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Best type of condenser for solvent distillation?

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hostilis

hostilis

Rising Star
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Hello everyone!

I have a question for those familiar with distillation apparatuses. What is the best type of condenser for a distillation set up for solvent distillation? Graham, liebig, alihn, ect? Is there really any difference between them? I'll just be doing small solvent distillations to recycle my solvents. I've got all the other parts, just no condenser. I'll just be using an ethanol lamp heating mantle, boiling flask, Kjeldahl distillation bulb, and whatever condenser would work best for solvent distillation.

Thanks dudes.
 
Uhhm... I'd expect you to know this before vaporizing flammable liquids, but I'll answer your question.

You would probably want to use a liebig. You typically only use an alihn under reflux conditions. A grahm is seldomly used, I've used it for downward distillation/vacuum evaporations.

It also depends on the VP of the liquid you're using, you could add a column for purity but that requires more vapor.

You could probably get away with a distillation head and an ice bath.

Edit: Did you say you want to distill using an ethanol lamp? Are you insane!!!??

Stop what you're doing right now, and think about it until it makes sense. You are going to vaporize flammable liquids in the presence of an open flame. Presumably in your home?

Game. Over.
 
Don't use an open flame to boil flammables. Think about the risk of the boiling flask breaking halfway the destillation.

If you cannot find or afford a fancy chemistry hotplate, use a small electric deep frying pan as a heat source. These have a crude temperature control and some built in safety against overheating. Use (fresh) regular frying fat and immerse your boiling flask partly into it as a heat bath. When after a few destillations, the fat becomes a bit smelly, replace it with fresh frying fat.

A liebig condenser is just fine.
 
Uhhm... I am doing research and talking to more experienced people BEFORE vaporizing flammable liquids...

Yeah just thought about that ethanol lamp part. Haha. That would be very stupid. :oops: I also have a heating mantle that's round for boiling flasks that I've never used. I'll use that.... Typed this out last night when I was super tired. Lol. Thanks for the tips.
 
By the way 1ce. I don't really want to get anything too complicated like purification columns ect... I have most of the stuff already from a long time ago and I just need to buy a condenser (if I decide to do this.) Don't want to get a bunch of other expensive attachments since I'm only looking to do really small (under 100ml usually) distillations of solvents (naptha, heptane, xylene) just for the sake of saving money/saving recourses.

The simplest distilation set up I saw when researching was the boiling flask to distillation bulb (or just a curved connector thing, but I already have the bulb) to a condenser that just drips into a collection flask, which is what I'm going for. Still not even sure if I'm gonna do it, but it would be nice to be able to recycle my solvents. I don't have a lot of experience with using equipment like this so maybe it's not worth the danger.
 
Here's an example. It's not mine, but it's basically what I was thinking of using.
 

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100ml would be a barbaric waste of time, I will explain why:

Before anything distills, that solvent must vaporize. It must fill the free space in the flask with vapor, in order to push other vapor up to the condenser. This space increases as the solvent distills over. Thus some of your solvent will be lost as vapor. Depending on the size of your setup, that might range from all of it, to mostly all of it.

Recycling solvent isn't bad idea by any means, you just need to look at it a little differently. What I do is I toss my solvent into stoppered erlenmeyer, and distill it once it's full. Perhaps you could find a similar solution to make it a more worthwhile process. Distillations aren't any different than any other purification process: They take time, and an understanding of what you're doing.

I recomend for a simple distillation a rbf, 3way take off adapter, a glass stopper, (you're probably not going to watch the temp for purity/fraction control). The solvent will be quite hot and you may loose some distilate due to its vapors running off, so I'd recomend a vacuum adapter w/ a jointed flask sitting on an ice bath. This will help ensure nothing escapes as vapor.

Best of luck!
 
Thank you for the information 1ce! I appreciate it. Saving my old solvent till I have a bigger amount is a good idea. I'm definitely not going to rush into this. Been trying to soak up some information and experience before I go out and buy equipment.

Thanks,
hostilis
 
Practice with water first. It's got a similar boiling temp to most of those solvents. Usually within just a few degrees. Then maybe try mixing a controlled amount of acetone/water since they do not form an azeotrope. Check the amount of acetone you have before/after. Record temperatures too. It'll give you an idea of how the altitude of where you live affects your distillation temperatures.

Play around, you'll get the hang of it.
 
Thanks man. Really appreciate the help! I'm a beginner with all this stuff so excuse me for my ignorance of certain aspects. Or blind stupidity like with the ethanol lamp idea. :oops: :surprised Haha. Took about 2 seconds of rational thought to realize that was stupid. Especially considering the heating mantle that's made for boiling flasks I have access to.

Anyways, I think you've answered all my questions.

Thanks,
hostilis
 
Pre-destilling solvent is a good idea too. Solvent as bought from the store may contain various impurities or even additives. Destillation removes the involatile ones. See this thread for a possible example.

I read many times about the need to use only glass for extractions and how bad the chemicals are that leach from plastics. Yet the solvents that most people use have probably been in contact with all kinds of plastics, for example the bottle it came in. Unless it is bought from a fine chemicals supplier, solvents are never sold in glass bottles. Even if sold in metal containers, these are lined with plastics on the inside.

A cautionary tale when destilling larger amounts of used solvent:

One time I was helping a friend cleaning up several liters of used solvent that he had saved over time. The amount exceeded the capacity of the still pot and it had to be recharged a few times. We somewhat carelessly did this throught the side arm that holds the flask thermometer while the destillation was still going.

The first couple of refills only let out an insignificant whiff of naphta. As the destillation progressed, the solvent in the pot became hotter, because it was concentrating the higher boiling fractions. Every later recharging caused a sudden intense boiling of the lower boiling fractions in the used naphta being added. More and more, the smell of DMT became noticeable at recharges, and eventually the still pot became hot enough to codistill significant quantities of DMT.

At one of the final recharges, so much DMT vapour escaped through the side arm that I saw the destillation rig turn into a fractal. Thankfully this effect was only short lived.
 
pitubo said:
At one of the final recharges, so much DMT vapour escaped through the side arm that I saw the destillation rig turn into a fractal. Thankfully this effect was only short lived.
Click to expand...
I lol'ed! - you were kinda lucky there...

An addition funnel is a handy thing 😉

My, how I love distillation. Now, where's that picture?
 
pitubo said:
Pre-destilling solvent is a good idea too. Solvent as bought from the store may contain various impurities or even additives. Destillation removes the involatile ones. See this thread for a possible example.

I read many times about the need to use only glass for extractions and how bad the chemicals are that leach from plastics. Yet the solvents that most people use have probably been in contact with all kinds of plastics, for example the bottle it came in. Unless it is bought from a fine chemicals supplier, solvents are never sold in glass bottles. Even if sold in metal containers, these are lined with plastics on the inside.

A cautionary tale when destilling larger amounts of used solvent:

One time I was helping a friend cleaning up several liters of used solvent that he had saved over time. The amount exceeded the capacity of the still pot and it had to be recharged a few times. We somewhat carelessly did this throught the side arm that holds the flask thermometer while the destillation was still going.

The first couple of refills only let out an insignificant whiff of naphta. As the destillation progressed, the solvent in the pot became hotter, because it was concentrating the higher boiling fractions. Every later recharging caused a sudden intense boiling of the lower boiling fractions in the used naphta being added. More and more, the smell of DMT became noticeable at recharges, and eventually the still pot became hot enough to codistill significant quantities of DMT.

At one of the final recharges, so much DMT vapour escaped through the side arm that I saw the destillation rig turn into a fractal. Thankfully this effect was only short lived.
Click to expand...

It removes volitile impurities as well. Watch the thermometer and cut your fractions.
 
Here it is: heating mantle, flange flask with in pot thermometer and dropping funnel, Vigreux column, still head with thermometer pocket, Davies double surface condenser, vented receiver adapter and conical flask.
 

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1ce - I will start with water/acetone first just as a tester. Thanks my friend!

Pitubo - That's insane man!!! Glad you didn't get too high while doing that. Might end up coming to to a major solvent spill.

downwardsfromzero - Of course I have a funnel. I think literally everyone has a funnel in their kitchen! Haha. Although mine is a glass chemistry one that came with my first chem set. And why is that picture photo-shopped? Is that supposed to be your set up?
 
Whatevs, this seemed useful: Choosing the right condenser

Hostilis: An addition funnel, with a tap and ground glass joints, in your kitchen?? ;) But that was originally addressed to pitubo 😁

The photo was very cluttered, so I tidied it up as a total rush job on a program with next to no meaningful functionality. It's a picture of a setup which I know to work. If it were to have the appropriate tubes attached in the appropriate places.
 
downwardsfromzero said:
Whatevs, this seemed useful: Choosing the right condenser

Hostilis: An addition funnel, with a tap and ground glass joints, in your kitchen?? ;) But that was originally addressed to pitubo 😁

The photo was very cluttered, so I tidied it up as a total rush job on a program with next to no meaningful functionality. It's a picture of a setup which I know to work. If it were to have the appropriate tubes attached in the appropriate places.
Click to expand...

And being operated by somebody with chemistry experience ;)

A simple distillation will work quite fine, I assure you. You just need 2 flasks and a condenser.
 
hostilis said:
1ce - I will start with water/acetone first just as a tester.
Click to expand...
Try it with wine, I would advise. Distilling wine is a good excuse for owning a still in a chemophobic world.

If the wine is very crappy and sour, just add a pinch of lye or soda befor distilling, or you'll codistill some of the acetic acid.

hostilis said:
Pitubo - That's insane man!!! Glad you didn't get too high while doing that. Might end up coming to to a major solvent spill.
Click to expand...
It is another danger of working with chemicals that I had not been so acutely aware of before it happened. It was a funny accident anyway.
 
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