Experimental and Predicted Vapor–Liquid Equilibrium for Diisopropanolamine with m-Cresol and 2,6-Dimethylphenol at 20.0 kPa

Measurements of isobaric vapor–liquid equilibrium (VLE) results for binary systems of m-cresol (MC) + diisopropanolamine (DIPA) and 2,6-dimethylphenol (DMP) + DIPA and the ternary system of MC + DMP + DIPA were conducted at the pressure of 20.0 kPa. The binary VLE experimental data showed that DIPA had stronger interaction with MC than DMP. The ternary system experimental VLE data showed that DIPA could improve the relative volatility of DMP to MC. The binary experimental data were checked by using Herington area and point test methods, and the checked results were thermodynamically consistent. Meanwhile, the VLE data were correlated by Wilson, nonrandom two-liquid, and universal quasichemical models, and the binary energy interaction parameters for these models were obtained. These activity coefficient models were used to predict the ternary system VLE data. The predictive results suggested that the Wilson model had the best prediction.