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Carbon Extraction from the atmosphere

  1. Oct 2, 2014 #1
    I sort of wandered in from the Science Fiction Forum before anyone could stop me. I have a thought that I simply lack the expertise to make use of, and I thought I would drop it in the laps of people who do have the expertise to make use of it.

    What would be involved to pull carbon directly from the atmosphere and turn it into a substance of commercial value (say, automobile frames & bodies)? Plants, after all, do this at room temperature.

    The reason I have this thought is that, rather than trying to solve global warming through regulation, it makes more sense to solve the problem through appealing to the greed of my fellow primates. Better to harness all that ingenuity into the pursuit of a buck than squander same ingenuity figuring out ways to get around regulations.

    I suppose I'll be looking for replies, but I'm far more interested in getting you people to talk to each other than to me. Thank anyone who reads this for there time.
     
  2. jcsd
  3. Oct 2, 2014 #2

    berkeman

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    Looks like there are already many conversations like this going on. I Googled the title of this thread, and got lots of good hits. Why don't you check a few of them out, and let us know what the top 3-5 candidate methods are... :)
     
  4. Oct 3, 2014 #3

    mheslep

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    One method proposed (published) was simply refrigerating air to -108F so that the CO2 condenses out. The system would be run in the like of Antarctica where not much is required to keep it that cold. The lack of any fuel to run the system at the remote location suggested a wind farm for power, as intermittent operation would not be a hindrance.
     
  5. Oct 4, 2014 #4
    It would appear that this thought was not as unique to me as I thought it was--which is not at all a bad thing. Thank you for your time.
     
  6. Oct 4, 2014 #5

    Astronuc

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    Plants do it all the time. CO2 is converted into complex molecules in the plants.

    There is also Fischer-Tropsch synthesis.

    However to separate the carbon from oxygen takes energy. Plants use sunlight. We would have to use chemistry, or radiation, combined with some chemical reaction to bind the oxygen and remove it from the carbon.

    Otherwise, carbon sequestration involves simply extraction CO2, compressing it and pumping it into reservoirs in the ground. Bascially, all the fossil fuels, e.g., oil, coal and gas, came from plants, which at one time had absorbed CO2 from the atmosphere.
     
  7. Oct 5, 2014 #6

    SteamKing

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    That's the problem with carbon sequestration: what do you do with the carbon or CO2 which isn't recycled by industry, agriculture, etc.? A recent example illustrates the dilemma.

    Before about 20 years ago, elemental sulfur was mined from the ground around salt domes using various methods, refined (or more accurately, purified to remove contaminants), and then sold on the market.

    At about the same time, petroleum refiners were finding it difficult to locate sources of low-sulfur crude and natural gas to turn into diesel fuel, etc. The refiners could use raw materials containing sulfur by separating out the sulfur compounds from the crude oil and natural gas. Soon, the major refiners were sitting on mounds of elemental sulfur which resulted from the refining process, and the mounds grew day by day. There was so much sulfur being produced as a by-product of the refining process that the traditional method of mining sulfur became uneconomical compared to just taking the sulfur by-product off the hands of the major refiners.

    The amount of sulfur produced has reportedly not quite reached equilibrium with the demand for elemental sulfur in other industries, so most major refineries have large mounds of sulfur stored nearby. Alternate uses for sulfur, like as binders in cement production, have been explored, but supply still outstrips demand.

    Although sulfur is a raw material in many chemical production processes (chiefly the production of sulfuric acid), transporting raw sulfur in dry form from an oil refinery to a chemical plant involves additional expense and handling problems, because sulfur can burn and create nasty oxides, which turn acidic and corrosive when mixed with moisture.

    http://en.wikipedia.org/wiki/Sulfur
     
  8. Oct 6, 2014 #7
    Well what I was hoping for was to take the carbon out of the atmosphere in the form of nanotubes, That is a vast oversimplification, but the general idea is still worth considering. It's the old, "How to make lemonade from the lemons life gives you" saw. I just find it wiser to try and make lemonade rather then regulate and proscribe lemons.
     
  9. Oct 6, 2014 #8

    SteamKing

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    That's just like recycling old plastic and making new park benches out of it. Pretty soon, you have more park benches than you have parks to put them in, and now, instead of a plastic waste problem, you have created a too-many-park-benches problem.

    The problem with carbon is not that it is a particularly scarce material, it's that it is combined with oxygen in the atmosphere and is present only at trace amounts. Thus, it takes a lot of energy to separate the carbon and oxygen and also to process a sufficient quantity of the atmosphere to accumulate a usable quantity of the substance. Currently, a lot of this energy comes from burning carbon, so, over time, you probably wind up putting more carbon into the atmosphere than you would take out.
     
  10. Oct 6, 2014 #9

    mheslep

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    The two elements don't have to be separated. The molecule can be remove from air by several means chemically or simply distilling it out.
     
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