Sciencemadness Discussion Board

vacuum distillation 1 mmhg - 30 mmhg

busybird - 23-11-2014 at 23:52

Can anyone recommend a vacuum pump for vacuum distillation at ranges 1 mm hg to 30 mm hg ? I was told I must have a turbo vac. Any suggestion on the pump I need?

Magpie - 24-11-2014 at 16:01

I don't know what a turbo pump is. This subject comes up frequently here. I kindly suggest that you use the search engine.

Metacelsus - 24-11-2014 at 18:19

Magpie: https://en.wikipedia.org/wiki/Turbomolecular_pump

Magpie - 24-11-2014 at 19:11

Quote: Originally posted by busybird  
I was told I must have a turbo vac. Any suggestion on the pump I need?


You don't have to have a turbo pump to reach P=1-30 mmHg. I reach that pressure range routinely in vacuum distillations when using a Harbor Freight single-stage pump (~$100).

Chemosynthesis - 24-11-2014 at 20:39

Quote: Originally posted by Magpie  
Quote: Originally posted by busybird  
I was told I must have a turbo vac. Any suggestion on the pump I need?


You don't have to have a turbo pump to reach P=1-30 mmHg. I reach that pressure range routinely in vacuum distillations when using a Harbor Freight single-stage pump (~$100).

You get down to 1mmHg?

Magpie - 24-11-2014 at 21:41

Yes - here's an example where I was distilling n-caproic acid:

Enlarge, then look at the Bennert manometer in the background. The height of the two mercury columns is very close to being equal. Each gradation is = 1mmHg.
recovery of n-CA by vacuum distillation.JPG - 87kB

[Edited on 25-11-2014 by Magpie]

Chemosynthesis - 25-11-2014 at 05:24

Wow, thank you for informing me. That is lower than I expected, and giving me ideas on my next shopping excursion.