khourygeo77
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Separating terpenes dissolved in ethanol from solution?
Hello,
I tried different methods and so far nothing.
I tried fraction distillation but the two distill together (azeotrope?)
I tried to dilute to form an emulsion and extract with a non polar solvent. Nothing as well. I tried to add salt or sodium acetate or potassium
carbonate to make the solution dense while extracting with non polar solvent. Nothing as well
I tried to saturate the louche with very soluble salts to make it dense but no oil floated.
i cant centrifuge of course
Any idea on how to perform this separation?
I am trying now to do a size exclusion chromatography but not sure if I'm doing it right and if it will yield any good result
[Edited on 26-5-2019 by khourygeo77]
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Boffis
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You need to give us some details about the solution. You refer to terpeneS ie plural but there are a lot of terpene type compounds and related
terpenoids. Also what are you trying to achieve, what is the end game?
While terpenes (ie oxygen-free compounds) tend to be almost insoluble in water the alcohol will greatly increase this solubility and also cause a
tendency to emulisfy as you have seen. Careful fractionation will remove most of the alcohol (I am presuming you mean ethanol) and the addtion of
water to the remainder will remove most of the remainder leaving a water insoluble oil that can be separated but you may need to be patient and let
the oil water mixture stand for a while and don't use virorous shaking or stirring. These compounds have penetrating odours so traces in the alcohol
will taint it but for chemical purposes that's probably not a big issue. After several fractional distillations try charcoal treatment; it may remove
most of the remaining odouriferous compounds.
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khourygeo77
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I have tried making an emulsion and leaving the solution to air dry. The alcohol would evaporate leaving water with no trace of oil. I had a success
once during which the ethanol evaporated but left the oil at the bottom but couldnt repeat that process. The oil was orange in color even though it is
supposed to be colorless.
How long do you mean I should let the water-alcohol mixture stand?
I was thinking about making a homemade centrifuge or using a certain kitchen device (salad spinner etc) that can work as centrifuge.
I am working with anise oil (mostly anethole). Though I am thinking about a more general method that can work in most or all cases like centrifuge.
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khourygeo77
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A perfect similar experiment is isolating thujone found in absinthe for which many articles are written though I am having difficulties with them as I
cant find a way to do a similar experiment.
http://www2.ups.edu/faculty/bdasher/Chem361/Review_Articles_... page 6
To reformulate the question I asked before if people didnt understand me correctly: The goal is to separate the emulsion known by "ouzo effect" which
can be obtained by diluting an alcoholic distilled beverage like pastis and absinthe. The oil cannot be separated from the alcohol in the above
mentioned ways for some reason.
Also a salad spinner seems like a good centrifuge alternative if I'm not mistaken.
[Edited on 26-5-2019 by khourygeo77]
[Edited on 26-5-2019 by khourygeo77]
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S.C. Wack
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C18-SiO2...how do we get from anise oil to terpenes in alcohol and water? Where did the anethole go?
[Edited on 26-5-2019 by S.C. Wack]
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SWIM
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So you're trying to get terpenes from anise oil, or are you trying to get anethole without terpenes in it?
When you did distillation, did you have a column with enough plates for the temperature difference between the expected constituents, and if that
meant more than a 4 or 5 plates, did you use some sort of partial take-off or at least a small condenser below the distillation head so the reflux
ratio was something like the number of plates used?
Were you distilling in vacuum? Anethole oxidizes pretty easy at elevated temperatures.
have you tried adding a small amount of solvent to the anise oil and freezing to see if the solids deposited are different than what's left in
solution? I know adding and equal amount of ethanol to calamus oil and freezing tends to deposit asarones while the other materials are left in
solution.
That was not a clean separation, but repeated a few times it left a product which gave an almost theoretical yield of the pseudonitrosite. The asarone
did not have the proper melting point, but I didn't try to free it of traces of ethanol.
I suppose I should have done so with freezing/thawing/refreezing under high vacuum, but characterizing it by the pseudonitrosite was good enough for
me.
Pet ether is probably better for this purpose than ethanol as it ought to dissolve terpenes better than anethole, but ethanol worked fairly well .
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khourygeo77
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Quote: Originally posted by SWIM  | So you're trying to get terpenes from anise oil, or are you trying to get anethole without terpenes in it?
When you did distillation, did you have a column with enough plates for the temperature difference between the expected constituents, and if that
meant more than a 4 or 5 plates, did you use some sort of partial take-off or at least a small condenser below the distillation head so the reflux
ratio was something like the number of plates used?
Were you distilling in vacuum? Anethole oxidizes pretty easy at elevated temperatures.
have you tried adding a small amount of solvent to the anise oil and freezing to see if the solids deposited are different than what's left in
solution? I know adding and equal amount of ethanol to calamus oil and freezing tends to deposit asarones while the other materials are left in
solution.
That was not a clean separation, but repeated a few times it left a product which gave an almost theoretical yield of the pseudonitrosite. The asarone
did not have the proper melting point, but I didn't try to free it of traces of ethanol.
I suppose I should have done so with freezing/thawing/refreezing under high vacuum, but characterizing it by the pseudonitrosite was good enough for
me.
Pet ether is probably better for this purpose than ethanol as it ought to dissolve terpenes better than anethole, but ethanol worked fairly well .
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I thought anise oil was mainly terpenes, I got confounded after looking up about many oils which largely consisted of terpenes. What I want exactly is
separating the volatile compounds from ethanol. The anethole, the terpenes etc. in a beverage like absinthe or pastis or ouzo. It doesnt have to be
necessarily anise but can be wormwood or anything else.
The condenser I use is a bottle inserted inside a 15L container filled with water. I regulate the temperature properly (common hot plate) so only the
ethanol distills very slowly and water is left out.
I tried freezing many times, and I'd get solids then sweet transparent oils and the louche effect got remarkably reduced which means that a certain
part of volatile substances remain only. (not sure how to separate them). Centrifuge?
However, let's say I make a distilled beverage with lemon. I will have limonene in the distilled beverage with a freezing point of -70s deg C. How
else can I separate the limonene in this case?
I tried to strip the anethole from distilled beverage by using hexane and diethyl ether. Both failed.
[Edited on 26-5-2019 by khourygeo77]
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khourygeo77
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| Quote: Originally posted by S.C. Wack | C18-SiO2...how do we get from anise oil to terpenes in alcohol and water? Where did the anethole go?
[Edited on 26-5-2019 by S.C. Wack] |
Sorry I meant volatile compounds in general: anethole and other volatile compounds in the case of anise, and terpenes in other cases (pinene,
limonene) or other volatile compounds. How can I separate these volatile compounds from a louche of these compounds consisting of them in ethanol
water solution.
siO2 concerns column chromatography. I read about it but couldnt perfectly understand the process. Can I use some other solids like nacl or sodium
carbonate or sand for example
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S.C. Wack
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Sand will not substitute as indicated by the price and how suitable it should be in theory. The question now is why add water and ethanol to essential
oils, for the purpose of extracting the same oil from water and ethanol.
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Ubya
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| Quote: Originally posted by S.C. Wack | | Sand will not substitute as indicated by the price and how suitable it should be in theory. The question now is why add water and ethanol to essential
oils, for the purpose of extracting the same oil from water and ethanol. |
I think he's trying to distill some liquors, and isolate the fragrant molecule from the ethanol/water bulk.
My advice is, don't add water to make an emulsion, just buy a proper FRACTIONATING column, and a proper hotplate with variable power (not the ON/OFF
cycle kind), a bottle is not a suitable column.
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Tsjerk
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Forget about size exclusion, I don't think that is even possible at the size you are thinking about.
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khourygeo77
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| Quote: Originally posted by Ubya | | Quote: Originally posted by S.C. Wack | | Sand will not substitute as indicated by the price and how suitable it should be in theory. The question now is why add water and ethanol to essential
oils, for the purpose of extracting the same oil from water and ethanol. |
I think he's trying to distill some liquors, and isolate the fragrant molecule from the ethanol/water bulk.
My advice is, don't add water to make an emulsion, just buy a proper FRACTIONATING column, and a proper hotplate with variable power (not the ON/OFF
cycle kind), a bottle is not a suitable column. |
Well, I think I was misunderstood
The hotplate that I have makes it possible to switch between different modes. 1 mode has a heat precise enough that makes distilling ethanol possible
while leaving water behind. Or is this not precise enough?
Condenser is a flexible tube that links the receiver to the flask. The receiver is sunk in 15L water. I think everything is good, but I am not sure if
the few degrees difference will make it count as putting the alcohol&water to air dry wont leave any residue (oils etc) ...
[Edited on 28-5-2019 by khourygeo77]
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Ubya
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| Quote: Originally posted by khourygeo77 | 1 mode has a heat precise enough that makes distilling ethanol possible while leaving water behind. Or is this not precise enough?
Condenser is a flexible tube that links the receiver to the flask. The receiver is sunk in 15L water. I think everything is good, but I am not sure if
the few degrees difference will make it count as putting the alcohol&water to air dry wont leave any residue (oils etc) ...
[Edited on 28-5-2019 by khourygeo77] |
You can't boil just alcohol from a mixture of ethanol and water, doesn't matter how low the temperature, if it boils, the vapor is a mixture of water
and ethanol. There is no shortcut, if you want to separate the components or you use a proper fractionation column or you distill multiple times
shrinking the temperature range of the fractions each time
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khourygeo77
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I'm not sure about this. But I will try to explain some other experiments I did with the same hot plate
Ethanol forms an azeotrope with water at 95%. And I think the proof that only this is begotten is because many times I leave an ethanol & water
solution (let's say 20% alcohol) and distill, only 16 or 17% of the essential volume is begotten and if I leave the heat on for another 24hours
nothing distills almost.
I dont see the solution of ethanol and water boiling during distillation so water isnt boiling. And around 2 drops get condensed in a minute, which I
think is a temperature that can be accurate enough for the most volatile part.
I even once tried testing a ~100 degrees (proof) alcohol to see if it was ~100% or ~50%. It turned out the latter and I knew this because only ~50%
distilled, and after that ~50% distilled nothing happened. The solution in the flask wasnt boiling but was hot as can be seen with some vapors
condensing on the neck of the flask but not reaching the condensing system.
[Edited on 29-5-2019 by khourygeo77]
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khourygeo77
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so I was reading and found out 2 possible way of separating water from oil:
"Flotation
Flotation introduces gas bubbles to enhance oil removal. The gas bubbles attach to the oil droplets to increase the rise rate of the oil. Various
flotation methods such as dissolved gas flotation (DGF), dissolved air flotation (DAF), and induced gas flotation (IGF) may be used. Typically this
separation step is used following a primary oil–water separation step which is able to remove a large portion of the free oil."
Also
"Wastewater purification of oils and contaminates by electrochemical emulsification is actively in research and development. Electrochemical
emulsification involves the generation of electrolytic bubbles that attract pollutants such as sludge and carry them to the top of the treatment
chamber. Once at the top of the treatment chamber the oil and other pollutants are transferred to a waste oil tank"
Is it possible to do something at home?
Can an aquarium bubbler or other common bubblers achieve the separation as well?
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pneumatician
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Separating oil from lemon peels from water??? anise oil???
I think you are crazy mixing ethanol and water for extraction reasons??? or ethanol or water, but both? 
https://www.youtube.com/watch?v=tJfdeeGYGwo
look my separating F. kamikaze hanged 
well I use white wine for anise oil, so I get "water" and ethanol mixed with oil
you get a milk like product like this?
https://www.youtube.com/watch?v=2qpP7bZhdAw
Well, the best separating method is the passive, so I put the mix in a cold place near freezing but not freeezing, 1 or 2 weeks and voila! sometimes
only days.
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