Investigation of the Performance of Iron Nanocatalysts in Liquid Fuel Production from Synthetic Gases: Empirical Studies and CFD Modeling

In this work a computational fluid dynamic (CFD) and experimental study of Fischer–Tropsch Synthesis (FTS) process in a fixed-bed reactor is presented. The reactor was a 1.2 cm diameter and 80 cm length steel tube in which ceramic particles were employed to dilute the catalyst bed and thus prevent the emergence of hot spots in it. An axi-symmetric CFD model with an optimized mesh of 22016 square cells was developed to model hydrodynamics, chemical reaction and heat and mass transfer in the reactor. Non-ideal thermodynamic behavior of gas mixture was modeled using Peng-Rabinson equation of state. Kinetic models for FTS and Water–Gas-Shift (WGS) reaction rates based on Langmuir–Hinshelwood type for each of species were employed. Good agreement was achieved between bench experimental data and the model. Because of the high price of reaction experiments and also safety the validated model used as numerical setup and the CFD simulations considered as numerical experiments. A sensitivity analysis was carried out in order to find the effect of temperature, pressure, and GHSV and H2/CO ratio on the reactor performance.