Why not ammonia, NH3, as liquid fuel?

Discussion in 'Chemistry' started by Billy T, Feb 26, 2007.

  1. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Can you show or give reference? as this is not what I remember. Even if true, can fall back on your point that the over all process is exothermic.
    Most do not realize that a very high percent of the power that a jet engine makes is feed back to drive the compressor, so using part of the output to drive part of the process is not a "show stopper."
     
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  3. francois Schwat? Registered Senior Member

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    What about Na2B4O7·10H2O?
     
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  5. Nasor Valued Senior Member

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    Just look up the standard enthalpy of formation for NH3. Whatever units you find it in, it will be a negative number, meaning it's exothermic to make NH3 from H2 and N2. So it must be endothermic to make H2 and N2 from NH3.

    But the reaction where you combine the hydrogen with the oxygen is exothermic enough to make up for it and leave you with an excess of energy.
     
    Last edited: Mar 2, 2007
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  7. a_ht Registered Senior Member

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    Just for the records, the standard entalphy formation information refers to the energy needed to make NH3 from N & H & H & H as opposed to N2 & H2.
     
  8. Nasor Valued Senior Member

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    No, the standard enthalpy of formation is the energy needed to make a product if you start with elemental reactants in their "standard state". For nitrogen and hydrogen, the standard state is diatomic H2 and N2.
     
  9. Jeff 152 Registered Senior Member

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    As far as actually obtaining the ammonia, what about using human urine as a source? I know it contains ammonia, but is it enough such that you could like filter out your own ammonia fuel in your house? Or at least if new plumbing lines were made in homes just for urine and these would lead to a local plant which could filter out the ammonia somehow and then would be just a supplemental supply of ammonia? Maybe people could even get tax breaks or incentives based on how much ammonia they contribute ( I can see it now, ID swipe cards at public toilets to add to your ammonia contribution lol)

    But in all seriousness, is urine a viable source of ammonia?
     
  10. Sciencelovah Registered Senior Member

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    Are you suggesting that the toilet for light toilet (urinating) and heavy toilet
    (excretion of faecal matter) is separated

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  11. Sciencelovah Registered Senior Member

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    Well, as far as I know, so far household wastewater is only separated
    into greywater and blackwater.


    Anyway if you refer to this:


    let say in the city where I live, with nearly 1 million inhabitants, the city can
    collect 4.55 million kg N per year, or 12.5 ton N per day. Hmm... this isn't
    really bad..

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    but you have to consider this:
    • population: the city should be at least metropolis (over half a million of inhabitant)
    • the cost to separate ammonia from the blackwater (90% of Nitrogen in blackwater is in form of ammonia)...
    • how much is the fuel demand
    • etc etc..

    umm... somebody could make a PhD for that :truce:
     
  12. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    If you want to recover/ use human produced NH3, I suggest you go piss on the ground near a plant you want to grow faster. Spread it around a little. In winter, with snow, be artistc.
    (Man, not woman, was first artist - probably why, in general they are better artists. :shrug: - Man's special gift is in their jeans.

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    )
     
    Last edited by a moderator: Oct 19, 2007
  13. Sciencelovah Registered Senior Member

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    he asked about ammonia for fuel, not for fertilizer :shrug:

     
  14. Carcano Valued Senior Member

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    Me too!

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    A small steam turbine to recharge the battery.
     
    Last edited: Oct 20, 2007
  15. Carcano Valued Senior Member

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    Isnt that where Jackson Pollack got his inspiration?

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  16. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    Not that simple. First, to break down molecules and to make molecules require energy. It often also require some other kind of molecule to exchange atoms. Thus, you must think about the energy required to make the chemical transactions and the bi-products that the reaction may produce, not only how easy it is to transport the chemicals.

    For one thing, breaking down and creating H2O takes quite a bit of energy...

    So... what substance do you propose to use in order to break down a molecule of NH3? O2?

    NH3 + O2 + H2 = H2O + NH2 + H + energy.........?

    Huuumm..... :scratchin:
     
  17. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    Darn... I haven't done chemistry for so long I forgot all the rules....! :bawl:
     
  18. Nasor Valued Senior Member

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    He was proposing going from NH3 (that you store in your car's tank) and O2 (that you get for free from the air) to make N2 and H2O. Thermodynamically it would work, since you release a lot of energy when you combine ammonia with oxygen to make N2 and water. Most of the energy comes from combining the hydrogen with he oxygen to make water...basically the ammonia is just a better way to store the hydrogen. It might be the only sensible idea about alternative energy to be posted in the history of sciforums.
     
  19. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    So how much energy is required to do the reaction?
     
  20. Nasor Valued Senior Member

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    It take 46 kj/mol to turn the ammonia into N2 and H2, then releases 363 kj/mol when you burn the H2. So you get a net energy output of about 317 kj/mol of NH3.
     
  21. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    Sounds good to me? So what's stopping it from happening? The smell?

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  22. nh3 fuel Registered Member

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    Yep, NH3 makes a great fuel

    All--

    I just ran across your forum. Most everything you say is true (except an earlier statement that NH3 is mostly made using electrolytic H2--it's actually mostly made using H2 from reforming natural gas). NH3 is a carbon-free clean fuel that has been used in vehicle engines since the 1930s. It can be used in spark-ignited ICEs, diesel (with ~5% high-cetane co-fuel), combustion turbine, and direct-NH3 fuel cells. Perhaps the best thing about ammonia is that it can be synthesized from simply air and water using renewable (or nuclear) energy electricity. E.g. wind or solar to ammonia. There is much going on in the world regarding NH3 fuel. www dot energy.iastate.edu/Renewable/ammonia/ammonia dot htm .

    Also, look in a few weeks for the new web site of the Ammonia Fuel Network, a non-profit organization promoting NH3 fuel, at www dot ammoniafuelnetwork dot org .

    Keep up the good work and ideas.
     
  23. It's highly caustic, and has a relative low flash point.
    Burning is not wise, as it is not clear. Trying to recall, 20% remains unburned.

    So, anyone behind you, or in front, will Emit DEATH!

    Not to mention, it trickles with eddy currents. And preventing back-flash could easily be over-ridden. By anyone whom wished with the tap of a hammer.

    BOOM!
     

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