angelhair
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Pet Ether from petrol
If you distill ether from unleaded gas up to say 60 deg C, can you use it as is for work on ketones and amines or will the junk
interfere?
Thanks.
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MagicJigPipe
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No. There is so much other stuff boiling in that fraction you would be lucky to get 50% ether. Is there really even that much ether in gasoline, if
any?
"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any
question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and
that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think,
free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
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angelhair
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I distilled at least 30% of the total volume up to 58 deg C. So by your "no" do you mean that it's OK to use as is?
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MagicJigPipe
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I'm sorry I thought you meant ethyl ether. You should be able to obtain decent petroleum ether if you use a column.
"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any
question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and
that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think,
free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
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bio2
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Unleaded gas in USA contains a high percentage of MTBE (methyl tertbutyl ether)
so to get low and/or medium boiling petroleum ether from gasoline use a high octane premium grade that doesn't contain MTBE.
Save the fraction to 70 degrees. The higher the octane the larger percentage of low boiling components (pentanes/hexanes).
Aviation gasoline of the highest grade will give the best results.
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smuv
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MTBE undergoes hydrolysis in strongly acidic solutions, additionally many ethers form water soluble etherates in strongly acidic solutions. That
being said, I would assume that washing the obtained distillate a few times with a concentrated HCl solution should remove a large majority of the
mtbe. The distillate then could be washed with water to remove any methanol formed. Finally after a second distillation theoretically a reasonably
pure product will be obtained.
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MagicJigPipe
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Just sounds like A LOT of work for something so easily obtainable. Some "Napthas" are actually petroleum ether with a naptha label. Check out some
MSDSs and you'll see what I mean.
Also, technically, naptha isn't very far from being petroleum ether itself.
[Edited on 4-14-2008 by MagicJigPipe]
"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any
question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and
that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think,
free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
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not_important
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The term "naphtha" covers a rather wide range of hydrocarbons. The common VM&P is mostly C5 to C7 aliphatic hydrocarbons, with some aromatics,
and boiling mostly between 110 and 150 C so it is more ligroine than pet. ether.
http://www.brown.edu/Administration/EHS/resources/NPG/npgd06...
http://palimpsest.stanford.edu/byform/mailing-lists/cdl/2007...
Winter grade petrol has a goodly amount of C5 through C7 alkanes in it.
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MagicJigPipe
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I didn't say VM&P, though. I'm not sure if they are lying but I have seen several "napthas" that claim C6-C12(or something similar) hydrocarbon
petroleum ether content.
"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any
question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and
that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think,
free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
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bio2
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Heptane boils at 98.4 so the VMP boiling mostly 110-150 must be mostly C8 and higher rather than much C5-C7 alkanes.
This from the link by not important.
[Note: VM&P Naphtha is a refined petroleum solvent predominantly C7-C11 which is typically 55% paraffins, 30% monocycloparaffins, 2%
dicycloparaffins & 12% alklybenzenes.]
Synonyms & Trade Names
Ligroin, Painters naphtha, Petroleum ether, Petroleum spirit, Refined solvent naphtha, Varnish makers' & painters' naphtha
MW: 87-114 (approx)
BP: 203-320°F
[Edited on by bio2]
[Edited on by bio2]
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unionised
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I have a vague recollectioon that "zippo" type lighters use a fuel that's pretty much pet ether.
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smuv
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Zippos use a higher boiling mixture; which makes sense because you don't want a fuel which will burn out of control; putting pet ether in a zippo
would likely give you something akin to a super crack torch.
@MJP Most napthas that you find OTC are Ligroin; The fact of the matter is, a solvent which boils at ca 50 degrees and has a really high vapor
pressure at room temperature is not all that useful around the house. While the procedure I posted is a bit of work; its damn cheep and if you have
the time it might be a good way of getting large amounts of solvent.
[Edited on 15-4-2008 by smuv]
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angelhair
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Before I posted this thread, I tested some SHELL "v-Power" Which I believe is 98 octane and the amount of distillate that came over through a column
was very poor indeed, So I tried CALTEX unleaded 91 which gave me about 30% up to 58 deg C.
In Australia, shell has a blend simply called "racing" which includes 5% EtoH. I guessing that it's just 100 octane, aviation fuel with the added
alcohol. I'll give that a go as well as some AV gas from the local airport.
It is a pain in the butt though cause years ago I used to fill up my motocross bike with AV gas, and you had to fill in a huge form declaring you
weren't going to street race with it.
I hope HCL will do the trick because it's not worth all the H2SO4 I used to clean it with, according to the proceedure in vogel
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angelhair
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What is the fraction that comes over at about 19 deg C? Is it useful for anything?
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smuv
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Thats probably C4 and C5 hydrocarbons... just keep it and mix it with your pet ether; alternatively discard it if you want your pet. ether to be less
volatile.
Also with some petrochemicals, they use natural gas to pump it out of tanks, so you can also get some dissolved C1-C3 hydrocarbons mixed in from this.
"Titanium tetrachloride…You sly temptress." --Walter Bishop
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starman
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Angelhair if living in Australia check out "shellite"http://www.diggersaust.com.au/files/Shellite.pdf
Its a little expensive and has a wide boiling range (50 - 135C) but at least 50% comes over at 60-80C.
I have found it suitable as an extraction solvent from A/Bs ,recrystallizations etc.
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Istari
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If you are going with AvGas, you also have to worry about lead, specifically TEL, which boils at 83C. I'm not sure how stable it is either and
whether other lead compounds may be formed in the mixture with the alkenes which might hitch a ride into your recieving flask.
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