Effect of mass transfer on the deactivation model and GPLE parameters of Co/?-Al2O3 catalysts in the Fischer Tropsch synthesis

The activity of catalysts with various sizes was compared in a fixed-bed Fischer-Tropsch reactor under similar operating conditions by determining the deactivation model. Catalyst size had no impact on the type of deactivation model. The smaller catalyst showed a smaller deactivation constant of catalyst (k(d)) and a lower deactivation rate in the initial stage. The decline in the activities of the catalyst with a mesh size of 40 was lower than the other catalysts, suggesting its higher long-term stability (a(ss)). Larger catalyst sizes led to the fouling of carbon and heavy hydrocarbons, decreasing the specific surface of the catalyst, thus increasing the pore diffusion resistance and further decrementing the catalyst activities. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The size of catalysts has no impact on the type of deactivation model. Smaller catalysts have a smaller deactivation constant and higher long-term stability. Larger catalyst sizes tend to accumulate carbon and heavy hydrocarbon fouling, leading to decreased specific surface area and lower catalytic activity.