Modeling The Fixed-Bed Fischer-Tropsch Reactor In Different Reaction Media

Reactor modeling is a very useful tool in the design and scale-up of commercial reactors, enabling prediction of the system behavior under different operating conditions without the need for expensive and time-consuming experimentation. In this paper we present our approach towards developing a comprehensive fixed-bed reactor model for Fischer-Tropsch synthesis (FTS) on a cobalt-based catalyst using a detailed mechanistic model to predict the FTS product distribution. In the current study, we developed a multi-scale approach to mode the FTS reactor whereby we combine the use of a detailed mechanistic kinetic model with a particle diffusion model to account for heat and mass transfer limitations both locally and in the whole reactor bed. Simultaneously, we have implemented a fixed-bed reactor model, also in MATLAB (R) that is capable of predicting the whole bed behavior taking into account the heat and mass transfer resistances in the reactor bed such as the loss in catalytic activity due to diffusion in the catalyst pores. For experimental validation of the model, a high pressure bench-scale reactor unit has been utilized. The kinetic model developed here is to be integrated into a model of the whole reactor bed, with a view towards facilitating the optimization and scale-up of novel FTS reactor bed designs for both the conventional gas phase FTS and the supercritical phase FTS.