02-04-02 23:26
No 265177
Swim was at the auto parts store and ran across an item that contained dcm, toulene, and methanol in a spray can. Swim was wondering what would be the best way to seperate the dcm from the other two. Any ideas?
We'll soon FIND OUT if I'm a chemist or not!
(Junior Service Representative)
02-04-02 23:40
No 265179
Distillation by boiling point as long as temperatures are far enough apart, and no azeotropes form. SWIP found a can containing DCM + Propane(as the propellant); however, the liquid look milky upon being dispensed..
PB
*BTW, can repeated (fractional?) seperation reduce the concentration of one of the components within the azeotropic solution?
(Hive Bee)
02-05-02 04:30
No 265290
Wash the methanol out with water. Then distill.
VL_
(Hive Bee)
02-05-02 05:34
No 265319
Swim was reading some older posts about dcm and found some interesting stuff. After searching on the net found a distributor for dcm under flushing solvent. Swim needs to start saving the dcm he uses instead of throwing it out .
We'll soon FIND OUT if I'm a chemist or not!
(Junior Service Representative)
02-05-02 06:08
No 265331
Yes, and you should also have learnt a thing or two about plexi-glass, as well...
,PB
(Hive Bee)
02-05-02 07:23
No 265360
Pooh, swim tried the plexiglass route and gave up. Couldn't find anything. Maybe swim was looking in the wrong places.
We'll soon FIND OUT if I'm a chemist or not!
(Hive Addict)
02-05-02 12:17
No 265417
If you're looking for DCM and can't find it (you're not looking hard enough, visit a shop that uses it to join sheets of plexiglass together), consider using TCE. TCE, or perc, or perchloroethylene, is used as a solvent to clean brake lines. It evaporates quickly, doesn't smell quite as nice as DCM. It's BP is higher at 120C and can substitute in a lot of places for DCM (ie for separations, as it doesn't boil at the same low temperature, it can't substitute everywhere...). Plus TCE is better for the environment, it breaks down more easily and isn't as soluble in water.
(Stoni's sexual toy)
02-05-02 12:21
No 265420
> Swim needs to start saving the dcm he uses instead of throwing it out .
OH MY FUCKING GOD!
Bees are pouring their DCM down the drain?!?
Don't do that! Shit, a drop of DCM or other chlorinated solvents will ruin shitloads of water. Even water which has been in contact with DCM shouldn't be disposed of by pouring it down the drain.
Collect all your DCM containing waste and redistill.
I'm not fat just horizontally disproportionate.
(Junior Service Representative)
02-05-02 13:38
No 265435
And what does one do if they start getting visits from Freddy (you know, from Nightmare on Elm St.
) and are forced to stop their dreams semi-permanently? Fire?
PB
(Chief Bee)
02-05-02 14:08
No 265446
You increase your karma to the former level by spending half of your allotted lab time on finding a cheap, environmentally friendly method of breaking down DCM to chloride and carbonate, and then give away your patent for free in exchange for the buyer to clean up your "home lake" using your newest technology.
(Hive Bee)
02-05-02 19:30
No 265541
As for getting the methanol out, yes, an extraction with dH2O would work. But cheese wonders if the toluene and DCM would form two layers without the methanol in it, because DCM sinks on water and toluene floats on water. It's just guess. Probably the two are miscible and are separated difficulty.(very slow fractional distillation)
May The Source Bee With You....Always.
- OB1KNoBee
(Stoni's sexual toy)
02-05-02 23:11
No 265617
The boiling points of the components are about 40, 65 and 110°C. Just distill the shit.
And no, DCM and toluene do not spontaneously separate. They are completely miscible, but since the difference in BP is 70°C they are easily separated by distillation.
I'm not fat just horizontally disproportionate.
(Moderator)
02-06-02 00:03
No 265638
The boiling points of the components are about 40, 65 and 110°C. Just distill the shit.
Since methanol and toluene form an azeotrope boiling at 63.7° C that is composed of 27.6% toluene and 72.4% methanol, it would probably be best to separate the methanol first with water 
(Stoni's sexual toy)
02-06-02 00:09
No 265639
Ooops.
I'm not fat just horizontally disproportionate.
(Junior Service Representative)
02-06-02 03:21
No 265694
Does MeOH and water form an azeotrope? Would distillation get the MeOH anhydrous w/o the use of drying agents?
PB
(Hive Bee)
02-06-02 04:24
No 265716
Yes it forms an azeotrope no distillation won't get it anhydrous.
(Hive Addict)
02-06-02 04:51
No 265729
If that mixture only contained methanol and DCM, would simple distillation work for separating the two, or would they form an azeotrope as well?
If Pacman had influenced us, we'd run around dark rooms eating pills and listen to repetitive music
(Junior Service Representative)
02-06-02 05:17
No 265740
I've heard some suggest removing MeOH by using water, maybe followed by MgSO4 afterwards?
PB
(Hive Addict)
02-06-02 05:34
No 265748
MeOH and water definitely do not form an azeotrope.
Distilling DCM from MeOH works well enough to use it for A/Bs.
(Hive Bee)
02-06-02 10:24
No 265858
So Toluene/DCM are miscible in MeOH, but MeOH and water are miscible, yet toluene/dcm aren't miscible in water, that's cool, alcohol's miscible in water and toluene/dcm?
May The Source Bee With You....Always.
- OB1KNoBee
(Hive Bee)
02-06-02 10:33
No 265867
oops chromic, my bad, there is something in the merck about boiling points of different methanol water soln's. Anyways you can't get dry methanol by distillation.
(Hive Addict)
02-06-02 11:45
No 265900
You can get virtually dry MeOH by distillation. However, you require a very, very long column and a careful, slow distillation to properly separate it from water (400mm at the least)... and a very accurate thermometer.
Yeah, MeOH is miscible with DCM and with toluene and with DCM/toluene. And water is miscle with MeOH. But MeOH/DCM/Toluene/water will form two layers. One with mostly water, some DCM, some toluene.. the other with mostly DCM and toluene and some water.
(Hive Bee)
02-09-02 18:21
No 267438
Take some and add water and a drop of food coluring. Then add a fuck of a lot of salt (the plain kind) shake and let it settle you will ger 3 layers. You can figure it out from there...
Don't look at me I didn't do it!