Supercritical fluid (SCF) is a fluid whose temperature and pressure are higher than its critical value at the same time.
SCF has unique properties. Its density is close to that of liquid, and its diffusion coefficient and viscosity are close to those of gas. Not only does it have an extraction ability equivalent to that of liquid solvents, but also the mass transfer rate of supercritical fluids is much greater than that during chemical reactions and separations. The rate in the liquid state, especially near the critical point, a small temperature or pressure change will cause the properties of the supercritical fluid (such as density, viscosity, dielectric constant, diffusion coefficient, and solvation ability, etc.) to change significantly, so it can Continuously adjust its physical and chemical properties by changing temperature and pressure to achieve efficient separation and reaction under specific conditions.
Since the 1960s, supercritical fluid technology based on the characteristics of supercritical fluids has developed rapidly.SCF technology mainly includes: supercritical (fluid) extraction, supercritical (fluid) chromatography, supercritical fluid) micronization, supercritical Chemical reactions under conditions (such as chemical reactions in supercritical carbon dioxide, supercritical enzyme-catalyzed reactions, various chemical reactions in supercritical water, especially supercritical water oxidation technology, etc.), and other supercritical fluid application technologies expanded in recent years (Such as supercritical dyeing, supercritical cleaning, supercritical drying and supercritical spraying, etc.).
Relevant academic organizations have been established internationally.International and regional conferences on supercritical fluids are held regularly.A large number of papers, patents and monographs are published every year.Many SCF technologies have entered the pilot phase from laboratory research and development. Part of the supercritical fluid technology process is moving towards industrialization.SCF technology has been applied in many fields such as chemical industry, energy, pharmaceuticals, food, spices, analytical chemistry, etc. and penetrated into new areas such as functional materials, biotechnology, and environmental pollution treatment technologies, which has become the current international Scientific and technological development frontiers and research hotspots.
With the continuous development of SCF technology, this green technology will definitely produce huge economic and social benefits.