Liquid–liquid equilibrium data for water + formic acid + solvent (butyl acetate, ethyl acetate, and isoamyl alcohol) at T = 291.15 K

Liquid–Liquid Equilibrium (LLE) data for the {water + formic acid + solvent (butyl acetate, ethyl acetate and isoamyl alcohol)} ternary systems have been determined experimentally at 291.15 K and 1 atm. Solubility data were obtained using the cloud-point titration method. Refractive index measurement was employed to determine the concentration of all species in each phase. The tie-line data were correlated using the NRTL model. Moreover, the binary interaction parameters of this model were obtained thanks to two evolutionary techniques: the Genetic Algorithm (GA) and the Particle Swarm Optimization (PSO). In addition, the reliability of the experimental tie-line data was checked by the Othmer–Tobias method as well as the Hand correlation. Finally, the distribution coefficients and separation factors have been measured in order to evaluate the ability of each one of the three solvents to extract formic acid from water. It is found that butyl acetate is the best solvent for the separation of formic acid from water.