Phase Equilibrium and Thermophysical Properties of 2-Phenylethanol Aqueous Mixtures with Organic Solvents

Abstract

2-Phenylethanol is a yeast-derived aroma compound whose Ehrlich-pathway production is limited by product inhibition above 2–3 g·L–1, making in situ liquid–liquid extraction essential. This work reports ternary liquid–liquid equilibrium data for water +2-phenylethanol + solvent systems with 1-hexanol, 1-octanol, 2-methyl-2-butanol, 2-methyl-3-buten-2-ol, 2-octanone, and methyl isobutyl ketone at 303.15 K and 101.3 kPa, together with isobaric vapor–liquid equilibrium data for the corresponding binary 2-phenylethanol + solvent mixtures at 101.3 kPa. Density and dynamic viscosity are also reported for binary mixtures with 1-hexanol, 1-octanol, and 2-methyl-2-butanol from 293.15 to 333.15 K. The two-phase region narrows in the order ketones > long-chain primary alcohols > short-chain branched alcohols, whereas water coextraction follows the opposite trend, identifying ketones as the most suitable solvents. PC-SAFT combined with entropy scaling describes density, excess molar volume, viscosity, vapor–liquid equilibrium, and liquid–liquid equilibrium within one framework. Predictive calculations capture most properties, while one temperature-independent binary interaction parameter per system correlates equilibrium properties.