Limiting activity coefficients in the 1-alkanol + n-alkane systems: survey, critical evaluation and recommended values, interpretation in terms of association models

Abstract

The survey of critically evaluated experimental limiting activity coefficients for 1-alkanol (C1C10) + n-alkane (C5C16) systems prepared on the occasion of the 1991 IUPAC Workshop on Vapor-Liquid Equilibria in 1-alkanol + n-alkane mixtures has been updated by newly available data. Major update is due to a recent experimental effort of our research group which carried out extensive and accurate measurements using several experimental techniques. Thanks to our own measurements, forming now 27% of all available data, the accuracy of our knowledge of limiting activity coefficients in the given systems has clearly improved. The methodology employed for the critical assessment of data is described and illustrated by a number of examples. Recommended values and their uncertainties generated as a result of the process of critical evaluation are reported. For systems, where the underlying experimental information justify the determination of a temperature dependence, a smoothing equation is presented, otherwise a recommended value is given at a single temperature only. Reported and discussed are also some interesting statistical characteristics inferred from the comprehensive 1-alkanol + n-alkane data file. Several athermal and non-athermal association models have been fitted to the critically evaluated data. Performances of these models are compared mutually and to those of three leading group contribution prediction methods.