This New Tech Makes CBD And THC Extraction Faster: How Liquid Nitrogen Works

This article was originally published on Cannabis & Tech Today and appears here with permission.

The multi-billion-dollar CBD/THC industry continues its rapid growth and products are multiplying. Now, the ability to ramp up production to industrial scale while maintaining quality depends on using the most effective processes to extract cannabinoids like cannabidiol (CBD) and tetrahydrocannabinol (THC) from hemp and marijuana.

The conventional ethanol extraction process, however, places considerable limitations on the speed of production. For optimum efficiency, ethanol must be quickly chilled to -40° to -80°C for the best quality extraction. Traditional chilling techniques cannot quickly achieve or maintain these sub-zero temperatures. The result is additional processing steps and a lower-quality oil extract.

“The traditional freezing methods used in our industry only lower ethanol to about -40°C at best, and at higher volumes when you add warm plant material, the temperature rises 25 to 30 degrees. At those temperatures, you extract too much wax, and not the full spectrum of cannabinoids,” says Dave Schenk, former President of Speedy Grow Inc., a Colorado-based nutraceutical manufacturer that offers a wide variety of quality, natural stock formulations featuring high-quality CBD oil.

Fortunately, liquid nitrogen technology, established in pharmaceutical and medical applications, is now being used to design chillers specifically for CBD and THC extraction. The technology enables very fast, accurate, cryogenic temperatures along with expedited processing and enhanced product quality.

“To produce fully purified, high-value CBD and THC oil, the ability to use liquid nitrogen chillers to quickly bring ethanol to -80°C is a gamechanger for our industry,” says Schenk. “We cut extraction and distillation time in half by eliminating unnecessary reprocessing, while producing a significantly better product,” says Schenk.

Schenk, who has decades of experience in supplement manufacturing, discovered the technology while searching for a more efficient way to extract CBD from the hemp that Speedy Grow harvests. Common industry techniques at the time included freezing drums of ethanol in walk-in freezers or soaking jugs in dry ice for 12-24 hours. Hemp was sometimes pre-chilled in small coolers so it wouldn’t raise the temperature of the ethanol. However, these techniques were not adequate to run 1,500-2,500 lbs. of hemp that Speedy Grow wished to process daily.

“The walk-in freezers were not capable of bringing the ethanol down to the required temperatures and when you are manufacturing CBD in higher volumes, it is not practical to chill hemp biomass in a bunch of small chest freezers,” says Schenk. 

So, Schenk approached Reflect Scientific, Inc. RSCF, an Orem, Utah-based OEM that develops and markets innovative, proprietary cryogenic cooling technologies for the medical, biotechnology, pharmaceutical, and cannabis markets. The company holds more than 30 patents relating to the use of liquid nitrogen with low-temperature chillers, freezers, and refrigerated systems.

With Schenk’s input, the company manufactured Cryometrix chillers customized to the needs of the CBD and THC industry that circulate liquid nitrogen within the cooling chamber, enabling the rapid chilling of ethanol. Liquid nitrogen is an inert cryogenic fluid with a temperature of -196 °C. The chillers circulate liquid nitrogen within the chamber, allowing quick ethanol chilling to -80°C within an hour.

For high volumes, the L-80 Max can chill 120 gallons of ethanol down to -40°C in just 25 minutes, and -80°C in less than one hour. Compared to conventional methods, the rapid chilling process dramatically reduces cycle time and speeds production. 

To further ensure product quality, the L-80 Max provides state-of-the-art temperature and data logging, which can be easily accessed through a touch screen or downloaded to a computer. Temperature is adjustable from +20°C to -80°C with uniformity ± 1°C throughout.

“This is the only equipment that can rapidly take ethanol down to -80°C and keep it below the critical -40°C threshold throughout the extraction process,” says Schenk, adding that when the temperature of ethanol rises above -40°C, excess wax in the plant matter is extracted along with the oil, which must be filtered out during distillation. 

“In many cases, multiple reprocessing steps are required. So you have to get more chilled ethanol and go through the entire process, hoping that this time around, you will be able to keep the wax out. Most CBD and THC oil manufacturers are resigned to reprocessing the product multiple times, but it is much more efficient to avoid extracting any wax in the first place by keeping the ethanol below -40°C,” says Schenk.

According to Schenk, the Cryometrix liquid nitrogen chillers have significantly reduced time and labor required for extraction and distillation. 

“I cut extraction time in half using the Cryometrix chiller. I saved even more time in the distillation process. Overall, production is at least 70% more efficient with the system, which far offsets any cost for the equipment and the liquid nitrogen,” says Schenk.

Liquid nitrogen chilling also helped to improve product quality. Because there is a limit to the amount ethanol can absorb, achieving the optimal sub-zero temperatures keeps the wax in the plant material in solid form and allows more cannabinoids to be extracted.

_{Achieving the optimal sub-zero temperatures keeps the wax in the plant material in solid form and allows more cannabinoids to be extracted.}

“Testing showed that we were extracting a broader spectrum of cannabinoids,” says Schenk. “CBD gets all the credit, but many other cannabinoids do the heavy lifting. There are over a hundred different cannabinoids, and you also want to extract the CBDA, CBG, and others that have beneficial properties,” says Schenk.

To streamline implementation for manufacturers of CBD/THC products, Cryometrix provides a turnkey solution. This includes the insulated holding tank, cryogenic pumps to fill and drain the chilled ethanol, and all the controls for automatically chilling the liquid. The manufacturer only needs to provide liquid nitrogen and plug the system into a 110V outlet.

For those with lower extraction volumes, the company also offers a more compact unit, the L-80 Lite, which can chill 30 gallons to the same temperature range even faster than the larger unit with the same uniformity. The L-80 Lite is manually operated with a modular design that allows easy upgrades in the field with more features and automation as production needs increase.

Until recently, the CBD/THC industry’s production was limited by an inability to sufficiently chill ethanol to the low temperatures required for more efficient processing. Today, by utilizing proven liquid nitrogen technology, CBD manufacturers can dramatically improve not only their processing speed but also product quality. 

“Liquid nitrogen chiller technology is extremely unique, and most of the CBD industry still has no idea it even exists. Manufacturers who take advantage of it will gain an edge over the competition in the marketplace,” concludes Schenk.