As in the extraction process, the distillation process that is used to fully purify CBD/THC oils requires closely controlled temperature, pressure and source material feed rates to ensure that the necessary interactions produce a high-quality finished product with characteristics that generate the highest possible value.
The most common pieces of equipment are wiped film, molecular short-path stills. In this approach, the feedstock of oil is fed into a jacketed vessel that is often heated with an oil circulating TCU to achieve temperatures up to 343°C (650°F), though the typical distillation temperature range is 130 -180°C (266-356°F). In these systems, the feed stock is distributed on the evaporation chamber wall with a special wiper. The resulting thin film allows the more volatile terpenes to evaporate through the top of the chamber into their own external collection vessel, while the CBD/THC is collected along a TCU controlled central condenser unit which is cooler (typically 60-70°C / 140-158°F) than the evaporation chamber and serves to attract the cannabinoid vapor. The final step in the process is solvent removal, which is accomplished in a separate, external cold trap, which is also temperature controlled with a chiller.
Once the extraction process is complete a processor is left with “crude extract” that is 55-75% cannabinoid and that may in some instances, be sold without any further processing. For the majority of processors however, further separation of the remaining elements is necessary to obtain fully purified, high value CBD/THC oil.
Distillation Process – Temperature control consideration
Temperature control is necessary throughout all the steps in the process, but precise extraction chamber temperature control is absolutely essential to managing final product quality and characteristics. This high level of control must also be replicable from one batch to another and in fact on a continuing basis over a large number of batches. Controlling temperature to within .275°C (.5 °F) is a standard that permits a consistent finished product. It is also important to note that repeatability, in addition to accuracy is extremely important for producers as it allows them to replicate the process over time, and thus insure consistent product quality.
Current extraction processes include CO2, butane or propane, and ethanol. In each of these methods, the extraction agent is cooled down to temperatures that can reach -80°C (-176°F) and then compressed until it is liquefied. The temperature reduction is achieved using a chiller, which can be a standard piece of equipment or a custom unit designed to meet unique temperature profile requirements.
Delta T Systems – Your partner in Pure Temperature Control
For CBD or THC extraction and distillation temperature control, Delta T Systems has the experience, expertise and capability to give processors and OEM equipment manufacturers standard or custom equipment to meet all aspects of the process’ requirements. All systems are designed for process repeatability. Our equipment lowers production costs, improves temperature accuracy, and delivers long lived quality and ease of maintainability.
A distillation process is then conducted to complete the separation of the remaining elements and produce the purest possible CBD or THC oil. It is worth noting that even though a source material has been winterized, as much as 40% of the remaining feedstock may consist of undesirable materials. Also, in the case of ethanol extraction, ethanol must then be evaporated to separate it from CBD/THC components.
What is CBD distillate?
Short path distillation
All of these formulations are reliant on a producer’s ability to purify each of the plant components through distillation. This way, any select combination of cannabinoids and terpenes can be created for a distinctive product tailored to the needs of the consumer. From the standpoint of a manufacturer, this is a crucial part of any cannabis market.
Falling film distillation
Similar to rotary evaporators, falling film distillation equipment is great for solvent removal and uses lower viscosity oils. This occurs by allowing the oil to drain down the inside of a heated column. This continuously creates a thin film on an evaporative surface before being collected on a chilled condenser.