Radial behavior in riser and downer during the FCC process

Deng, Ruixue; Wei, Fei; Liu, Tengfei; Ye, Jin

doi:10.1016/s0255-2701(01)00140-4

Cited by 36 publications

(25 citation statements)

References 15 publications

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“…For those reactions with two or more products, the approximate methods may also lead to wrong estimation in product selectivity. As an example, the FCC process is simulated by adopting the model in [7] and the results are shown in Table 2. It can be seen that the adoption of Approx.…”

Section: Influences Of Varying Sgv On the Product Yieldmentioning

confidence: 99%

“…The hydrodynamics study [1][2][3][4][5][6] shows that the radial distribution of flow parameters such as particle velocity, gas velocity and solids concentration in the downer is more uniform than in the riser, and it was also stated that the radial flow structure does not result in severe radial non-uniformity even in a fast reaction like fluid catalytic cracking (FCC) [7]. Therefore, the importance of the axial flow structure becomes very significant.…”

Section: Introductionmentioning

confidence: 99%

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Axial flow structure at the varying superficial gas velocity in a downer reactor

Deng

Liu

Wei

et al. 2004

Chemical Engineering Journal

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Section: Influences Of Varying Sgv On the Product Yieldmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Axial flow structure at the varying superficial gas velocity in a downer reactor

Deng

Liu

Wei

et al. 2004

Chemical Engineering Journal

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“…Despite the complex hydrodynamics present in these reactors, most numerical studies in FCC risers that take into account cracking reactions and related phenomena simplify some important fluid dynamics aspects, like considering that the riser follows a plug flow model [14][15][16][17][18] or applying empirical radial dispersion models to consider the coreannulus patterns [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

“…Through the simulation of FCC process using three different models (plug flow, one-dimensional, and twodimensional dispersion models), Deng et al [21] showed that the consideration of radial nonuniformity is necessary since it provides a better approximation, reflecting in better results for conversions and yields when compared with experimental plant data. Afterward, Lopes et al [22] simulated an industrial riser using 3D models and showed that the flow presents nonuniformities and asymmetric patterns which are dependent upon feed flow rates.…”

Section: Introductionmentioning

confidence: 99%

CFD Study of Industrial FCC Risers: The Effect of Outlet Configurations on Hydrodynamics and Reactions

Lopes

Rosa

Mori

et al. 2012

International Journal of Chemical Engineering

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Fluid catalytic cracking (FCC) riser reactors have complex hydrodynamics, which depend not only on operating conditions, feedstock quality, and catalyst particles characteristics, but also on the geometric configurations of the reactor. This paper presents a numerical study of the influence of different riser outlet designs on the dynamic of the flow and reactor efficiency. A three-dimensional, three-phase flow model and a four-lump kinetic scheme were used to predict the performance of the reactor. The phenomenon of vaporization of the liquid oil droplets was also analyzed. Results showed that small changes in the outlet configuration had a significant effect on the flow patterns and consequently, on the reaction yields.

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“…Modeling of a fluidized bed is usually based on simple models such as the dispersion model (Deng et al, 2002) and the two-region model (Brereton et al, 1988). These models are based on many simplifications.…”

Section: Introductionmentioning

confidence: 99%

Dem Modeling and Simulation of a Down-Flow Circulating Fluidized Bed

Limtrakul

Thanomboon

Vatanatham

et al. 2008

Chemical Engineering Communications

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A mathematical model based on the distinct element method (DEM) was developed to investigate the hydrodynamics in a gas-solid down-flow circulating fluidized bed reactor (downer). The models consist of the equations of particle motion and fluid motion. The contact force is calculated by using the analogy of a spring, dashpot, and friction slider. Simulation results show that the radial solids holdup and particle velocity profiles are uniform in the core region. Near the wall, the solids holdup is higher with lower particle velocity. An increase in the particle size decreases the solids holdup and increases the particle velocity. The solids holdup decreases with superficial gas velocity but increases with solids circulation rate. Particle velocity increases with gas velocity and solids circulation rate. The solids holdup and particle velocity are almost uniform along the height of the downer except near the distributor. The hydrodynamic behavior from this simulation showed trends similar to those of the experimental results. The results obtained from this model fit better with the experimental results than Kimm's and Bolkan's models do.

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Radial behavior in riser and downer during the FCC process

Cited by 36 publications

References 15 publications

Axial flow structure at the varying superficial gas velocity in a downer reactor

Axial flow structure at the varying superficial gas velocity in a downer reactor

CFD Study of Industrial FCC Risers: The Effect of Outlet Configurations on Hydrodynamics and Reactions

Dem Modeling and Simulation of a Down-Flow Circulating Fluidized Bed

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