CO2 Extraction Technology: A Complete Technical Guide
Introduction to CO2 Extraction
Supercritical CO2 extraction has become one of the most popular methods for botanical extraction, offering a clean, tunable, and solvent-free process.
Understanding Supercritical CO2
When CO2 is heated above 31.1°C and pressured above 73.8 bar, it enters a supercritical state where it behaves as both a liquid and a gas. In this state, CO2 becomes an excellent solvent with tunable properties.
Key Parameters
- Pressure: 1,500-5,000 PSI typical operating range
- Temperature: 35-60°C for most cannabis applications
- Flow rate: Affects extraction speed and selectivity
- Time: Cycle times range from 2-8 hours depending on parameters
Advantages of CO2 Extraction
- No residual solvents: CO2 evaporates completely at room temperature
- Tunability: Adjust pressure and temperature to target specific compounds
- Safety: Non-flammable, non-toxic solvent
- Sustainability: CO2 can be recycled in closed-loop systems
- Regulatory acceptance: Widely accepted by regulatory bodies
Optimization Strategies
Subcritical vs. Supercritical
- Subcritical (lower pressure/temp): Better for terpenes and lighter compounds
- Supercritical (higher pressure/temp): Better for cannabinoids and heavier compounds
- Combined approach: Run subcritical first for terpenes, then supercritical for cannabinoids
Pre-Processing
- Properly dried and ground material improves extraction efficiency
- Target 8-10% moisture content
- Medium grind size (avoid powder)
Decimal CO2 Systems
Our LE Series CO2 extractors are designed for consistent, high-quality extraction with intuitive controls and full GMP compliance.
Explore CO2 equipment or request a quote.
FAQ
What is supercritical CO2 and why is it used for extraction?
When CO2 is heated above 31.1°C and pressurized above 73.8 bar it enters a supercritical state, behaving as both a liquid and a gas. In that state it becomes an excellent solvent whose strength can be tuned by adjusting pressure and temperature, which is what lets operators target specific compounds.
Is CO2 extraction safe?
CO2 is non-flammable and non-toxic, and it evaporates completely at room temperature, so finished extracts carry no residual solvent. It can also be recycled in closed-loop systems, which is part of why the method is widely accepted by regulators.
Should I run subcritical or supercritical CO2?
Subcritical conditions (lower pressure and temperature) are better for terpenes and lighter compounds, while supercritical conditions favor cannabinoids and heavier compounds. Many operators combine the two: a subcritical pass first to capture terpenes, then a supercritical pass for cannabinoids.
How long does a CO2 extraction cycle take?
Typical cycle times range from 2 to 8 hours depending on pressure, temperature, and flow rate. Parameter choices trade extraction speed against selectivity.
How should I prepare biomass for CO2 extraction?
Properly dried and ground material extracts more efficiently: target 8–10% moisture content and a medium grind size. Avoid grinding to a powder, which hurts flow through the extraction vessel.