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A Distillation Approach to Phase Equilibrium Measurements of Complex Fluid Mixtures



Megan Harries, Marcia L. Huber, Thomas J. Bruno


Building on the successful development and broad implementation of the Advanced Distillation Curve (ADC) approach to measuring the volatility of fluid mixtures such as fuels, the ADC with Reflux or ADCR technique was developed to address the inability to experimentally determine the vapor-liquid equilibrium of fluids containing more than two components. For fuels and other complex mixtures, the ADCR collects data about the chemical composition of both liquid and vapor phases across a variety of temperatures, elucidating the entire two-phase region at a constant pressure. Two simple mixtures were used to demonstrate the ADCR method: an n-decane/n- tetradecane binary and the Huber-Bruno surrogate, a ternary mixture developed to represent the volatility of an aviation turbine kerosene. These mixtures were chosen to develop and test the approach because they have been extensively measured and modeled in previous work. For both test fluids, the measurements of vapor-liquid equilibrium were in good agreement with model predictions. The data were also used to improve the model binary interaction parameters. We conclude that the ADCR is a valuable and useful method for measuring the T-P-x-y behavior of fluid mixtures with many components. The experimental approach presented may support forensic analysis done by headspace methods, especially arson fire debris analysis, by providing quantitative, low uncertainty data describing the relationships between the vapor and condensed phases of a fuel subjected to thermal weathering.
Energy and Fuels


distillation curve, vapor liquid equilibrium, VLE


Harries, M. , Huber, M. and Bruno, T. (2019), A Distillation Approach to Phase Equilibrium Measurements of Complex Fluid Mixtures, Energy and Fuels, [online],, (Accessed June 24, 2024)


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Created June 24, 2019, Updated October 12, 2021