Edit: Deleting this post. It’s starting to get controversial, but that’s OK. Not what I planned on, but whatevers.

  • becausechemistry@lemm.eeEnglish
    702·
    4 months ago

    No no no no no.

    I’m a chemist. Organic chemistry PhD, now a process chemist in the industry. I do this for a living. Do not distill isopropanol that’s been exposed to air for any meaningful length of time.

    Isopropanol slowly reacts with oxygen in the air to generate peroxides that, when you concentrate them down, EXPLODE. Source. Sorry, not an open access journal. But please take my word for it.

    Unless you have a way of confirming the peroxide levels in your isopropanol are near zero, do not concentrate it down by distillation. You’ll blow up your glassware, which will probably expose what you’re distilling to your heat source, which will generate a secondary fireball.

    PLEASE do not do this.

      • becausechemistry@lemm.eeEnglish
        7·
        4 months ago

        The issue with isopropanol peroxide formation is that exposing it to air – even when just using it, like when you’re cleaning parts – starts the process. The air in the head space of your containers is also enough to form them over time. You don’t necessarily need to see solids in the containers for it to be dangerous, since they’ll crystallize out as you concentrate the solution during distillation.

        It’s also a numbers game. It probably won’t explode the first time you do it. But there’s a chance each time. Do it enough, and you’ll have an incident.

        There are chemical reductants that can clear peroxides. For industrial scale isopropanol distillation, I’m not sure what they use. It may be that they just never distill down to the point that peroxides concentrate to a dangerous level.

  • brbposting@sh.itjust.worksEnglish
    6·
    4 months ago

    How much $ you saving (or any other motivations)?

    Don’t have frames of reference so perhaps what proportion less are you paying by doing this?

    Assuming it’s no small sum/% given risks called out by you and a couple others. Glad you got a discussion going so you can give it all more thought!

  • xmclark@lemmy.worldEnglish
    3·
    4 months ago

    Yo, this thread caught my eye, but because it’s deleted, it’s unclear exactly what it’s about. Can someone summarize exactly what I’m to avoid?

      • xmclark@lemmy.worldEnglish
        2·
        4 months ago

        That is shocking because many articles on the internet suggest this, and I myself have been distilling IPA for years.

        Not trying to challenge or argue, but I’m just surprised and a little embarrassed.

        Can anyone comment why this hasn’t been a problem for me? Is this a matter of potency? Or number of cycles of distilling?

        • Prunebutt@slrpnk.netEnglish
          2·
          4 months ago

          This post goes into detail why you shouldn’t do it: https://lemmy.ml/post/19598195

          As to why there are so many articles on the internet: if there are many articles recommending jumping off a cliff… /j

          That stuff is dangerous. Don’t trust anyone on that stuff, just because they have a homepage.

          I’m guessing you were just lucky.

  • NaibofTabr@infosec.pubEnglish
    3·
    4 months ago

    Do you take any steps to clean the wash before boiling it? Filtering or anything like that?

    I’ve had some success using aluminum sulfate to precipitate resin out of the wash based on this guy’s work: Recycle Isopropyl Alcohol FAST! | Recovering IPA From 3D Printer Resin Wash

    I haven’t tried distillation… as you say, it’s risky.

    What does your waste look like after distillation? And… what would you think about using an alcohol still for this, instead of lab glassware?

  • plandeka@lemmy.worldEnglish
    2·
    4 months ago

    What I do is just expose the dirty isopropanol to sun or UV in general - the resin will precipitate. Then just filter it out and you have clean isopropanol.

      • plandeka@lemmy.worldEnglish
        4·
        4 months ago

        I see, to be honest I have not checked how clean it actually is. It is visually transparent, as opposed to the used one, but you are probably correct.