Author Topic: Make acetone anhydrous? (Read 418 times)

iknowjt · « **Reply #20 on:** September 27, 2009, 04:25:53 AM »

a note on the original topic:

according to this document:

Quote

Acetone 56 0.791 -18 K2CO3; Molecular sieve 0.3nm; CaCl2
Acetic acid 118 1.049 +40 P2O5; CuSO4
Acetic anhydride 136 1.082 +49 CaCl2
Acetonitrile 82 0.782 +6 CaCl2; P2O5; K2CO3; calcium hydride; Molecular sieve 0.3nm
Aniline 184 1.022 +76 KOH; BaO
Anisole 154 0.995 +51 CaCl2; Na; distillation
Benzene 80 0.879 -10 CaCl2; distillation; Na; Pb/Na; ; calcium hydride; Na wire; Molecular sieve 0.4nm
1-Butanol 117 0.810 +29 K2CO3; distillation
2-Butanol 100 0.808 +24 K2CO3; distillation
tert-Butanol 82 0.882 +11 CaO; Freezing
n-Butyl acetate 127 0.882 +33 MgSO4;
Carbon disulphide 46 1.263 -30 CaCl2P2O5;
Carbon tetrachloride 77 1.594 none distillation; P2O3; Pb/Na; Molecular sieve 0.4nm
Chlorobenzene 132 1.106 +29 CaCl2; distillation;P2O5
Chloroform 62 1.486 none CaCl2; P2O5; Pb/Na; Molecular sieve 0.4nm
Cyclohexane 81 0.799 none Na; Na/Pb; LiAlH4; Molecular sieve 0.4nm
Cyclohexanone 155 na na Distillation
Decahydronaphthalene
(Dekalin) ~190 0.886 <54 CaCl2; Na; Pb/Na
Dichloromethane 40 1.325 none CaCl2; Pb/Na; calcium hydride; Molecular sieve 0.4nm
Dicyclopentadiene:
(cyclopentadiene dimer) 170 na na Refractionation: distillate at 40 - 42°C. (Use at once! or keep in dry ice/acetone bath no longer than 1 Hr.)
Diethyl carbonate 126 0.975 +25 Na2SO4; K2CO3
Diethylene glycoldibutyl ether 225 0.885 +118 CaCl2; Na
Diethylene glycol dimethyl ether 155
165 0.906 +70 CaCl2; Na
Diethyl ether 34 0.714 -40 CaCl2; Na; Pb/Na; LiAlH4; Na wire/benzophenone; Molecular sieve 0.4nm
Di-isopropyl ether 68 0.726 -23 CaCl2; Na; Molecular sieve 0.4nm
Dimethyl formamide 153 0.950 +62 distillation; Molecular sieve 0.4nm
Dimethyl sulfoxide 189 1.101 +95 distillation; Molecular sieve 0.4nm
1,4 Dioxane 101 1.034 +11.8 CaCl2; Na; Molecular sieve 0.4nm
Ethanol 79 0.791 +12 CaO; Mg; MgO; Molecular sieve 0.3nm
Ethyl acetate 77 0.901 -4 K2CO3; P2O5; Na2SO4; calcium hydride; Molecular sieve 0.4nm
Ethylenediamine:
(1-2 diaminoethane) 118 na na Simple distillation.
Ethylene glycol 197 1.109 +111 distillation; Na2SO4
Ethylene glycol monoethyl ether 135 0.930 +41 distillation
Ethylene glycol monomethyl ether 125 0.965 +52 distillation
Ethyl formate 54 0.924 -20 MgSO4; Na2SO4;
Formamide 211 1.134 155 Na2SO4; CaO
Glycerol 290 1.260 +176 distillation
Heptane 98 0.684 -4 calcium hydride; Na wire
n-Hexane 69 0.659 -23 Na; Pb/Na; LiAlH4; calcium hydride; Na wire/benzophenone; Molecular sieve 0.4nm
Isobutanol 108 0.803 +28 K2CO3; CaO; Mg;
Isobutyl methyl ketone 117 0.801 +15.5-4 K2CO3;
Methanol 65 0.792 +11 Mg; CaO; Molecular sieve 0.3nm
Methyl acetate 57 0.933 -10 K2CO3; CaO;
1-Methyl-2-pyrrolidone 202 1.026 +95 Na2SO4; distillation; Molecular sieve 0.4nm
Methyl Ethyl ketone 80 0.806 -44 K2CO3;
Nitrobenzene 211 1.204 +92 CaCl2; P2O5; distillation;
n-Pentane 36 0.626 -49 Na; Pb/Na;calcium hydride; Na wire
Pet ether mixture na na calcium hydride; Na wire/benzophenone; Molecular sieve type 4A
1- Propanol 97 0.804 +15 CaO; Mg
2-Propanol 82 0.785 +12 CaO; Mg; Molecular sieve 0.3nm
Pyridine 116 0.982 +20 KOH; BaO; Molecular sieve 0.4nm
Tetrahydrofuran 66 0.887 -17.5 Molecular sieve 0.4nm
Tetrahydronaphthalene
(Tetralin) 208 0.973 CaCl2; Na
Thionyl chloride 48 na na Redistill.
Toluene 111 0.867 +4 distillation; Ca; CaCl2; Na; Molecular sieve 0.4nm
Trichloroethylene 87 1.462 none distillation; Na2SO4; K2CO3
Xylene 137/140 -0.86 +25 distillation; Na; CaCl2; Molecular sieve 0.4nm

TO DRY

USE ONE OF THE FOLLOWING DRYING AGENTS

Alcohols Anhydrous forms of potassium carbonate; magnesium or calcium sulphate; quicklime.
Alkyl halides
Aryl halides Anhydrous calcium chloride; anhydrous sodium, magnesium or calcium sulphate; sodium pentoxide.
Saturated and
Aromatic hydrocarbons Anhydrous calcium chloride or sulphate; metallic sodium; phosphorus pentoxide.
Aldehydes Anhydrous sodium, magnesium or calcium sulphate.
Ketones Anhydrous sodium, magnesium or calcium sulphate; anhydrous potassium carbonate.
Organic bases
(amines) Solid potassium or sodium hydroxide; quicklime; barium oxide.
Organic acids Anhydrous sodium, magnesium or calcium sulphate.

potassium carbonate would be the better choice(maybe this predated mol sieves 3A?) but i imagine the which particuler alkali metal it is isn't terribly important.

Quote from: Naf1 on September 24, 2009, 02:19:06 AM

(zeolite) Molecular sieve 3A is the best method going for drying Acetone, Alcohols etc. Will produce bone dry acetone quickly! They are acquired easily and cheaply OTC and can be regenerated by drying them, and used again.

Naf1 thanks for this info. In lite of it, I decided to actually test just how quickly the sodium carbonate dries acetone:
A few good shakes inbetween a few, 2-3min sitting periods, in a tightlly stoppered bottle: bone dry
under 10min total
I add the drying agent 1/4 or 1/3 the volume of the acetone.

Naf1 · « **Reply #21 on:** September 27, 2009, 05:47:45 AM »

"Acetone 56 0.791 -18 K2CO3; Molecular sieve 0.3nm; CaCl2"

They actually document the three methods widely used, K2CO3 = Patassium Carbonate, Molecular Sieve 0.3nm = 0.3nm refers to the pore size which translated to commercially available zeolites is 3A. And CaCl2 = Calcium chloride. I would still recommend mole sieve 3A for drying Methanol/Ethanol/Acetone etc.

Thanks for the results of your tests, if you store your acetone over your desiccant you can be assured that when you go to use it, it will be dry.

Sedit · « **Reply #22 on:** September 27, 2009, 05:53:41 AM »

Quote

Naf1 thanks for this info. In lite of it, I decided to actually test just how quickly the sodium carbonate dries acetone:
A few good shakes inbetween a few, 2-3min sitting periods, in a tightlly stoppered bottle: bone dry
under 10min total
I add the drying agent 1/4 or 1/3 the volume of the acetone.

While I have no doubt about the power of the carbonates as a drying agent I do know from experiance that they take a little while to work. You say 2-3 minutes its bone dry but I would love to see you test this with something very powerful such as a small amount of lithium. I don't think that will react with a dry acetone but would more then likely create an alcohol if its wet.

iknowjt · « **Reply #23 on:** September 27, 2009, 07:20:21 AM »

thanx for feedback from all

Quote from: Naf1 on September 27, 2009, 05:47:45 AM

I would still recommend mole sieve 3A for drying Methanol/Ethanol/Acetone etc.

Oh in no way was I proposing that sodium carbonate is better than molec sieves for this purpose, clearly that's the proper choice. I'm only presenting a case for sodium carbonate as a not-so-shabby substitute, esp. if prepared this way making it:
1. ensured that the dessicant is dry
2. available 24hours/day at any kwikeemart/bodega/sleven/most people's fridge

and this info should at least be helpfull for folks like me a month or two ago still using that nasty epsom salt, for this purpose anyway.
I've seen some conflicting info on CaCl2 for this purpose.

Quote from: Sedit on September 27, 2009, 05:53:41 AM

While I have no doubt about the power of the carbonates as a drying agent I do know from experiance that they take a little while to work. You say 2-3 minutes its bone dry but I would love to see you test this with something very powerful such as a small amount of lithium. I don't think that will react with a dry acetone but would more then likely create an alcohol if its wet.

I've also been very troubled by uncertainty of the acetones dryness. Same for MEK and alcohols come to think of it.
I checked by liberally washing a certain amine salt, (I needed to do it anyway)
After only a quick drying of acetone out of the can, as I described above.
Evaporating the acetone afterwards revealed that it certainly was as dry as multiple hours, along with multiple changing of dessicant, of MgSO4 drying would get it...and as dry as I would ever need it.

Interesting test method:)

lugh · « **Reply #24 on:** September 27, 2009, 03:35:43 PM »

The addition compounds formed from calcium chloride and acetone are CaCl2-(CH3)-CO and CaCl2-(CH3)2-CO

Never use calcium chloride when drying amines as it forms complexes with them as well

Vesp · « **Reply #25 on:** September 27, 2009, 05:58:23 PM »

Almost forgot the best method of making any carbonate of the alkali metals:

NaHCO3 + NaOH = Na2CO3 + H2O
Easy to do, and can obviously also work to make K2CO3 if one uses the hydroxide and bicarbonate of the potassium salt. Boiling after words ensures that no NaHCO3 is left, and to ensure no NaOH is left one might choose to use an excess of NaHCO3.

A mixture of Na2CO3 and K2CO3 would probably be pretty useful for drying acetone, and considering K2CO3 isn't commonly OTC one could make it by adding KOH with NaHCO3.

lugh · « **Reply #26 on:** September 27, 2009, 09:13:16 PM »

Magnesium sulfate dried under a vacuum of about 10 torr and gradually heated to 300 degrees Centrigrade can be used to dry acetone to .05% H2O

Calcium sulfate will dry acetone to .01%; 3A or 4A molecular sieves are more efficient

Prepuce1 · « **Reply #27 on:** October 17, 2009, 06:54:15 AM »

There's a huge amount of really useful information in this thread. Besides that, it's the most concise discussion on the topic I believe I've ever seen. I love this place!

Every time I've looked up drying acetone, the references I've found have recommended MgSO4. They neglected to mention the need to cook it at 10 torr prior to use, so thanks to Lugh for helping me to understand why my acetone used to keep me so regular.

Thanks also for the references on locating the molecular seive material. I'd like to have about ten pounds of it on hand all the time. Now I intend to do so.

Iknowit, I never doubted what you were saying about making NaCO3, not at all. I kept going back to washing soda because I've been using it for so long, and in so many ways. Force of habit, I guess. It's really cheap, but then so is baking soda. Most pool stores sell the food grade in 50 lb. bags. But after reading this thread, who needs it any more?

I've been away for a couple of weeks, so thanks for everyone's patience as I try to catch up all at once.

Cheers,
PP

German · « **Reply #28 on:** October 17, 2009, 07:01:44 AM »

I'm confused. The MSDS for the Acetone at Home Depot says %100 Acetone. When they are %99 the MSDS says %99 but Acetone is one of the few that actually says %100. So what's with trying to make anhydrous something that already is?

iknowjt · « **Reply #29 on:** October 17, 2009, 08:46:24 AM »

Quote from: German on October 17, 2009, 07:01:44 AM

I'm confused. The MSDS for the Acetone at Home Depot says %100 Acetone. When they are %99 the MSDS says %99 but Acetone is one of the few that actually says %100. So what's with trying to make anhydrous something that already is?

i would imagine its sort of like the situation with Damprid. The MSDS refers to what was put in and packaged, when the product came off the 'assembly line'. If the acetone where kept completelly and utterly sealed off from ambient moisture, then it would still be anhydrous. But the water it attracts during shipping/distribution, etc. is not the manufacturers fault or responsibility.

Its for this reason that I tried heating damprid brand CaCl2 once, and lo and behold the dessicant was twice as potent.

Prepuce1 · « **Reply #30 on:** October 18, 2009, 04:50:05 AM »

Quote from: German on October 17, 2009, 07:01:44 AM

I'm confused. The MSDS for the Acetone at Home Depot says %100 Acetone. When they are %99 the MSDS says %99 but Acetone is one of the few that actually says %100. So what's with trying to make anhydrous something that already is?

Strictly speaking, you could call acetone 100% as long as that's at least 99.5% true. Based on volume your gallon could contain something like 22.7ml of water and still qualify.

PP

Prepuce1 · « **Reply #31 on:** October 30, 2009, 03:09:13 AM »

IknowIt, FWIW I think you could put sodium bicarbonate in a dry flask with a tube submerged in another flask of water. Put the first flask on heat, and when no more bubbles appear it should be fully converted.

PP

Sedit · « **Reply #32 on:** October 30, 2009, 05:27:04 AM »

My DMSO on the bottle German says, 99% Pure DMSO.....90%DMSO/10% H2O. When they state 99% pure it only means the measure that they add of that substance to the mixture. So I guess its only 89.5% pure DMSO or something along those lines from my point of view.

iknowjt · « **Reply #33 on:** November 03, 2009, 11:56:01 AM »

Quote from: Prepuce on October 30, 2009, 03:09:13 AM

IknowIt, FWIW I think you could put sodium bicarbonate in a dry flask with a tube submerged in another flask of water. Put the first flask on heat, and when no more bubbles appear it should be fully converted.

PP

yeah that would be reliable, same idea as dissolving sodium bicarbonate in water and heating until fizzing stops, but would be much faster since it wouldn't be limited to <100°C, which takes a half hour
for experimental purposes, another approach could be to take two identical spoons, attach them to either end of a ruler, and hang the ruler balanced by a string. Then add a bit of sodium bicarbonate to both spoons so they are balanced. Then light a candle under one spoon, and see how long it takes for the weight to reduce down to a factor of 105g/168g = .625

That would be a closer to realistic simulation of the frying pan method, since an enclosed glass flask would heat much slower and very differently. Metal is great for this sort of thing esp, since the goal is to just hit a specific temp and then cool right back down. Would be cool if someone did this.

For simple application, the signs of completion are hard to miss. Sodium carbonate is a powder of a different form, much more dust-like consistensy. When shaking in a bottle with the acetone to be dried, it will settle right away not even a cloudy mist lingering after a few short moments.

Prepuce1 · « **Reply #34 on:** November 27, 2009, 01:57:14 PM »

Iknowit, I made NaCO3 following your instructions (the frying pan) and nothing cold have been easier. I believe it's also cleaner than what I've been buying ready made, and it's already powdered. Thanks for the tip. A microwave oven works too.

I also got my hands on some 3A molecular sieve. Anyone have some advice on using it? I've found conflicting information on the web.

Thanks,
PP

NeilPatrickHarris · « **Reply #35 on:** November 28, 2009, 04:06:02 AM »

i've had loads of trouble finding the best desiccant for acetone too, strictly because of all the contradictory information on the web about how reactive acetone is with desiccants and even mol sieves. so i've always stuck with using MgSO4 for piece of mind even though everyone claims it's a weak desiccant for this purpose.

Prepuce1 · « **Reply #36 on:** November 29, 2009, 05:11:22 AM »

I just happened to notice that one of the links for molecular sieves posted by poisoninthestain says this about their 13x type sieve:

"The preferred Molecular Sieve adsorbent for dynamic dehydration in a closed gas or liquid system. Used commercially for general gas drying, air plan feed purification (simultaneous removal of H2O and CO2) and liquid hydrocarbon and natural gas sweetening (H2S and mercaptan removal)."

Isn't H2S what they use to denature OTC nitrous oxide?

PP

iknowjt · « **Reply #37 on:** November 29, 2009, 11:08:47 AM »

Quote from: Prepuce on November 27, 2009, 01:57:14 PM

Iknowit, I made NaCO3 following your instructions (the frying pan) and nothing cold have been easier. I believe it's also cleaner than what I've been buying ready made, and it's already powdered. Thanks for the tip. A microwave oven works too.

My pleasure PP. Yes, Cleaner, freshly dried, and don't forget the real extra-special prize: it's food grade.

Author Topic: Make acetone anhydrous? (Read 418 times)

iknowjt

Re: Make acetone anhydrous?

Naf1

Re: Make acetone anhydrous?

Sedit

Re: Make acetone anhydrous?

iknowjt

Re: Make acetone anhydrous?

lugh

Re: Make acetone anhydrous?

Vesp

Re: Make acetone anhydrous?

lugh

Re: Make acetone anhydrous?

Prepuce1

Re: Make acetone anhydrous?

German

Re: Make acetone anhydrous?

iknowjt

Re: Make acetone anhydrous?

Prepuce1

Re: Make acetone anhydrous?

Prepuce1

Re: Make acetone anhydrous?

Sedit

Re: Make acetone anhydrous?

iknowjt

Re: Make acetone anhydrous?

Prepuce1

Re: Make acetone anhydrous?

NeilPatrickHarris

Re: Make acetone anhydrous?

Prepuce1

Re: Make acetone anhydrous?

iknowjt

Re: Make acetone anhydrous?