Using Supercritical Fluids for Solid Particle Production with Suitable Size Distribution

In many of chemical processes, the narrow and suitable size distribution for solid products and raw materials is necessary. Traditional processes such as crushing, milling and drying have problems like high energy consumption, solvent residue in product as well as thermal decomposition of product. Therefore, research about alternate methods instead of traditional procedures is of interest the researchers. One of these alternatives is the use of supercritical fluids. The supercritical fluids are used for solid particle production with small size and narrow size distribution using different processes with different roles. Rapid expansion of supercritical solution (RESS) method can be used to produce particles which have significant solubility in supercritical fluid. In supercritical anti-solvent (SAS) process, pressure term is more dominant; however its problem is solvent residue in the product. The procedures of the gas-saturated solution (PGSS) and the depressurization of expanded liquid organic solution (DELOS) processes are different with the previous mentioned methods. These two processes do not use advantage of supercritical fluid properties as solvent or anti-solvent, but they use the large cooling effect of supercritical fluid when expansion occurs suddenly.