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evil_lurker
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Official ether from starting fluid thread...
I never really thought about it, but its so crazy it just might work... using water to separate the heptane from starting fluid. I make no claims and
knowlege as to whether it will work or not, but I'm gonna try it on a small scale and see what happens.
Of course there is no real substitute for distillation, but it might actually be a good form of pre-separation to get rid of virtually all of the
heptane in one step.
From what I understand, ether is sparingly soluble in water... 70 grams or so per 1000ml at 25C.
Now then, that ain't a whole lot and it'd take quite a few runs thru a small separatory funnel to accumulate any significant qantities. Plus you gotta
have some way of getting it out when your done... it would suck to have to distill that amount of water.
Here is what I propose. Take two 5 gallon buckets, rig up a drain with shutoff valve on the bottom of each and fill one with oh say hell about 12
liters of water. Take some aquarium air line tubing and silicone/rubber cement in one of those lil red straws you see on carb cleaner cans into one
end, and weight down the other. Immerse the weighted end of the hose in the bucket, and proceed to fill up the bucket with 10 cans or so of starting
fluid.
Let sit for a little while, then drain the contents of the bucket into another bucket and add in a shitload of water softener salt. This should
hopefully salt out the ether and cause it to float to the top. Drain off the brine, and then decant the remaining ether thru a separatory funnel to
get rid of most of the water.
Supposing the starting product is only 30% ether, or about 3 fluid ounces per 11 ounce can, then that should be about all the water and the bucket
will hold. I'm being conservative on all my numbers, and the 30%... well your YMMV wildly... Prestone starting fluid is supposed to be at minimum 40%
and 70% max ether content according to the household products database. It probably wouldn't hurt to distill one can to see exactly what the
percentage is so ratios may be ajusted accordingly.
Figuring in say 25-30% for losses, that still means 600+ grams of pure (but wet) ether recovered from 10 cans of 30%.
Currently Wally World sells SuperTech brand for $1.42 per can. Add that and a coupla bucks for salt and your looking at maybe $18 (if it works) for
nearly a liter of Et2O.... that would pay the hazmat fees alone on one order from a chem supply house.
Distill and work up as normal...
[Edited on 24-1-2006 by evil_lurker]
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Fleaker
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It appears to be a good plan, but I think it would be inadvisable to buy all 10 cans at the same location! This method does seem much safer than
distilling it.
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Magpie
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I also think this is worth a try. I would try just one can first and see if it is worth doing on a larger scale. I think your success will depend on
how much heptane goes along with the ether when it is dissolved in the water. This is a ternary system and its behaviour is not predictable without
data. But that is what you are about to get! 
Let me summarize the essence of your plan to see if I understand it:
1. Mix well the contents of a can of starting fluid in enough water to dissolve all of the ether based on published values of ether solubility in
water.
2. After a period of settling, decant off the floating heptane layer.
3. Saturate the water/ether solution with NaCl. Hopefully this will cause the ether to come out of solution and float on the water.
4. Decant off the ether and purify as required.
Have I missed anything?
The single most important condition for a successful synthesis is good mixing - Nicodem
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garage chemist
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As Ether has low to medium solubility in water, but indefinite solubility in heptane, it would actually work the other way around, meaning that you
could efficiently extract ether from its aqueous solution using heptane.
Only a fraction of the ether would go into the water. And who says that the salting out would even work?
To obtain ether there are several possibilities:
- order it in a pharmacy (best idea)
- make it yourself from H2SO4 and ethanol (I've done it before, it works but the distillate needs extensive purification to get rid of the unconverted
ethanol, and the temperature control is also critical)
- fractionally distill starting fluid (safe if a ground- glass distillation setup with long condensor and icecold water is used) if it really has to
be OTC
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evil_lurker
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Fleaker: Just go into walmart and buy a case of starting fluid at a time, tell the little old lady at the cashier you got a older big semi truck and
the compression is going down on it and you need to use a lot ether to get it cranked up so you buy it a case at a time. It don't hurt to buy a case
of motor oil at the same time either.
Magpie: you got the gist of it.
Garage Chemist: That is what I was afraid of.
Actually if I weren't wanting to use ether in a Grignard I would just distill it off using a fractionating column. Even though there is a 62C
diffrence in their boiling points (ether 36C, heptane 98C, some Heptane would probably be carried over due to it still having having a slight pressure
at the boiling point of ether say maybe around 80 torr... I'm not up on all the gas pressure laws and I don't have a complet set of data to work from
so I can't really say.
[Edited on 24-1-2006 by evil_lurker]
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garage chemist
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Well, if you use a fractionation column you will get quite pure ether as long as you distill slowly and pay constant attention to the temperature at
the column head.
A column can separate substances with much smaller bp differences than 62°C, and that's what they are designed for.
It doesn't play any role what the vapor pressure of the heptane is, this would only matter if you didn't use a column.
For Grignards you'll have to dry your ether first with KOH for a few days and then with sodium, that's understood.
Heptane traces won't be of concern in grignards though, as heptane is inert.
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BromicAcid
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Still, you have to wonder how much ether you will extract out of the heptane everytime. Inversely one could have a solution of ether in water and
realistically hope to extract it by shaking with heptane and distilling from that. Although I recently purchased some starting fluid of the type
mentioned in this thread so since I may have some time and the premise to test I will likely get to giving this a try about 6 days from today although
I wouldn't be suprised if someone beat me to it.
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wa gwan
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| Quote: | Originally posted by garage chemist
For Grignards you'll have to dry your ether first with KOH for a few days and then with sodium, that's understood.
Heptane traces won't be of concern in grignards though, as heptane is inert. |
In actual fact it is recommended to add a little inert hydrocarbon where anhydrous-ness? is important.
Drying ether with sodium is a pernicious and pervasive practise and frankly a waste of good sodium! The hydroxide crust limits its ability to really
dry at all.
Freshly activated 3A sieves (iow heated to 350C for 3-4 hours, preferably under vacuum) will really do the job.
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Magpie
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After thinking about this some more I think garage chemist is right. The problem comes down to which solvent, water or heptane, is the ether more
soluble. I think we can agree that it is much more soluble in heptane.
That doesn't mean that some ether will not stay with the water. It just may be very little and consequently the yield would be very low.
Whether the salting out technique works or not could be independently determined if one had some pure ether.
The single most important condition for a successful synthesis is good mixing - Nicodem
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evil_lurker
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Ok so the thread is heading into the distillation direction I decided to rename it.  Hope nobody gets lost.
I wasn't exactly sure if heptane would interfere with a grignard therefore I thought it best to get rid of it completely.
Anyhoos, a 4a sieve is better for drying ether, especially ether made from the sulfuric acid catalyst process, as it will absorb any ethanol in the
ether.
I also came across a website that stated molecular sieves will not only inhibit peroxide formation, they will REMOVE them... at least of the
non-dialkyl kind.
Makes sense somewhat... if one were to put an excess of sieves they should float on top (maybe) and this would work to absorb any oxygen in the
container... every time it is opened.
Hopefully I'll be able to get around to doing some distillation in the next week or so... I'm having to get some sieves and waiting for some reagent
bottles to come in from cynmar.
I just got their 2006 catalog in and they added some 1000ml amber glass bottles with shatter resistant plastisol safety coating and teflon liners in
the cap for like $6.70. 
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Sublimatus
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Prestone Premium Starting Fluid is available at Wal-Mart, and likely other big box and automotive retailers, in the US. The product label claims that
it contains diethyl ether and n-heptane.
Finding that most discussions here on the forum on the subject of fractionating starting fluid never actually included demonstration of the point, I
figured I'd give it a shot and post the results.
The can was sprayed into a flask cooled by an ice bath. This gave 278 mL of a colorless liquid expelling a volatile gas made apparent by optical
aberrations visible in the air at the mouth of the flask. Distillation through a Vigreux column yielded two distinct fractions.
The first fraction was received at ~34.5 C. This liquid was colorless and had the characteristic odor of ethers. In total 76.6 mL were collected.
The density of this fraction was 0.733 g/mL (a 2.75% difference from the literature value of 0.71340 g/mL).
The second fraction was received between 90.5-94 C. The majority of the liquid came over between 90.5-92 C, with only a small portion boiling at 94 C
near the end of the distillation. In total 203 mL of this fraction were collected. The density of this fraction was 0.658 g/mL.
I suspect that this second fraction is a mixture of heptane isomers. 2-methylhexane, 3-methylhexane, and 3-ethylpentane have boiling points of 90-91
C, 92 C, and 93-94 C respectively. Their densities all center around ~0.680 g/mL. It's interesting to note that the boiling point of n-heptane is
98-99 C. Unless there is a lower boiling point mixture of the combined heptane isomers (a literature search turned up nothing), this seems to suggest
that there is actually no n-heptane at all in this product.
To sum this all up, this brand of starting fluid contains ~27% diethyl ether (probably more, but dispensing from the can without loss is difficult)
and ~72% mixed heptanes. The can was purchased for $3.28, placing the price of the diethyl ether at around $43 a liter. This beats the heck out of
the few quotes I can find on a well-known auction site and other vendors who will sell to private citizens.
Remember, always work in a well-ventilated area with ether, as it's flammable and an intoxicant. Be responsible and don't abuse our sources of
readily available chemicals, lest we arrive in a future where one even needs a license to handle distilled water.
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bahamuth
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If you want to recover maximum out of a aerosol can, put it in the freezer for some hours. Emptying it further decreases the temperature of the can
"system" aiding in the recovery.. I did something similar, but i poked a little hole in the top of the can while it was standing upright to get rid of
the "propelling" gas, butane or similar IIRC, and then when it was at ambient pressure but still frozen i just increased the size of the hole and
poured the content out virtually without any loss.
Any sufficiently advanced technology is indistinguishable from magic.
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triplepoint
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Interesting. How vigorous was the out-gassing of the chilled propellant?
Do you know what propellant was present?
Edited to add 2nd question.
[Edited on 10-11-2012 by triplepoint]
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triplepoint
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Interesting. How vigorous was the out-gassing of the chilled propellant?
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Dr.Bob
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Quote: Originally posted by Sublimatus  |
I suspect that this second fraction is a mixture of heptane isomers. 2-methylhexane, 3-methylhexane, and 3-ethylpentane have boiling points of 90-91
C, 92 C, and 93-94 C respectively. Their densities all center around ~0.680 g/mL. It's interesting to note that the boiling point of n-heptane is
98-99 C. Unless there is a lower boiling point mixture of the combined heptane isomers (a literature search turned up nothing), this seems to suggest
that there is actually no n-heptane at all in this product. |
The octane rating (by definition) from n-octane is 0, and for trimethylpentane (isooctane) it is 100. So n-heptane would be close to 0, making it bad
for an engine, but certainly easier to start. So I would guess that they use some methylhexanes, but more so the 3-ethylpentane, and/or isomers of
dimethylpentane and trimethylbutanes, in order to keep them highly flammable (for starter fluid this is key) but also higher octane. These
hydrocarbons should not interfere with most chemistry, so traces will not both most ether based reactions, other than not being as good a solvent for
more polar compounds.
Bahamuth, your idea is excellent, that will certainly help to chill the can first, even dry ice might work. And the material that you distill away
from the ether can be poured right into your gas tank to recover some value for it, unless you want to use it as pet. ether or instead of hexanes.
It should work well for chromatography as the non-polar solvent. And again, traces of ether should not hurt that.
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UnintentionalChaos
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When distilling the blue cans of cheapo walmart starter fluid, I found it necessary to use a fractionating column and pull the ether off at a fairly
slow rate to maintain the stillhead at ether's bp. Going higher would invite some hydrocarbon content, not that it would likely matter much. This was
obnoxious, but worked. I believe that the yellow prestone cans are a considerably better deal given the higher ether content.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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Sublimatus
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An MSDS for the Prestone brand mentions CO<sub>2</sub> as the propellant. I smelled no propene, which I believe was mentioned in another
thread on this same topic.
I didn't mention it, but I had the same experience as UnintentionalChaos. Distillation without a fractionating column gave a vapor mixture with a
boiling point somewhere in the 60 C range, if memory serves. Addition of the Vigreux column cleared that right up.
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*FWOOSH*
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Found this for anyone interested, 49-60% ether according to the MSDS and $2.19/can with ~320ml/can. Shipping is fedex ground so ~$11 but if you buy 12
cans it comes out to less than a dollar per can. Could be worth it for the extra ether content.
It also contains Isobutane, propane, heptane, CO2 and a bit of lubricating oil. So I wouldn't cut these open, but there should be that much less to
distill it from . After the butane, propane and CO2 dissipate you're looking at
~160ml ether mixed with ~80ml Heptane and ~5ml lubricating oil.
Seems like less of a mess to clean up to me .
EDIT:
Just got some of this from my local O'Reilly's, they only carry the 7.5 oz can
($2.23+tax), after leaving it in the freezer for an hour and holding it upside down (these cans have siphon dispensers ) and spraying out most of the
gaseous components I was able to puncture it with a cold chisel with minimal pressure release and pour it into a flask for distillation. I'm thinking
I'll order some of that starting fluid soon, anhydrous (no clumping present when I added anhydrous sodium sulphate) DEE for $20/L + a half hour of
labor does not sound bad at all 
I feel like I should add that buying a lot of starting fluid isn't all that suspicious, it's often sold by the 12-case online to landscapers and the
like.
[Edited on 20-3-2014 by *FWOOSH*]
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I Like Dots
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If you are going to order starting fluid online, then go through the trouble distilling it you might as well buy it online, its cheaper!
I got a few liters (ACS anhydrous) @ 17.50 each after shipping/taxes.
edit-www.rightpricechemicals.com
Im going to resell on ebay, the only other person charges $50 for 500ml!! I can
beat that!
[Edited on 21-3-2014 by I Like Dots]
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Mailinmypocket
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May be of interest:
https://www.sciencemadness.org/whisper/viewthread.php?tid=97...
Good luck shipping ether properly though... That is very cheap I've got to say. The last time I bought anhydrous ether it was 45$/liter plus shipping
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*FWOOSH*
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I've never seen that website before, has anyone purchased from them before? That is a VERY good price for ether. Let me know how your purchase goes?
I'd be interested in using them if they're legit.
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I Like Dots
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Yes FWOOSH, I recently did. Expect a month+ for your delivery though.
I noticed he has other items for sale like Barbituric Acid and Benzaldehyde. Even though there is nothing on the page it still raised a flag.
Also, there are two listings for ether, http://www.rightpricechemicals.com/buy-diethyl-ether-anhydro... and
http://www.rightpricechemicals.com/buy-ethyl-ether-reagent-g...
I ordered the latter (cheaper) and to my surprise the label lists it as anhydrous also. I have not opened the bottles yet, when I do I will test if it
is anhydrous, or just a misprinted label.
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*FWOOSH*
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Ok, good to hear verification. If you have some 4a sieves you could throw them in and see what happens, if you have a technical grade product it might
be anhydrous but still contain ethanol as an impurity. Probably not a big deal unless you need it for grignards though.
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Ax165Xj
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I run a GC that focuses on hydrocarbons. As such, I would have no trouble analyzing a few different extraction procedures. I can measure ether,
heptane, and many other hydrocarbons down to the hundredth of a percent or so. If anyone can suggest the top 2-3 extraction procedures, I can give
them a test and let you guys know what's up.
I have a 24/40 distillation setup with two 200mm Snyder columns (like a vigreaux but with the floating glass ball valves) and plenty of other random
supplies.
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*FWOOSH*
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My favorite has been to drive down to the auto parts store and buy the "premium" brands of ether (most brands will do, check the MSDS first though,
some contain some kind of glyme).
I freeze them for an hour or so, hold them upside down and release the CO2 propellent.
Then I use a cold chisel to cut them open and pour out the contents into an rbf and I distill the pooled contents through a ~300mm vigreux column. I
usually let the distillation run for a few hours to keep it nice and slow.
I capture the fraction condensing from 20-~39 C, I'm not horribly worried about impurities as they'll be mostly heptane, which is inert anyway.
I keep the really low temp parts because of ethers volatility at RT. I have successfully performed a grignard reaction with this ether without drying
or further purification so I'd say it's both anhydrous and relatively pure.
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