Cannabis has already travelled far from the bud. However, a new production technique is now hitting the commoditised world of weed. It is called distillation. It is also very likely to be the future of commercial marijuana.

Distillate – in other words, cannabinoids that have been distilled from concentrate or plant matter – has arrived. Distillation is a technique for creating cannabis extracts that are pure on a molecular level. It is possible to isolate specific cannabinoids. It is also possible to create odourless and tasteless THC (or CBD) that is 99% pure concentrate.

This is the next stage of cannabis science. And it is likely to show up near you, no matter if you are a recreational or medical user. This technology is very likely to catalyse some major changes worldwide.

What is cannabis distillation?

Cannabis distillation is a post-processing extraction technique done subsequent to an initial solvent-based extraction.

In practice, and by way of example, the raw oil (sometimes referred to as “crude” oil) from the cannabis plant will first be extracted via the use of a PX1 or PXP system. Depending on a number of factors, that crude oil will have a THC/CBD concentration of 60-80%.

What is not THC and CBD in the crude oil will be a blend of flavors and smells, known as terpenes, and a variety of other plant-based components from vitamins, antioxidants and additional consumable substances.

In order to further purify the oil, it will then be subject to the distillation process with a specialized commercial distillation unit such as the CDU 1000. The distillation process isolates specific compounds, such as THC and CBD, thereby producing a refined oil (or “distillate”) of over 90% purity.

The remaining terpenes and other non-THC/CBD compounds will have an insignificant effect on the flavor and smell of the product. By targeting THC and CBD, for example, one can see how flavor, smell and potency may not be controlled by the producer.

The Basics of Cannabis Distillation

Let’s take a look at how distillation works. First, let’s consider the basic components of the cannabis plant:

1. Cannabinoids – These are extracted from the cannabis plant (phytocannabinoids), with the two most prominent being cannabidiol (CBD) and tetrahydrocannabinol (THC). Both of these have medicinal qualities, although only THC causes intoxication. Maximizing the concentrations of these cannabinoids is the ultimate goal of cannabis distillation or THC distillation (if THC is the cannabinoid being targeted).
2. Terpenes – These are aromatic oils that are secreted by the same glands as CBD or THC. Over 100 different kinds of terpenes have been identified in the cannabis plant, with each strain having a unique composition and combination of terpenes. These also enhance or complement the medicinal properties of the cannabinoids.
3. Flavonoids – These are frequently overlooked in discussions about cannabis and its more than 200 bioactive compounds. However, flavonoids account for approximately 10% of these compounds with over 20 varieties existing in various strains of the cannabis plant. Furthermore, these are also what give the plant and its extracted products their distinct flavor.

These three different chemical components have different properties that play a role in the distillation process, with the most important being their boiling points at standard pressure (1 atmosphere). This boiling point can also be referred to as a vaporizing point (because the compounds are being vaporized). Due to these properties, a delicate process of extraction is applied to rip off the layers of chemicals and “distill” down to the good stuff: cannabinoids. Ultimately, that’s what this is all about!

Consider the following boiling points (at standard pressure of 1 atmosphere):

1. THC – 157 degrees Celsius / 315 degrees Fahrenheit.
2. CBD – 160 to 180 degrees Celsius / 320 to 356 degrees Fahrenheit.
3. Terpenes – Depending on the precise compound, anywhere between 119 C / 246 F and 157 C / 315 F.
4. Flavonoids – Depending on the precise compound, anywhere between 134 C / 273 F and 178 C / 352 F.

Why are these boiling points important? Because the process of distillation is fundamentally a process of vaporization and condensation. In other words, an apparatus that heats a solution to a specific temperature will vaporize some specific compound (say, THC in this example) without destroying it. These vapors will then be condensed, resulting in a THC-rich final product.

Consider the following purification process: you take a volume of water, heat it to its boiling point (100 C / 212 F) until it turns into water vapor. This vapor is then rapidly cooled, causing condensation, and the water has been purified. In other words, distillation is fundamentally a process of purification. If you want pure and potent THC or CBD distillate, then distillation is the way to go.

How does cannabis distillation work?

In its most basic form, distillation is accomplished by using an apparatus that heats a solution to a specific temperature to vaporize a specific compound of a solution without destroying it, then condensing the vaporized compound back into a liquid.

A simple example of this is the process of purifying water. Heating water to 100°C (212°F) will vaporize H₂0 molecule, leaving behind any undesirable compounds. Rapidly cooling this water vapor causes it to condense into distilled, purified water.

The same principle used in water distillation can be applied to cannabis. A short-path distillation unit is a one of the most common apparatuses used in cannabis distillation.

Short-path distillation units have three major components: a boiling flask, a condensing head, and a collection flask. The cannabis compound being distilled is heated in the boiling flask. The vapor then passes through the condensing head (turning the vapor to a liquid) and collects in the collection flask, thereby isolating the THC and CBD components.

Various Distillation Methods

There are three essential vacuum distillation methods that processors apply. These include short path, wiped film and fractional.

1. Short-Path – In this distillation, a specific apparatus that has a multi-position receiver separates the components. Under vacuum, the oil is then heated in a flask, generally with a short path distillation attachment. Using a recirculating chiller, the condenser is then cooled to allow cooling for condensation of the particular component vapors. When the vapor temperature rises, it indicates a new mixture or compound fraction. By adjusting the multi-position receiving flask, different fractions of CBD, THC, and terpenes are isolated.
2. Wiped Film – Wiped film distillation is slightly different from short path distillation, in that it can operate in continuous or batch modes. The oil is poured on a heated vertical cylinder while under vacuum. As the oil is introduced to the cylinder, it comes across rollers or rotating wipers that develop a thin line on that heated surface. A certain long and slender condenser located in the middle of the distillation process is cooled with the recirculating fluid and, in turn, condenses the vapor. The receiving vessels collect the produced condensate, as well as the high-temperature residue at the apparatus’s bottom. A specific recirculating heater enables temperature control of the outer jacketed wiped film body and the feed container. Refrigerated circulators are responsible for cooling the vacuum trap and the condenser. Process optimization of the temperatures, vacuum, and the feed rate must be carried out to achieve the most suitable component composition in the specific distillate. This method minimizes the oil’s exposure time and can enhance productivity if it is conducted in a continuous mode.
3. Fractional – Fractional distillation implements a longer fractionating column that is built between the condenser apparatus and the vessel with heated oil. This can comprise of different types of columns (Oldershaw, Vigreux, etc.), allowing finer isolation of the components. The extended length of that fractionating column causes the vapor to eventually equilibrate with the liquid state; therefore, allowing refined isolation of the components.

Conclusion

Irrespective of the vacuum distillation method applied, the distillation process might require to be repeated until the most suitable composition, as well as purity, is achieved. We hope that you have gained more insight into the best techniques you can make use of to improve the manufacturing of your cannabis product.