Role of Zeolites in Heat and Mass Transfer in Pelletized Multifunctional Cobalt-Based Fischer–Tropsch Catalysts

The role of a zeolite in the H-form in heat and mass transfer in pellets of a composite Co catalyst for Fischer–Tropsch synthesis (FTS) has been studied. It has been shown that the introduction of a heat-conducting additive—metallic aluminum—into the catalyst composition leads to an increase in the thermal stability of the pellets; however, it does not provide high productivity. The introduction of a zeolite into the catalyst contributes to the intensification of mass transfer owing to a decrease in the density and average boiling point of the resulting liquid hydrocarbons. In this case, heat transfer is further improved due to heat removal owing to the heat capacity of the removed products. According to the studies on the conversion of liquid hydrocarbons under FTS conditions, a mechanism of the simultaneous occurrence of these processes in the presence of a cobalt–zeolite catalyst has been proposed.