(596c) Cake Filtration of Catalyst Materials

Cake filtration is widely used in catalyst production. This traditional process is still largely empirical. There is often a lack of knowledge about the required pressure drop or the resultant flow rate or the actual rate of filter cake formation, especially for fine particles. Our approach is to develop a laboratory scale test that can provide insight into how a particular material of interest would behave in a manufacturing scale filtration process. This study will examine the dependence of the Darcy permeability coefficient on the operating parameters during filtration. An additional aim is to map the filter cake microstructure and the variation in particle size distribution and bulk density at different axial locations along the filter cake.

In this work, we have developed tools and protocols for filtration experiments using a benchtop Nutsche filter device, a model material of 5 microns diameter nonporous glass beads and porous catalyst materials. The applied pressure is varied and we aim to relate filtration behavior to particle physical properties, such as bulk density, air permeability, size distribution and zeta potential. Particle size distribution and bulk density within filter cake layers were analyzed. Furthermore, additional recycling and washing steps of the filtration process were included and the displacement of fine particles through the layers of the cake was obtained as well as changes in the bulk density profile.