Extraction of Propionic Acid from Waste Water Using Rosmary

Experimental liquid–liquid equilibrium (LLE) data for the extraction of propionic acid from water by rosmary at 291.15 K and at ambient pressure were investigated. Data for the binodal curve have been determined by cloud-point titration method and conjugate points on tie-line were obtained by correlating the refractive index of the binodal curves as a function of composition. The reliability of the tie lines generated from the composition data was tested and verified by two correlation models: Hand and Othmer, which were found to fit the data very well, producing high values of correlation coefficient (R2). In addition, these experimental tie line data were also correlated with NRTL model and the binary interaction parameters of the model have been obtained by regression with experimental data. Finally, the distribution coefficients and the selectivity factor of the solvent used were calculated and presented.