VERIFICATION OF A CFD-TFM MODEL FOR A FLUIDIZED BED CATALYST IN THE FISCHER-TROPSCH PROCESS
Authors:
1.
Kazan National Research Technological University
2.
KNITU
3.
KNITU
4.
Kazan National Research Technological University
5.
KNITU
6.
Kazan National Research Technological University
Russian Federation
Russian Federation
Type:
Article
Pages:
from 153
to 158
Status:
Published
Received:
14.02.2026
Accepted:
03.03.2026
Published:
05.04.2026
Language:
Russian
Keywords:
FISCHER-TROPSCH PROCESS, FLUIDIZED BED, TWO-FLUID MODEL, DISCRETE ELEMENT METHOD, COMPUTATIONAL FLUID DYNAMICS
Funding:
Rabota vypolnena v ramkah gosudarstvennogo zadaniya «Molekulyarnyy dizayn katalizatorov s primeneniem iskusstvennogo intellekta», soglashenie № 075-00021-26-00 ot 12.01.2026.
Abstract:
The Fischer-Tropsch (FT) process is a polymerization-type catalytic reaction that enables the synthesis of liquid hydrocarbons from carbon monoxide and hydrogen. This process represents a promising method for converting alternative carbon feedstocks - such as natural gas, coal, and biomass - into motor fuels and high-purity chemical products, including olefins and oxygenates (alcohols, aldehydes, ketones, and acids). Efficient industrial implementation of the FT process requires the use of fluidized bed reactors, which provide intensive heat and mass transfer and facilitate catalyst particle circulation. However, the hydrodynamics of such systems are difficult to predict during scaling, and full-scale experiments are prohibitively expensive, necessitating the development of advanced numerical methods. In this work, the verification of a two-fluid model (CFD-TFM) for an FT catalyst fluidized bed was performed by benchmarking it against CFD-DEM simulation results, which were adopted as the high-fidelity reference. Based on the CFD-DEM data, specific values for the empirical parameters of the Kinetic Theory of Granular Flow (KTGF) closure relations were determined: packing limit (0.63), frictional packing limit (0.6), angle of internal friction (30°), and the restitution coefficient for catalyst particle collisions (0.89). To account for interphase interaction discrepancies arising from different treatments of particle polydispersity, it was necessary to introduce an empirical drag correction constant (0.225 relative to the Gidaspow model).Comparative analysis revealed that the TFM overestimates the bed pressure drop by approximately 25 Pa compared to the DEM and fails to reproduce pressure fluctuations due to the continuum approximation of the particulate phase. The solid phase behavior in the TFM is characterized by higher "viscosity," suggesting a need for more refined frictional models. Despite these required adjustments, the developed TFM provides acceptable accuracy in calculating hydraulic resistance and achieves a qualitatively correct representation of bed hydrodynamics. The primary advantage of the TFM is its significantly lower computational cost compared to the DEM, enabling the simulation of larger reactor segments. Furthermore, this approach facilitates the integration of Fischer-Tropsch polymerization kinetics into the modeling of industrial-scale apparatuses.
The Fischer-Tropsch (FT) process is a polymerization-type catalytic reaction that enables the synthesis of liquid hydrocarbons from carbon monoxide and hydrogen. This process represents a promising method for converting alternative carbon feedstocks - such as natural gas, coal, and biomass - into motor fuels and high-purity chemical products, including olefins and oxygenates (alcohols, aldehydes, ketones, and acids). Efficient industrial implementation of the FT process requires the use of fluidized bed reactors, which provide intensive heat and mass transfer and facilitate catalyst particle circulation. However, the hydrodynamics of such systems are difficult to predict during scaling, and full-scale experiments are prohibitively expensive, necessitating the development of advanced numerical methods. In this work, the verification of a two-fluid model (CFD-TFM) for an FT catalyst fluidized bed was performed by benchmarking it against CFD-DEM simulation results, which were adopted as the high-fidelity reference. Based on the CFD-DEM data, specific values for the empirical parameters of the Kinetic Theory of Granular Flow (KTGF) closure relations were determined: packing limit (0.63), frictional packing limit (0.6), angle of internal friction (30°), and the restitution coefficient for catalyst particle collisions (0.89). To account for interphase interaction discrepancies arising from different treatments of particle polydispersity, it was necessary to introduce an empirical drag correction constant (0.225 relative to the Gidaspow model).Comparative analysis revealed that the TFM overestimates the bed pressure drop by approximately 25 Pa compared to the DEM and fails to reproduce pressure fluctuations due to the continuum approximation of the particulate phase. The solid phase behavior in the TFM is characterized by higher "viscosity," suggesting a need for more refined frictional models. Despite these required adjustments, the developed TFM provides acceptable accuracy in calculating hydraulic resistance and achieves a qualitatively correct representation of bed hydrodynamics. The primary advantage of the TFM is its significantly lower computational cost compared to the DEM, enabling the simulation of larger reactor segments. Furthermore, this approach facilitates the integration of Fischer-Tropsch polymerization kinetics into the modeling of industrial-scale apparatuses.
Keywords:
FISCHER-TROPSCH PROCESS, FLUIDIZED BED, TWO-FLUID MODEL, DISCRETE ELEMENT METHOD, COMPUTATIONAL FLUID DYNAMICS
FISCHER-TROPSCH PROCESS, FLUIDIZED BED, TWO-FLUID MODEL, DISCRETE ELEMENT METHOD, COMPUTATIONAL FLUID DYNAMICS
