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  • Turning CO2 into fuel

    A step in the right direction?

    http://gas2.org/2009/11/26/scientist...comment-135636
    I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

  • #2
    How did they say they are getting the rings to 2700 deg F??

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    • #3
      from the article:

      The rings’ outer edges–made of iron oxide–are solar heated to 2,700 degrees which forces the composite to lose oxygen atoms

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      • #4
        Gobal warming solved???? No.

        Just remember that you can't get more energy out than you put in. Whatever the increase in potential energy that occurs in the form of changed binding energy must come from somewhere. That is the sun of course and it deposits around 1 kilowatt per square meter per hour on a good day. The amount of energy it takes to "unburn" a fuel is the same as it released when burnt, plus losses.

        While this is interesting it isn't going to come close to solving the problem of CO2 emissions. To do so will require even more solar energy than it would take to replace the fuels in the first place. 1 gallon of gas produces 34 killowatts of power when burnt and about half of that ends up as CO2.

        If the conversion efficiency of the above mentioned process is 10 percent then it will take 1500 square metre hours of sunlight to unburn the CO2 produced by burning a tank of gasoline.
        Free software for calculating bolt circles and similar: Click Here

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        • #5
          1 * ((32/2)/10%) = 160

          Even so, it's an elegant measure of how efficiently they waste our tax dollar.

          Cheers,

          BW
          ---------------------------------------------------

          http://www.cnccookbook.com/index.htm
          Try G-Wizard Machinist's Calculator for free:
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          • #6
            I prefer the old fashioned way.

            Paul A.

            Make it fit.
            You can't win and there is a penalty for trying!

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            • #7
              Solar energy as a means to reverse so-called global warming seems to be the least effective way to do it. In fact if they placed flat mirrors of the same area such that all the energy they receive is reflected back out to space it would actually reduce global warming. The energy would go away. It is an excess of solar energy that is causing global warming - trapping more here is not going to help.

              Edit: Got interrupted...

              So using solar energy to create more carbon based fuel to be burned a second time will ensure that all the energy that went into creating it the first time and which was released as green house gases, will be released again as green house gases, and all they've done is added more heat to the system with the solar reflector. It's madness in the finest form.
              Last edited by dp; 12-07-2009, 12:18 PM.

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              • #8
                Paul raises a point.

                Alcohol distilled from grain or cane and vegetable oil pressed from seed is big time inefficient. It would take all the US arable land to raise enough grain and cane to fuel our transportation industry to 100%. We use about 1/3 of our petroleum consumption for transportation. We still need the other 2/3 for space heating and process heat. Then where will we raise our food? Bio-fuel does not pencil out except as a niche supplement.
                Last edited by Forrest Addy; 12-07-2009, 12:25 PM.

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                • #9
                  Originally posted by Forrest Addy
                  Old fashioned way? You mean alcohol distilled from grain or cane? It would take all the US arable land to raise enough grain and cane to fuel our transportation industry to 100%. We use about 1/3 of our petoleum consumption for transportation. Bio fuel does not pencil out except as a supplement.
                  When you do that people complain you're burning food in your SUV while people are starving in the world. It's been tried.

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                  • #10
                    Originally posted by dp
                    When you do that people complain you're burning food in your SUV while people are starving in the world. It's been tried.
                    I've always been curious how much petroleum in the form of fertilizer, cultivation, harvesting, processing, and transportation goes into a litre of biofuel.
                    Design to 0.0001", measure to 1/32", cut with an axe, grind to fit

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                    • #11
                      The rings’ outer edges–made of iron oxide–are solar heated to 2,700 degrees which forces the composite to lose oxygen atoms
                      Right. That's a lot of solar power. Couldn't we just convert that 2700 deg F to steam, spin some turbines, and reduce the demand on a coal-fired power plant?

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                      • #12
                        1 * ((32/2)/10%) = 160

                        Even so, it's an elegant measure of how efficiently they waste our tax dollar.
                        Tank of gasoline is about 10 gallons.
                        Free software for calculating bolt circles and similar: Click Here

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                        • #13
                          Researcher’s hope to achieve an efficiency of a few percent which is about double that of real-world photosynthesis.
                          I don't know how many % a few is but it sounds like this is a very poor option for solar power...

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                          • #14
                            Originally posted by Evan
                            Gobal
                            1 gallon of gas produces 34 killowatts of power when burnt and about half of that ends up as CO2.
                            I think you mean 34 kilowatt-hours of energy.

                            And way more than half ends up as CO2 when measured by mass. A gallon of gas has a mass of 2.6 kilograms and produces about 8 kilograms of CO2 when burnt.
                            I'm an abstract poet and I didn't even think I was.

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                            • #15
                              A kilowatt hour is a measure of power, energy is watts, power is watts per unit time.

                              It isn't the mass that matters, it's the binding energy change, called enthalpy.

                              edit: I realize I left off hours in that sentence but I refered to watt hours in the other parts of the example.
                              Last edited by Evan; 12-07-2009, 01:04 PM.
                              Free software for calculating bolt circles and similar: Click Here

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