HYDRODEMETALLATION CATALYST PELLETS WITH NONUNIFORM RADIAL PORE SIZE DISTRIBUTION

Hydrodemetallation catalysts typically become inactive by pore mouth plugging, leaving a portion of the catalyst in the interior unutilized. By designing the pore size distribution so as to accommodate larger amount of metal deposit, improved performance can be attained. In this work the effect of nonuniform radial pore size distribution on catalyst performance is explored theoretically. Under the constraints of fixed total internal surface area and local void fraction, it is shown that catalysts with linear radial pore size distribution have larger metal deposit capacity. Furthermore, plugging of the pore mouth is delayed and therefore catalyst lifetime also increases.