My chemist friend was wondering, would it be possible to use a liquid CO2 extraction solvent under pressure, as used to extract caffeine from coffee beans and eugenol from cloves. If possible, this method would be cheaper and a lot faster.
-Most essential oils from plants are 100% soluble in liquid CO2
-CO2 can be made to condense to a liquid under certain conditions (-56.6 C and 5.2 atm)
-liquid CO2 can be used as a solvent to extract and filter essential oils from plants
-15 ml Polypropylene centrifuge tube
**This one is important, make sure its polypropylene. If it's too weak you just built a hand grenade.
Paperclip should work
Some cotton should work but you will likely lose product unless you run it quite a few times
-Finely ground plant material
Coffee beans for caffeine, cloves for eugenol, That sort of thing
Grab a fair amount cause it evaporates quick. 5lb=~5$
Not necessary but make life easier
-1 liter soda bottle
Speeds reaction and blast shield
-2 liter soda bottle
Backup blast shield (Trust me, if anything goes wrong, it goes REALLY wrong)
Wind up the piece of wire so that it creates a coil that will fit tightly inside the centrifuge tube. This should rest in the centrifuge tube at roughly the 1.5 ml mark.make sure you leave a long tail leading to the top of the tube so that this can easily be removed. Place this into the test tube. add a tiny bit of glass wool or cotton to completely filter out particles. Keep in mind this soaks up extracts so try to use as little as possible. After you make the plug, fill the tube with finely ground plant material till around the 7-8 ml mark.
At this point you should be putting on goggles and probably a kind of thick and shitty sweater you dont care about. Think protection, leather coat is good. I've added some safety features to my original proof of concept, but that one put shrapnel through a shisha tin we used as a cover.
Cut off the neck of the 1 liter bottle and fill it with slightly warm tap water. make sure the test tube can fully submerge in the bottle. Cut neck off 2 liter bottle. Make sure that the 2 liter can be inverted onto the 1 liter without disturbing the setup.
Take test tube with wire stopper, glass wool filter, and plant material and fill with crushed dry ice. Pack it down and use gloves if possible, this stuff is REALLY cold. Pack the test tube full of dry ice and cap it. Allow the tube to float in the 1 liter soda bottle upright. PLace the 2 liter soda bottle upside down on top of the whole assembly, and make sure it is not touching anything.
At this point, if you packed it correctly the dry ice should sublimate into CO2 gas, until it reaches 5.11 atm pressure in the test tube. at that point te gas will begin to condense into CO2 liquid and will filter through the plant material, dissolving any essential oils. eventually, the test tube will begin to leak and release CO2 gas, and the liquid at the bottom will evaporate. This process will take about 15 min at least.
Once all the liquid has evaporated, you should be left with some oil at the bottom of the tube. or crystals along the sides. Carefully open the test tube, as it will release pressure. Refill with dry ice up to five more times.