Mixtures in Nonequilibrium

Due to cross-coupling and, possibly, a large number of components, transport processes in mixtures are rather rich. This chapter aims at giving some insight by studying binary mixtures in simple settings. Driving forces for diffusion are discussed, including separation of gas mixtures in centrifuges. Combined convective and diffusive transport across semi-permeable membranes for desalination and pressure retarded osmosis is used as an instructive example. The chapter closes with a motivation of the Arrhenius law for reaction rates by extension of the principles of Linear Irreversible Thermodynamics towards nonlinear expressions.