CHRIS25
National Hazard
Posts: 951
Registered: 6-4-2012
Location: Ireland
Member Is Offline
Mood: No Mood
|
|
Separating oil from water and diethyl ether
After a frustrating and disappointing 10 days of trying to perfect this distillation of calendular oil and then limonene from orange peel I finally
got success. Oil floats on top of water...well not very well I am afraid! Having got about 1 mL of oil and not having a separatory funnel I put
distillate into the burette thinking that the narrowness would force my precious little oil to the top, It did not, in fact all I ended up with was
the whole lot stuck to the inside of the burette. A second attempt I decided to leave in test tubes and pour into beaker, same thing happens, all the
oil sticks to sides of test tube and I have nothing. I even tried to syringe the surface with a needle attached to a 2 mL syringe. Any suggestions?
Or is it really necessary to buy diethyl ether, mix with the distillate and evaporate?
I know the answer is to distill bigger, but I can not, as it is I have adapted a 1000 mL erlenmeyer flask the equivalent of 6 spanish valencias
chopped is all that I can safely fit.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Extraction of the oil (which usually has some limited solubility in water anyway) from the oil/water mix is often inevitable. A water insoluble
solvent with a low boiling point (allowing for easy evaporation) is ideal.
Diethyl ether is hard to get nowadays and harder to home prepare. Dichloromethane (CH<sub>2</sub>Cl<sub>2</sub> - DCM) can
often be used instead and is much easier to get and fairly cheap. I think it can be purchased on eBay.
If during the evaporation you actually want to recover the solvent for future re-use, you need to use a condenser cooled with iced water because the
BP of DCM is only about 40 C.
|
|
|
hyfalcon
International Hazard
Posts: 1003
Registered: 29-3-2012
Member Is Offline
Mood: No Mood
|
|
Wow, you could run that distillation with an incandescent light bulb.
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
One can salt out the oil to increase density difference.
About solvent extraction one can also use chloroform (CHCl3 not far from CH2Cl2) made from very OTC aceton/ hypochlorite.
Ether can be done from boilig conc H2SO4 and ethanol dropped into it with good temperature control (too hot and you get ethylene) but ether is
dangerously flamable and volatile so rather risky.
Note for extraction that ether is upper phase while CH2Cl2 or CHCl3 would be bottom phase
One may aslo use hexane for extraction as volatile upper layer.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
One can salt out the oil to increase density difference.
About solvent extraction one can also use chloroform (CHCl3 not far from CH2Cl2) made from very OTC aceton/ hypochlorite.
Ether can be done from boilig conc H2SO4 and ethanol dropped into it with good temperature control (too hot and you get ethylene) but ether is
dangerously flamable and volatile so rather risky.
Note for extraction that ether is upper phase while CH2Cl2 or CHCl3 would be bottom phase
One may aslo use hexane for extraction as volatile upper layer.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
CHRIS25
National Hazard
Posts: 951
Registered: 6-4-2012
Location: Ireland
Member Is Offline
Mood: No Mood
|
|
Alright well thanks folks. I can get my hands on diethyl ether very easily so that is not a problem. I could make it myself but having read the
dangers I decided I could not trust myself to do it without making some mistake somewhere along the line. I tried adding salt to the pure water to
add ions to increase separation but this seemed to have no effect. I also notice now that I have collected more oil that the oil does not actually
sit on the surface at all, it is literally just beneath the surface but micro mLs. The DCM I will look into, but the diethyl ether has a much lower
vaporization point so is ideal because one only needs to put the solution into a hot water bath to recover the oil and evaporate away the ether,
(without breathing any in I understand). It would be useful I think to have some solvent now in house permanently. I think I will experiment with a
saturated salt solution of water within which there is some oil.
By the way Gert, temperatures in the still, with foil wrapped around the still and erlenmeyer flask never reached above 60.1, and this was at boiling
for a few minutes, the same happened with the calendular though that was 59. No matter maybe this is the max vapour temperature for these oils when
mixed with the water vapour.
Phil, really? chloroform? and guess who would be found sleeping next to my distillation tomorrow morning?
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
I suspect you do have an ordinary funnel ?
You could suspend that in a beaker of water, pour in your mixture, then wait for separation.
By raising the funnel gradually, it may be possible to get the liquid into just the spout part of the funnel, so that the top is just visible.
From there you could possibly pipette out the oil.
Gonna be tricky every which way with 1ml of oil.
Edit: Maybe invert the funnel and do it the other way round.
[Edited on 4-7-2014 by aga]
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by CHRIS25  | By the way Gert, temperatures in the still, with foil wrapped around the still and erlenmeyer flask never reached above 60.1, and this was at boiling
for a few minutes, the same happened with the calendular though that was 59. No matter maybe this is the max vapour temperature for these oils when
mixed with the water vapour.
|
There is something seriously wrong there but I don't know what it is. Position of probe? Has probe been checked for 0 C (ice + water) and 100 C
(boiling water)? ...
A mixture of so little oil with water would come over at 100 C, give or take a centigrade. So your measurement is definitely at fault but why, oh why?
[Edited on 4-7-2014 by blogfast25]
|
|
|
CHRIS25
National Hazard
Posts: 951
Registered: 6-4-2012
Location: Ireland
Member Is Offline
Mood: No Mood
|
|
Ah....Hi Aga, I've gone up in the world to 2 mLs now at the least. No I will get a separation funnel since I am still perfecting this distillation
and am beginning to understand the low yield when I know I should be getting at least 10 mLs at a time. Besides, the funnel has other uses as well,
so a worthwhile investment. A number of factors here at play:
1. not too much peel, and this must be dried and then liquidized
2. not too much water, just enough to prevent caramalization that has happened twice due to having a too small magnetic follower, so need a triangular
one and 5 cm length at least.
3. maintain a good temperature for simmering not boiling.
So these things have discovered after many attempts. I began with lumps of wet orange peel boiled in way too much water, highly inefficient so it
seemed.
Just put the beaker of water and oil in the freezer. Let it freeze and hey presto, 3 mLs of limonene poured out.
[Edited on 4-7-2014 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Chris:
I think the faulty temp. measurement may have been due to time lag. If you use the set up with the thermometer well (with a bit of water in it), on a
short run that part may not have time to reach the steam's true temperature. Only on longer runs with that probe indicate true temperature.
[Edited on 4-7-2014 by blogfast25]
|
|
|
CHRIS25
National Hazard
Posts: 951
Registered: 6-4-2012
Location: Ireland
Member Is Offline
Mood: No Mood
|
|
Hi Gert, I always place the thermometer in the well and keep it in all the time, up to 5 hours on a couple of runs. Though I have never put any water
in. I have been puzzled by this because some documents on essential oils talk about a distillate vapour at 98 sometimes including the orange. Maybe
I should wrap foil around the well and on top of the well around the thermometer - a more accurate reading? Or do you really suggest putting water in,
I could do both I suppose.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Seals !
Check the seals, and use (sparingly) some vaseline on the ground glass joints.
I have seen people use Keck clips and gaffer tape just to make sure the seals do not break on the joints.
Edit: without the air-tight seal, the temperature/pressure equilibrium thing doesn't get going properly.
[Edited on 4-7-2014 by aga]
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
| Quote: Originally posted by CHRIS25 |
Phil, really? chloroform? and guess who would be found sleeping next to my distillation tomorrow morning? |
Yes really!
Ether was used in the past as sleeping media aswel...
If you can handle CH2Cl2 (potential hepatotoxic) or ether, yu can handle chloroform; both vapour can knock you out just as good as CHCl3 would or many
volatile solvents).
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
CHRIS25
National Hazard
Posts: 951
Registered: 6-4-2012
Location: Ireland
Member Is Offline
Mood: No Mood
|
|
Ok Phil.
Aga, seals, Mmm...I use vaseline but maybe you have a point on this one, keck clips I can not get, so will think of something else. thanks.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
I got some Keck clips the other day.
Until then i used the retort clamps to make sure the glass all stayed firmly shoved together.
Personally i will use the clips, but i trust the clamps and pressure more.
Without a tight seal on all the bits of glassware i saw a serious temperature drop/lack of achieving the 'right' temperature.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Oh, without water (or oil, for higher boiling distillations) you won’t get enough heat transfer to the probe and your reading will be deficient, in
all likelihood. I think that's what's going on there...
| Quote: Originally posted by aga | Edit: without the air-tight seal, the temperature/pressure equilibrium thing doesn't get going properly.
|
Hmmm… unless your still leaks like a cracked colander, you should still get more or less the correct reading at the still head.
| Quote: Originally posted by PHILOU Zrealone | | If you can handle CH2Cl2 (potential hepatotoxic) or ether, yu can handle chloroform; both vapour can knock you out just as good as CHCl3 would or many
volatile solvents). |
Chloroform is far more dangerous than ether: it’s the one you don’t always wake up from. But use as a solvent is safe if you ventilate well.
Apparently it takes quite a bit to knock a person out and a continuous flow of it to keep them out.
Obviously neither ether nor chloroform are still used as anaesthetics today.
Regarding clamps, kecks and pressure: remember you’re operating at ambient pressure inside the still. Small amounts of Vaseline and intelligent
clamping up should suffice to keep your apparatus together. Remember also that sections of it will expand on heating.
[Edited on 5-7-2014 by blogfast25]
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Here's a way to make a 'florentine vase' kind of arrangement out of beakers.
The trick is to tilt the beaker to about 20 degrees (any further and the oil tends not to run down the glass), and then to add the water slowly at the
back end of the beaker.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
aga:
I give it a month before you show up with a separation funnel...
|
|
|
CHRIS25
National Hazard
Posts: 951
Registered: 6-4-2012
Location: Ireland
Member Is Offline
Mood: No Mood
|
|
As you know I froze mine in and scooped the oil from the top, very easy. I also took a syringe and needle and dipped the needle just below the
surface of the oil and sucked up all the water to leave oil and very little water at the bottom. But waiting for a funnel at the moment....
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Got two as it happens 
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
