Equilibria Data for the CO2 + Ethanol + Ketoprofen Systems – Experimental and Modeling

Abstract

This study investigated the solid–fluid and vapor–liquid equilibrium of varying the molar fraction of ketoprofen in binary system (CO2 + ketoprofen), 3.14 × 10e-5, 4.70 × 10e-5 and 8.11 × 10e-5, and the concentration of ketoprofen in ternary system (CO2 + ethanol + ketoprofen), 0.05073 and 0.10277 mol Ketoprofen/kg ethanol, on a CO2-free basis for both systems. The aim was to study the solubility of ketoprofen at different molar fractions and predict its behavior over a wide range of temperatures and pressures by means of thermodynamic modeling. Experiments were conducted as a function of temperature from 313 to 333 K and pressure up to 14 MPa, using a visual synthetic static method with a variable volume cell. The collected data highlight an increase of the ketoprofen solubility with the temperature, while a ketoprofen content has a low impact on the bubble point pressure of the tested ternary system. Data were then correlated by using the thermodynamic modeling employed the Redlich - Kwong - Peng - Robinson equation of state (RK - PR EoS) with quadratic mixing rules for fluid phases and a pure solid model for ketoprofen. Then, a number of complete isopleths at set global composition were computed for the CO2 + ketoprofen binary system being indicated solid - fluid, solid - fluid - fluid, and fluid - fluid regions. The obtained results suggest that the thermodynamic models used in this work were able to describe the experimentally observed phase behavior.