Stage 7. Fractionation and concentration of CBD from the cannabinoid-enriched material.
There are a number of processes that could be applied to the cannabinoid-enriched material to isolate a CBD-enriched product. These include Supercritical Fluid (CO2) Extraction (SFE), Centrifugal Partition Chromatography (CPC), Molecular Distillation, Crystallization, etc. Ultimately, we are seeking to produce an purified extract that contains at least 98% of the desired cannabinoid.
Method | Advantages | Disadvantages |
Adsorption Chromatography | Low capital cost, Easily Scalable to 1-10Kg of extract per run | Difficult to achieve 98%+ purity in a single adsorption step |
Supercritical Fluid (CO2) Extraction (SFE) | May be able to achieve 98%+ purity in a single step | High capital cost |
Centrifugal Partition Chromatography (CPC) | May be able to achieve 98%+ purity in a single step | High capital cost |
Molecular Distillation | May be able to achieve 98%+ purity in a single step | High capital cost |
Crystallization | May be able to achieve 98%+ purity in a single step | Probably needs a process prior to crystallization. Time to achieve a high purity crystal. Might need several crystallization repeats. |
Further steps. There are a number of distinct downstream processing steps that can further increase the purity of the extract towards 100%. These include fractional distillation, preparative HPLC, crystallisation, etc. The number of steps and the final purity of the finished extract will depend on the requirements of the end user and the equipment available.
Author Dr. Craig Davis