Modelling of phase equilibria and related properties of mixtures involving lipids

Larissa Cunico

Research output: Book/ReportPh.D. thesis

1323 Downloads (Pure)


Many challenges involving physical and thermodynamic properties in the production of edible oils and biodiesel are observed, such as availability of experimental data and realiable prediction. In the case of lipids, a lack of experimental data for pure components and also for their mixtures in open literature was observed, what makes it necessary to development reliable predictive models from limited data. One of the first steps of this project was the creation of a database containing properties of mixtures involved in tasks related to process design, simulation, and optimization as well as design of chemicals based products. This database was combined with the existing lipids database of pure component properties. To contribute to the missing data, measurements of isobaric vapour-liquid equilibrium (VLE) data of two binary mixtures at two different pressures were performed using Differential Scanning Calorimetry (DSC) technique. The relevance of enlarging experimental databank of lipids systems data in order to improve the performance of predictive thermodynamic models was confirmed in this work by analyzing the calculated values of original UNIFAC model and by proposing new interaction parameters for original UNIFAC model and lipids systems. Available thermodynamic consistency tests were applied before performing parameter regressions for well-known thermodynamic models such as NRTL, UNIQUAC and original UNIFAC. The performance of the excess Gibbs energy (GE) based models was also evaluated for lipids data and the fitted parameters contributed to the extension of the created dababase. The consistency of the available VLE data has been checked using a general and robust approach developed by the Thermodynamics Research Center (TRC) of the National Institute of Standards and Technology (NIST). For SLE data, consistency tests based on the Gibbs–Duhem equation are not feasible, thus in this project new consistency tests have been developed. Moreover, a methodology that combines solute activity coefficients in the liquid phase at infinite dilution and a theoretically based term to account for the non-ideality in dilute solutions is discussed. The SLE consistency test and data evaluation is performed in a software containing options for data analysis, model analysis and parameter regression.
Original languageEnglish
Place of PublicationKgs. Lyngby
PublisherDanmarks Tekniske Universitet (DTU)
Number of pages239
ISBN (Electronic)978-87-93054-69-1
Publication statusPublished - 2015


Dive into the research topics of 'Modelling of phase equilibria and related properties of mixtures involving lipids'. Together they form a unique fingerprint.

Cite this