This is to introduce the vacuum drying process in CBD extraction and vacuum pumps used for this process.
Industrial Hemp is cannabis with a THC (tetrahydrocannabinol) content of less than 0.3% (or 0.2%, depends on the regulations of different countries). Cannabidiol (CBD), which is derived from THC and mitigates the psychoactive effects of THC, has high value for industrial and medical use. In CBD extraction from industrial hemp, vacuum drying is an indispensable process, which directly affects the quality of CBD.
Function & legality
CBD can be used in treating various physical and mental health issues such as anxiety, pain, inflammation, seizures, etc. In over 50 countries it’s now legal to purchase and consume CBD oil and related products. The legality stimulates the market growth greatly. The CBD market in America for example, is increased from 90 million dollars (2015) to 2.1 billion dollars (2020).
The CBD extraction process is complex, which includes harvesting, drying, crushing, extracting and vacuum drying. Vacuum drying is a technique that uses a vacuum pump to displace air and vapor in a chamber and evaporate excessive water from the material by heating conduction.
Currently the CBD is commonly made by solvent extraction or CO2 extraction. Both process methods require a pollution-free vacuum drying environment. High quality CBD means high profit. The reference price for 99% pure CBD is 8,000 dollars per kilogram and the price is 10 times more for the one with a purity with 99.99 percent .
A rotary vane vacuum pump is usually used to in the vacuum oven to finish vacuum drying. However, it’s necessary to fill vacuum oil into such pump, for sealing and lubrication purpose. The possibility of oil return, whatever how tiny that risk is, may contaminate the material severely. The alternative as a better solution in recent years, is to use a scroll dry pump. It’s a sophisticated pump and no oil is required during operation, which ensures the CBD purity although the cost is much higher.