Myriad cannabis processing operations have taken root. Cannabis processing labs have sprouted in all areas of the industry and recent developments promise to make 2019 a banner year in many respects.
Whether the lab is designed to ensure consistency in potency and safety or to simply check cannabinoid levels in grow operations, processors should be aware of the best extraction methods and equipment sources appropriate for their needs.
Equipment involved in cannabis preparation
The initial step in cannabis extraction entails raw material preparation. The scale and the source of the material (hemp, indica, sativa, cannabis product) will dictate the type and throughput of the grinding or milling equipment. Here are a few examples:
- Small-scale indica/sativa flower and leaf cutting and milling can be accommodated by a Knife Mill
- Larger-scale comminution of tough, fibrous hemp stalks can be accommodated by a high-torque, adjustable speed, sieve-type mill or Cutting Mill
- Cryogenic grinding and pulverizing of plant seeds, leaves, roots, and products can be accommodated by a Cryomill
Other examples may be more appropriate for the scale, speed, and the required output for the subsequent extraction process.
Equipment used for cannabis extraction
A grow operation or farm may need a quick method for extraction and analysis of cannabinoid content. A commercial producer of CBD distillate may require an industrial-scale extractor. A research lab may use several different cannabis extracts and require suitable equipment for each.
Again, the product, the scale, and the budget will dictate the equipment. Here are a few examples:
Distillation – full-spectrum cannabinoids
Small scale, low-throughput total cannabinoid extraction is compatible with ethanol, butane, or propane extraction and distillation using rotary evaporation for solvent removal.
Vacuum distillation – cannabinoids and terpenes
Labs with requirements for higher-yields and heat-sensitive extractions may be more inclined towards vacuum distillation, involving the use of a vacuum pump-enabled rotovap for solvent removal: 5 Liter Scale rotovap – 20 Liter Scale rotovap– 50 Liter Scale rotovap
Fractional distillation – cannabinoids and terpenes – high-purity
Those seeking to obtain fractional distillation of higher-purity cannabis compounds may opt for vacuum distillation instruments fitted with regular or short path distillation columns:
Wiped/thin film distillation – cannabinoids and terpenes – high-purity – heat-labile
Labs seeking to isolate and preserve high-yields of thermally sensitive compounds may opt for wiped film or centrifugal molecular distillation units, inlcuding Falling Film – Lab Scale – Pilot Scale distillation systems.
A benefit with these devices is extraction can be run in continuous-mode, thereby increasing throughput.
Winterization – cannabis isolates – high-purity
Some labs will seek to increase the purity of cannabinoids and other organic compounds in cannabis extracts through the process of winterization – which serves to remove plant lipids, fats, waxes, and other contaminants. Extracts are diluted in low temperature (< -20 °C) ethanol to stimulate precipitation, followed by filtration and solvent removal. Temperature control is critically important in the process:
Decarboxylation – cannabis isolates – high-purity
Yet other labs may be interested in production of high-purity THC and/or CBD in the decarboxylated forms – a process that typically involves incubation of dry plant material or extract for sufficient time at 100-150 °C in an oven, such as a safety oven for flammable solvents.
Super critical carbon dioxide extraction – low residual solvent – full-spectrum or high-purity cannabis isolates
Still other labs may require supercritical CO2 extraction for production of high-yield product with low residual solvent content. Certain systems can add fractionation to obtain high-purity isolates. Temperature control is critical in these systems, which can include lab scale to industry scale throughput.
Laboratory Equipment for Cannabis Research
Often the composition of cannabis products is determined through distillation with laboratory equipment such as heating mantles and evaporating flasks. These are used to separate samples into their constituent parts based on their weight.
The importance of assessing the composition of cannabis samples using reliable laboratory equipment is particularly prevalent for quality control (QC) and quality assurance (QA) of new products. This ensures that strains of the plant contain optimal levels of cannabidiol (CBD) and, or, tetrahydrocannabinol (THC). CBD is thought to regulate the psychoactive behavior of THC and is speculatively-linked to many of the purported health benefits of medicinal cannabis. By comparison, THC is the primary psychoactive component of the plant.
Researchers at the University of Bath and King’s College London have conducted extensive research into the concentration levels of CBD and THC in both herbal and cannabis resin. It was carried out to determine changes in the potency and price of the drug across EU member states, alongside Norway and Turkey. The study found that both products experienced a significant increase in THC concentration between 2011 – 2016. Cannabis resin THC concentration grew from 10 – 17% in that time, while CBD concentration remained relatively stable. This is concerning as CBD is thought to mitigate the harmful effects of THC .
Improved laboratory equipment can support legislators in determining safe concentration levels in cannabis products for either medicinal or recreational uses. This is integral as the move towards cannabis legalization gains traction worldwide.
