Simulations and Experiments of Dry Catalyst Impregnation for Improved Content Uniformity

The dry impregnation of catalysts is widely used in the preparation of heterogeneous catalysts, however, there is very little work done at the computational level. In this work, Discrete Element Method (DEM) simulations coupled with a novel algorithm allowing the transfer of fluid to and between particles were used in combination with geometrically equivalent experiments to model dry catalyst impregnation. Specifically, the effects of flow rate, volumetric fill level, metal solution type, particle dimensions, and morphology were explored within a double cone geometry blender, where the process parameters were optimized for the best overall mixing and content uniformity within the granular bed. While the developed model and corresponding algorithm have shown good agreement with experiments, the double cone blender itself does not establish an optimal content uniformity alone, and as a consequence, various improvements were introduced and subsequently analyzed within the system including baffles and various nozzle configurations. It was found that the addition of baffles to the system greatly improves the mixing and fluid content uniformity during dry impregnation, and additionally, baffles allow for greater volumes of catalyst support to be processed than traditionally acceptable using the double cone geometry. The culmination of this work has been the development of simulations capable of analyzing dry catalyst impregnation in limitless parameters, geometries, and conditions for improving overall mixing, content uniformity, and product quality.