lbrande

My most beloved "enemy".

rmalarz Loc: Tempe, Arizona

--Bob

ken_stern Loc: Yorba Linda, Ca

Always good to have Jesus on your side

NMGal Loc: NE NM

Lol. Good one.

petrochemist Loc: UK

Your Mom was wrong. Alcohol has saved more than a few of my lenses & can be essential to complete a day at work in the lab.

If you get the right type it can even be used for drinking, sadly the stuff at work is not fit for that :)

paulrph1 Loc: Washington, Utah

And I thought you were going to get technical, like ethanol, methanol, isopropyl, denatured. Oh well.

Julian Loc: Sarasota, FL

Great logic! Good luck with that...

petrochemist Loc: UK

I can if you like Paul. Those who don't want to bother with a load of irrelevant technical talk won't miss anything photography related if they skip this post. :)

It was actually the methanol & iso-propanol that I've needed to get through at work enabling me to flush polar material off a aminosilcate HPLC column. Iso-propanol being miscible with our usual mobile phase and with methanol so making a suitable intermediate flush - methanol is immiscible with hydrocarbons. Neither of these are safe to drink, methanol being classed as toxic & i believe iso-propanol in trace quantities is one of the things that causes hangovers.

The site as a whole has vastly more ethanol (bio derived) than other alcohols but unfortunately even this is unsuitable for drinking being used for gasoline blending instead. I believe 'bitrex' is added to bio-ethanol (& methylated spirits) during the denaturing process specifically to make it extremely unpalatable. For the drinkers among you our bio-ethanol is at least 164% proof, so perhaps I should investigate to see if I can remove bitrex & other trace impurities without adding anything unpleasant.

There are quite a few other alcohols I run into as well, n-propanol (can be used in the same way as iso-propanol but is less common except as an impurity), then there's four different butanols (normal, secondary, iso & tertiary) The last of these is a fairly common gasoline blending component. The only one of the pentanols I regularly come across is tertiary amyl alcohol (another approved gasoline component). I've had to develop a method to measure all of these to ppm levels in hydrocarbons. I think I also have small quantities of some of the hexanols, hetanols, octanols, decanols and perhaps even higher alcohols on hand but very rarely have need of them.

Fortunately the company's plans to produce diacetone alcohol have long since been ditched. Analysis of all the by products was a pain especially since many of them decompose during GC injection.

Is that technical enough, or do you want to go into the relative polarities, polyfunctional alcohols (glycols etc.) GC retention characteristics & FID responses...

I'm not an expert in alcohols, they're merely a sideline in the hydrocarbon analysis I do routinely, and of course I try a few of the ethanol based variants, in my free time :)

junglejim1949 Loc: Sacramento,CA

raymondh Loc: Walker, MI

Bigmike1 Loc: I am from Gaffney, S.C. but live in Utah.

Well, I don't drink alkyhall but I have found a number of uses for it.

Craig H

I’m puzzled about the meaning of “164% proof.”

paulrph1 Loc: Washington, Utah

Hi again and thanks for the info. I believe we have talked before about ethanol free gas? Much of what you wrote is above me. But I am a pharmacist, I believe you call them chemists. Just the basics in alcohol is enough and we do not need to go into the others like phenol. Or others with -oh groups.
We refer to methanol here as wood alcohol and my father used to tell me how men would, in the olden days drink it because they were alcoholics and it would cause them to go blind. And we have denatured alcohol which is grain (ethanol) alcohol which have ingredients added that will make it toxic and not drinkable. Grain alcohol (ethanol) is the drinkable kind, written for others who are inquisitive. tell me more about the ethanol based variants.

petrochemist Loc: UK

The proof rating of alcohol is quite an old one, I believe 100% proof is the concentration that will spontaneously combust when mixed with gunpowder. Pure ethanol is quite a bit higher I think 180% proof but I'm not totally sure. Methylated spirits is readily available at 64% 'overproof' (ie. 164% proof) I believe it's this methylated spirits the alcoholics drink rather than methanol itself.
Methylated spirits is a mixture, mainly ethanol but with a few percent of methanol that's been used to break the azeotrope between water & ethanol allowing more water to be removed by distillation.
(Azeotropes are constant boiling mixtures of compounds at a specific ratio that can't be separated by distillation. Instead of getting two fairly pure products from distilling a mixture you end up with one compound & the azeotrope. They can make life interesting by introducing unexpected problems) IIRC ethanol/water/methanol forms another azeotrope with a higher alcohol content. Ethanol actually forms quite a lot of binary & tertiary azeotropes. I think there's one with benzene that gets up to around 99% ethanol.

Yes Paul I recall the discussions on gasoline. I personally prefer to refer to people in your line of work as pharmacists since I'm a chemist but not a pharmacist so like to keep the distinction - every time I mention I'm a chemist people assume I'm a pharmacist. I know very little about biochemistry & even less about prescription drugs. I guess historically there was a lot less in the way of medicines & the 'chemists' shop would be the place people would go to for household solvents, acids etc. all now frequently brought prepackaged in supermarkets.

There are a nice range of names for most common chemicals to confuse the world. Wood alcohol (named after the way it used to be produced) is also methyl alcohol. Things get more complicated when we get to isopropanol (rubbing alcohol?) which is also iso-propyl alcohol, IPA, and 2-propanol... I'm not sure if there are any compounds with just a single name in the English language even water is 'dihydrogen monoxide' if you want to scare the public about it's presence (there are some lovely tales of a campaign to get it banned).

I'm sure most people are familiar with the ethanol based variants I was referring to (it's after all the reason for this thread). Beer is one of the most popular - personally I'm not a big fan of the pale wishy-washy stuff sold as larger. It reminds me of what my body produces after I've had a few good dark ales. In wines I also prefer darker coloured variants. Cider may be the same colour as larger but IMO has much nicer flavour, I can happily drink too much of that too.
With the stronger stuff I 'll happily sample most types (generally preferring paler versions if having a heavy session as these are less prone to giving hangovers). An incident at University has left me with an abiding distrust of rum so I leave that alone.

tommystrat Loc: Bigfork, Montana