Sciencemadness Discussion Board

Separating volatile oil in water emulsion to 2 separate layers

khourygeo77 - 30-1-2017 at 04:15

Any idea how this can be done?

During distillation, I get a white water as distillate, which is composed of water and oils. However, I cant separate the oil from the water, except if i expose the distillate to the sun for like a month or 2.

I tried on several herbs, like orange blossom flower, anise seed and thyme

I am looking for an easy homemade way without using chemicals like hexane, dcm ether etc... or even the expensive centrifuge process

Thanks

DJF90 - 30-1-2017 at 04:48

You could try salting it out by saturating the aqueous phase with NaCl...

Chlorine - 30-1-2017 at 06:36

Change the density of water so it seperates, use a salt like NaCl or magnesium sulfate.
Then decant off the oil layer.

Amos - 30-1-2017 at 09:23

Usually increasing the amount of material you distill from helps this in my experience. Are you distilling these oils on a very small scale?

khourygeo77 - 30-1-2017 at 09:44

Nacl doesnt do anything shortly, maybe it will speed up the process of separation from a month to 2 weeks though.

I'm not sure from where to get magnesium sulfate, as chemicals here are rare and sold at very high prices.

I'm saturating the water with material and distilling, but plants are low in essential oils...

DJF90 - 30-1-2017 at 10:15

NaCl should work fine; 25 %w/w is about saturated at RT, so make sure you're using enough in order to maximise the difference in density between the aqueous and oil phases. The presence of ionic solute in the aqueous phase also reduces any aqueous solubility of the oil.

[Edited on 30-1-2017 by DJF90]

violet sin - 30-1-2017 at 17:37

Magnesium sulfate = epsom salt for baths and soaking sore feet. Usually available all over the place, but to be honest I don't travel much or far.

The milky water is called hydrosol no? Usually used as is from my understanding. While the material may not have much oil in it, what I believe Amos correctly points out is, a lot of such material used overall or at once or both, will still provide actual self separating oil. Can you attempt cold temperature for some time to effect separation perhaps?

What kind of oil are you after that is in that low of proportions, and how exactly are you distilling it? Like submerged bath or steamed through the plant material? My brother has been getting very little cedar oil while he said the lavender kicked out a big load by comparison. So just curious what you have going.

khourygeo77 - 31-1-2017 at 00:33

Quote: Originally posted by DJF90  
NaCl should work fine; 25 %w/w is about saturated at RT, so make sure you're using enough in order to maximise the difference in density between the aqueous and oil phases. The presence of ionic solute in the aqueous phase also reduces any aqueous solubility of the oil.

[Edited on 30-1-2017 by DJF90]


Iirc I tried it before, it sounded it would work theoretically but it didnt work. I will try it again maybe. I think the separation doesnt happen because the oils were in small quantities.

khourygeo77 - 31-1-2017 at 02:02

Quote: Originally posted by violet sin  
Magnesium sulfate = epsom salt for baths and soaking sore feet. Usually available all over the place, but to be honest I don't travel much or far.

The milky water is called hydrosol no? Usually used as is from my understanding. While the material may not have much oil in it, what I believe Amos correctly points out is, a lot of such material used overall or at once or both, will still provide actual self separating oil. Can you attempt cold temperature for some time to effect separation perhaps?

What kind of oil are you after that is in that low of proportions, and how exactly are you distilling it? Like submerged bath or steamed through the plant material? My brother has been getting very little cedar oil while he said the lavender kicked out a big load by comparison. So just curious what you have going.


I did a small search and it seems epsom salt = english salt in my country

the milky water is called hydrosol, yes. I even tried freezing the water before. Nothing. I think I should make more experiments. I should try saturating water with salt , or even epsom salt which is better, then get the temperature to around 4 deg C, in which water is densest and try again. I remember I could get many oils to separate once out of the distillate after freezing it for 2 or 3hours. However, I repeated the same experiment again, nothing happened.

I tried with thyme and orange flower for example. I covered them with water and distilled (hydrodistillation). I didnt steam distill. The distillate would have a particular taste, which means much of the plant's volatility is present.

I think the reason oils dont separate well, is because of plant volatile salts that distill with the oils and act as surfactants. They are bitter and dont seem to be alkaline. I tried to react the with vinegar, but both didnt react which means salt wasnt basic. The salt can be spotted by rectifying (distilling the distillate again), as it would stay at the bottom