Vapor-liquid equilibria and excess enthalpies of the binary systems 1-pentanol or 2-pentanol and 1-hexene or 1,2,4-trimethylbenzene for the development of biofuels

Abstract

Accurate experimental data of vapor-liquid equilibria (VLE) and excess enthalpies are reported for four binary systems: (1-pentanol þ 1-hexene), (2-pentanol þ 1-hexene), (1-pentanol þ 1,2,4- trimethylbenzene) and (2-pentanol þ 1,2,4-trimethylbenzene). An isothermal total pressure cell was used for measuring VLE at T ¼ 313.15 K. The data were fitted using Margules, Wilson and NRTL equations. Excess enthalpies were measured at two different temperatures T ¼ (298.15 and 313.15) K using an isothermal flow calorimeter and were correlated by the Redlich-Kister equation. All systems present a positive deviation from the Raoult's Law. An azeotropic behavior with maximum pressure is observed for the mixtures 1-pentanol or 2-pentanol with 1,2,4-trimethylbenzene. In addition, an endothermic behavior, which increases with temperature, is obtained when the alcohols are mixed with these hydrocarbons.