Liquid-liquid phase equilibria for the ternary (neopentyl glycol + sodium formate + water) system

Abstract

ABSTRACT. Liquid–liquid equilibrium data and the phase diagrams were measured for the ternary (neopentyl glycol + sodium formate + water) system at various temperatures of 303.15, 313.15 and 323.15 K. The effect of temperature on the conjugate phase and the tie-line length of the investigated system have been studied. The results showed that the length of the tie-line increases and the two-phase area was slightly increased by decreasing temperature. The fitting parameters of the Pirdashti and Merchuk equations were obtained with the temperature dependence expressed in the linear form, respectively. Compared with the Pirdashti equation, the binodal curves were satisfactorily described using the Merchuk equation at T = (303.15, 313.15 and 323.15) K, and the critical points at different temperatures were estimated by extrapolation. Furthermore, the Hand, Othmer-Tobias and Bachman models were used for the correlation of the phase behavior of the studied system. According to the reported correlation coefficients values, it was found that the measured tie-line data have acceptable consistency and the better fitness was with Othmer-Tobias equation.  

KEY WORDS: Liquid–liquid equilibrium, Neopentyl glycol, Phase diagram, Merchuk

Bull. Chem. Soc. Ethiop. 2022, 36(4), 915-922.                                                           

DOI: https://dx.doi.org/10.4314/bcse.v36i4.16