Prediction of vapor-liquid equilibria for hydrocarbon binary systems by regular solution model

Abstract

Vapor-liquid equilibria (VLE) of hydrocarbon binary systems: hexane + benzene (25°C), toluene + octane (60°C) and cyclohexane + toluene (50°C) were predicted by using a regular solution model. In the present model, the mixing entropy term (Flory-Huggins equation) is included and an interaction parameter between unlike molecules is introduced. Solubility parameters and molar volumes at each temperature required in calculation are estimated by previously proposed methods. VLE of hexane + benzene and toluene + octane were well predicted by introducing no interaction parameter. On the other hand, to correlate VLE of cyclohexane + toluene, the interaction parameter was needed. VLE of hydrocarbon systems may be predicted or correlated by the regular solution model. Previously proposed methods are useful to estimate solubility parameter and molar volume at given temperature.