A CFD modeling of the gas–solid two‐phase flow in an FCC riser under the electrostatic conditions

Abstract

Electrostatics is an inevitable phenomenon in fluidization processes and granular flow, where collisions between particulates and walls with different materials occur. In this work, a two-dimensional computational fluid dynamics model based on the Eulerian-Eulerian approach was applied and coupled with a first-principles electrostatic model to describe the gas-solid two-phase flow behavior in a fluid catalytic cracking (FCC) riser reactor under the electrostatic conditions. The coupled model was used to predict the main gas-solid flow distribution parameters in the FCC riser, such as electric potential, particle volume fraction, gas-phase temperature, and gas-phase component fractions. The simulation results showed that the electrostatic had a significant influence on the particle distribution in the bottom dense region of the FCC riser, whereas it had a weak influence in the upper dilute region at the cold-flow conditions. The simulation results also showed that the electrostatic had a weak influence on the particle concentration, gas-phase temperature, and lump concentration distributions when the cracking reaction was considered.

Fine Mesh Computational Fluid Dynamics Study on Gas-Fluidization of Geldart A Particles: Homogeneous to Bubbling Bed

“…The Eulerian–Lagrangian approach is more rigorous than the Eulerian–Eulerian approach but less suitable for a large scale due to its computational intensity . Both approaches were used to study bubbling beds − and riser flows. − For riser flows, even industrial scale simulations were attempted using filtered TFM equations. , However, modeling studies on homogeneous expansion and bubbling transition are yet to reach this extent of progress. One reason for this is the dependace of Eulerian−Eulerian models on constitutive relations or closures because until date there is no theory that is generally applicable to all flow regimes. , Further, there are well accepted closures for drag and frictional stress available in literature for continuous modeling − but none for interparticle forces (IPFs), which have been shown to affect homogeneous expansion. − The multiple causes of IPFs are van der Waals interactions, liquid bridges, solid bridge sintering, and electrostatic effects.…”

Computational Fluid Dynamics (CFD) Analysis of Phthalic Anhydride’s Yield Using Lab Synthesized and Commercially Available (V2O5/TiO2) Catalyst

“…Both commercial and labprepared catalysts showed 10 -6 convergence in 2hrs with 90 and 100 iterations respectively. The lab prepared catalyst showed a sudden drop when it reached 80 iterations in residuals which may be because of composition change [10]. The temperature and concentration were recorded at every point of the reactor.…”

“…The porosity of bed effects the rate of turbulence which leads to variations in heat transport [2,18,23]. The CFD modeling done in this work provided point to point temperature and conversion by specifying the following conditions: a) inlet and outlet temperatures b) inlet composition of feed gas c) reactor surface temperature d) gas mass flow rate e) reactor size f) type of reaction g) size of catalyst [10,11]. The study of this type of reactor and reaction system is highly sensitive to even a small variation in temperature, which can directly affect the concentrations of the reactants and inlet gas temperature.…”

A Computational fluid dynamics (CFD) comparison of 3-Lump and 4-Lump kinetic models for predicting gasoline, light gases and coke yield in fluid catalytic cracking (FCC) riser

“…This study is novel because 3-lump and 4-lump kinetic models are compared numerically first time by the using computational fluid dynamics (CFD) with the finite volume method (FVM). Some details of the FVM used by the solver are carefully discussed when implementing terms in the governing equation and boundary conditions (BC) [6][7][8][9]. The basic difference between 3-lump and 4-lump kinetic models is the availability of additional lump in 4-lump kinetic model.…”