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Supercritical fluid extraction (SFE) is the process of separating one component (the extractant) from another (the matrix) using supercritical fluids as the extracting solvent. Extraction is usually from a solid matrix, but can also be from liquids .
Supercritical fluids have found application in a variety of fields, ranging from the extraction of floral fragrance from flowers to applications in food science such as creating decaffeinated coffee, functional food ingredients, pharmaceuticals, cosmetics, polymers, powders, bio- and functional materials, nano-systems, natural products ...
Supercritical fluid chromatography (SFC) [1] is a form of normal phase chromatography that uses a supercritical fluid such as carbon dioxide as the mobile phase. [2] [3] It is used for the analysis and purification of low to moderate molecular weight, thermally labile molecules and can also be used for the separation of chiral compounds.
2 is used as an extraction solvent, for example for determining total recoverable hydrocarbons from soils, sediments, fly-ash, and other media, [7] and determination of polycyclic aromatic hydrocarbons in soil and solid wastes. [8] Supercritical fluid extraction has been used in determining hydrocarbon components in water. [9] Processes that ...
Supercritical fluid extraction is a relatively new technique for extracting fragrant compounds from a raw material, which often employs supercritical CO 2 as the extraction solvent. When carbon dioxide is put under high pressure at slightly above room temperature, a supercritical fluid forms (Under normal pressure CO 2 changes directly from a ...
They key step is the use of supercritical fluid extraction to remove water from the gel while maintaining the gel structure, which is typically done with supercritical carbon dioxide, [45] as NASA does. [23] The resulting aerogels are very effective thermal insulators because of their high porosity with very small pores (in the nanometre range).
Past this point, the supercritical fluid is converted into the gaseous phase upon an isothermal de-pressurization. This process results in a phase change without crossing the liquid-gas phase boundary. This method is proven to be excellent at preserving the highly porous nature of the solid network without significant shrinkage or cracking.
It is called supercritical fluid. The common textbook knowledge that all distinction between liquid and vapor disappears beyond the critical point has been challenged by Fisher and Widom, [8] who identified a p–T line that separates states with different asymptotic statistical properties (Fisher–Widom line).