbon dioxide, attempting to suck it out would require moving a whole lot of air through the scrubbers. These scrubbers would then have to process almost 250 times more air than flue gas to capture an equal amount. And, of course, this process would do nothing to tackle other GHG commonly spewed by power plants.
Still, if it all goes according to plan (a big "if," we know), Zeman's proposal could go a ways toward helping reduce atmospheric levels of carbon dioxide.
Via ::Environmental Science & Technology: The CO2 sponge (journal)
See also: ::Venting Our (Carbon Dioxide) Problems into Space, ::International Team Of Scientists To Test South Atlantic Carbon Sink In 2009
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Shouldn't we change the way we do things instead of just figuring out how to clean our shit? People just don't get it.
It must be part of the job description of being a research chemical engineer to ignore the fact that lime is made in lime kilns by heating with huge amounts of natural gas. And ignore that NaOH is made most often as a byproduct of chlorine manufacture - another very energy intensive process.
Once a carbon cap is mandated, energy used to make NaOH and lime will become far more expensive, and the 200/t will double or so.
What this is a perpetual motion cash transfer machine.
Hmm, interesting idea, but I wonder if the gas scrubbing technology could be miniaturised and used directly on vehicles (as a part of the exhaust system?) The technology is beyond me but perhaps when the car is filled with fuel the CO2 could be pulled out of the vehicle and stored. Not a long-term solution obviously...
Wet scrubbers are great for industrial applications, but as soon as you add one to a moving combustion engine there are a couple problems. The big problem is the performance hit as soon as you increase the back-pressure in order to push through a caustic solution. You may scrub a certain percentage of the exhaust, but your engine is also less efficient. The scrubber solution also needs to be replaced rather frequently.
More like "STUCK on this CO2"
Why go through so much trouble and expense when clean energy technologies exist. Let's improve the cost of using them. Duh.
I'm glad someone tried this to see if this is feasable, but it doesn't sound like it is without heading down a path we ought to avoid - continuing to use dirty energy when clean energy is abundantly available.
With the amount of R&D $ spent on oil exploration and the like,
we could have a lot of alternative energy in place. Then we could shut down these filthy machines and go have a Mai Tai on the beach.
I'm pretty sure trees are a heck of a lot cheaper, not to mention a technology thats been around for a few million years or so.
Well, if you want clean air without the multi-billion dollar whiz-bang, go down to the local garden
center and buy up a bunch of seeds for different
stuff, and fling em into the nearest bare earth. Mother Nature has been at the CO2 removal
business for a lot longer than we have been making it...did I mention that humans emit CO2?
Hold your breath, over there...air pollution, you know...
I prefer the idea of pushing air through water tanks with algae and collecting the oil content from it. this has been writted about in on this site and I think it makes the most sense. If we get to a point when the oil is not needed for fuel, because we will presumably using cleaner energy sources/conserving energy, than maybe we can pump the oil into old wells for carbon sequestration. It seems to me to be a more stable option than pumping gaseous CO2, trying to liquify it under pressure, or using expensive processes to convert it into some other inert material.
I feel that carbon capture technology will be an important part of the transistion to alternative fuel sources. It is looking like it will be a long time before are able to ween ourselves off fossil fuels and until we do, I think we are wise to find clean ways of using them. In 2004 the world energy system still relied on 85.7% fossil fuels. Although cleaner renewable sources of energy are being developed, it will be a long time before we can power our cities without burning fossil fuels or Biofuels. Nuclear and Hydro-Electric sources are still the next biggest alternatives when it comes to reductions in air pollution, but they still only represent 9% of our energy sources. I would love to live in a dream world where all our power comes from the sun and the wind, but the truth is that it's a long way off. It could be 50 years or more before solar and wind technology start to even make a dent in the energy demand, until then I think any technology that helps keep our air clean is a good idea. I would also like to mention that much of the developing world is going to be burning fossil fuels as their main source of power for a very long time, if we can provide these countries with ways of keeping their energy systems cleaner, we are helping ourselves just as much as them.