Accuracy: Paramount for Cannabis Oil Extraction Equipment

December 2020 witnessed an event that granted legitimacy to medical cannabis. The United Nations (UN) voted to remove cannabis resin and cannabis from the list that defined the “most dangerous substances” under the 1961 Single Convention on Narcotics Drugs. Even before, many countries were legalizing or decriminalizing medical cannabis.

So far, so good. But then, it is the detail where the devil resides. For one, cannabis is not a monolith. It comes in two main varieties based on chemical composition. And, one of these is a banned narcotic. It is the thin dividing line between the non-narcotic and the narcotic that gives the former a bad name.

For this reason, selectivity is a paramount requirement for cannabis oil extraction equipment – to extract only the medically benevolent and legally permissible elements, not those that invite trouble from the law.

Chemical Considerations for Cannabis Extraction Equipment Companies

CBD or cannabidiol is the cannabinoid (element) of main interest in cannabis extraction on account of its medicinal properties. The opposite is true for THC or tetrahydrocannabinol, a psychoactive cannabinoid. THC too is blessed with some healing powers but is psychoactive i.e. it can cause intoxication – get you high.

It is the concentration of THC in cannabis and cannabis products (by dry weight) that determines its legal status:

• Hemp is cannabis with under 0.3% THC content. It is this variety of cannabis that is being increasingly legalized across the world for its medicinal and industrial applications.
• Marijuana is cannabis that contains 0.3% THC or more. A narcotic, marijuana is banned in most countries.

Extraction equipment has to draw out maximum CBD while leaving THC virtually untouched. This is important not just from the legal perspective, but also from the point of view of health and business. The lower the THC content, the lesser are the expenses associated with post extraction processing. And healthier is the product.

Processing & Extraction Methods of Medical Cannabis:

Various methods employed for extraction include:

• Cryogenic Ethanol Extraction utilizes ethanol at -40⁰C for extraction of cannabis oil from the finely milled raw material. The method reduces extraction time from hours to minutes, and eliminates one of the post extraction procedures.
• Supercritical Fluid Extraction (SCFE) passes a supercritical fluid (SCF) through ground raw material. Supercritical carbon dioxide (sCO₂) is the most popularly used SCF. Precise pressure control enables selective extraction.
• Solvent Extraction employs a solvent such as butane or hexane to first dissolve the required product from the raw material. The dissolved product is then separated out from the solvent. Because the solvent does not completely disassociate from the product, the extract has limited purity. 
• Hydrodistillation dissolves the product from raw material in steam or heated water. Distillation separates the two. The use of heat may distort the chemical composition of the product, thereby lowering its purity.
  

Specialized cannabis extraction equipment companies prefer SCFE and Cryogenic Ethanol Extraction set ups as these offer pure extraction. Cannabis product makers too prefer these equipment for the same reason, notwithstanding the high cost of these set ups.

Processing can be:

• Pre Processing that involves sorting, drying, and grinding of cannabis raw material to improve the yield of extraction.
• Post Processing includes multiple processes that refine the extract. In chronological order, these are:
• Winterization eliminates fats, lipids, and waxes from the cannabis oil. This procedure is not required for cannabis oil obtained via Cryogenic Ethanol Extraction. 
• Decarboxylation converts inactive acids into CBD and THC to improve the concentration of these cannabinoids.
• Distillation isolates CBD, flavonoids, terpenes, and THC based on their different boiling points.
• Chromatography is often employed as an alternative to distillation. Because it does use heat, the chances of thermal distortion are lowered. 
• THC Remediation is optional and is used by those producers who want to remove THC completely.
  

Summing up, the overall aims of processing and extraction methods of medical cannabis are:

• Maximize CBD.
• Eliminate THC, or at least minimize its concentration.
• Retain traces of flavonoids and terpenes which respectively provide the extract with a desirable flavour and aroma.
  

Analysis ofCannabis Oil Extraction Equipment: SCFE & Cryogenic Ethanol Extraction

SCFE uses a supercritical fluid (SCF) i.e. one whose pressure and temperature respectively exceed its critical pressure and critical temperature. The beauty of a SCF is that it can selectively extract the required product from the raw material at a certain pressure. When set to extract CBD, it will extract virtually no THC.

Following are the desirable features of SCFE equipment:

• Accurate pressure control for selective extraction.
• Intuitive HMI for ease of monitoring and control.
• Precise flow control to optimize yield.
• Smooth pressure drop management between Extractor and Separator.
  

Cryogenic Ethanol Extraction is a cool process, literally. At cryogenic temperatures i.e. between -150⁰C and -273⁰C, materials are extremely ordered. This explains the smooth extraction. Advantages of Cryogenic Ethanol Extraction include:

• Rapid as low temperature ethanol does not extract unwanted waxes and lipids that are otherwise removed from the extract via winterization.
• Scalable with the equipment available in various capacities.
• Economical because with a higher boiling point vis-à-vis butane (used in Solvent Extraction), its storage requirements are less exacting.
• Safe for it does not require high operational pressures. And its higher boiling point compared to butane’s makes it safer.
• Standardizable because cryogenic cooling is controllable and therefore more compatible with Good Manufacturing Practice (GMP).
  

Finally

Few are endowed with the gift to tell between virtually identical twins. As far as cannabis oil extraction is concerned, it is Cryogenic Ethanol Extraction and SCFE equipment that come armed with this capacity.