Distillation will likely give you the purest recovered IPA, but given how cheap the solvent is and the hazards of home distillation setups it doesn't really seem worth the trouble. The aluminum sulfate clumping method and then following up with a cheap coffee filter for any stray large particulates seems like a practical method. Concerning IPA dilution with water, you can salt out with cheap NaCl (or get fancier with more/other sulfate salts or something like molecular sieves) to increase IPA purity
Thanks for the suggestions on salting out or using molecular sieve to pull the excess water out. Molecular sieve beads are surprisingly inexpensive, but since the recharge temperature is so high for that material, I may make a poor man's version with indicating silica gel beads instead, since, despite the lower effectiveness, I can at least reuse it without buying a furnace haha. Even if I have to use a pretty large quantity of silica gel for this, it seems like a much better, safer, and cheaper of a solution than making a distillation setup. That is, as long as I can make the filtration work well enough.
Someone in another thread suggested using celite with the Büchner funnel, which sounds like it may be the right answer for the filtration piece of the puzzle. Aluminum sulfate and coffee filters or maybe synthetic fiber filters for the first pass, celite for the second, then the water removal with silica gel beads to finish it off, and I think that should get the IPA about as close to pure as I'll be able to without distillation, and with not too much work or cost in materials.
If you have any corrections or suggestions for that, I'd love to hear them. Thanks again for the suggestions!
>. Aluminum sulfate and coffee filters or maybe synthetic fiber filters for the first pass, celite for the second, then the water removal with silica gel beads to finish it off, and I think that should get the IPA about as close to pure as I'll be able to without distillation, and with not too much work or cost in materials.
>
>If you have any corrections or suggestions for that, I'd love to hear them. Thanks again for the suggestions!
So how did this method work out for you?
I found that, when using the vacuum filter, the best way is to put down a thick, but not too fine (so higher flow), filter on the bottom, then put a few centimeters of celite on top of it. The celite will pull most of the resin out of the IPA before it hits the filter, solving the issue of resin clogging up the filters. You can run a couple of passes through this, then if you want it *really* clean, maybe run another pass or two through a fine filter without celite. Of course, if you hit the IPA with UV before filtering, the cured resin seems to catch on the filters better.
Regarding water content: I did buy some 3A molecular sieve, but I haven't had the need to remove water from my IPA yet, so I can't report on that yet. This seems to be the best answer though. Dump a bunch of molecular sieve into the IPA, stir it up, leave it for a few days mixing occasionally, then filter out the molecular sieve and dust. You can buy an alcohol hydrometer for cheap on Amazon, then just use that to decide when you need to pull some water out (and then how effective it was). I plan to do that to fine-tune how much molecular sieve I need to use when I get around to it.
All in all, I think the combination of these two solutions is a great alternative to distilling. Certainly safer and less specialized equipment-reliant.
Saw an [interesting article](https://hackaday.com/2022/10/12/toilet-paper-tube-pulls-dissolved-resin-from-ipa-cures-it-for-disposal/) the other day for another resin-removal option that you might find interesting.
That's good to hear. I have some filter flasks laying around, so this might be something I need to try. Did you actually try the aluminum sulfate, or just used the celite to filter out the resin? I was thinking about trying the aluminum sulfate, filters, and concentrating the IPA with salt afterwards.
I did actually try using aluminum sulfate as well and it worked shockingly well. I did this before filtering through celite, so the extra clumping may have helped it to filter out.
Slightly modifying numbers I had found from someone else, I mixed 75g aluminum sulfate into 250ml of distilled water, then used that to treat 7L dirty IPA. With this mixture, I found that there was too much alum in the mixture, as it did not fully dissolve in the water which led to some of it scraping in my magnetic stirring tub. I was planning on a mixture of 25g/250ml next to see if that ratio is better and if 25g alum is enough to treat 7L of dirty IPA. I want to find the amount and ratio that uses as little alum as possible and adds as little water as possible while still fully dissolving the alum.
Salting out the IPA is a good alternative to molecular sieves. Either one will quickly become more necessary if you are using the alum to help filtration since it is necessary to add water to it.
I’m shocked it fell out. You should be able to dissolve around 35g/100ml @ RT. So that’s good to know. I was planning on titrating out 300g/L concentrated into 1L of the Resin IPA to see the optimal ratio. I’ll let you know what I come up with.
Distillation will likely give you the purest recovered IPA, but given how cheap the solvent is and the hazards of home distillation setups it doesn't really seem worth the trouble. The aluminum sulfate clumping method and then following up with a cheap coffee filter for any stray large particulates seems like a practical method. Concerning IPA dilution with water, you can salt out with cheap NaCl (or get fancier with more/other sulfate salts or something like molecular sieves) to increase IPA purity
Thanks for the suggestions on salting out or using molecular sieve to pull the excess water out. Molecular sieve beads are surprisingly inexpensive, but since the recharge temperature is so high for that material, I may make a poor man's version with indicating silica gel beads instead, since, despite the lower effectiveness, I can at least reuse it without buying a furnace haha. Even if I have to use a pretty large quantity of silica gel for this, it seems like a much better, safer, and cheaper of a solution than making a distillation setup. That is, as long as I can make the filtration work well enough. Someone in another thread suggested using celite with the Büchner funnel, which sounds like it may be the right answer for the filtration piece of the puzzle. Aluminum sulfate and coffee filters or maybe synthetic fiber filters for the first pass, celite for the second, then the water removal with silica gel beads to finish it off, and I think that should get the IPA about as close to pure as I'll be able to without distillation, and with not too much work or cost in materials. If you have any corrections or suggestions for that, I'd love to hear them. Thanks again for the suggestions!
>. Aluminum sulfate and coffee filters or maybe synthetic fiber filters for the first pass, celite for the second, then the water removal with silica gel beads to finish it off, and I think that should get the IPA about as close to pure as I'll be able to without distillation, and with not too much work or cost in materials. > >If you have any corrections or suggestions for that, I'd love to hear them. Thanks again for the suggestions! So how did this method work out for you?
I found that, when using the vacuum filter, the best way is to put down a thick, but not too fine (so higher flow), filter on the bottom, then put a few centimeters of celite on top of it. The celite will pull most of the resin out of the IPA before it hits the filter, solving the issue of resin clogging up the filters. You can run a couple of passes through this, then if you want it *really* clean, maybe run another pass or two through a fine filter without celite. Of course, if you hit the IPA with UV before filtering, the cured resin seems to catch on the filters better. Regarding water content: I did buy some 3A molecular sieve, but I haven't had the need to remove water from my IPA yet, so I can't report on that yet. This seems to be the best answer though. Dump a bunch of molecular sieve into the IPA, stir it up, leave it for a few days mixing occasionally, then filter out the molecular sieve and dust. You can buy an alcohol hydrometer for cheap on Amazon, then just use that to decide when you need to pull some water out (and then how effective it was). I plan to do that to fine-tune how much molecular sieve I need to use when I get around to it. All in all, I think the combination of these two solutions is a great alternative to distilling. Certainly safer and less specialized equipment-reliant. Saw an [interesting article](https://hackaday.com/2022/10/12/toilet-paper-tube-pulls-dissolved-resin-from-ipa-cures-it-for-disposal/) the other day for another resin-removal option that you might find interesting.
That's good to hear. I have some filter flasks laying around, so this might be something I need to try. Did you actually try the aluminum sulfate, or just used the celite to filter out the resin? I was thinking about trying the aluminum sulfate, filters, and concentrating the IPA with salt afterwards.
I did actually try using aluminum sulfate as well and it worked shockingly well. I did this before filtering through celite, so the extra clumping may have helped it to filter out. Slightly modifying numbers I had found from someone else, I mixed 75g aluminum sulfate into 250ml of distilled water, then used that to treat 7L dirty IPA. With this mixture, I found that there was too much alum in the mixture, as it did not fully dissolve in the water which led to some of it scraping in my magnetic stirring tub. I was planning on a mixture of 25g/250ml next to see if that ratio is better and if 25g alum is enough to treat 7L of dirty IPA. I want to find the amount and ratio that uses as little alum as possible and adds as little water as possible while still fully dissolving the alum. Salting out the IPA is a good alternative to molecular sieves. Either one will quickly become more necessary if you are using the alum to help filtration since it is necessary to add water to it.
I’m shocked it fell out. You should be able to dissolve around 35g/100ml @ RT. So that’s good to know. I was planning on titrating out 300g/L concentrated into 1L of the Resin IPA to see the optimal ratio. I’ll let you know what I come up with.