Separating Toluene from N-Butyl Acetate

Quote: Originally posted by Fery

Luckily they seems not to form any azeotrope: http://www.sciencemadness.org/talk/viewthread.php?tid=14484 How much pure do you need them? I performed a column distillation of a mixture with similarly narrow b.p. differences (fermented apples) - methanol, 80% ethanol, ethyl acetate, water. Methanol boiled first, then an azeotrope of ethyl acetate+ethanol+water, then main fraction azeotropic ethanol+water. I used 1 meter long 30 mm diameter Hempel column packed with Raschig rings (cca 5-10 x 5-10 mm), insulated the column with a lot of turns of newspaper (vacuum jacket would be better) and variable ratio reflux distillation head with reflux:takeoff ratio cca 5:1. My friend performed a gas chromatography analysis and concentrations of contaminants (methanol, ethyl acetate, higher alcohols) were all below 0,1%. But do not expect such good separation when using less efficient column (like Vigreux, or a colum without good efficient packing) and when not using reflux ratio adjustable distillation head.

Quote: Originally posted by Fery

Luckily they seems not to form any azeotrope: http://www.sciencemadness.org/talk/viewthread.php?tid=14484 How much pure do you need them? I performed a column distillation of a mixture with similarly narrow b.p. differences (fermented apples) - methanol, 80% ethanol, ethyl acetate, water. Methanol boiled first, then an azeotrope of ethyl acetate+ethanol+water, then main fraction azeotropic ethanol+water. I used 1 meter long 30 mm diameter Hempel column packed with Raschig rings (cca 5-10 x 5-10 mm), insulated the column with a lot of turns of newspaper (vacuum jacket would be better) and variable ratio reflux distillation head with reflux:takeoff ratio cca 5:1. My friend performed a gas chromatography analysis and concentrations of contaminants (methanol, ethyl acetate, higher alcohols) were all below 0,1%. But do not expect such good separation when using less efficient column (like Vigreux, or a colum without good efficient packing) and when not using reflux ratio adjustable distillation head.

Ok... That's lucky. But... I only have a simple Vigreux... and I haven't even heard of a variable reflux ratio distillation head. Could this still work? I saw some videos on Youtube distilling Toluene out of laquer thinner using only a Vigreux Column but their thinner didn't contain anything that had such a close boiling point to the toluene.

Quote: Originally posted by greenlight

How long is your column? You could pack it with broken glass pieces for extra surface area for condensation which should increase the separation of the boiling points.

Quote: Originally posted by greenlight

You could use the allihn as a column without water circulating through it and pack it with broken glass too. You want to have decent surface area but ensure that the vapour flow isn't completely restricted resulting in pressure build up. The problem with long columns is that they can be difficult to get the heat all the way up entire length to the still head especially if the climate is cold. I used to wrap it in a thin layer or roof insulation "fleece" surrounded by aluminium foil back in the day when doing vacuum distillation of high boiling oil mixtures. Even sometimes had to use a hair dryer to warm the column on very cold winter days or nights.

Quote: Originally posted by greenlight

Its not really a complex mixture, you have a difference in boiling point of 16°C. The 300mm vigreux should be fine on its own. Just bring the heat up as gradually as you can. [Edited on 30-6-2024 by greenlight]

Perfect. Thank you I hope it works. I don't have a precise heater in the slightest, but I figured out around where I can set it close to the temperature of 126 degrees. Once, I get to the distillation, I'll let you know how it went!!

Quote: Originally posted by DraconicAcid

If you can't pack your column with broken glass, we use copper ribbon. Copper wire would probably work just as well.