Molecular sieve ethanol dehydration

Looking for some help with drying ethanol. We get 200proof ethanol in totes and with our new lab coming up we plan to process about 300 gallons / shift (30 gallon runs going through the system multiple times).
I know we need 3A molecular sieve beads but am unsure if we need to run the ethanol through them with pressure or let them soak, in a gas or liquid stage, or how much we would need.
The calculations I’ve seen say 3A will hold about 20% of its weight, so 25lbs of beads should hold 5lbs of water but how does that translate to water content in biomass. If we get biomass that has 1% water content, 30lb batches (0.3lb water/batch) we should be able to run 16 full batch through before needing to swap beads?
If anyone has any experience with this that would be a great help!

Check out: Formula for Molecular sieves?

It was in cannabusiness till moments ago…

Don’t guarantee your answer is in there, but it’s worth a peak.

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We used to just keep sieves in the bottom of our solvent bottles in the chem labs to keep the solvents dry. No pressure needed.

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If you freeze your biomass before extraction you’ll get a better output product (since you aren’t mixing cold ethanol with room temp biomass) and some amount of the moisture in your biomass will collect on the evaporator core of your freezer and (assuming you have a system which does so) get defrosted every few hours and drained off.

1% moisture by weight seems like a low estimate. I would also suspect that your ethanol won’t pull 100% of whatever moisture content your plant material has in it. In a similar vein, whether you’re using a screw press or a centrifuge you’re going to leave a minimum of 3-4% ethanol in your output biomass which will need to be made up with fresh ethanol every so often.

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Doubt you can call ethanol dried over sieves dry thou over 1050 ppm of water even after 72 hours

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You don’t need pressure, since you aren’t going to anhydrous conditions, a quick soak is ok, though as they get towards the end of their life, they need to sit longer. Assume you are pulling all of your water (equal to the yield of cannabinoid extraction; 95%). Test them to see how much water they pull and add change out accordingly, or not. Test periodically to make sure they aren’t losing strength; I’m not sure but they could lose performance over time after repeated cycling (loss of surface area). Unless you need to be at 100% ethanol, you can just go to 95% and save a lot of time.

It really depends on what your setup is; if you’d like to have redundancy and robustness, you should have and extra 0.5-1 volumes of ethanol and sieves if you want to let it sit longer, a machine breaks or a process slows over time.

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Yeah, except you don’t want but 190proof/95%