Thermodiffusion in Multicomponent Mixtures presents the computational approaches that are employed in the study of thermodiffusion in various types of mixtures, namely, hydrocarbons, polymers, water-alcohol, molten metals, and so forth. We present a detailed formalism of these methods that are based on non-equilibrium thermodynamics or algebraic correlations or principles of the artificial neural network. The book will serve as single complete reference to understand the theoretical derivations of thermodiffusion models and its application to different types of multi-component mixtures. An exhaustive discussion of these is used to give a complete perspective of the principles and the key factors that govern the thermodiffusion process.
Most naturally occurring fluids are multicomponent mixtures. Nevertheless, measured diffusion coefficients are almost exclusively for binary mixtures. Even for ternary mixtures, data is extremely limited. Molecular diffusion is fundamentally different in multicomponent than in binary mixtures due to cross molecular diffusion. All diffusion coefficients are non-trivial functions of composition, temperature, and pressure. Consequently, ternary diffusion coefficients cannot be obtained from binary data.
The International Meeting on Thermodiffusion provides a unique opportunity for sharing ideas about theoretical, experimental and numerical results on diffusion- and thermodiffusion related research. The successful series of IMT meetings aims to provide a forum for discussion, face-to-face interaction between scientists and technologists, and a mechanism for developing new collaborations. The IMT15 is aimed to discuss the latest results on transport properties in multicomponent fluids: innovative theoretical approaches, new experimental results and techniques as well as state of the art numerical methods. The most fundamental aspect of the conference will be the discussion amongst scientists, the sharing of ideas and creating new and reinforced existing collaborations.
Thermodiffusion describes the coupling between a temperature gradient and a resulting mass flux. Traditionally, the focus has been on simple fluids, and it is now extending to more complex systems such as electrolytes, polymers, colloidal dispersions and magnetic fluids. This book widens the scope even further by including applications in ionic solids. Written as a set of tutorial reviews, it will be useful to experts, nonspecialist researchers and postgraduate students alike.
Thermodiffusion is a mass diffusion phenomenon induced by a temperature gradient and has attracted increasing interests from theorists and experimentalists. In this work, the modelling of thermodiffusion in fluids is theoretically treated in the framework of non-equilibrium thermodynamics. The method developed in this work for thermodiffusion calculation have been incorporated into a computational fluid dynamics program to study the influence of the thermosolutal convection caused by residual gravity and g-jitter. The results have shown that the influence of microgravity environment would become stronger with an increase in the acceleration level, while at the same acceleration level, the effect would decrease at higher frequencies. For an isopropanol-water mixture under a typical microgravity condition for thermodiffusion measurement, the effect of residual gravity lower than 10--5G or the g-jitter components with an acceleration level of 10--4 G and frequencies higher than 0.0005 Hz may be negligible. The analysis in this work has indicated that under the expected microgravity environment on the International Space Station, the influence of g-jitter on the thermodiffusion measurement may be negligibly small for frequencies lower than 1 Hz. Based on four postulates in non-equilibrium thermodynamics, a non-equilibrium thermodynamic approach has been developed for thermodiffusion in associating fluid mixtures. Using the thermodynamic properties provided by the PC-SAFT Equation of State, this approach was used to evaluate the thermal diffusion factor alphaT in aqueous alkanol solutions, including methanol-water, ethanol-water and isopropanol-water mixtures. Using two adjustable parameters calculated from experimental data, the approach has shown a successful estimation of the sign change in the thermodiffusion factor for these mixtures, which was an unresolved problem in thermodiffusion research. In addition to the new model for thermodiffusion in associating mixtures, the current approaches for thermal diffusion estimation in multicomponent hydrocarbon mixtures have been evaluated by comparisons with recent experimental data. Three equations of state, including Peng-Robinson, volume translated Peng-Robinson and PC-SAFT were used in the calculation. The Firoozabadi model combined with vtPR or PC-SAFT was shown to be applicable to thermal diffusion estimation for hydrocarbon mixtures, while PC-SAFT combined with the Firoozabadi model would be a promising choice for mixtures other than hydrocarbons due to the wide applicability of PC-SAFT.
This book presents the theory of non-equilibrium thermodynamics in a pedagogical and practical way that targets engineering applications. In it, tools to take advantage of the second as well as the first law of thermodynamics are provided.The book starts by explaining how the entropy production is the cornerstone of non-equilibrium thermodynamics — the basis to describe coupled transport phenomena, which are highly relevant for several renewable energy technologies. The book also uses entropy production as the foundation for a systematic methodology to analyze and improve energy efficiency, and shows how entropy production can be used to test the consistency of transport models. The link between transport theory and energy efficiency is also shown, and the relationship to exergy analysis is demonstrated. The theory is applied using examples from practical cases like evaporation, heat exchange, reactor optimization, distillation and more.Non-Equilibrium Thermodynamics for Engineering Applications may be used as a textbook for undergraduate and graduate university curricula containing thermodynamics or energy conversion issues at large, chemical and mechanical engineering, applied chemistry and applied physics.
Multicomponent Diffusion discusses the multicomponent diffusion of the three phases of matter. The book is comprised of nine chapters that cover studies of multicomponent diffusion and mass transfer with an emphasis on the chemical characteristics responsible for multicomponent diffusion. Chapter 1 provides an introductory discourse about multicomponent diffusion. Chapter 2 discusses binary diffusion, while Chapter 3 covers multicomponent flux equation. The measurement of ternary diffusion and the estimation of ternary diffusion coefficients are also explained in the book. A chapter then covers the interacting systems, and the subsequent chapter talks about membranes without mobile carriers. The text also discusses carrier-containing membranes and the multicomponent mass transfer. The book will be of great use to researchers and professionals whose work requires a good understanding of multicomponent diffusion.
