REACTION-DIFFUSION MODELLING: QUANTITATIVE STUDY OF GEOMETRY-ACTIVITY RELATIONSHIP OF FINNED ZEOLITE CATALYST & MODEL STUDY OF MAXWELL-STEFAN FORMUALATION WITH DIFFERENT ADSORPTION MECHANISMS

The improved catalytic performance of nano-sized zeolite with considerably reduced internal diffusion limitation has stimulated the research on the synthesis of new structure/geometry of catalyst for industry application. In 2020, Rimer’s group developed a new finned zeolite catalyst with significant reduced internal diffusion limitation by epitaxial growth of finned like protrusion.[4] The first chapter of this thesis focusses on the simulation of the effect of geometry of this finned zeolite on selectivity and diffusion limitation. A reaction-diffusion mathematical model is built to examine the geometry-selectivity relationship via simulation of two parallel liquid phase reactions (self-etherification and alkylation). Finned catalysts with four different geometries are chosen and compared with conventional sphere catalyst of similar size. The second chapter of this thesis is about the modelling of zeolite catalyzed reaction, adsorption, and diffusion inside the zeolite crystal via using Stefan-maxwell and Langmuir-Hinshelwood formulation. Two mostly common adsorption approach, multicomponent Langmuir isotherm (MCL) and Ideal adsorption solution theory (IAST) are applied in the model. By simulating gas n-Hexane isomerization reaction in MFI zeolite, the difference of reaction-diffusion models with IAST model and MCL model is shown. The simulation results are compared with results reference papers