Thanks for the info. Based on that info and our application of removing specifically water I don’t see how adjusted by ion exchange is benificial if all we are after is the water and activated alumina with it’s non adjustable ion exchange will still picks up more water.
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13x is great for stripping terps as well as moisture from your solvent, GMO always leaves my tane smelling like hot ass stew if I don’t CRC or 13x sieve.
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To piggyback on this with a related topic, if one uses nitro assist and is passively recovering from collection tank, through a molsieve and into the solvent tank after burping excess nitro pressure out of collection tank (never to 0psi), there would inevitably be remaining nitro flowing through the sieve along with the gaseous butane correct?
Assuming this is true, nitrogen has a molecular diameter of approx 3.7 angstroms so wouldn’t the 4A, 5A, and 13x sieve beads adsorb the nitrogen as well as the water and other unwanteds? My concern here, if my logic is accurate, is that the nitrogen would fill the pores in the sieve beads and block the adsorption of more water.
Water molecules are approx 2.75 angstroms so the 3A beads would work for water while also not adsorbing the nitrogen. I am probably thinking about this incorrectly since I have read many comments by vastly more experienced extractors than I saying they use a mixture of 3A, 4A, 5A and 13x but I would still like to wrap my head around the explanation here. Thanks!
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I’ve never tried myself but have been told by pros here nitro will recover. And they use a sieve for every run. It will be slow but my understanding is some will go in
Are u looking up liquid nitrogen or nitrogen vapors. Bc w nitro bump you only get nitrogen vapor tank not LN2 . there is no liquid in the tank
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Yes nitrogen vapor. The N2 molecule and the H20 molecule are both small enough to be adsorbed into a 4A and larger sieve bead that’s why I am wondering if that renders the 4, 5 and 13x beads less effective than the 3A at adsorbing moisture if they’re already “full” of N2. Or is there not nearly enough N2 to “fill” the beads?
But like you said, I also have seen that the pros use a mixture of the different beads but it just bothers me when I can’t figure out the “why”.
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I would introduce the solvent that needs to be dried in the order of smallest angstrom to biggest.
Id imagine the 3a will catch as much as it can and w/e doesnt get caught in there just keeps retrying until it gets to the 13x. If you go biggest to smallest most of ur 13x would get filled up with stuff that should be caught in the smaller ones, then things that should have been caught by the 13x are now passing through, because the 13x is saturated.
Now that i do more research, i see what your saying. Most info states that 13x is best used to purify oxygen from the air by catching the nitrogen in the beads.
Looks like we should probably be pushing our solvents around with helium instead? 
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Please no!
Until we learn how to make more, gratuitous use of Helium should be kept to an absolute min.
…and we need to learn how to make more soon, or we’re never getting off this rock.
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Why not use 13x for your mol sieve?
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3A just grabs water. Anything larger also binds to hydrocarbons. They can be used between oven and vac pump to keep that exhaust clean, but if you put 4A and up in your extractor it’s will fill up quickly with your solvent
I’ve got some 13x and what I’ve found is that it can adsorb quite a lot of solvent… it should not be used in as great of a quantity as 3a mol sieve is due to the that fact.
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I don’t run solvent across it except when I first load it to clean it. It’s meant for vapor in this instance
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Right, I use it for vapor… that’s when I saw it picking up solvent
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Interesting? I’m not sure if I’ve noticed solvent loss. I’m going to pay closer attention now.
I wonder if stepping down to 10a would resolve that
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If it collects vapors as well, which it seems to, it appears you’d need to use 3a exclusively. n-Butane shows being adsorbed by even 4a based on the table presented higher up in this thread.
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At this point I only use it when I need to remove mercaptans in new solvent. When I use it it’s not in a 3" spool like my 3a sieve, it’s in it’s own 1.5" x 12" triclamp spool.
Doesnt 13x have 10a pores already?
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It does have the same pore size, yea. I do like how it keeps my solvent clean. But, I’m definitely going to look and see if I can notice a solvent loss through it
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4a does not absorb Alkanes though?
Supposedly 4A does not absorb alkanes, no. But it is very close to the size of butane/propane - 4.2-4.3A . Like scoobiedoobie said, using it to clean out mercaptans would be fine but good quality gas shouldn’t have them these days anyway. If you get to 5A pore size or higher like 13x (10A) you will absolutely be absorbing hydrocarbons. Look at https://www.deltaadsorbents.com/ for more details.
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I think I remember someone saying that heptane can actually get bound up in 4a mol sieve but cant remember who said it.
Edit: I was wrong its 5a and it was @SkyHighLer
Tell that to the state of California 
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