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Thread: Thermolysis: Water decomposition at high temperatures to extract hydrogen

  1. #1 Thermolysis: Water decomposition at high temperatures to extract hydrogen 
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    As wiki states under Thermolysis water heated to around 2500 C will break the bonds of H20 into H2 and O2.

    If you reached this temperature instantly would the H2O just change into a gas (that would look like thin air) and could the H2 be extracted and cooled out to some storage unit, like a compressor if you were using something like tungsten pipes and tanks?

    What would happen to H2 at such temperatures?

    Seems like it should be achievable but since no one is doing it on at least a small production level it must not be?


    Last edited by sifi; December 5th, 2011 at 04:03 AM.
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  3. #2  
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    After some more reading I found an Israel team The Weizmann team already started to achieve this back in 1995 (read here). Now they have a brochure claiming a two-step H2O-splitting thermochemical cycle based, in which they have patented it already so hope they are not to greedy.

    This video of a team in Arizona, which is what got me wondering about this subject in the first place, showing a solar furnace melting steel shows that this team is not far off either.


    Last edited by sifi; December 5th, 2011 at 04:02 AM.
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  4. #3  
    Geo
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    A temperature change is a physical change. You're talking a chemical change.

    There's an energy loss in your process. That's why we don't have water engines.

    What's the triple point of water.
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  5. #4  
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    "There's an energy loss in your process. That's why we don't have water engines."

    Whats the energy loss you speak of if the bond breaker is concentrated heat from the sun? The idea is not to have water engines but to produce H2 for direct use in cars.

    As someone else pointed out to me the question is how do you extract the H2 from the O2 at the decomposition temperature?
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  6. #5  
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    bottom line is it takes more energy to do this than you recover-so useless
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  7. #6  
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    I think the OP agrees, but states that using solar power DIRECTLY might make decomposing water feasible and then further wants to know how you can recover the separated H2.

    -R
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  8. #7  
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    You might find electrolysis more efficient than thermal dissociation.
    "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." ~ Douglas Adams
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