CO2 is emerging as a spotlight solvent in the extraction of essential oils, spanning multiple industrial fields from medicine to food, beverage, perfumery, and recreational applications. Supercritical fluid is a phase of matter in which a substance maintains the properties of both gas and liquid. This is ideal for use as a solvent for several reasons:
•The density remains relatively high, up to the density of liquid, which is ideal for carrying essential oils.
•The viscosity remains relatively low, and cannot reach liquid levels of viscosity. This is ideal for moving oils through the medium.
•The high pressures necessary for a supercritical state ensure that the oils are efficiently pressed out of the botanical sample.
How it Works?
The closed loop system drives the flow of the carbon dioxide through a botanical sample using a gravity fed solution. The flow is enabled by a heater-condenser pair which takes liquid at the bottom of the loop and adds sufficient heat to evaporate the CO2, thereby leaving the oil at the bottom of the collection well. The vapor expands up into the chilled piping, where enough energy is taken out of the vapor to condense the gas back into liquid CO2. The liquid flows down through the sample, carrying out essential oils from the modular chamber down to the heater. Additionally, the flow of liquid creates a siphon-like effect, pulling gas from the vapor pipe into the condenser loop, so the system maintains some flow inertia.