Mass Transfer Advantage of Hierarchical Structured Cobalt-based Catalyst
Pellet for Fischer-Tropsch Synthesis
Abstract
The low effectiveness factor of catalyst pellet caused by high internal
diffusion limitation is a common issue in fixed-bed reactor.
Nevertheless, hierarchical structured catalyst provides a promising
solution for the contradiction between reaction activity and diffusion
efficiency in large catalyst pellets. Herein, we studied the effect of
pore structure parameters of the meso-macroporous catalyst on
Fischer-Tropsch synthesis performances through experiment and pellet
scale reaction-diffusion simulation. The pellet simulation firstly
elucidated the reason for the significant improvement on activity and
product selectivity for the meso-macroporous catalyst observed in our
experiment. Further optimization via pellet simulation indicated the
critical influences of wax filling degree and that the perfect matching
between reaction and mass transfer rates by increasing macropore size
and adjusting porosity within pellet enables the C5+ space-time yield to
the maximum. This work could provide a theoretical guideline for the
engineering design of the hierarchical structured catalyst pellet.