RogueRose
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Why is denatured ethanol so pricey?
I can get E85 for $1.99/gallon. I suspect this is either petroleum, coal or natural gas derived ethanol - which is fine with me as I use it for
cleaning and other non-consumption uses. Either way, at that price, that is even less than gasoline so that means the ethanol is less than $1.99 per
gallon!!!
Getting the "right" (meaning denaturing formula) denatured alcohol in the stores is a PITA as well. I know I want 3A or 3C for certain applications
but there is no way to tell which it is. It should have to be on the bottle, with the denaturing additives and %'s. I have a problem spending $20+
/gal for something that may not be what it was the last time & not be appropriate.
The problem is that I have had the same brand be different from time to time and it wasn't too long from one purchase to another.
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j_sum1
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Around here you can buy "methylated spirits" from the hardware store or supermarket. The MSDS says 95% ethanol with the remainder methanol, water and
(presumably) enough bitrex to discourage idiots. It sometimes contains colourants and presumably has MEK, acetone and other contaminants. It comes
in overpriced at about $3-$4 per litre (AUD).
If I need something better there is a product called bio flame that is 99+ ethanol with a bit of bitrex. Similar products are available in other countries with similar names. (Biofuel I think.)
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CRUSTY
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Quote: Originally posted by j_sum1  | Around here you can buy "methylated spirits" from the hardware store or supermarket. The MSDS says 95% ethanol with the remainder methanol, water and
(presumably) enough bitrex to discourage idiots.
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Wow, 95% EtOH isn't bad at all for hardware store grade. Where I live, the best I've been able to find is ~60:40 ethanol to methanol. On the contrary,
I've yet to find anything containing bitrex or the like, which is kinda nice since there's a lack of the more complex impurities.
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RogueRose
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There are probably 100 or more formulas to denature ethanol and two that are popular are 3A and 3C which is a 95/5 mix of Ethanol/Methanol and
Ethanol/IPA (not Irish Pale Ale...) respectively. These two mixes work very well for applications that require ethanol and aren't sensitive to either
of the other 2 substances.
As far as price, I looked the other day and it was $13.99/32 oz of denatured alcohol and $26.99 for a gallon (these are US prices). IMO these prices
are kind of insane, especially if the source is a fossil fuel and not a grain, startch or sugar.
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Praxichys
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A good choice is Klean-Strip "Green" denatured alcohol.
http://www.homedepot.com/p/Klean-Strip-1-qt-Green-Denatured-...
The "green" version is azeotropic ethanol with 5% methanol and 1.5% ethyl acetate.
To prepare it for the lab, I reflux one liter at a time over sodium hydroxide to convert the ethyl acetate to ethanol and sodium acetate. I then
distill off the ethanol/methanol mix, and add potassium carbonate with gets it down to about 2500ppm water. This can be used as-is or shaken with 3A
sieves, refluxed with magnesium, etc to get it to ca. 100 ppm H2O.
Make sure you don't get the regular "S-L-X denatured alcohol" which is like a 60/40 MeOH/EtOH mix.
The above procedure makes good solvent alcohol for general use. If you need small amounts of high-purity ethanol (for making specific esters, etc) a
great way is to start from MEK substitute. It is sold by the same brand and is usually in the same location as the alcohol, and is pure ethyl acetate. Refluxing this over
sodium hydroxide will yield pure ethanol which is dry enough to skip right to the sieves after the initial distillation, and gives pure ethanol.
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Melgar
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With the gallon of denatured alcohol, you're paying for the container and aa whole separate distribution system. Also, don't forget that E85 is
government-subsidized, thanks in part to Iowa having an oversized influence on presidential elections.
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RogueRose
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| Quote: Originally posted by Melgar | | With the gallon of denatured alcohol, you're paying for the container and aa whole separate distribution system. Also, don't forget that E85 is
government-subsidized, thanks in part to Iowa having an oversized influence on presidential elections. |
While I know that a lot of ethanol is made from corn and possibly sorgum (down south) & sugar beets, I wonder how much is made from fossil fuels
like oil, coal or natural gas? Does anyone know if big oil is making ethanol from oil or NG, or Big Coal making it (it can be made form syngas using
a bacteria!!)?
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Dr.Bob
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Most ethanol in fuels is from corn or other biomass, as that gets a huge tax break, it costs about $3-4 per gallon to make it, the government gives it
a huge tax credit. Fully denatured ethanol is cheap, such as that mixed 50:50 with MeOH or other large amounts of things that make it hard to
repurify. "Specially denatured" mixes, which by name are "Special" cost much more as they are more regulated in making, selling, and using, thus the
high price. You would be better off just buying a large amount of E85 and distilling it a few times to get you solvent grade ethanol, but that will
never be pure of all hydrocarbons. It is also likely illegal without a license.
Very little ethanol is made from fossil fuels, the only practical route is hydrating ethylene, which works, but requires ethylene, which is much more
valuable in making polyethylene, and get no tax break. Methanol, however, is almost ALL derived from fossil fuels, it can be made from coal, oil, or
natural gas, but oil used to be so much more expensive that most processes avoided it. There are traces of methanol made from biomass, "green"
methods, CO2 hydrogenation (sold as a "carbon neutral fuel", but still uses enegery to make it.), and a few other methods.
If you work for a university or other business, you can get an ATF license to buy un-denatured alcohol for research use, and that can be much less
expensive, although if you buy from Fisher or VWR, they up the price to sky high as well, because they can. If you buy from ADM or similar sources,
it is $5 a gallon. Methanol is under $2/gallon in bulk, since it comes from natural gas or other cheap sources.
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Loptr
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| Quote: Originally posted by Praxichys | A good choice is Klean-Strip "Green" denatured alcohol.
http://www.homedepot.com/p/Klean-Strip-1-qt-Green-Denatured-...
The "green" version is azeotropic ethanol with 5% methanol and 1.5% ethyl acetate.
To prepare it for the lab, I reflux one liter at a time over sodium hydroxide to convert the ethyl acetate to ethanol and sodium acetate. I then
distill off the ethanol/methanol mix, and add potassium carbonate with gets it down to about 2500ppm water. This can be used as-is or shaken with 3A
sieves, refluxed with magnesium, etc to get it to ca. 100 ppm H2O.
Make sure you don't get the regular "S-L-X denatured alcohol" which is like a 60/40 MeOH/EtOH mix.
The above procedure makes good solvent alcohol for general use. If you need small amounts of high-purity ethanol (for making specific esters, etc) a
great way is to start from MEK substitute. It is sold by the same brand and is usually in the same location as the alcohol, and is pure ethyl acetate. Refluxing this over
sodium hydroxide will yield pure ethanol which is dry enough to skip right to the sieves after the initial distillation, and gives pure ethanol.
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What's funny is that I can't find MEK substitute. I have access to plenty of MEK on the shelves! I have specifically looked for it at Lowes and Home
Depot, and its no where to be found. 
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Melgar
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You can get a license to distill and ferment your own, for "alternative energy" purposes. Did that in college, it cost $6-$10 a gallon, even using
expensive cane sugar. Corn syrup would be considerably cheaper.
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Praxichys
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| Quote: Originally posted by Loptr |
What's funny is that I can't find MEK substitute. I have access to plenty of MEK on the shelves! I have specifically looked for it at Lowes and Home
Depot, and its no where to be found. |
What's even funnier is that I decided to visit the Home Depot while I was picking up lunch today at the office... and guess what? I took a stroll down
the paint solvents aisle, and MEK is back and the substitute is GONE! WTF.
This has been a long time coming. I'm pretty sure they took MEK off the shelves around here in 2011-2012.
http://www.sciencemadness.org/talk/viewthread.php?tid=17652
http://www.sciencemadness.org/talk/viewthread.php?tid=22630
http://www.sciencemadness.org/talk/viewthread.php?tid=20953
http://www.sciencemadness.org/talk/viewthread.php?tid=17401#...
That said, you can still get EtOAc from certain nail polish removers. It is also relatively cheap in bulk online. You can get it for $50 per gallon on
eBay with free shipping, which works out to $13.20 per liter or $12.50 per quart, which is only a few dollars more than the hardware store stuff was.
I'm bummed though. I think I have a quart and a half left.
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Herr Haber
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| Quote: Originally posted by RogueRose |
While I know that a lot of ethanol is made from corn and possibly sorgum (down south) & sugar beets, I wonder how much is made from fossil fuels
like oil, coal or natural gas? Does anyone know if big oil is making ethanol from oil or NG, or Big Coal making it (it can be made form syngas using
a bacteria!!)? |
Seing how much they are investing over here in bioethanol I'd say no.
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gdflp
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Try going to ACE Hardware. MEK Substitute was discontinued by the Klean Strip a few months ago, but the turnover in smaller stores like ACE is much
slower than the big chains, so many of them still have it in stock. I have two nearby, one has about 20 1L cans left in stock, possibly more in the
back, and the other has a similar number of gallon cans for slightly under $20 IIRC. I've currently got about 1.5L left as well, thinking about
picking up another gallon just in case.
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Praxichys
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I also have two ACE locations nearby. I'm going to stop by tomorrow around lunchtime and buy it up if they have it.
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Melgar
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| Quote: Originally posted by gdflp |
Try going to ACE Hardware. MEK Substitute was discontinued by the Klean Strip a few months ago, but the turnover in smaller stores like ACE is much
slower than the big chains, so many of them still have it in stock. I have two nearby, one has about 20 1L cans left in stock, possibly more in the
back, and the other has a similar number of gallon cans for slightly under $20 IIRC. I've currently got about 1.5L left as well, thinking about
picking up another gallon just in case. |
I couldn't care less about ethyl acetate, and hate the smell of it, but I do really miss ethyl lactate, which was the only ingredient in Kleen-Strip's
"from natural sources" paint thinner, and sold for one glorious moment in 2010. Sure, it was $12 a quart, but it smelled like coconuts and cherries,
rather than the harsh nail-polish smell of ethyl acetate. Now I can't even find ethyl lactate on eBay. Alibaba has it listed but you'd have to buy
drums of the stuff. Other products only sell it as minor components of mixtures.
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Praxichys
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Well, bad news for me. I went to ACE just now and they didn't have any of the MEK substitute left in stock. I ended up walking out with another gallon
of 93% sulfuric acid though, so it wasn't a total loss.
I also found a whole gallon of 99% isopropanol for under $10. Wow.
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Loptr
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The Lowes by me has a gallon of ~32% hydrochloric acid for like $6 or $7. I thought I must be dreaming when I first saw it, thinking it had to be some
sort of mixture. No, they had a "reduced fuming" formulation beside it, but sure enough the normal acqueous acid was that cheap. 
Why was ethyl acetate pulled from the shelves. I thought they pulled MEK a while back because of drugs or something like that, but if its back, I
guess the legit demand was just too great. I think I have a couple of liters of ethyl acetate around here somewhere--I don't use it that often. I
guess I will complain about them pulling MEK substitute when I run out of my reagent grade stuff.
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