Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Extraction of ethanol

  1. Dec 31, 2007 #1
    Homemade Extraction

    Suppose I have an aqueous solution of acetone and ethanol.

    >While a simple or fractional distillation will do the job in a lab,
    Are there any "homemade" methods (i.e., using materials generally found in a home,
    non-laboratory setting) that can be used to extract ethanol from such a solution?

    Would boiling the solution in salt water (i.e, saturated with NaCl) allow me to extract the ethanol?
    (i.e., via SN2 substitution by chloride anion on carbonyl carbon, producing sodium 2-chloro-2-propanoxide, which can be later removed (as precipitate after cooling or via 'homemade' distillation*). I do not think this will work, though I have not tried this...)
    *Homemade distillation:
    -Pour the solution (to be distilled) into a large bowl, and place a small cup in the center.
    -Loosely cover the large bowl with plastic wrap, and place a few ice cubes in the center above the wrap
    -Carefully heat (or place outside on a sunny day, if you can wait). The distillate will evaporate and condense upon the plastic wrap, trickling down towards center (where the ice cubes are weighing down the wrap, hence the "loose" covering) to drip slowly into the cup.

    *While this procedure is nowhere near as precise and efficient as a lab distillation apparatus,
    it can be used to separate compounds with sufficiently large differences in boiling points. Sadly, this is not the case with acetone and ethanol; hence, this thread!
    Last edited: Jan 1, 2008
  2. jcsd
  3. Jan 4, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Yes, it would be 'extracted' into the atmosphere.
    Don't bother. Salt doesn't do that.
    Acetone is added to ethanol as a denaturant to keep people from consuming it (without taxation, that is). It is very difficult to remove it without specialized apparatus (specialized = illegal for home use). The boiling point of ethanol is 78C and acetone is 56C. Acetone and water form an azeotrope at 56C and consists of 88% acetone and 12% water. Acetone and pentane form an azeotrope at 33C consisting of 80% pentane and 20% acetone. I'm not sure about the ternaries.
  4. Jan 4, 2008 #3

    jim mcnamara

    User Avatar

    Staff: Mentor

    If you are not sure, the practical definition of a positive azeotrope (what chemistree listed above) is that you cannot distill a mixture beyond its azeotrope - you can never get rid of all the acetone in an acetone/ethanol mixture by distillation, for example.

    If you want alcohol, it is completely legal to brew wine or beer. In the US the regulations limit production to 600 gallons per year for personal use. I guess the people who promulgate ATF regulations are BIG drinkers.... ~2 gallons of wine per day? Whoa.

    In the US, you can also buy 95.4% alcohol (azeotrope for water and ethanol) from the store if you are over the legal drinking age and your state is not a crazy-quilt of ABC regulations - it is sold under various brand names like 'Everclear' and is labelled 190 proof.

    In the lab, 95% ethanol is a common solvent. It is also coveted by sneaky graduate students. We used Phenolphthalein, a pH indicator and a strong laxative, mixed into our 95% as a sneaky graduate student indicator. Works real well. Has long-lasting deterrent effects, too.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook