As compression technology continues to advance, the applications and markets it’s used in also continue to evolve. Through expanding legalization and wider acceptance in medicinal practices, the cannabis concentrate market is a key driver in the compressed gas market – expected growth in the next three years is over 30% for the cannabis market as a whole.
Advancing high-pressure compression systems used in extraction processes are improving efficiencies and safety. Many compression systems are being designed to meet the high-pressure demands of supercritical CO2 extraction, making improvements to maximize operations and throughput.
To meet increasing demands, manufacturers must employ the latest technologies for clean, efficient cannabis oil extraction. Several extraction methods can be used to draw botanical oils:
While each method has pros and cons, supercritical CO2 extraction methods offer significant advantages to manufacturers through high yield, improved safety, and enhanced levels of purity.
Supercritical CO2 retains features of both gases and liquids making it the solvent of choice for the medical cannabis industry. In its supercritical state, CO2 is a unique solvent that can be customized, through adjustment of temperature and pressure, to extract very specific compounds, eliminating harmful residues and varying levels of purity that disrupt other extraction methods.
Safe, Standardized, and Cost-Effective Extraction
Beyond the tight controls and purity, supercritical CO2 extraction methods offer an opportunity for standardized production in multi-state or global companies regardless of differing regulations across jurisdictions.
While supercritical extraction systems may pose a higher upfront cost, they also offer significant advantages in comparison to combustible solvent extraction methods:
As regulations go into effect around vaping-related illnesses and the dangers of vaping product contaminants, further emphasis is put on both purity and controls. Today's legitimate extraction processes are safer than in the past and innovation in high-pressure systems have further increased reliability and safety.
Maximizing Efficiency of CO2 Extraction
During the extraction process, supercritical CO2 must be recirculated, extending run times. Depending on the extraction technique, secondary processing may also be needed on the oil. CO2 can require substantial secondary processing if the extraction is done quickly at high pressure. The lower the extraction pressure, the slower the extraction time, but less secondary processing or refining is required.
The CO2 is fed into the extractor vessels at pressures greater than 1,000 psi and temperatures greater than 90 degrees F, then recovered from the extraction vessel at approximately 250 psi, re-pressurized and heated until the desired results are achieved.
An example extraction process set-up.
A CO2 circuit is a mechanically and thermodynamically complicated system. Manufacturers use gas boosters, pumps, or a combination of the two to meet pressure requirements with maximum throughput and efficiency. With a broadening array of high-pressure solutions, including hydraulic and electric boosters that can reduce total production costs, manufacturers have new options in designing supercritical CO2 lines. High-volume manufacturers using supercritical CO2 extraction are standardizing around 5 gpm of liquid CO2, which is readily achieved with an electric booster such as Haskel’s Q-Drive.
Careful manufacturing process design and high-pressure system selection can significantly improve yield to meet rising market demands. As supercritical CO2 extraction technologies catch on, gas bottlers must meet rising demands to avoid a supply shortage. Their requirements for increased yield and efficiencies in gas compression mirror those of their customers.
Compressed gas companies can help meet demands by understanding and supporting customers’ manufacturing processes to increase their yield, purity, and quality control.
Haskel’s Q-Drive electric gas boosters are designed for clean, quiet, and efficient operation while delivering significant energy savings, allow greater process control, and improve reliability during the supercritical CO2 extraction process.