Determination of Isobaric Vapor-Liquid Equilibria Data for Four Alcohol plus Water Binary Systems at Low Alcohol Mole Fractions 10-6 to 10-2

Information on vapor-liquid equilibria in the extremely dilute regions is necessary for developing high-grade purification processes. In this study, we examine the vapor-liquid equilibria (x-y-T-P) of liquids containing 1x10-6 to 1x10-2 mole fractions of alcohols for four binary systems, i.e., methanol+water, ethanol+water, 2-propanol+water, and 2-methyl-2-propanol+water, at 101.325 kPa using two Rose-Williams stills with a special device for a sampling system. The infinite-dilution equilibrium ratios K1 infinity were measured, and the infinite-dilution activity coefficients obtained from K1 infinity were compared with the literature and predicted values using modified UNIFAC (Dortmund) and ASOG. The x-y-T-P data at the finite composition regions were then calculated using Wilson parameters obtained by the infinite-dilution activity coefficients.

Automated summary

This study investigates vapor-liquid equilibria in dilute alcohol solutions, measuring infinite-dilution equilibrium ratios and comparing activity coefficients with literature and predicted values. The x-y-T-P data at finite compositions are then calculated using Wilson parameters based on infinite-dilution activity coefficients.