Numerical Simulation of the Pilot-Scale High-Density Circulating Fluidized Bed Riser

Wang, Min; Lan, Xingying; Wang, Chengxiu; Gao, Jinsen; Yu, Aibing; Kuang, Shibo

doi:10.1021/acs.iecr.1c00170

Cited by 12 publications

(4 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Eulerian–Eulerian two-fluid model (TFM) was applied to the gas–solid flow system in which both the gas and catalyst particles were regarded as the interpenetrating fluid. , The fluid dynamic properties of solid particles were calculated based on the kinetic theory of granular flow (KTGF) . The relevant expressions of conservation equations about mass, momentum, drag model, and turbulence are shown in Table . − For governing equations, the subscripts “g” and “s” represent the gas phase and solid phase, respectively.…”

Section: Computational Modelmentioning

confidence: 99%

“…CFD technology is always based on Eulerian–Eulerian or Eulerian–Lagrange methods to simulate the gas–solid flow system. Wang et al adopted a combination of the Eulerian–Eulerian two-fluid model and modified the drag model in a simulation of a three-dimensional (3D) riser. Complicated particle clustering phenomena were observed in a high-density circulating fluidized bed (HDCFB) and low-density circulating fluidized bed (LDCFB).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Simulation of Hydrodynamics of the Riser Reactor for Catalytic Cracking of Crude Oil to Chemicals

Wang

Jiao

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Direct catalytic cracking of crude oil to chemicals (ccCOTC) has become the development trend in the petrochemical industry. A riser is one of the key reactors in a ccCOTC process. In this work, a two-fluid model (TFM) was used to simulate a relationship between the reactor geometry and gas–solid flow in a typical riser (inside diameter of 17 mm and height of 4.5 m) established in our laboratory, with the aim of improving chemical yield and optimizing the reactor geometry in a ccCOTC process. The effects of key geometric parameters, including the angle between an oblique pipe for catalyst return and the vertical riser (α), the distance between the nozzle orifice and catalyst return oblique pipe (L), the ratio of height to diameter in the prelifting zone (H/D), and the number of catalysts returning to oblique pipes (n), on the distribution of catalyst particles and product profiles were studied. An optimized reactor geometry was proposed according to the index of gas–solid dispersion evenness. To further know the effect of the riser geometry on the product distribution, the two-fluid model (TFM) coupled with a four-lumped kinetic model was used to predict the cracking product profiles along the riser axial. It was found that the ccCOTC riser can remarkably enhance the yield of target chemicals (C2–C4 olefins, benzene, toluene, and xylene), which was approximately 3.1% higher than the result from the pilot test (using the riser before geometry optimization). This work could provide fundamental support on the design of a reactor to maximize light olefins and monocyclic aromatic hydrocarbons in the ccCOTC process.

show abstract

Section: Computational Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simulation of Hydrodynamics of the Riser Reactor for Catalytic Cracking of Crude Oil to Chemicals

Wang

Jiao

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Chen et al [2] used the EMMS drag model to simulate the mixing and flow of gas-solid two-phase flow in the feed mixing section of riser. Zhang et al [3] used the discrete element coupling method to numerically simulate the flow characteristics of FCC particles in the riser tube of the circulating turbulent fluidized bed. Theeranan Thummakul et al [4] simulated the turbulent flow of gas-solids in the lifting tube and the particle exchange capacity in the tube.…”

Section: Introductionmentioning

confidence: 99%

Study on circulating characteristics of circulating fluidized bed

Yu,

Liu

2023

IJMEE

View full text Add to dashboard Cite

Based on the Euler-Euler two-fluid model, the circulating fluidized bed was simulated using the computational fluid dynamics (CFD) method. The physical model of the circulating turbulent fluidized bed had an inner diameter of 76mm and a height of 2000mm. The circulating material consisted of class B particles, with an initial bed material mass (Mp) of 0.188kg. Air was uniformly introduced at a velocity of 0.3m/s at the bottom of the riser, and secondary air was introduced at a velocity of 0.9m/s at the secondary air inlet. Numerical simulations were conducted to study the gas-solid flow characteristics of the entire circuit. The turbulent bed, fast bed particle concentration, material circulation rate, and pressure drop gradient were analyzed to evaluate the performance of the entire circuit. The results showed that the particle concentration at the bottom of the riser was higher in the overall circuit flow, and a turbulent state could be achieved at low gas velocities. The particle concentration in the transport bed was low, indicating good gas-solid interaction. Strong backmixing occurred at the connection between the return valve and the turbulent bed. Additionally, there was intense gas-solid reaction at the secondary air inlet.

show abstract

“…Such models treat all the phases involved as Newtonian fluids and calculate the particle–fluid interaction using the fluid viscosity that particles do not affect. Their effectiveness mainly depends on the constitutive relations describing solid stresses, and the establishment of such relations represents an important research area of granular flow . Differently, one or two research groups treated the mixture of fine particles and liquid as one phase and other particles as different phases; on this basis, they calculated the particle–fluid interactions using the mixture viscosity in a mixture model for hydrocyclones. , In many industries, the slurry consisting of fine particles and liquid could be a non-Newtonian fluid, and the fluid rheology model could vary case by case.…”

Section: Introductionmentioning

confidence: 99%

How Particles with Sizes Close to Cut Size Affect the Multiphase Flows and Performance of Hydrocyclones

Chu

et al. 2021

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

Hydrocyclones classify particles by size but face inefficiency in handling particles with sizes close to the cut size (referred to as cut-size-near particles). This paper presents a numerical study on the cut-size-near particle behavior and its impacts on cyclone performance using a validated two-fluid model. The particle size distribution of interest follows a Johnson’s SB distribution, with a median size of d 0.5 and a spread of σj. The case of d 0.5 close to a reference cut size is focused, where values of σj accord with various fractions of cut-size-near particles. The numerical results show that a larger σj decreases the water split and separation precision while increasing the cut size and pressure drop. Generally, the effect of σj exerting on a larger hydrocyclone is more apparent, even causing a plateau in partition curves. These phenomena are elucidated by the detailed analysis of multiphase flows and forces acting on particles.

show abstract

Numerical Simulation of the Pilot-Scale High-Density Circulating Fluidized Bed Riser

Cited by 12 publications

References 51 publications

Simulation of Hydrodynamics of the Riser Reactor for Catalytic Cracking of Crude Oil to Chemicals

Simulation of Hydrodynamics of the Riser Reactor for Catalytic Cracking of Crude Oil to Chemicals

Study on circulating characteristics of circulating fluidized bed

How Particles with Sizes Close to Cut Size Affect the Multiphase Flows and Performance of Hydrocyclones

Contact Info

Product

Resources

About