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Scientists Accidentally Convert CO2 into Ethanol

Discussion in 'Energy, Environment, and Policy' started by woof, Oct 21, 2016.

  1. woof

    woof Model X 75D Blue, 6 seats

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    Scientists Accidentally Convert CO2 into Ethanol, Potentially Solve Climate Change
     
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  2. Ulmo

    Ulmo Active Member

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  3. AudubonB

    AudubonB Mild-mannered Moderator Lord Vetinari*

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    FYI, I had reported this in the SpaceX sector of TMC, more or less as it could apply strictly to Mars. Think terra-forming.

    To answer your specific question, the likelihood that anyone ever before attempted this is minuscule, given the nanotechnologies needed here: they've not been around for long enough.

    More importantly, however, is that your leap to propose that it would end oil and coal extraction is, to my mind, so far off base as to seem delusional. Occam's Razor says that to the extent this technology can be scaled up, it has just decriminalized fossil fuel combustion, not put an end to it.
     
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  4. ohmman

    ohmman Maximum Plaid Member

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    That was my initial reaction as well. However, if this is indeed scalable (and that's plenty questionable), I think what @Ulmo is saying is that we can convert CO2 to a portable, high density fuel source at low cost. That cost has the potential to undercut fossil fuel extraction, and make the oil and gas industry economically defunct.

    At least until global cooling begins. ;)
     
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  5. Cosmacelf

    Cosmacelf Active Member

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    Wouldn't this be used in fossil fuel power plants to scrub exhaust of co2? Of course, you'd probably have to isolate the co2 first...
     
  6. AudubonB

    AudubonB Mild-mannered Moderator Lord Vetinari*

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    Yes to Cosmacelf - that is the obvious first choice, and that is why it might be the silver bullet for detoxifying the atmosphere (and, of immense concern to me, the hydrosphere) of excess CO2. One can go a lot further with this line of thinking and postulate that, successfully implemented, it could provide both for "clean"* combustion of hydrocarbons for electrical generation....and for the electricity needed to power EVs (this is for those who believe other sources of electricty aren't available at cost-effective rates).

    Isolating the CO2 in order thus to treat it is not seemingly a high hurdle. The cheap (Cu) spiky little fellas that are the activating catalysts appear to be something that feasibly could be attached to the scrubber walls/pipes/conduits of exhaust stacks. HOWEVER...I'm strongly of the opinion that this kind of technology, while of high potential for power plants, would NOT likely be feasible on the small scale of vehicular combustion and exhaust systems. Not important: we could have clean power plants and clean EVs. Win-win.

    Those of you (so far, Ulmo and Ohmman, it appears) who are suggesting this could supplant hydrocarbon production as a source of energy have to demonstrate to me there is a feasible source of lots of CO2 other than from fossil fuels. I think you'll not be able to find one.

    *Clean: that is, with respect to carbon dioxide output. No effect on fossil fuel power plants' output of NOXs, Hg, radionuclides or other nasties.
     
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  7. thimel

    thimel Member

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    The referenced paper says electricity is needed to convert the CO2 to ethanol. Hence using it to clean the exhaust from a power plant is pointless. It would use more electricity than was produced.
    However, it could provide a good way to convert solar energy to a liquid fuel.
     
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  8. ItsNotAboutTheMoney

    ItsNotAboutTheMoney Well-Known Member

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    It always comes down to the same problem: nanotechnology is hard to scale. Crack nanotechnology and the world's problems disappear.

    Anyway, to answer Audie's point, I'd argue that any scalable, economical process that can convert electricity and CO2 into fuel would be sustainable, because (a) renewable electricity is sustainable (b) renewable electricity energy potential is at least a magnitude greater than we need (c) you can consider the process as a closed loop x% efficient energy storage system using mCO2+ nH2O (d) sources of H20 and CO2 are at least a magnitude greater than we need.
    The energy challenge humanity has is affordable conversion of electricity into energy-dense storage, that is clean at point of use and does not result in a net increase in atm8spheric greenhouse gases. The described process could theoretically satisfy the requirements.
     
  9. Roger_wilco

    Roger_wilco Member

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    Thank God a final solution to my reef aquarium issues. Excess CO2 is lowering pH level and bacteria cannot consume excess nutrients due to lack of carbon source, like ethanol. Now both seems solved :D couldn't be any happier!
     
  10. Matias

    Matias Active Member

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    Yes. Efficiency is always less than 100%. This requires electricity and some percentage off energy is lost in conversion e.g. as waste heat. So this is not a net energy source. This is more like a method to transform electricity into ethanol and it is useful as energy storage with renewable energy.
     
  11. Johan

    Johan Took a TSLA bear test. Came back negative.

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    Yes but the bonus kicker is that CO2 could be captured from the atmosphere thus counteracting global warming. The ethanol made could be burned and the CO2 released once again captured, over and over. I.e. CO2 recycling, with electricity from solar PV as the energy source. The ethanol becomes the equivalent of the battery. Much simpler and easier to handle than compressed hydrogen.
     
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  12. Cosmacelf

    Cosmacelf Active Member

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    The question is, how much energy does this catalytic reaction take?
     
  13. AudubonB

    AudubonB Mild-mannered Moderator Lord Vetinari*

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    The answer is, from the article (ref'd it in my pretty moribund SpaceX thread), -1.2V. But I couldn't determine what on earth the denominator, so to speak was. That means I believe they are referring to the electropotential of the chemical reaction.
     
  14. AndreN

    AndreN Member

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    Burning, say, ethanol and producing CO2 is an exothermic reaction. We get energy out of it. To reverse the reaction requires putting at least that amount of energy back in. The other problem, activation energy, or extra energy required to make the reaction happen at all (to get over the "hump" in the curve), is apparently handled here by the new nanotech-based catalyst. So it's "easier" to make the reaction go backwards, but still needs more energy than was released when the fuel was burned that produced the CO2.
     
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  15. Cosmacelf

    Cosmacelf Active Member

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    Volts is not energy. Joules, kWh, etc. is energy. If the research article stated an estimate of the energy used in joules/mole of CO2 converted, then you could figure out if it might make economic sense to use as a fossil fuel CO2 scrubber, given that the reaction also produces energy in the form of ethanol (which, BTW, is the same kind of alcohol that we consume in drinks).
     
  16. 3Victoria

    3Victoria Active Member

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    Oh good, this means I can have a bottomless glass of Vodka with just a 1.5V battery and the catalyst ... yum yum.
     
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  17. Cosmacelf

    Cosmacelf Active Member

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    Yes, it would be funny if the best use of this technology would be to extract co2 from the air and turn it into alcohol for a home alcohol generator.
     
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  18. SageBrush

    SageBrush Active Member

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    #18 SageBrush, Oct 22, 2016
    Last edited: Oct 22, 2016
    There is already a massive excess of CO2 in the atmosphere. If the process works we are setting up a cycle since the Etoh will likely be metabolized or combusted once again to CO2.

    Unless we plan to bury the Etoh, this approach has no more chemical merit than just directly using sun energy gained cleanly instead of further fossil fuel combustion. The only question becomes which process is more efficient and 30% PV along with 80% battery is quite a hurdle. It might make for a cheaper energy time shifter though, which is probably why the researchers highlighted that application.
     
  19. SageBrush

    SageBrush Active Member

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    Specifically, *faster*
     
  20. mblakele

    mblakele radial cross member

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    I tend to be skeptical about scientific breakthroughs, so I went hunting for a more critical take. I found Researchers Discover Novel Method to Convert CO2 into Ethanol

    Scientists with the Oak Ridge National Laboratory have come up with a relatively efficient way to convert CO2 into ethanol, but its viability or importance as a scaled-up technology is still uncertain.
    ...
    As the authors concede in the study itself, the technology as currently developed is likely not economically viable because of its high overpotential (which is the difference between the mathematically determined theoretical electrode voltages and the actual electrode voltages needed to drive the reaction at the desired rate in practice)
    ...

    Leaving aside the question of reproducibility, this technique appears to be practical only in situations when energy is free, such as at times of day when solar or wind production outstrips grid demand. This sounds like competition for battery storage, more than anything. Unfortunately we don't know what the total cycle efficiency of this method will be, whenever it reaches commercial application. And that's years away, so whenever it arrives it'll have to measure up against battery storage costs at some future time.

    Finally note that the process used in the paper used CO2 dissolved in water, not in air. It's unclear to me whether they used naturally dissolved CO2 or dissolved it especially for the experiment, but I expect they dissolved CO2 in purified lab water. Using ordinary fresh water, seawater, or air with ordinary concentrations of CO2 might not be viable.

    Bottom line: for at least 2017-2020 batteries are probably still our best bet.
     

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