The extraction of the material of the marijuana plant & the purification of distinct fractions is a step-by-step process. The outcome of each step will be a smaller amount of material in an enhancing purified form. We will do the production of pure CBD extract that is free from all of the possible contaminants present in the plant. For instance, waxes, chlorophyll, terpenes, cannabinoid, and any other chemicals.
There will also be the possibility of isolation of other cannabinoids, for instance, THC, etc. from the original extracted material. The extraction process must take place at low temperatures which are less than 60 degrees celsius. It is for retaining cannabinoids in their acid form for the minimization of decarboxylation.
Step 1: Selection & development of the appropriate plant cultivar.
You can grow the most appropriate marijuana cultivar under greenhouse conditions. Probably these plants will be clones of a cultivar for the isolation & purification of CBD with high CBD that is >5% & low THC that is <0.5%. The selection & cultivation of the most applicable marijuana cultivars has been established.
Step 2: Harvesting of the bud material from the mature marijuana plant.
The harvesting of the marijuana plant may happen only when the level of cannabinoids in the bud material is maximal. The harvesting of the fresh stems along with the leaf & twig may happen at the optimal time. This material will comprise <5% CBD that is wet weight.
Step 3: Drying & Milling of the bud material.
There is a need for careful drying of the bud material from the marijuana plant at 50 degrees celsius for 8-12 hours. It is for the production of a product that is comprising <10% moisture. There will be milling and sieving of the dried plant material to a fine powder that is about 1-2mm screen. You have to mix each batch of dried marijuana powder with homogeneity, label, vacuum packed, and store it at 4 degrees celsius. 100kg of fresh marijuana plant will do the production of about 10kg of dry leaf material. This material will comprise about 1% THC and CBD up to 50% dry weight.
Step 4: Primary extraction of the dried & milled marijuana plant material
The extraction of the dried & milled plant material occurs at room temperature. It happens with a proprietary gaseous solvent for the generation of a liquid extract of the marijuana plant. This crude oil will comprise waxes, terpenes, and cannabinoids along with chlorophyll and other chemicals.
100kg of marijuana plant will do the production of about 2.5L of this green goop. This material will comprise 5%-7% THC & 50%-70% CBD (w/w). Alternative solvents are inclusive of other gaseous solvents which are mainly CO2, butane, propane, etc. Or these are liquid solvents, for instance, hexane, acetone, methanol, ethanol, etc.
There is a requirement of concentration of solvent-extracted material by the evaporation of the solvent from the extract. When the product returns to the atmospheric pressure, this occurs automatically with gaseous solvents.
The solvent must carefully go through evaporation with liquid solvent extracts for the concentration of the extracts. There is a requirement for the employment of careful processing conditions or minimal heating. It is for retaining the cannabinoids in their acid forms. The choice of the primary extraction solvent has the requirement of consideration of the extraction efficacy & selectivity of the extraction, etc.
Efficacy refers to get a big proportion of the cannabinoids out of the plant material. On the other hand, selectivity of extraction refers to get the cannabinoids out of the plant material without any undesired components like chlorophyll. After the process, the minimal presence of residual extraction solvent and comprehensive extraction. These are the two things that are the base of the choice of this proprietary gaseous solvent.
As is the case with numerous solvents, the obtained green goop comprises a significant amount of chlorophyll. As the product further becomes purified it has to be removed. Under cold conditions, there is a possibility of reducing the amount of chlorophyll by extracting the plant material.
Step 5: Removal of Chlorophyll from the marijuana extract.
The green goop comprises a huge amount of chlorophyll that makes the isolation & purification complicated. It is about the isolation & purification of the more crucial groups of phytochemicals from the marijuana extracts. You can mix the green goop with a solvent (e.g. ethanol) and apply it to a resin. For instance, silica, alumina, charcoal, etc. It binds some of the chlorophyll from the crude extracts. It happens while leaving most of the waxes, terpenes, and other chemicals unbound.
Step 6: Removal of plant waxes from the marijuana extract.
When in a sealed container, the decolorized extract in 5 volumes of ethanol becomes cool to -20 degrees celsius for 2-3 days. Then with filtration of the cold ethanol solution, there will be solidification & removal of the waxes.
Step 7: Fractionation & Concentration of CBD from the cannabinoid-enriched material.
There are a huge number of processes that you can apply to the cannabinoid-enriched material. These are for the isolation of a CBD-enriched product. These are inclusive of Centrifugal Partition Chromatography (CPC), Molecular Distillation, Supercritical Fluid (CO2) Extraction (SFE), etc.