Adding water to alcohol fuel

Discussion in 'Stove Forum' started by Twoberth, Dec 6, 2019.

  1. Twoberth

    Twoberth United Kingdom Subscriber

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    Hello,
    I have been following recent and old threads on alcohol fuels, and there are several references to water additions preventing/reducing sooting of pans.

    I don’t understand why adding water to alcohol would reduce the sooting of cooking pans. Even if the flame is burning rich, extra water in a flame will not affect the burn cleanliness - since it doesn’t add any extra oxygen or consume any carbon. In fact water, as steam, is one of the stable products of complete combustion.


    So, as the water is both oxygen and carbon neutral in the combustion process, does the extra steam in the exhaust just stop the soot from sticking to the pan?
     
  2. gieorgijewski

    gieorgijewski Subscriber

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    sooting is insufficent oxygene in flame area
    in that process (burning) we can not (easy) add extra oxygene
    but We can make "slower" carbon flow from the tank by adding extra transported capacity (water)
     
  3. Majicwrench

    Majicwrench Subscriber

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    I certainly don't know the chemistry involved, I do know Trangia recommends adding water.

    I use Everclear for fuel, and I feel a bit of water helps prevent the burner from getting out of control too.
     
  4. gieorgijewski

    gieorgijewski Subscriber

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    :)
    adding the water makes proper air–fuel ratio for combustion
    the same what makes carburettor...
    but air flow is constant
    pressurised fuel flow (depends on construction) is "as is"
    "rich" or "pour" fuel - is the way to set up proper air–fuel ratio
     
  5. Lennart F Sweden

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    In the new versions of some alcohol fuels where the methyl alcohol part is replaced by some propyl- and butyl alcohol, it seems that water mix doesn't limit the excessive sooting.
     
  6. BradB

    BradB United States Subscriber

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    Each brand of ethanol may burn a bit differently. I think you need to add progressive amounts of water till you are happy with the cleanliness. My testing showed my ethanol will burn quite clean with water added, at the price of diminishing the power. My undiluted ethanol is not so bad; I have decided to add no water and carry a rag or paper towel to wipe off the small amount of soot. Brad
     
  7. Marc

    Marc Subscriber

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    My yellow HEET leaves no soot at all.
     
  8. BradB

    BradB United States Subscriber

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    Ah yes, but Heet is methanol. I think the gist of the discussion was how to use safer to use and handle ethanol. There is no doubt that the Kleenstrip types as well are very clean burning. If one has no objections to using and burning methanol then the decision is easy.
     
  9. Ed Winskill

    Ed Winskill United States Subscriber

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    I have no objections to using and burning methanol, especially when it is mixed into ethanol.

    I haven't had pan sooting with basic Kleenstrip-typed denatured alcohol.
     
  10. Alcoholic Australia

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    Just bumping this old thread to add my 2c. As I understand it, adding water means evaporating an inert compound. Thus we get the evaporating cooling effect without the combustion heating effect, thereby adjusting the air / fuel ratio.

    Fuel supply is governed by the rate of evaporation and air supply is weakly related to heat. Adding water then cools the burner, reducing fuel evaporation / supply and leaning out what is naturally a rich mix, reducing the soot. Many also notice less soot in colder conditions for the same reason.

    The alcohols carry oxygen within their chemistry so burn cleaner in open air than pure hydrocarbons. Methanol has more oxygen in it than ethanol, relative to its carbon and hydrogen atoms, so it burns leaner, at the expense of lower energy density. Which is due to the same reason - oxygen doesn’t have any energy of its own.

    Wicking stoves like the speedster or origo types also run leaner as the wick limit the rate of evaporation of the fuel, yielding a fuel/air mix that is closer to ideal stoichiometry. The downside is lower power but the upside is better efficiency. Similar outcomes can be achieved in a Trangia by using the summer ring, which also limits evaporation for obvious reasons.

    It’s a classic power vs efficiency problem and there are a few ways to solve it, whichever end of that argument you want to end up...
     
  11. snwcmpr

    snwcmpr SotM Winner Subscriber

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    Is there a difference between the older Trangia burner and the newer burner?
    I remember that it was mentioned here recently that Trangia, at some time recently, added something to the wick. Possibly to make the flame visible???
     
  12. geneislucky

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    snwcmpr
    A fine question. I recall trangia flame as blue. My newer burners are yellow/orange. I have never seen a explanation from Trangia. I have seen speculation by types like us that sodium burns yellow and a treatment of the wick inside the burner is why flames are colored. Which would improve safety as invisable flames are always warned about. So i do not KNOW the why or the how. But I expect it is an intentional safety improvement by chemically treating the wick. I would have expected Trangia to have taken credit. Love to hear a definitive answer.
     
  13. Ed Winskill

    Ed Winskill United States Subscriber

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    I had heard that it was a deliberate thing, a few years back when I bought my new Trangia.

    That was the one disappointing thing, actually. The stove works fine, but I much prefer the pure blue flame.
     
  14. snwcmpr

    snwcmpr SotM Winner Subscriber

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    Which begs the question.
    Chemists... how do we remove that added chemical from the wick?
     
  15. Lennart F Sweden

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    It is very common that the methanol is replaced by butanol and propanol in the alcohol mixes that has been popular as stove fuels - this makes the flames more or less yellowish.
     
  16. Ed Winskill

    Ed Winskill United States Subscriber

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    I don't think that's it. The stuff I get burns blue elsewhere.
     
  17. Hazet

    Hazet Subscriber

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    Från: Jon <xxxxxxx@yahoo.com>
    Skickat: den 3 december 2020 14:57
    Till: Customer Support, Trangia AB <customersupport@trangia.se>
    Ämne: Wick material in spirit burner

    Hello
    How are you?
    I was wondering what the wicking material is made from in the spirit burner.
    Is it chemically treated to make the flame burn a yellow-ish color?
    Thank you, and have a great day.
    Jon

    From: Customer Support, Trangia AB <customersupport@trangia.se>
    To: Jon <xxxxxxxx@yahoo.com>
    Sent: Friday, December 11, 2020, 01:09:38 AM EST
    Subject: Sv: Wick material in spirit burner

    Hi Jon,
    The wick is made from 100% cotton, it os not treated with anything.
    I would say it is the fuel you use that makes the color of the flame.
    Let us know if there is anything else.

    Med vänlig hälsning / Best regards
    Anna Johansson


    Alsenvägen 16
    835 96 Trångsviken
    Sweden

    Customer support
    Tel. +46-640 68 13 30
    Internet: www.trangia.se

    Webshop: https://shop.trangia.se/sv/
    Facebook: trangia.sweden
    Instagram: trangia_sweden


    I'm gonna say it again: If there is ever a question about a Trangia product, I find it very easy to send them an email and ask. It helps cut down on the "I read it on the internet so it must be true" conjectures, and conversely, can confirm thoughts about the "what" and "why" of what they produce.
    I have always found them to be receptive to questions, and helpful in their replies. Even though they are an international company, I find them to be most personable when corresponding with them.
     
    Last edited: Dec 11, 2020
  18. snwcmpr

    snwcmpr SotM Winner Subscriber

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    Guilty as charged.
    I assumed since I read it here it was treated.
    So, begs the question why the colored flame if it is not the fuel.
     
  19. ArchMc

    ArchMc Subscriber

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    There were some posts about solutions you could soak a wick in to make it an easier-to-see color. If I remember, baking soda would give the flame a yellow color, so a priming flame would be more visible in daylight.

    ....Arch
     
  20. Alcoholic Australia

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    IMO the burner is rich by design. In an alcohol stove this helps power output at the expense of efficiency, a trade off that Trangia has clearly made as more people desire more speed from a spirit burner than desire more efficiency. And the stove design is already very efficient.

    If a leaner / more efficient burn is required, then a speedster / origo design is better - or just add some felt to the inside of your trangia burner up to 2/3 full. Or add some water to the meths to slow vaporisation. Trade off will be reduced power...