While the cannabis (marijuana, hemp) plant has been used for medicinal purposes for millennia, modern science has identified terpenes, flavonoids, and over 100 types of therapeutically active compounds known as cannabinoids.
Due to the significant synergy between different cannabinoids and terpenes (fragrant oils responsible for the aroma of the cannabis plant), it is considerably more beneficial to utilize natural cannabis-based preparations, rather than any single purified or synthetic cannabinoid.
According to a study published by CAT Scientific in Germany,
“Recent in vitro and animal research using extracted THCA or CBDA reveals measurable actions on certain enzymes and receptor sites, suggesting some potential therapeutic effects for these cannabinoids and necessitating the elucidation and refinement of specific extraction techniques that preserve these particular acidic forms of these cannabinoids in order to provide material for further experimentation and research.”
As more governments and its states legalize the medicinal use of cannabis, there must be a safe and efficient methodology to extract and isolate the phytocannabinoids.
Alcohol extraction is the oldest and most common method of botanical extraction. With excellent solubility in lower alcohols like ethanol and isopropanol, cannabinoid extraction is efficient as long as there is little water content in the alcohol. Before prohibition began, ethanol cannabis tinctures were part of traditional Pharmacopeia, and readily available for various ailments from the corner pharmacist.
Although many lower alcohols are suitable for efficient cannabinoid extraction, the extraction industry prefers to use ethanol due to its availability, safety regarding handling and health and it does not require high pressure for extraction. Most interestingly, the extraction with ethanol will yield a full spectrum extract which aids in the synergistic activity of phytocannabinoids to exert an excellent pharmacological activity.
Ethanol contains both polar and nonpolar parts and can dissolve both hydrophilic and hydrophobic molecules. Ethanol’s polar group dissolves hydrophilic compounds like chlorophyll, pigments, and tannins. Whereas Ethanol’s nonpolar group works with the hydrophobic components like plant waxes/lipids, oils, cannabinoids, terpenes and any other substance that is present inside or on the outside of the plant.
On an average, cannabis plant buds yield about 12.5 % of the extracted concentrate. Since during extraction the buds must be covered entirely, the solvent volume to plant mass ratio has to be about 20 or more, which reduces the viability of the process and project as one has to distill out a vast volume of solvent, ethanol.
Whatever the solvent used for extraction, a careful and proper design of an extractor and the extraction process is imperative in the phytocannabinoids extraction industry as to get the maximum yield with maximum cannabinoids without any thermal degradation in the extract. This level of quality shall be achieved by playing with the temperature parameters and other physical process steps in extraction.
Clean Green Biosystems has developed an integrated cryo ethanol extraction process after a long research of 5 years. The extraction system comprises of ASME and cGMP complaint process equipment like Extractor, shell and tube heat exchanger, condenser, pumps, and accessories. The entire process shall be operated using a PLC-SCADA software. The system is fixed in an SS cladded skid.
The extractor is an SS 316 jacketed vessel with a high torque agitation system with FLP motor and a gearbox, whose RPM shall be adjusted by a VFD. The bottom of the extractor is detachable using a hydraulic power pack which helps in the simple disposal of spent cannabis materials. A recirculation line is available utilizing an FLP pump with VFD, to regulate the flow of miscella.
A suitable shell and tube heat exchanger is the part of the system, through which the ethanol moves into the extractor. Liquid nitrogen passes into the shell side of the heat exchanger which cools the ethanol to cryo temperature. This liquid nitrogen is recirculated using a liquid nitrogen transducer. The liquid nitrogen can also be passed to the jacket of the extractor to maintain the process temperature.
Frozen and size reduced cannabis plant material is charged into the extractor. The size of the cannabis plant material is critical in this case. Simultaneously the cryo ethanol is sent into the extractor. The programmed PLC will switch on the agitator at a specific time. After few hours of extraction, the recirculation starts as to ensure a highly efficient extraction. The integration of agitation and recirculation maximizes the extraction efficiency. Once the extraction is complete, the system comes to a standstill, and the recirculation pump collects the cannabinoids rich miscella in a tank. This miscella is taken for further processing.
To learn more about Clean Green Biosystems visit their website at www.cleangreenbio.com.