Slashdot Mirror


Removing CO2 From the Air Efficiently

Canadian scientists have created a device that efficiently removes CO2 from the atmosphere. "The proposed air capture system differs from existing carbon capture and storage technology ... while CCS involves installing equipment at, say, a coal-fired power plant to capture CO2 produced during the coal-burning process, ... air capture machines will be able to literally remove the CO2 present in ambient air everywhere. [The team used] ... a custom-built tower to capture CO2 directly from the air while requiring less than 100 kilowatt-hours of electricity per tonne of carbon dioxide."

7 of 487 comments (clear)

  1. Natural device? by TheMidnight · · Score: 5, Insightful

    Don't we have a device that removes CO2 from the air? I thought they were called "trees."

    1. Re:Natural device? by Anonymous Coward · · Score: 4, Insightful

      They won't be making a pile of cash out of trees.

      Can't resist:

      1) Identify a possible source of trouble
      2) Invent a fix, no matter how convoluted it is
      3) Patent it and market it
      4) Profit

      Just wonder how much do we have to wait for a fart capture device (cow farts are actually a major source of trouble)

    2. Re:Natural device? by MightyYar · · Score: 4, Insightful

      Cant we just grow up now and realise we have to
      be moderate in our consumption of the planets resources instead of trying to trick our way out ?

      I don't think you understand human nature. Your solution requires changing a significant percentage of the population's behavior - I don't give it much chance of success.

      --
      W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
  2. If they want to remove CO2... by Mashiki · · Score: 5, Insightful

    Goto where the farmers are burning down the rain forests, teach/give/train them how to plant high yield crops and stop them from clear cutting/burning them down. And shock...you'll get somewhere.

    Sometimes the most obvious solutions are sitting in front of their faces.

    --
    Om, nomnomnom...
  3. Space missions by Anonymous Coward · · Score: 4, Insightful

    expedient and efficient removal of CO2 at atmospheric concentrations could have profound implications in space.

    Currently, CO2 is scrubbed using lithium salts, which are not only heavy, but also caustic, and have a limited service life before requiring replacement.

    A purely electric, and solid state device capable of continuous operation would allow for superior space vehicle designs which could theoretically operate much longer than currently available ones.

    If they discover a way to electronically reduce the carbon dioxide into elemental carbon, things will be even more interesting.

  4. Re:CO2 is good by Ambitwistor · · Score: 4, Insightful

    A warmer planet is good.

    Good for who? Norway? Or West Africa?

    A warmer climate leads to more arable land and longer growing seasons.

    Depends on where you are. If your plants are temperature limited in a temperate climate, maybe. If they're already in a warm climate, maybe not. And don't forget precipitation. When rain belts get shifted around, a lot of people end up unhappy.

    CO2 is good - it is the world's best fertilizer.

    This has got to be the most oversold benefit of CO2. CO2 fertilization helps, up to a point, if you have C3 photosynthesizers; C4 plants don't benefit. But direct manipulation FACE experiments show that this effect quickly saturates, and CO2 is often not the rate-limiting nutrient in photosynthesis; often it's water or nitrogen availability. The initial promise of CO2 fertilization hasn't really panned out; see here. It does help, but it doesn't quite help as much as one thinks, and it is often more than offset by negative climate changes.

    Of course, all recent evidence points to warming having ended,

    I hate to break it to you, but 10 years of below-average warming in a highly noisy system doesn't exactly overturn anthropogenic global warming.

    and having been due to natural climate variability and/or solar cycles.

    Natural climate variability counts against your claim, not for it. See the above: natural climate variability is quite large on short time scales, which makes short-term trends very unreliable evidence of anything. Over the long term, "natural climate variability" utterly fails to account for temperature trends over the 20th century; the only really long term cycles within the climate system itself are oceans, and the space/time pattern of ocean warming indicates the atmosphere is warming the ocean, not the other way around. Turning to external influences, there are solar cycles. Solar trends have been pretty much flat since the 1950s, and completely disagree with the warming experienced since then. They can account for some of the warming in the early 20th century, but very little of it since then.

  5. Physically impossible! by DancesWithBlowTorch · · Score: 4, Insightful
    Hey guys, this is the physics police talking here. I'm sorry, but we'll have to enforce the laws of thermodynamics in this case.

    According to David MacKay:

    The unavoidable energy requirement to concentrate CO2 from 0.03% to 100% at atmospheric pressure is kT ln 100/0.03 per molecule, which is 0.13 kWh per kg. The ideal energy cost of compression of CO2 to 110 bar (a pressure mentioned for geological storage) is 0.067 kWh/kg. So the total ideal cost of CO2 capture and compression is 0.2 kWh/kg. According to the IPCC special report on carbon capture and storage, the practical cost of the second step, compression of CO2 to 110 bar, is 0.11 kWh per kg. (0.4 GJ per t CO; 18 kJ per mole CO; 7 kT per molecule.)

    In other words: It'll be at least 200kW per tonne, unless they think the CO2 will somehow magically compress itself to be stored, which is not going to happen. That, or they just invented a perpetuum mobile.