Estimation of the density of co /organic solvent systems with peng-robinson equation of state

Supercritical fluids are the high density fluids in the state beyond the critical temperature and pressure. They have gas-like as well as liquid-like properties. In recent years, many attempts had been made to apply the supercritical fluids as alternative solvents and/or reactants. Among these fluids, supercritical water, carbon dioxide and alcohols (methanol and ethanol) have been attracting much attention from their environmentally benign, chemically stable natures. In particular, from its low critical conditions, non reactive and non-toxic natures, and the low price, supercritical carbon dioxide (scCO­2) have been regarding as a promising solvent, and is expected to be applied to various industrial fields such as extraction, drying, polymer processing, and particle synthesis. To design these processes, physical properties of the solvents are the essential. A physical property measurement under high pressure requires specialized apparatus and takes up much time. Therefore, limited numbers of data were reported. Since many processes are mixture systems, the physical properties data of mixtures under high pressure are also required. However, from the stand points of cost as well as time, to measure all of the data is impossible. Thus, establishment of the estimation method with a high accuracy is inevitable.