Rotary Evaporation Techniques For Cannabis Processing

With the cannabis market raking in $6.7 billion in 2016 in the U.S. and Canada and the market expected to hit $20.2 billion by 2021, processors are looking for the best ways to increase their product quality and grow profit margins.

With a predicted compound growth rate of 25%, the market is expected to be bigger than even the dotcom boom, according to Forbes.com.

To produce the highest-quality products, processors are looking to more traditional methods of extraction and isolation. Using techniques long established in the botanical, chemical and distilled spirits industries, cannabis processors have several options to improve their manufacturing techniques.

Here’s a look at how processors can use rotary evaporation to better isolate the extracts and components:

Applying Rotary Evaporation To Cannabis Processing

A fixture in many labs, the rotary evaporator is a common tool for solvent removal. The process allows the solvent to be removed in a controlled manner under vacuum.

It’s also easily scalable, ranging from smaller bench top flasks up to 5 liters to pilot scale, using flasks of 20 liters and more. This flexibility makes it very adaptable when processing cannabis.

How use rotary evaporator in cbd oil extraction process?

Cannabis extracts require lower evaporating temperatures to minimize thermal decomposition, so we need to guarantee the process must allows the solvent to be removed in a controller manner under vacuum. This is why rotary evaporator is an idea solvent removing equipment during cbd oil extraction process.

Rotary evaporator whole set should include rotavapor, vacuum pump, vacuum controller and chiller.

It’s better to fill your cbd extracts sample in evaporation flask to 50% volume, power on vacuum pump and vacuum controller, the the pressure is reduced in rotary evaporator, the boiling point of the solvent (enthanol) is lowered, we could set and control an approprite vacuum to evaporation system lowers the boiling piont,so as to miniminze thermal decomposition of cbd extracts.

The water bath / oil bath of rotary evaporator could be started heating to 30-40℃, power on the chiller circulating bath, to control the condenser temperature, which could set to -10℃ to 0 ℃. Please wait the water bath and condenser temperature have reached your set points, the evaporation flask of rotary evaporator can start rotating from 150-200rpm. You will find a thin film on the upper surface of glass flask, which could increase the solution area and enhance the solvent evaporation rate.

During this process, suitable vacuum system is very important. When use rotary evaporator in cbd oil extraction process, ethanol is the common solvent in cbd extracts, in order to achieve a better target, we could set the vacuum to achieve an ethanol vapor temperature of 15-20℃.

Compared with wiped film evaporator, rotary evaporator is more economical for cbd oil solvent removal, and for rota evaporator, it’s very easily scalable, 1L, 3L, 5L, 10L, 20L, 50L, 100L Lab – Pilot – Industry wide capacity range, such as 50L rotary evaporator, you could choose 5L, 10L, 20L, 30L evaporation flask, this flexibility makes it very adaptable when processing cannabis.

Things To Watch For When Using Rotary Evaporators

While it may be tempting to try to tweak the process by increasing the evaporation rate by lowering the vacuum and/or increasing the water bath temperature, this will cause capacity overload on the condenser. Doing this actually causes the evaporation rate to exceed the condensation capacity of the recirculating chiller.

This causes ethanol vapor to pass through the condenser and into the vacuum pump. Cannabis extracts require lower water bath temperatures to minimize thermal decomposition. So the condenser temperature of -10°C to 0°C will require a chiller with adequate cooling capacity at those low temperatures.

There are other ways to increase throughput while still maintaining quality. There are a variety of options for automatic vacuum control and refilling accessories, both manual and automated, that can be added to rotary evaporators.