(To me) obvious problem with this: if you then burn the ethanol, aren’t you back where you started as far as…

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7 responses to “(To me) obvious problem with this: if you then burn the ethanol, aren’t you back where you started as far as…”

1. 

   October 18, 2016

   Gilmoure deTrimar

   Using concentrated solar energy to reverse combustion, a research team from Sandia National Laboratories is building a prototype device intended to chemically “reenergize” carbon dioxide into carbon monoxide using concentrated solar power. The carbon monoxide could then be used to make hydrogen or serve as a building block to synthesize a liquid combustible fuel, such as methanol or even gasoline, diesel and jet fuel.

   energy.sandia.gov – Sunshine to Petrol

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2. 

   October 18, 2016

   Walter Roberson

   Drink the ethanol? Mandatory drinks for everyone since so much would be produced?

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3. 

   October 18, 2016

   Fred Hicks

   Your post seems to assume a delayed release rather than a self-feeding loop. I don’t get that.

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4. 

   October 18, 2016

   Gilmoure deTrimar

   For the PM article (and the Sandia S2P as well): Energy sources are formed by converting energy into more complex potential energy. This can be as simple as pumping water to an elevated reservoir or tank, with the potential energy of weight falling down being the stored energy.

   In the case of chemical storage, you’re fighting against the energy release of complex hydrocarbons, in essence, un-burning them, and making them complex again. We have systems that do that all the time, called plants and animals, only here, we’re doing on a much cruder and simpler scale.

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5. 

   October 18, 2016

   David Friedman

   What is being described isn’t an energy source or a way of reducing CO2 in the atmosphere (unless you never use the ethanol), it’s a battery. An inexpensive and efficient way of storing lots of power would make intermittent power sources such as solar and wind more competitive with fossil fuel as a power source.

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6. 

   October 19, 2016

   Fred Hicks

   If it’s ~60% efficient at capturing CO2 and storing it as ethanol, then why not do the feedback loop of burning the ethanol and running emissions through a filter using the same process, thereby releasing only 40% as much CO2, it seems that, starting with a given X quantity of CO2, and getting into a (lossy, admittedly) loop like this, that it could reduce total CO2 over time. So to the extent I understand it, it’s a battery, sure, but a battery that could recapture a significant portion of its output with each cycle, and one which would have an abundant starting input of CO2 that could be locked down into battery form over time.

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7. 

   October 19, 2016

   Walter Roberson

   Fred Hicks Suppose you start with 100 tonnes of CO2. 60% efficiency so 60 tonnes gets captured as ethanol and 40%, 40 tonnes, goes up the chimney uncaptured. Burn the 60-tonnes equivalent of ethanol to produce 60 tonnes of CO2; scrub it at 60% efficiency to capture 36 tonnes of ethanol and have 24 tonnes go up the chimney uncaptured. At this point we have 36 tonnes of ethanol on hand and (40+24) = 64 tonnes has escaped. Run it through more cycles and you get more and more escaping and less and less ethanol.

   What might make sense, potentially, is to use the 60 tonnes-equivalent of ethanol to run a different capture process on the 40 tonnes that you did not have available energy for before. I would need to trace the math to see if that would work out; I am not sure that it would as long as our highest priority is removing CO2. But if we used the energy for removing (say) Sulfur that we could not otherwise have afforded to remove, then it might end up making sense.

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