ABSTRACT
Solvents are used in large amounts in the chemical, pharmaceutical, food, and naturalproduct industries. In the search for environmentally friendly solvents, increasing attention is being paid to supercritical fluids (SCFs) for a wide variety of applications. For instance, supercritical solvents are used in extractions, material processing, micronization, chemical reactions, cleaning, and drying, among other applications. SCFs and near-critical fluids add a new dimension to conventional (liquid) solvents: their density-dependent solvent power. The density of SCFs can be easily tuned to the process needs, with changes in temperature, pressure, and/or composition. Other important properties of SCFs are their very low surface tensions, low viscosities, and moderately high diffusion coefficients.
