Isobaric Vapor−Liquid Equilibria for Tetrahydropyran and Alcohol Systems

Abstract

The vapor-liquid equilibria (VLE) data of systems including tetrahydropyran (THP) are very important for the design of manufacture processes. However, these data are scarce in the literature. The boiling points of eight binary systems containing THP at six pressures from (40.00 to 98.66) kPa were measured using a hold-up compensable ebulliometer. The systems consisting of THP + 2-butanol, THP + 2-methyl-1-propanol, and THP + 1-butanol are nonazeotropic, while those of THP + methanol, THP + ethanol, and THP + 2-propanol are azeotropic. The nonexistence of azeotropic points for THP + 1-propanol and THP + 2-methyl-2-propanol systems depends on the pressures. The measured boiling points were satisfactorily correlated using the NRTL equation. The average deviations between the experimental and calculated boiling points were 0.09 K for THP + methanol, 0.06 K for THP + ethanol, 0.04 K for THP + 2-propanol, 0.06 K for THP + 1-propanol, 0.04 K for THP + 2-methyl-2-propanol, 0.05 K for THP + 2-butanol, 0.04 K for THP + 2-methyl-1-propanol, and 0.08 K for THP + 1-butanol systems. The ASOG group pair parameters for the OH and pyran groups were also determined.