[BigJohnny]

Just curious how you can tell when molecular sieve is full of water and needs to be recharged.

Also is there any way to clean off any possible BHO residue that may be stuck too it after filtering BHO through it? Like wash it with alcohol first then dry it in the oven?

[Gray Wolf]

Originally Posted by BigJohnny

Just curious how you can tell when molecular sieve is full of water and needs to be recharged.

Also is there any way to clean off any possible BHO residue that may be stuck too it after filtering BHO through it? Like wash it with alcohol first then dry it in the oven?

Usually by weight.

The more you handle mol sieve, the more dust you have to deal with. I would leave the BHO residue alone, unless its excessive, and then I would replace the beads.

[BigJohnny]

so what other compounds aside from water will get absorbed by the 3A sieve, and will those compounds also burn/bake/boil off when I bake the sieve to recharge it?

[G.O. Joe]

Anything covering the surface that doesn't evaporate easily is subject to carbonization. Degradation of the zeolite and binder depends on operator manufacturer and what's gone by. Tossing a casserole of water wet sieves in the oven at 425 for instance is not the same as gradually heating a shallow layer of air dried sieves in a vacuum oven.

[Douglas.Curtis]

**deleted** diplomacy fail...

[clearheaded]

Well typically u rinse them after each use. Forget what we did in the lab but wanna say an acid then di water. I am sure u can look up proticol online.

[Pangea]

Going to jump in with some related questions if thats alright?

Would using a jacketed spool w/ mol sieve beads with sufficient heat and vacuum level applied, negate the need to transfer the beads to a vac oven and lessen handling/dust?

Also, I know its been discussed many times previously, but perhaps there is less or a change in consensus, BigJohnny, mentioned his 3A sized beads. Where do people stand on 3A vs 4A?

How much weight of beads are people running on medium to larger systems?

Some places seem to sell smaller sized spools which seem undersized but I dont know. Ive been upgrading my setup and planned on going overboard and using a 4"x36" jacketed spool and fillin'er up. Im planning on doing a lot of wet work so figure more beads the better.

Thanks.

[G.O. Joe]

Hot gas in place is fine also. If the zeolite has been in contact with cannabinoids it goes without saying it should be washed with butane before heating. Acids and bases would be a last resort. I have reused my same old 3A sieves drying many gallons of solvents usually homebrew many times in the oven but I'm cautious about it. It's like epsom salt drying protocol - the difference between nice dry MgSO4 crystals and a big mess - but the effect is harder to see with sieves. Dust shouldn't be a problem if you wash it off before sealing the system? Maybe the problem isn't dust but containment with a pre and post filter perhaps of coarse silica gel? And another thing, wet zeolite may have more capacity to absorb more water, but the stream it's trying to dry will come out wetter.

[mobin]

i have sieve traps with built in heaters for my diffusion pumps. old school shit for semiconductor work.

the way i was taught, run a pair of them together. bake one into the other changing order as needed.

you sieve material should have a bakeout temperature listed.

they have magical color changing sieve as well. you can see the blue/black -->grey white when full.

[mobin]

Originally Posted by Pangea

Also, I know its been discussed many times previously, but perhaps there is less or a change in consensus, BigJohnny, mentioned his 3A sized beads. Where do people stand on 3A vs 4A?

Generally speaking 3A sieve is used for purifying methanol and ethanol. 4A is used for removing C02 and ammonia from natural gas streams as well as being a desiccant for refrigerants, medicines, and electrical components. 5A is used for sweetening natural gas and purifying hydrocarbon gas and liquid streams. 13X (which is really 10 Angstrom) is a multipurpose sieve, it can adsorb the all the particles that previous 3 sieves can adsorb, but it is usually used to sweeten natural gas streams and purify petrochemical liquids and gases. Ultimately the pore size of sieve can have a very specific use like 3A or it can have wide range of uses like 13X, it all depends on what you wish to accomplish.

For this example 3A sieve works best because the size of water molecule is approximately 2.8 angstrom and the size of an ethanol molecule is 3.8 angstrom. The 3A sieve adsorbs all of the water molecules because they are small enough to fit inside the pores. The ethanol molecules, which are too large to fit in the pores, are free to pass by thus separating water from ethanol. If this person were to use 4A, 5A, or 13X sieve it would not work because the pore sizes are large enough to adsorb both the ethanol and water molecules, and thus no separation would occur.
https://hengyeusa.com/community/mole...eve-pore-sizes

for drying of ethanol specifically they have a special 3A EDG grade, for getting anhydrous. they claim x>1%
https://www.deltaadsorbents.com/3a-e...ieve-desiccant