Comparative 2D and 3D analysis on the hydrodynamics behaviour during biomass gasification in a pilot-scale fluidized bed reactor

Cardoso, João; Silva, Valter; Eusébio, Daniela; Brito, Paulo; Boloy, Ronney Arismel Mancebo; Tarelho, L.A.C.; Silveira, José Luz

doi:10.1016/j.renene.2018.07.080

Cited by 40 publications

(12 citation statements)

References 49 publications

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“…It is demonstrated that the simulation values agree well with the experimental values at different temperatures, with an error within the permitted range. , Concerning the time-averaged volume fraction of outlet gas species, the error between simulation values and experimental values gradually decreases as the gasification temperature rises, which can be attributed to two facts. For one thing, the water-gas shift reaction is sensitive to gasification temperatures and relative gas-phase composition, which means that the reaction can reach a balance more easily at a relatively high operating temperature . For another, a high temperature facilitates the further pyrolysis conversion of tar products in the actual gasification process, which helps to decrease the model error caused by the ignorance of tar production in modeling …”

Section: Resultsmentioning

confidence: 99%

“…The simulation is inspired by the experiment of Loha et al 28 The schematic of the BFBG employed in the experiment is shown in Figure 1, which has a 1200 mm height and a diameter of 50 mm. Cardoso et al 5 carried out a systematic 2D and 3D comparison on the hydrodynamics of biomass gasification in a pilot-scale fluidized bed reactor, revealing that both 2D and 3D simulations were capable of correctly predicting the syngas compositions. In view of that, a 2D model of the BSFBG is adopted in the present study considering the higher cost of 3D simulation.…”

Section: Mathematical Model and Simulationmentioning

confidence: 99%

“…For one thing, the water-gas shift reaction is sensitive to gasification temperatures and relative gas-phase composition, which means that the reaction can reach a balance more easily at a relatively high operating temperature. 5 For another, a high temperature facilitates the further pyrolysis conversion of tar products in the actual gasification process, which helps to decrease the model error caused by the ignorance of tar production in modeling. 21 3.1.2.…”

Section: Mathematical Model and Simulationmentioning

confidence: 99%

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Modeling and Optimization for Gas Distribution Patterns on Biomass Gasification Performance of a Bubbling Spout Fluidized Bed

Kang

et al. 2020

Energy Fuels

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Gas distribution patterns exert a great impact on the gas–solid flow, heat and mass transfer, and reaction characteristics and thus affect significantly the thermal conversion efficiency inside the biomass gasifier. In this study, a two-dimensional biomass gasification model for a bubbling spout fluidized-bed gasifier (BSFBG) is established based on the kinetic theory of granular mixture (KTGM), and the prediction accuracy of the model is verified through a comparison between simulation values and experimental values. Furthermore, with the total mass flow rate of the inlet gas set constant, the study has investigated how the ratio of the inlet cross-sectional area to reactor area (A m/A) and the auxiliary gas velocity (U f) affect the gas–solid flow, heat transfer, and gasification performance in the BSFBG. As the results indicate, with A m/A increasing, the local particle flow structure becomes increasingly complex, particle volume fraction and temperature get more evenly distributed, and the volume fraction of outlet key gas species (CO, H2, and CH4) and the lower heating value (LHV) is gradually rising. Besides, compared with the even gas distribution condition (A m/A = 100%), the formation of overall and local counterclockwise particle circulation is facilitated by either a relatively high U f with a low A m/A (≤50%) or a relatively low U f with a high A m/A (≥75%). The circulation structure strengthens the gas–solid mixing in the pyrolysis zone and gasification zone in the middle-upper part of the dense phase bed, which makes the volume fraction of outlet key gas species and LHV increase significantly. In the meanwhile, when A m/A = 75% and U f = 1.0U mf, both the volume fraction and LHV reach the maximums, indicating that the overall gasification performance achieves the optimal state. In conclusion, this study is of reference value for the investigation and intensification of the gasification process, which helps to optimize BSFBG design and thus improve the biomass thermal conversion efficiency.

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Section: Resultsmentioning

confidence: 99%

Section: Mathematical Model and Simulationmentioning

confidence: 99%

Section: Mathematical Model and Simulationmentioning

confidence: 99%

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Modeling and Optimization for Gas Distribution Patterns on Biomass Gasification Performance of a Bubbling Spout Fluidized Bed

Kang

et al. 2020

Energy Fuels

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“…Hence, a reasonable match of particle propertiesand operating velocity is a key to achieve the segregation of a binary mixture. (Cardoso et al, 2019) Figure 8: Variation of mixing index with jetsam particle size at different velocities. (Owoyemi et al, 2010).…”

Section: Diameter and Density Affection Mixture And Segregationmentioning

confidence: 99%

Simulation of Particle Mixing and Separation in Multi-Component Fluidized Bed Using Eulerian-Eulerian Method: A Review

Zhang

Ran

Jin

et al. 2019

International Journal of Chemical Reactor Engineering

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In practical engineering applications, the mixing and separation behavior of multi-component particles is importance to the fluidized bed operation. The development of many practical processes is inseparable from the knowledge of particle mixing and separation, such as material processing of ash-soluble coal gasification, multi-phase flow in boilers, and petrochemical catalytic processes. In recent years, due to the obvious advantages of the Eulerian–Eulerian model, many researchers at home and abroad have used it to study the mixing and separation behavior of particles. The paper reviews the use of Eulerian–Eulerian model to study the mixing and separation of multi-component particles in fluidized beds. The Eulerian–Eulerian model describes the gas-phase and each of the individual particles as continuums. The mechanism of particle mixing and separation, the influence of different factors on the particle mixing and separation including differences in particle size and density, the differences in apparent air velocity, the differences in model factors are discussed. Finally, an outlook for the use of Eulerian–Eulerian model to study the mixing and separation behavior of three component particles and related research on the drag model between particles.

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“…Fluidized bed reactors (FBR) have been widely used in industry, including silicon chemical vapour deposition, biomass gasification, and fluid catalytic cracking processes. [1][2][3] This technology is preferred because of its efficient heat and mass transfer between phases. Industrial FBR often contains a binary mixture of particles, which results in mixing and segregation of the particles and significantly affects the chemical reaction process inside the reactor.…”

Section: Introductionmentioning

confidence: 99%

A bubble structure dependent drag model for CFD simulation of bi‐disperse gas‐solid flow in bubbling fluidizations

Liu

2021

Can J Chem Eng

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In this work, the bi-disperse gas-solid flow system inside a grid cell is decomposed into subsystems, and a bubble structure dependent drag model is proposed. The bi-disperse drag correlation derived from direct numerical simulation is coupled to calculate the drag coefficient in subsystems. The effects of slip velocity, particle composition concentration, and solid concentration gradient are considered in the novel drag model. Three simulation cases are carried out to validate the effectiveness of the novel drag model. It is found that smaller particles strongly influence the heterogeneity of larger particles. Solids concentration gradient is obvious at the bubble surface, gas inlet, and the bed upper surface, indicating the dramatic change of interphase drag force in these regions. Simulation results predicted by the novel drag model are more accurate than the traditional drag model. The comparison between 2D and 3D simulations for a pseudo-2D fluidized bed are also presented.

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Comparative 2D and 3D analysis on the hydrodynamics behaviour during biomass gasification in a pilot-scale fluidized bed reactor

Cited by 40 publications

References 49 publications

Modeling and Optimization for Gas Distribution Patterns on Biomass Gasification Performance of a Bubbling Spout Fluidized Bed

Modeling and Optimization for Gas Distribution Patterns on Biomass Gasification Performance of a Bubbling Spout Fluidized Bed

Simulation of Particle Mixing and Separation in Multi-Component Fluidized Bed Using Eulerian-Eulerian Method: A Review

A bubble structure dependent drag model for CFD simulation of bi‐disperse gas‐solid flow in bubbling fluidizations

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