Using SPD to pull heptane off my denatured ethanol?

I have a brand new 20L LS SPD. I want to use it to purify my heptane from my ethanol (I currently have a 95%etoh/5%hep solvent) before my first run. You guys think this is a feasible idea? the boiling points between the 2 solvents is quite different.

Appreciate any feedback!


its denatured with heptane cause its azeotropic and cannot be easily seperated.

I am currently advising a major corp on denaturants for hemp and MJ processors, check the thread on limonene denatured ethanol for links


Gotcha. I would think there is mol sieve to remove heptane. I may look into that.

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Zeolite 13X and 5A are said to remove heptane much more efficiently than distillation can.


I believe that is Zeolite 3A is the last stage that distilleries use to get ETOH from 195 to 200 proof.

If you are doing ETOH extractions, you should run your ETOH through molsiv every time, after you recover it from your roto.

We run ours through Zeolite 3A, 12X and handful of silica gel beads after every extraction. By now there’s probably not much heptane left, what we have was much cheaper than real food-grade from upta Bangor distillery. So it is also a cheaper way to get almost food-grade ETOH.

The column will warm up if you are doing it right. Don’t just suck it all through, it takes time to work. We let it dribble slowly through the chromo column without any vac then test each batch with a distillers gauge thingie.

We notice a performance difference between 195 and 200 proof. 200 pulls more material more easily. Below 190 performs much less efficiently.

If you just keep using the same ETOH without rehabbing it, eventually you will get what looks like white wine instead of moose piss.

You only need 3A to pull off water and thus recondition your ETOH. The 12X specifically targets heptane.

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I’ve never heard of heptane being removed with the use of mol sieve, could you point me to where u read that @SIMSAM


I typoed, I meant 13x.

The info I’m finding says 13X Zeolite filters branched-chain hydrocarbons which heptane is one of. Best I can do.

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Ordered some 13X, thanks for saving me digging for that info. I’ll report back on how the process goes.

We used to do this all the time in ChemE University Lab. Just couldnt recall which mol sieve it was we used. I think it’s pretty common in industry.

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3A EDG molecular sieve beads are specifically for ethanol purifying

specifically for removing water actually.


Silly question but how would one use the sieve beads in the process to clean the ethanol… In line as the ethanol vapor is being pulled through the roto? I’m about to try some cryo ethanol extraction and would like to incorporate a sieve into my process. I’m researching a lot on how to best maintain my ethanol supply

There are many heptane isomers but one isn’t branched… n-heptane


yes, for ethanol. I never stated for heptane just that theres specific beads made for ethanol/water versus people thinking any “bead” for water will work.

Put the sieves in the rotovap flask.

Add ethanol

The sieves will grab the h2o and refuse to give it up til they are heated to 400-500f

I packed a 48x4” column with sieves that has been