experimental investigation and thermodynamic modeling in liquid-liquid equilibrium of water + propionic acid + cyclic alcohols at t= 303.2, 313.2, and 323.2 k

Propionic acid extraction is of economic and environmental importance. in the present study, the liquid-liquid equilibrium data of the ternary system of water + propionic acid + cyclic alcohols (cyclopentanol and cyclohexanol) was obtained at 303.2, 313.2, and 323.2 k temperatures. phase behavior of type-1 has been observed for studied systems. the hand and bachman equations confirm the validity of the measured data. for correlation of liquid-liquid equilibrium data, the nrtl and uniquac thermodynamic models have been used and the coefficients of the inter-molecular interaction have been determined. rmsd values for nrtl and uniquac models in cyclopentanol-containing systems were 0.0107 and 0.0057, respectively, and for cyclohexanol 0.0108 and 0.0076 respectively, which showed the accuracy of these models in correlation liquid-liquid equilibrium data. the values of the selectivity factor for both solvents larger than the unit are obtained, which indicates the ability of the solvents to extract propionic acid.