Q: What is decarboxylation?
RVL: When you have cannabis biomass from the field, typically the THC is in the form of THCa. The A stands for acid. What makes it an acid is that it has a carboxyl group attached to it, which is a hydroxyl (OH) and carbonyl (O) group attached to a carbon atom. The reason you want to decarboxylate is because, when you distill your product, that carboxyl group breaks off in the form of CO2 and water vapor, which is counteractive to a deep vacuum. When you’re distilling THC or CBD, your vacuum is a lot deeper than when you’re distilling solvents off, since cannabinoids don’t have a significant vapor pressure. If you don’t decarboxylate your product properly, the increased vapor load inside of your wiped film distillation unit is going to affect the results of distillation, resulting in a poorly made product. So the main purpose of the decarboxylation reactor is to remove the CO2 from the oil before you distill it, but also has a benefit of activating the oil into a form that your body can process as well, depending on if you are distilling the oil or not.
Q: At what stage of the process does that happen? Is that at the very end, the middle, the beginning?
RVL: That’s going to be after solvent recovery. As far as steps go, your first step is going to be cooling down your solvent. We have our InstaCool lineup for that, it pumps solvent from a holding tank at room temperature, and chills solvent down to -40F inline. You hold the cold solvent in a storage tank. Meanwhile, you place a bag full of cannabis inside a centrifuge. You dump the cold solvent on top of it and it will agitate it, much like a washing machine, for a couple minutes back and forth. Next it drains that solvent out, which now has your cannabis oil dissolved in it. The centrifuge spins out and drains the bag, so now you’ve got what’s called miscella, solvent with oil in it. There’s still a little bit of particulate contaminant from the centrifuge, and typically we’ll send that through a filter to remove all the particles because these particles would foul the insides of the downstream equipment and eventually clog it. After you filter your miscella, you then send it to the AutoVap for solvent recovery, and after the AutoVap you decarboxylate it in our DR-10. From decarboxylation you would then run it through our EVO Wiped Film Evaporator to evaporate your cannabinoids from the solution. The final step from there to achieve 99%-plus purity would be crystallization, where you take the distillate from the wiped film unit and you dissolve it in a nonpolar solvent such as pentane, drop the temperature, and that will drop out CBD crystals, which are usually recrystallized several times to increase the purity, then dried and crushed into a powder. Now it’s important to know that decarboxylated THC will not crystallize, so for specific products in the cannabis retail market, you would not want to decarboxylate the THC-A for texture and flavor reasons. CBD is the opposite; decarboxylated CBD will readily crystallize to form 99%+ isolate after repeated recrystallizations. CBD-A will also precipitate, but not as readily, so typically CBD products are decarboxylated first for the sake of easy post-processing. Most of our equipment lineup is more focused toward mass production of either CBD isolate or THC distillate, which is what is typically used for vape pens. Distillate is also really good for edible or topical products because it has no taste to it.