Isobaric ternary vapour–liquid equilibrium of methanol(1) + diisopropyl ether(2) + isopropyl alcohol(3) along with methanol + isopropyl alcohol binary data at atmospheric and sub-atmospheric pressures

• Experimental VLE data of Methanol + DIPE + IPA, Methanol + IPA at sub-atmospheric and local atmospheric pressures.
• Binary VLE data correlated with Wilson, NRTL, UNIQUAC, UNIFAC, PR and SRK with WS mixing rules.
• NRTL model represents the binary system's VLE behaviour better than the other models used here.
• NRTL represents all three constituent binaries well and gives good predictions of ternary VLE behaviour.

Experimental vapour–liquid equilibrium (VLE) data of the ternary system methanol(1) + diisopropyl ether(2) + isopropyl alcohol(3) at 53.33, 66.66, 79.99 and 95.33 kPa, studied using a Sweitoslawski-type ebulliometer over the entire composition range is reported here. VLE data of one of the constituent binaries of this ternary system, methanol(1) + isopropyl alcohol(3) was also measured at 53.33, 66.66, 79.99 and 94.79 kPa. Wilson, NRTL, UNIQUAC, Peng–Robinson (PR) and Soave–Redlich–Kwong (SRK) equations of state (EoS) combined with Wong–Sandler (WS) mixing rules were used to correlate the experimental binary data. The experimental binary data has also been compared with predictions from UNIFAC model. NRTL model was found to represent the methanol(1) + isopropyl alcohol(3) system best. Experimental ternary VLE data was found to be in good agreement with predictions from NRTL model with an average root mean square deviation of 0.1164 between experimental and predicted temperatures.