Abstract

To simulate adsorption in industrial applications and gain more insight into the coupling of fluid flow and adsorption performance, adsorption models at larger scales than just single particles are needed. In this thesis a model of the adsorption on moving particles is applied to the lattice Boltzmann method using an Euler-Euler approach. The adsorption model is based on mass transfer as described by the linear driving force model and can incorporate several mass transfer mechanisms, such as film diffusion, surface diffusion and pore diffusion. Particles, their adsorbate loading, and the solute are described by the advection diffusion equation with an adsorption source term.

Using analytical solutions for a batch and fixed bed reactor the model and its coupling with the fluid is validated. Grid studies are conducted to show the convergence of the model. The applicability of the model to complex flow problems is demonstrated in a static mixer with moving particles.

Problem Statement and Approach

Adsorption is ostensibly best described using individually resolved particles. This approach however becomes untenable when larger and more complex fluid problems need to be solved. Therefore the goal of this thesis was the development of an adsorption model for the Euler-Euler approach where particles are treated as a continuum. The linear driving force model was chosen because it is suitable for this approach while still being reasonably accurate and based on physical mechanisms.