hey there,
i was wondering if I could distill 500ml of the NPS (Bp. 40°-65° ) from the first pull half way and then reuse the distilled half again for the next pull...continuing until i have all Spice in one flask. Would use a water bath. what could potentially go wrong? any recommendations? why isn't this a thing?

Thanks a lot dear peps, wish you a great ending for this shitty year

Some of us do recover solvents by distillation. It's not discussed much because distilling hazardous solvents is best left to those who have had the appropriate training as well as having the necessary equipment. If you fall into this category would you really be asking what could go wrong? Or, being aware of the safety aspects, are you simply referring to possibilities for your extraction being spoiled?

With that low boiling range you'd be best off using iced brine in your condenser water and making sure all the joints in your apparatus are properly gas-tight. You also need to be aware of hexane neurotoxicity.

What do you imagine might possibly go wrong if you were to try distilling your solvent in this fashion? The extreme flammability of pentane and the capacity for the heavier-than-air vapours of these kinds of volatile hydrocarbons to form explosive mixtures with air should warn you away from proceeding with this method if you lack the experience and the confidence.

A Nexian before has described their experience with a solvent vapour explosion that caused them significant physical injury and required the intervention of the emergency services. Notable was the fact that vaporizing a large amount of DMT-laden solvent was found to be capable of producing a psychoactive effect, which is maybe something you'd want to avoid if you're simultaneously in the process of developing third-degree burns.

If you're into expensive apparatus, continuous liquid-liquid extraction would be the logical extension of the process you're outlining and would save you from having to transfer solvent back and forth.

Thanks for the reply! Nope, you're quite right about that, I have a lot of equipment but unfortunately no chemistry training. Thing is, I'm haunted by perfectionism (the unnecessary kind ) and I'm super curious and I hope I can learn anything, but of course I wanna keep the risks as low as possible, so I wouldn't just do it and burn the damn house down. I reckon its no fun being burned alive and i really hope the other lad is well again!

I just wanted to know if its possible in a safe way and what this way looks like. I'd probably do it outside with a fan blowing on the apparatus and all joints sealed with Teflon. Cooled with cooling liquid well below 0. and the pressure to a slight plus with a check valve and a gas trap. This way i thought the risk of volatile explosive gas mixtures floating around would be minimized. But there are always things one isn't aware of that's why I'm asking for advice rather more often.
Thank you

Distilling solvent like this is fairly routine, you just have to make sure there's no source of ignition within range of an explosive concentration of naphtha vapour. The naphtha itself is pretty stable in absence of an ignition source, which could include static electric discharge, sparks from electrical motors and the switching on or off of a thermostat. Besides a flammability hazard, well, the hazards should be written on the container in which you received the solvent.

If your equipment is set up correctly there shouldn't be a significant amount of vapour escaping from it to present a hazard, but bear in mind that glassware can fail. You can look up things like the autoignition temperature of the substances in question as well.

Your perfectionism should serve you well in first studying chemical laboratory safety as thoroughly as possible - there are some general principles and then things specific to particular activities and substances. Clearly, it's not worth studying something you're not likely ever to use, like maybe, I dunno, diiodoacetylene or whatever.

Checking materials compatibility for the substance used is standard practice and this includes its compatibility with your PPE.

The other thing to mention is don't leave your distillation unattended and don't attempt this when tired or intoxicated. If you start to feel drowsy, turn the heat source OFF. Naphtha fumes can cause drowsiness.

One more thing to make sure of is that the distillation apparatus can equilibrate freely with atmospheric pressure. Sealed apparatus can present an explosion hazard so make sure there is no chance of clogging or blockages, and that any valves are set to the correct position.

All that said, most of what you describe sounds fairly reasonable as a plan although using a fan when outside is overkill somewhat.

Ah ok, well i read a lot on safety and saw dozens of videos but you probably know best thats all incomplete without practical training. The fan outside would be just of a comfort reason to make sure there is nothing floating around the hot plate because there is the main chance of ignition. Even better would probably be a vacuum pump with a gas trap for that?
Thanks for your answers...i think my curiosity is served for now. I'll maybe do it one day but maybe its just not worth the risk and effort.

I'd highly recommend getting experience of distilling less hazardous materials first, such as water, salt water and then vinegar. This will instruct you in phenomena such as bumping, and the vinegar will indicate for you just how gas-tight your apparatus might be.

It's probably best not to start considering vacuum work until you've got experience of the basics.

I did quite a few distillations but always just acids or h2o2...or less flammable liquids like ethanol.

If you've experience of rectifying - redistilling - ethanol and not simply distilling from the wash then you should be fine with recovering naphtha, bearing in mind its lower flash point and heavier vapour.

I still wouldn't recommend your exact method as described for purposes of extraction. If your naphtha contains too little alkaloid to make freeze precipitation worthwhile, work it up with a mini A/B instead.