Still & condenser

It's got some minor metal work involved, but unfortunately no guns or
politics.....
I use quite a bit of methylated spirits to clean electronic PCBs as part
of a cottage business I run. The solvent becomes laden with dissolved
rosin flux & has to be discarded so I've been thinking about distilling
it for reuse. It's costing me 3 or 4 dollars per litre.
I was toying with the idea of electrically heating an old pressure
cooker vented through either a copper coil or an old refrigerator heat
exchanger. I'm not sure if draping wet cloth on the heat exchanger would
be sufficient cooling.
I think the BP of the methylated spirits is ~ 82 Celsius (180F).
Has anyone any experience doing this sort of thing (moonshine perhaps?)
Will it be worth the effort?
Reply to
Scromlette
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A mate makes his own whiskey, He uses a reflux still which I doubt you'd need and he says that trying to hold the correct temperature without using some sort of automatic controller is a bit difficult but doable.
(His current still is electric fired and all automated controls)
Reply to
John B.
A web search finds this:
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which helps my understanding of what that is. I've always called it denatured alcohol.
A couple thoughts.
First, that heater creates heat that has to go some where. Could be nice in the winter, when you are heating already to keep your self and shop warm. Not sure if the cost of the electric is less than the cost of the fluid.
Second, the flux and debris will accumulate in the pressure cooker. Nice to line that with aluminum foil, or a pie pan from Dollar Tree, so you can lift the foil / pan out and discard. Rather than junk the entire cooker.
Alcohol vapors are flammable. Know that, and work with whatever safety is needed.
With that boiling /
condensing temp, room air and a fan might be well enough to condense the vapors. Condensor off a dehumidifier might be enough, or use the evaporator out of an old frost free refrig.
I used to find auto dry gas for 50 cents for 12 ounces, now and again. That could work for your process. I have a bunch of bottles of drygas, that I don't use. The gov't makes the auto fuel guys put in 10% ethanol, so it's like having a bottle of drygas in every gallon of fuel. Using auto drygas might be cheaper and less labor intensive than recycling the denatured, and have to scrape out your cooker.
I'm curious to hear how this all works out. Please be kind enough to write again.
Vote for my guy, and shoot my favorite type of gun, also, please.
. Christopher A. Young Learn about Jesus
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Reply to
Stormin Mormon
Since the bloke isn't working from corn mash, it doesn't seem necessary to reflux. Simple one stage distil should do the job.
And, since he's starting with alcohol with some solids, it's less critical to maintain perfect temp. You'd (to the OP) need some kind of thermostat on the heating element, so it didn't get over 190F or some similar temp. Otherwise, it might tend to cook the resins in the pot.
. Christopher A. Young Learn about Jesus
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Reply to
Stormin Mormon
This can work, but be aware the some of the vapor will escape, and is *very* flammable. I would do this outside, well away from away buildings.
A long enough bit of copper tubing will work as a condenser, so long as there is adequate airflow.
The alcohol may destroy the seal rubber. Some pressure cookers will accept large viton O-rings. Maybe some makers use viton.
That sounds about right.
It's not a good idea to get the pot too hot. I'd set it up in a double boiler arrangement, unless you implement an automatic controller. Regulating temperature by hand without a double boiler is likely to cause trouble.
Lots of folk, but they are in the woods, and tend to shoot revenuers and other nosey people.
Depends on volume of alcohol to be processed.
Joe Gwinn
Reply to
Joe Gwinn
If you cool the condenser, vapor doesn't have to escape. In fact, you can seal the outlet with a cork or rubber stopper and put a simple gooseneck (a manometer) in the same stopper, and you can maintain *negative* pressure.
Yes, I've done it, with a fancy laboratory reflux still made of 100% glass, distilling ethyl alcohol (you blow off the fusel oil and light aromatics, waiting for the temperature to indicate ethanol, before turning on the cooling water). It works as well with copper, and it doesn't have to be reflux.
If this is methanol, check for a potential reaction between the alcohol and copper. Ethyl alcohol is no problem, obviously, but I don't know about methyl.
I've seen copper-coil condensers run through a bucket of water that will cool and condense the outlet to negative pressure. You just have to pour in cold water from time to time, and let the excess flow over the side of the bucket. That's what the gooseneck is for -- to tell you when you're getting positive pressure and you need to pour cold water around the condenser.
Reply to
Ed Huntress
Depends on the value of your time, and the volume you are processing. If your time is free, you can knock yourself out and save cash outlay - but if your time is worth something (which it should be, even in a "cottage business") then you'll have to work out if it costs you more than $3-4 worth of your time (and the cost of electricity to supply the heat) to reprocess a litre of sprits.
Additional hard to quantify costs may involve the opinion of your local fire department, insurance company, etc. regarding your processing of flammable liquids - probably best undertaken somewhere that won't be affected if the whole business managed to catch on fire, even though nothing you described _should_ result in that happening. An ounce of excess caution is worth a kilo of profound regret, etc...
Reply to
Ecnerwal
I don't know if it will be worth your effort but you can distill your alcohol without boiling it. This is probably the best way for your safety. If you heat the dirty alcohol to even 100 degrees F it will evaporate fairly quickly and it will have less water in it if you are not using a reflux still. The dirty stuff you have will have absorbed water from the air. The best you can hope for when the stuff is distilled will be 95% alcohol and 5% water. This is the azeotrope of ethyl alcohol and water. For experimenting you can use an aquarium heater that you submerge in the dirty alcohol. This will give you a thermostatically controlled heat source that will be unlikely to overheat and start a fire. Wrap some insulation around the heated dirty alcohol container and run your copper tubing through a cold water bath. If doing this in the USA it may be illegal. Eric
Reply to
etpm
You might see if filtering it through activated charcol works well enough. I have not tried it or heard of it being done (except as "charcoal mellowing" of whiskey), but it might be less trouble, expense and risk than setting up a still. Activated charcoal in bulk is much less expensive than when you buy it in the form of a water filter.
You also might want to ask other forums about what other low-volume PCB makers are doing.
Reply to
anorton
When I was a kid I remember my father gently shaking his new bottle of "Kentucky Springs" Bourbon. He said it was to mix the fusel oil. Is that true? Is fusel oil in better bourbon? (Kentucky Springs is pretty crappy bourbon)
Reply to
Tom Gardner
I think that's an excellent idea. I wish I had thought of it. And activated carbon (charcoal) is available in bulk for pretty cheap at aquarium stores. And while it lets ethanol right through it does capture a remarkable number of other substances that dissolve into alcohol. Eric
Reply to
etpm
"Heat exchanger" is the key to distilling liquids. Basically, from a person knowing the concept only, there are 3 long tubes bonded together in a side-by-side fashion for hi thermal conductivity between them. At one end the alchol enters one tube and exits another; from the remaining garbage exits. All are nearly the same temperature. At the other the input tube is wrapped in a few circles and connected to the output tube. The wrapped tube is contained in a heated chamber and given means to seperate the gas (alcohol) and liquid (garbage) and direct the liquid into the proper tube. Everything is wrapped with heaps of insulation so no heat is lost. First step to making such a gadget would probably be searching recent patent records for distilling methods. hello google...
Hul
Scromlette wrote:
Reply to
dbr
Fusel "oil" is actually an alcohol. It's the stuff that makes you spit out a drink and it gives you headaches. It's bad juju.
Bootleggers and low-rent distillers run their stuff once through a pot still. That leaves the fusel oil and some unpleasant esters in the distilled alcohol. There are three ways to get rid of it. One is to run it two or even three times through a pot still. The second is to use a reflux still for the first pass, which can be as good as three passes through a pot still.
The third is what makers of quality whiskey do: age it for 20 years in a charred oak barrel. Whether the charcoal actually absorbs it is controversial, but it gets rid of it somehow.
Reply to
Ed Huntress
If you decide to pursue this, here is a site with a lot of good info and designs:
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----- Regards, Carl Ijames
Depends on the value of your time, and the volume you are processing. If your time is free, you can knock yourself out and save cash outlay - but if your time is worth something (which it should be, even in a "cottage business") then you'll have to work out if it costs you more than $3-4 worth of your time (and the cost of electricity to supply the heat) to reprocess a litre of sprits.
Additional hard to quantify costs may involve the opinion of your local fire department, insurance company, etc. regarding your processing of flammable liquids - probably best undertaken somewhere that won't be affected if the whole business managed to catch on fire, even though nothing you described _should_ result in that happening. An ounce of excess caution is worth a kilo of profound regret, etc...
Reply to
Carl Ijames
Now I remember, it was "Echo Springs", not "Kentucky Springs". Did it probably have fusel oil in it? Did dad really mix it in? Does it float or sink? I don't shake "Maker's Mark" or Jack, I sure won't touch Echo Springs. (I probably drink a whole bottle of booze every year.)
Reply to
Tom Gardner
If it was cheap, it probably had some.
I don't know for sure, but I think it floats. I was taught to just keep the condenser warm, and aimed into a tin can, until the temperature got up to the boiling temp. of ethanol. Then dump what was in the can before hooking up cooling to the condenser and collecting the alcohol.
My still was a piece of lab equipment that was liberated from Princeton University by a chem-engineering friend. It had a socket on top of the reflux column into which you stuck a precision thermometer. It was pretty classy for making hooch, but it did the job.
I haven't owned a bottle for 20 years. I drink maybe two gin martinis and one glass of scotch per year.
Reply to
Ed Huntress
IIRC, I read something about making a filter with activated (charcoal or carbon?) in a few feet of tubing, run the alcohol through a few feet of tubing filled with activated charcoal and it was supposed to remove the nasties.
RogerN
Reply to
RogerN
It may. The straight info available for making hooch is much more widely available today than when I dabbled with it, around 40 years ago. The info I had was probably half nonsense.
Reply to
Ed Huntress
This is a cross-section of a commercial vapor degreaser.
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All the ones I used back in the 1970's were simple rectangular stainless tanks with a heater in the bottom and a coil of cooling water pipe near the top, with a gutter under it to catch the condensate. You could make one from two different-diameter tin cans with the smaller one inlet part way into the bottom of the larger to form the gutter jsw
Reply to
Jim Wilkins
True enough. But I'm assuming a homebrew still, far from lab grade. I'd start outside for sure.
Hmm. Never heard of this, but maybe. Perhaps one of our resident chemists will chime in.
Why do you want negative pressure, given that ethanol won't decompose from the heat at atmospheric pressure?
Joe Gwinn
Reply to
Joe Gwinn

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