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Topic: Redesigning a distillation experiment  (Read 4299 times)

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Offline curiouscat

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Redesigning a distillation experiment
« on: August 27, 2023, 12:27:42 AM »
We have a demonstration experiment for a three component seperation via distillation. Historically the experiment uses the system Methanol Ethanol Butanol.

The challange here is that analysis of various samples by GC is time consuming approximately 25 to 30 mins per sample. So I was trying to brainstorm a better experiment.

First, would there be a easier ( faster) way to analyse a Methanol - Ethanol - Butanol system? Eg spectrophotometeric or something that would give a fast or instantaneous assay. The method does not need to be very accurate. 1% or even a 2% accuracy should be fine.

Alternatively what other system of three components would lend itself to a faster assay? Some constraints may be:

1. Miscible components and not forming an azeotrope
2. Relatively easily available chemicals and nothing too exotic, toxic, nasty etc
3. Since it is an atmospheric distillation BP between say 60 C to 130 C so that temperatures don't get too high.

Any ideas?

Just to brainstorm could a system be amenable to assay using say color or conductivity or pH or density or absorbance or some combination of these? I mention these measurements since they are relatively fast and instruments easily available in a teaching lab.

Eg An FTIR or Raman etc would would but needs a more expensive instrument.

Any Suggestions?

Offline marquis

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Re: Redesigning a distillation experiment
« Reply #1 on: September 07, 2023, 07:39:03 PM »
Quick idear.  Maybe flash gc?  The column is heated on a metal block and the heating process is much faster.  The data system and detector system needs to be faster also.  Just an idea.  Good luck.

Offline marquis

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Re: Redesigning a distillation experiment
« Reply #2 on: September 08, 2023, 12:26:37 PM »
We  had the last hp5890s before the switch to the 6890.  Suddenly, it looked like we would need to run a bunch of emergency samples, quickly.  That meant much OT, a lot of 5-9s He, and so on. A quick call to Agilent came up with the fast GC mentioned above.  It would have taken some instrument modification, but the cost was relatively low.  And it would have dramatically saved time.  In the end, the extra testing was not needed, so I have no hands on experience.

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