Guide to Extraction Methods and Co2 Process
What is CO2 Extraction, and How Does it Work?
CO2 extraction is widely used in various industries, from essential oils to coffee decaffeination, one of the most renowned and successful industrial applications of CO2 extraction. Beyond coffee, this method can extract essential oils and compounds from numerous botanical sources.
CO2 extraction is commonly utilized in the supplements industry to obtain essential oil extracts. For example, hops, used in brewing beer, undergo CO2 extraction to capture the bitter flavors essential for beer production. This technique helps preserve and blend these flavors for consistent results.
A key area where CO2 extraction shines is hemp extraction, particularly CBD oil from hemp biomass. The process works by pressurizing carbon dioxide under specific temperature conditions to pull the desired cannabinoids from the plant. When CO2 reaches its supercritical state—achieved by carefully balancing pressure and temperature—it becomes an effective solvent for extracting high-quality cannabinoids. This supercritical CO2 extraction process ensures thorough extraction while maintaining efficient throughput, making it essential for producing CBD oil.
Understanding the CO2 Extraction Process
To understand how CO2 extraction systems work, let’s explore three key steps that demonstrate how CO2 is used as an extraction solvent under supercritical conditions:
- Supercritical CO2 extractors utilize carbon dioxide (CO2) at elevated temperatures and pressures to extract soluble compounds from natural products. It becomes a supercritical fluid when CO2 is heated above its critical temperature (31ºC) and pressurized above 1071 psi. This supercritical CO2 has enhanced capabilities for dissolving non-polar compounds, making it ideal for extraction processes.
- Under supercritical conditions, CO2 behaves similarly to liquid solvents like hexane, offering selective solubility. This characteristic allows efficient targeting and extraction of desirable cannabinoids, such as CBD. Increasing the temperature and pressure makes the extraction process even more efficient, reducing the time needed to extract oils.
- As the supercritical CO2 passes through the biomass, it dissolves non-polar compounds into the fluid. After extracting the desired cannabinoids, the CO2 is returned to a gaseous state, leaving behind a “crude oil” mixture containing CBD, terpenes, and residual plant materials. This crude oil is then ready for further refinements, such as distillation and product formulation.
This efficient method makes CO2 extraction a preferred choice for obtaining high-quality CBD and other essential oils.
Is CO2 Extraction Safe?
When considering the safety of CO2 extraction, this method stands out as having a significantly lower risk profile than alternative solvent-based techniques. CO2 is a non-toxic, naturally occurring compound. When used in extraction, it presents minimal risks to workers, consumers, and the environment. Unlike hydrocarbon solvents like butane or propane, CO2 does not possess flammability risks, reducing potential accidents in production facilities.
Residual-free High-quality Outputs
Furthermore, because CO2 extraction can occur at lower temperatures than other methods, it safeguards sensitive compounds within a product. This preservation of molecular integrity translates to a higher-quality output free from the residual solvents that might remain after the use of more volatile substances.
Safer Than Other Methods
CO2 extraction significantly minimizes exposure to harmful chemicals compared to solvent-based extraction methods. Solvent-based methods often require handling hazardous chemicals, which can pose health risks if ingested or inhaled. In contrast, CO2 evaporates entirely once extraction is complete, leaving behind no toxic residues.
- Butane and propane extractions raise concerns about explosive risks as these gases are highly flammable.
- Alcohol extractions, while less flammable, may contaminate end products if not properly purged.
- Conversely, CO2 extraction systems operate in a closed loop, mitigating the risk of accidental exposure or environmental harm.
Despite these advantages, equipment used for CO2 extraction needs to withstand high pressures and, therefore, adhere to stringent safety standards. Facilities invested in this technology must implement routine inspections and maintenance checks to ensure operational integrity and the continued safety of their staff and consumers.
What is the Difference Between Subcritical and Supercritical CO2 Extraction?
CO2 extraction can be performed at either supercritical or subcritical temperatures. This allows for beneficial variables based on a liquid’s viscosity—whether a specific method requires more or less heat to speed the extraction process without harming the purity of the end product.
Differ in Temperature and Pressure
Subcritical and supercritical CO2 extraction differ primarily in temperature, pressure, and solvent properties. Supercritical CO2 extraction occurs when CO2 is heated above its critical temperature (31°C) and pressure (1071 psi), creating a supercritical fluid with gas-like and liquid-like properties. This enhances its ability to dissolve a wide range of compounds, making the process faster and more efficient and yield higher amounts of essential oils or cannabinoids. However, post-processing is often required to remove unwanted materials like waxes.
In contrast, subcritical CO2 extraction operates below the critical temperature and pressure, keeping CO2 in a liquid state with lower solvating power. This results in slower extraction and lower yields but offers greater selectivity for lighter, volatile compounds like terpenes, preserving delicate flavors and aromas with minimal post-processing. While supercritical extraction is favored for large-scale, high-yield extractions, subcritical extraction is preferred when purity and compound specificity are essential.
Benefits of CO2 Extraction
We’ve seen how supercritical CO2 extraction systems work. Let’s see why many industries prefer CO2 as their extraction process.
Clean and Green
CO2 extraction systems are the cleanest for consumers, producers, and the environment. Because CO2 is a natural solvent, a producer can more readily become a certified organic manufacturer. It also eliminates the potential risk of chemical residuals and contamination that are of concern with ethanol extraction. This natural solvent also eliminates unwanted environmental emissions, making it the “clean and green” solvent in extraction systems.
Significantly Lower Operating Cost
CO2 extraction is much less expensive than ethanol extraction systems for producing a kilogram of oil. For example, CO2 is 4 cents a pound compared to ethanol, which is over $4 per pound. Solvent losses with ethanol extraction systems are a key cost contributor and drive a major increase in operating costs compared to CO2 extraction systems. For example, 1-ton-per-day ethanol extraction systems would see an estimated $1,260,000 in solvent costs in just one year compared to just $42,048 using CO2.
Safest Products for Consumers
Because no chemical denaturants or volatile solvents are left over in a ScCO2 product, it is undoubtedly the safest extraction process for creating a safe product for consumers. A natural and organic solvent means customer assurance without sacrificing product potency, making CO2 extraction systems the best choice for product formulation.
The Best Supercritical CO2 Extractors
With so many extraction methods in the market, there are many to choose from. However, with your newfound knowledge of CO2 extraction, you can see it is the superior choice. Get your hands on the best Supercritical CO2 Extraction Machines with the highest throughput, most cost-effective, and most efficient production in the market!
