Supercritical Fluid Extraction Improved by Power Ultrasonics
Ultrasonic extraction alone or in combination with alternative extraction methods such as solvent extraction or supercritical CO2 extractors is successfully used to extract the full spectrum of cannabinoids from the cannabis plant (hemp and marijuana). In marijuana, the main cannabinoid constituent is Δ9-tetrahydro-cannabinol (Δ9-THC) with its well-known psychotropic effects. Other important cannabinoids with less or no psychotropic activity can be found in both, hemp and marijuana, and include cannabidiolic acid (CBDA), cannabidiol (CBD), cannabigerol (CBG), cannabichromene (CBC), cannabinol (CBN), and cannabicyclol (CBL), along with other C19 associated homologs.
Ultrasonically Improved Supercritical CO2 Extraction
The combination of high-power ultrasound and supercritical fluid extractors (SFE) is highly efficient and clean method to accelerate and improve mass transfer processes. Mass transfer between raw material (e.g., botanicals such as leaves, flowers, buds etc.) and the solvent (e.g., supercritical CO2) is the limiting factor during extraction processes. Due to the limited mass transfer, the extraction efficiency is reduced. To compensate for the lacking efficiency, either extraction time must be incresed or extraction yield has to be sacrificed.
High-power ultrasonication is a well-proven technology to intensify slow reactions by improving mass transfer between to phases. By intense vibrations, shear forces, and agitating turbulences, power ultrasound exposes the extraction raw material at a significantly increased rate to the solvent. This results in superior extraction yields and a reduced extraction time. Ultrasonication enhances the extraction efficiency of any type of supercritical fluid extractor:
- by increasing yield
- by shortening the extraction time
- by reducing the required pressure
- by improving overall production capacity
Ultrasonic enhancement of mass transfer in supercritical CO2 extraction processes can be easily realized by implementing a high-performance ultrasonic probe such as a Cascatrode into the supercritical fluid extractor. Hielscher Ultrasonics probes (also known as ultrasonic horns, sonotrodes) can be connected via standard flange sealing and are compatible for swedge lock connectors. This makes installation and operation simple and safe. As all Hielscher ultrasonicators known for their robustness and continuous performance, an once installed system is of low maintenance.
Hielscher ultrasonicators and probes are available for
- small scale / lab supercritical fluid extractors
- semi-industrial scale
- industrial scale
Case Study for Ultrasonically Enhanced Supercritical CO2 Extraction
Ginger Extraction: Balachandran et al. (2006) investigated the efficiency of ultrasonically assisted supercritical CO2 extraction using the Hielscher ultrasonicator UIP500hdT. They studied the influence of ultrasound on supercritical extraction using freeze-dried ginger. “The yield of pungent compounds from ginger is significantly increased under the influence of ultrasound, with improvements of up to 30% towards the end of the extraction period.” (Balachandran et al. 2006)
Read more about ultrasonic ginger extraction!
- intensify mass transfer during SFE
- increase extract yields
- accelerate SFE extraction
- easily handle high-pressures
- handle various raw materials
- be retro-fitted into existing SFE systems
- be flexibly installed
- be precisely controlled
- be remotely controlled
- be safely operated
High-Power Ultrasonic Extractors for Supercritical Fluid Extraction
Hielscher ultrasonicators can be easily implemented in any regular supercritical CO2 extractor in order to improve mass transfer and thereby increasing extraction yield.
The ultrasonic probes of the CascatrodeTM type are especially suitable for the integration into an CO2 extractor, since Hielscher cascatrodes offer a high surface area, which emits strong cavitation into the large tanks of CO2 extraction systems and can thereby process large volumes easily. Hielscher Ultrasonics’ robust and reliable industrial ultrasonic processors can deliver very high amplitudes. Amplitudes of up to 200µm can be easily continuously run in 24/7 operation. For even higher amplitudes, customized ultrasonic sonotrodes are available. The reliable continuous operation of high amplitudes as well as the robustness and low maintenance of Hielscher ultrasonic extractors make them the ideal equipment for implementation into R&D and commercial supercritical / subcritical CO2 extractors.
- continuously high performance
- 24/7/365 operation
- precise process control
- low maintenance
- safe and easy to operate
- remote browser control
The table below gives you an indication of the approximate processing capacity of our ultrasonicators:
|Batch Volume||Flow Rate||Recommended Devices|
|10 to 2000mL||20 to 400mL/min||UP200St, UP400St|
|0.1 to 8L||0.2 to 2L/min||UIP500hdT|
|0.1 to 20L||0.2 to 4L/min||UIP2000hdT|
|10 to 100L||2 to 10L/min||UIP4000hdT|
|n.a.||10 to 100L/min||UIP16000|
|n.a.||larger||cluster of UIP16000|
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Literature / References
- S. Balachandran, S.E. Kentish, R. Mawson, M. Ashokkumar (2006): Ultrasonic enhancement of the supercritical extraction from ginger. Ultrasonics Sonochemistry
Volume 13, Issue 6, Sept. 2006. 471-479.
- Yanxiang Gao, Bence Nagy, Xuan Liu, Béla Simándi, Qi Wang (2009): Supercritical CO2 extraction of lutein esters from marigold (Tagetes erecta L.) enhanced by ultrasound. The Journal of Supercritical Fluids. Volume 49, Issue 3, 2009. 345-350.
- E. Riera, A. Blanco, J. García, J. Benedito, A. Mulet, J. A. Gallego-Juárez, M. Blasco (2010): High-power ultrasonic system for the enhancement of mass transfer in supercritical CO2 extraction processes. Ultrasonics, 50, 2010, 306-309.
- Ai-jun Hu, Shuna Zhao, Hanhua Liang, Tai-qiu Qiu, Guohua Chen (2007): Ultrasound assisted supercritical fluid extraction of oil and coixenolide from adlay seed. Ultrasonics Sonochemistry Volume 14, Issue 2, Feb. 2007. 219-224.