Kinetic modeling of Fischer–Tropsch‐to‐olefins process via advanced optimization

Abstract

The reaction kinetics of a Fischer–Tropsch (FT) process to produce lower olefins was modeled utilizing the experimental data produced using an in‐house synthesized iron‐based catalyst. Along with FT chain growth reaction that is assumed to follow alkyl mechanism, water–gas shift reaction was also taken into consideration due to its significance. Not only the rate constants but also apparent activation energies were obtained via an integrated approach utilizing multiobjective and constrained nonlinear minimization methods in order to define a model valid at a temperature range instead of a single point. The adaption of a hybrid optimization method utilizing both population‐ and individual‐based techniques enhanced prediction accuracy compared with the case where only multiobjective genetic algorithm is used. Thanks to the developed model, the effect of process parameters on product distribution was investigated. Finally, the kinetic model was compared with Anderson–Schulz–Flory model and the deviations observed were discussed.

Comprehensive kinetic study for Fischer–Tropsch reaction over KMoFe/CNTs nano‐structured catalyst

“…However, the absence of any term that represents these effects in the developed model influenced their molar flow rates in such a way as to cause a deviation from the ASF model. [ 77 ] The deviation from ASF product distribution can be assigned to dissolution in a liquid film on the catalyst surface and within the catalyst pores, increasing the readsorption probability of alkenes and the resulting secondary reactions, including hydrogenation, reinsertion, hydrogenolysis, and isomerization. Additionally, the readsorption of alkenes is carbon number‐dependent, and the following secondary reaction changes the FTS product distributions for heavier hydrocarbons.…”

Two-Step Conversion of CO2 to Light Olefins: Laboratory-Scale Demonstration and Scale-Up Considerations

“…These models are needed to better optimize the reactors, i.e., their dimensions, length of the catalyst bed and catalyst properties, such as particle and pore size. A kinetic model for FTO process with iron catalyst has been proposed by Turan et al [59], but a kinetic model for Rh-catalyzed RWGS is not currently available. Similarly, process models for RWGS+FT Power-to-Liquid processes are available, for example, as described by Marchese et al [60], but a model for CO 2 to light olefins process does not exist.…”