Delta-8-THC is generally present only in small amounts in cannabis/hemp plants. Therefore, extraction techniques involve additional steps to convert either cannabidiol (CBD) or delta-9-tetrahydrocannabinol (delta-9-THC).
Methods converting CBD to delta-8-THC are more complex compared to conventional extraction. According to Extraction Magazine, the process involves mixing a Lewis acid (in this case, p-toluenesulfonic acid) with an organic solvent and refluxing. After diluting, adding water, and mixing, the organic phase separates. Delta-8-THC can then be eluted, or removed. This process is outlined in a patent by Raphael Mechoulam and colleagues. According to the patent, the method “produce[s] higher yields and higher purity compared to prior art methods.”
Company Effex describes using glacial acetic acid for extended periods (3 days at room temperature) to produce roughly 50% delta-8.
Other methods center on distillation. Company Delta 8 Science employs fractional distillation followed by thin film distillation. They employ “variations in temperature and pressure” to procure delta-8-THC. Delta 8 Science boasts an 80% recovery rate for their method although further processing refines the concentration to higher levels.
BR Instruments notes a simpler process for the conversion of delta-9-THC. “Delta-8-THC isomer can be made from Delta-9-THC in a spinning band distillation system,” they note. Namely, 4% acidic alumina silicate is mixed with crude cannabis oil. This combination is then distilled, but the distillate will be the rearranged delta-8 molecule.
These are additional steps/supplies compared to the typical extraction procedure. The idea is to convert either CBD or delta-9-THC. Primary forms of cannabis extraction include:
- Hydrocarbon extraction: organic solvents like n-butane and propane
- Ethanol extraction: highly polar solvent
- Supercritical carbon dioxide extraction: tunable and clean solvent system
Due to the popularity of delta-8-THC, new hemp cultivars may emphasize this cannabinoid. However, the possibility of breeding this cannabinoid is unclear. The Mountain Strong Hemp Company, for example, vends a cultivar known as Sour Cherry CBD that infuses distilled delta-8 into the flower. Rare and desired, delta-8 remains somewhat unconventional in terms of extraction.