VLE and VLLE data for the system water-ethanol-1,4-dimethylbenzene

Abstract

Bioethanol can be used directly as an additive to gasoline. During its manufacture, it must be dehydrated to obtain pure ethanol. Commercially, this is done by ternary azeotropic distillation. Instead of obtaining absolute ethanol, it is possible to achieve a mixture of ethanol without water plus a hydrocarbon by means of heterogeneous azeotropic distillation, utilizing less energy. The ethanol + hydrocarbon mixture thus obtained could be employed as gasoline without the need of subsequent distillation. The hydrocarbon acts as an entrainer in the heterogeneous azeotropic distillation process. Vapour-liquid equilibrium (VLE) and vapour-liquid-liquid equilibrium (VLLE) data have been determined experimentally for the system water ethanol-1,4-dimethylbenzene (p-xylene) at normal atmospheric pressure. These data will permit study of the viability of an azeotropic distillation process using a component of gasoline such as 1,4-dimethylbenzene as entrainer.