The Extraction & Purification Process Of CBD

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There is a step-wise process for the extraction of marijuana plant material and for the purification of distinct fractions. The outcome of each step is a smaller amount of material in an enhancing purified form. You can do the production of pure CBD extract that is free from all of the possible contaminants in the plant. For instance, waxes, terpenes, chlorophyll, other cannabinoids, and any other chemicals.

There is also a possibility of isolation of other cannabinoids (e.g. THC, etc.) from the original extracted material. It is crucial to undertake the extraction process at low temperatures (<60 degrees celsius). It is for retaining cannabinoids in their acid form (i.e. to minimize decarboxylation).

Stage 1: Selection & Development of the relevant plant cultivar

You can grow the most relevant cannabis cultivar under greenhouse conditions. Perhaps these plants will be clones of a cultivar with low THC (<0.5%) & high CBD (>5%). It is for the isolation and purification of CBD. There has been the establishment of the selection and cultivation of the relevant marijuana cultivars.

Stage 2: Harvesting of the bud material from the mature marijuana plants

You can harvest marijuana plants at the time when the level of cannabinoids in the bud material is maximal. One can do the harvesting of the fresh stems at the optimal time along with twig and leaf material. This material consists of >5% CBD (wet weight).

Stage 3: Milling and Drying of the cannabis bud material

One has to carefully dry the bud material from the marijuana plant for producing a product consisting of <10% moisture. You have to dry the bud material at 50 degrees celsius for 8-12 hours. Then the dried plant has to be milled and sieved to a fine powder (1-2mm screen). There is a requirement for each batch of dried marijuana powder to have got mixed to homogeneity. It has to be vacuum packed, labeled, and stored at 4 degrees celsius.

100kg of fresh marijuana plant will do the production of about 10kg of dry leaf material. This material will consist of up to 1% THC (dry weight) and 50% CBD.

Stage 4: Primary extraction of the milled and dried marijuana plant material

You have to extract the milled and dried marijuana plant material at room temperature. It should be with a proprietary gaseous solvent for the generation of a liquid extract of the marijuana plant. This crude extract will consist of terpenes, waxes, and cannabinoids along with chlorophyll and other chemicals. 100kg of marijuana plants will do the production of about 2.5L of this green goop. This material will contain 5-7% THC and 50-70% CBD (w/w).

Alternative solvents are inclusive of other gaseous solvents, for instance, butane, CO2, propane, etc. Or it can include liquid solvents, for instance, hexane, acetone, methanol, ethanol, etc. You have to concentrate the solvent-extracted material by the evaporation of the solvent from the extract. As the product returns to the atmospheric pressure, this occurs automatically with gaseous solvents.

You have to carefully evaporate the solvents for the concentration of the extract with liquid solvent extracts. You must employ careful processing conditions for retaining the cannabinoids in their acid forms. There is a requirement of consideration of the extraction efficacy, for the choice of the primary extraction solvent.

It means to get a large portion of the cannabinoids out of the plant material. There is also the requirement of selectivity of extraction. It is about getting the cannabinoids out of the marijuana plant material without unwanted components like chlorophyll.

At the completion process comprehensive extraction and the minimal presence of residual extraction solvent. These two are the basis for the choice of this proprietary gaseous solvent. The obtained green goop with numerous extraction solvents consists of a significant amount of chlorophyll.

There will be the requirement of removing it as the further product is purified. There is a possibility of reducing the amount of chlorophyll by extracting the plant material. You can extract this under cool conditions.

Stage 5: Removing Chlorophyll from the marijuana extract

The green goop consists of a large amount of chlorophyll. It complicates the purification and isolation of other more crucial groups of phytochemicals from the marijuana extract. You can mix the green goop with a solvent (e.g. ethanol) and apply it to a resin. For instance, silica, alumina, and charcoal. While leaving most of the waxes, terpenes, and other chemicals unbound these bind some of the chlorophyll from the crude extract.

Stage 6: Remove Plant Waxes from the cannabis extract

When the decolorized extract in 5 volumes of ethanol has become cool to -20 degrees celsius. And that for 2-3 days in a sealed container. The waxes will get solidify and you can remove these with filtration of the cold ethanol solution.

Step 7: Concentration & Fractionation of CBD from the cannabinoid-enriched material

There are a number of processes you can apply to the cannabinoid-enriched material for the isolation of a CBD-enriched product. These are inclusive of Centrifugal Partition Chromatography (CPC), Supercritical Fluid (CO2) Extraction (SFE). Along with that Molecular Distillation, Crystallization, etc.