| Summary: | 博士 === 國立臺灣科技大學 === 化學工程研究所 === 81 === The objective of this study is to develop a model describing
the behavior of vapor-liquid equilibrium of electrolyte
solutions. Three major parts are included in this study. The
first part is accomplished by applying the Poisson-Boltzmann
equation to describe the ion-ion long-range interaction and the
concept of solvation to describe the ion-molecule short-range
interaction. The developed model contains three characteristic
parameters and is able to estimate mean activity coefficients
and osmotic coefficients fairly well for 144 aqueous
electrolyte solutions at 25.degree.C. In addition, the proposed
model has been also satisfactorily applied to non-aqueous
electrolyte solutions and systems with temperatures other than
25.degree.C. The only disadvantage of this model is the
necessity of solving an ordinary differential equation, thus to
overcome this, a much simpler model is proposed. The new model
is similar to the first proposed one containing three
characteristic parameters. It is as good as the original
model, although a slightly larger average deviations appear for
some systems, and has the major advantage of fewer parameters
comparing to the models available in the literature. The second
part of this study is the experiments of vapor- liquid-
equilibrium of electrolyte solutions. The experimental data
collected are vapor-liquid-equilibrium and vapor-liquid- liquid-
equilibrium. The later is important for the processes such as
distillation and extraction, and is seldom published in the
literature. The last part of this study is to develop a
predictive model for the vapor-liquid-equilibrium of
electrolyte solutions (one electrolyte, two solvents). The
parameters used in this model are directly obtained from the
binary systems, no additional parameters are needed. So this
model is simple and requires less computation effort. It
predicts well for both isothermal and isobaric systems.
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