Supercritical carbon dioxide systems for sustainable and efficient dissolution of solutes: a review

Green chemistry aims at replacing toxic solvents by safer solvents such as supercritical carbon dioxide (scCO₂), which displays zero surface tension, outstanding transport properties, high diffusivity, and tuned solubilization by changing the pressure and temperature, or adding cosolvents. Nonetheless, the practical application of scCO₂-based technologies under supercritical conditions requires sophisticated systems for optimal operation. Here, we review scCO₂-based systems with focus on dyeing, extraction, chromatographic, and cleaning systems. All scCO₂-based systems consist of a CO₂ supply and pump part, a cosolvent providing part, and a parameters controlling part, yet there are different reaction vessels depending on solute types and practical functions. Developing more normalized, intelligentized, and durable scCO₂-based systems should render the scCO₂-based technologies be more economic, controllable, flexible, and suitable for wider applications.