Supercritical fluid extraction systems use carbon dioxide or water in a supercritical fluid state to dissolve and extract materials. Supercritical fluid extraction (SFE) is an extraction process that uses supercritical fluids (SCF) as solvents. When fluids are taken above their critical temperature and critical pressure, they enter a supercritical fluid state. At this supercritical state, a fluid’s physical properties are in-between those of a gas and a liquid. The gas-liquid coexistence curve is known as the boiling curve. The density of can be changed by varying pressures of the fluid. When compressed at high temperatures, supercritical fluids can have a density ranging between that of gasses to liquid-like states. Supercritical fluid extraction systems are used to manipulate the pressure and temperature of the fluid (which acts as a solubilizer) for selective extraction.
Carbon dioxide is the most widely used fluid in supercritical fluid extraction systems. CO2 is safe, has appropriate physical compatibilities, offers environmental friendliness and inexpensive pricing, and is widely available. Other fluids may also be used in supercritical fluid extraction systems. Unlike traditional solvent-based processing systems, supercritical fluid extraction systems don’t use any harmful or toxic solvents. By using CO2, water, and safer fluids, these extraction systems have relatively low operating costs and can reduce post-processing steps, clean up, and safety assurance measurements.
Supercritical fluid extraction systems are used for extraction, fractionation, purification, reaction, coating, and cleaning. They are used widely in many industries, including natural products and medicines, pharmaceuticals, food processing material science, electronics, textiles, and cleaning. Supercritical fluid extraction systems are available with many features. Examples include the ability to pump gas or liquid carbon dioxide. Flexible multi-purpose systems and systems with a modular design, skid-mounting, PC-based control system, controllable pressure, and digital temperature controls are also available. Additional features for supercritical fluid extraction systems vary by manufacturer, model, and application.
Options for supercritical fluid extraction systems may also include recycling, counter current column, custom extraction and reaction vessels, co-solvent addition module, and a pre-heater. Supercritical fluid extraction systems are also available in process-scale or pilot-scale models. Other options may also be available for supercritical fluid extraction systems through certain manufacturers.