Vapor–liquid equilibria of binary systems composed of polyoxyethylene 4-octylphenyl ether and alcohols: Experimental measurements and correlation

• Isothermal binary (vapor + liquid) equilibrium data were measured by an autoclave apparatus.
• The investigated systems are polyoxyethylene 4-octylphenyl ether with 2-butanol, tert-butanol, and 1-pentanol.
• The saturated pressure data were fitted accurately to the Antoine equation.
• The UNIQUAC and the NRTL models were employed to correlate the phase equilibrium data.
• The solvent activities were also calculated.

Isothermal vapor–liquid equilibrium (VLE) data of polyoxyethylene 4-octylphenyl ether (POEOPE) with 2-butanol, tert-butanol, or 1-pentanol have been measured by using an autoclave apparatus. The temperature range is from 321.0 K to 424.5 K and POEOPE content ranging from 0.100 to 0.432 in mole fraction. The raw VLE data were fitted accurately to the Antoine equation. The validity of local composition models, the NRTL and the UNIQUAC, were tested by using the experimental data. It is shown that the VLE data are well represented by using both two models. The UNIQUAC correlates the data slightly better, with an average absolute relative deviation (AARD) of 3.3%, while that of the NRTL is 4.7%. Those VLE data were further used to calculate solvent activities and compared with the calculated values from the UNIQUAC and the NRTL models.