(525g) Prediction of Solid – Liquid – Gas Equilibria for Carbon Dioxide + Organic Compound System Using Peng-Robinson Equation of State and GE Type Mixing Rule

Particle micronization using supercritical fluids have been drawing increasing interest due to the relatively mild operating temperatures and non-toxicity of product formed. To design and operate such processes, accurate modeling of the system’s phase equilibrium is required. In this work, the solid – liquid – gas equilibria for supercritical carbon dioxide + solid organic compound systems were predicted by Peng-Robinson equation of state (PR EOS) and excess Gibbs free energy (GE) type mixing rule. The GE type mixing rules tested were the Modified Huron – Vidal (MHV1) and the Linear Combination of Vidal and Michelsen (LCVM) mixing rules. Activity coefficient models using molecular surface charge density were applied for the MHV1 and LCVM mixing rules. Different model combinations of activity coefficient model, combinatorial term and mixing rule were applied to several carbon dioxide + solid organic compound systems for solid – liquid – gas equilibrium calculation.　The organic compounds investigated were classified into three classes: aromatic hydrocarbons, organic alcohols and organic acids. The effects of mixing rule and activity coefficient model on the prediction performance of the solid – liquid – gas equilibria were investigated.