Sciencemadness Discussion Board

first vacuum distillation

Db33 - 8-1-2017 at 07:40

Since this is called Beginnings i figured id make a post about my first practice vacuum distillation ever. I dont have a chem degree but im a pretty quick learner and i love organic chemistry. I spent the last few months getting alot of the glassware and other equipment i need to start my own lab. Anyways i just setup some equipment to try my first practice vacuum distillation. There were a few issues, for one thing the hosing i was using for the vaccuum sucked in on itself so i need a thicker wall.
Also i just connected the vacuum straight to the vacuum adapter, i dont have a gauge or controller, is there someone that can link me to a place that sells something i can use to control the amount of vacuum that i can connect with this pump? Anyways i know the photo isnt great but im just getin started. Its a normal heating mantle/stirrer with a 1 inch stir bar inside, 1000ml 3 neck round bottom flask with a stopper, 250ml addition funnel, and vigreux column, then distillation adapter with thermometer and then 200mm liebig connected to vacuum adapter and then 500ml RB as the collection flask. Basic, and i was just distilling water. The temp said the water was coming over at between 30-40C is that normal for a pump like this?

Anyways thats all for my first vacuum distillation, i hope to do more practice setups soon.


IMG_0276.jpg - 90kB

aga - 8-1-2017 at 08:39

Nice new, clean and shiny equipment there Db33.

Sure about those temperatures ?

The vac will work better with hard-walled rubber pipe, like the orange stuff used for gas barbecues, then it won't collapse.

It'll work longer if there is a 'trap' in front of it to stop the gasses/liquids getting in.

Sulaiman - 8-1-2017 at 09:21

your pump looks similar to mine, an automotive air-conditioner service pump,
that is designed to vapourise and remove water in the pipes etc.
so I would expect a lower b.p. than 30 C

1 is the oil level correct

2 did you pull the seal off of the (blue plastic) exhaust port

I use thick pvc tubing with no problems yet.

Magpie - 8-1-2017 at 09:24

I noticed at Ace Hardware they sell a black thick-wall hose (likely Neoprene) for automobile use (gasoline line). I know some of it was 1/4" ID. This should make good vacuum tubing.

I buy the red lab thick-wall vacuum tubing through Carolina Biological:

http://www.carolina.com/lab-tubes-tubing/red-vacuum-and-pres...

[Edited on 8-1-2017 by Magpie]

Db33 - 8-1-2017 at 16:16

Magpie thas exactly the tubing ive been looking for! but i have a question, it says its 1/4" ID, is that going to fit my vacuum and distatillation adapter arm? i thought those were 3/8" but i could be wrong.

Db33 - 8-1-2017 at 16:18

Quote: Originally posted by Sulaiman  
your pump looks similar to mine, an automotive air-conditioner service pump,
that is designed to vapourise and remove water in the pipes etc.
so I would expect a lower b.p. than 30 C

1 is the oil level correct

2 did you pull the seal off of the (blue plastic) exhaust port

I use thick pvc tubing with no problems yet.



1. the oil level is near the high point.

2. i removed the top black part but the blue part i left on there cuz thats suppose to keep oil from going everywhere right?

3. And actually when i checked the temp later it was pulling the water over at 30 C, but i think the fact that my hose collapsed under the vacuum caused some issues.

Magpie - 8-1-2017 at 17:04

Quote: Originally posted by Db33  
Magpie thas exactly the tubing ive been looking for! but i have a question, it says its 1/4" ID, is that going to fit my vacuum and distatillation adapter arm? i thought those were 3/8" but i could be wrong.


It fits my 24/40 vacuum adapter which is 3/8". It also fits my 1L Erlenmeyer vacuum flask. Just shove it on.

macckone - 8-1-2017 at 21:45

Automotive vaccum tubing works well especially the viton lined stuff.

NedsHead - 8-1-2017 at 22:57

the vacuum hose looks like it sucked flat like a giant tape worm:)

PirateDocBrown - 9-1-2017 at 00:01

I'd support your condenser with a ring stand. Really, you should have more ring stands.

You will find it's useful to put the jack under the mantle, so heat can be rapidly removed.

But otherwise, good setup!