Scale-up of bubbling fluidized bed reactors — A review

Rüdisüli, Martin; Schildhauer, Tilman J.; Biollaz, Serge M.A.; Ommen, J. Ruud van

doi:10.1016/j.powtec.2011.10.004

Cited by 184 publications

(96 citation statements)

References 76 publications

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“…The chemical conversation of biomass, steam and other gas-solid components should also be considered while scaling the reactions. A scale change may influence on the mass transfer, reaction kinetics and fluid dynamics [75]. Further studies of scale dependence of the gasification reaction could be valuable for the scaling of gasification reactors from demonstration or pilot plant to the lab-scale hot models.…”

Section: Scaling Of Reacting Flow In Fluidized Bed Gasification Reactormentioning

confidence: 99%

Heat transfer optimization in a fluidized bed biomass gasification reactor

Thapa¹,

Halvorsen²

2014

WIT Transactions on Engineering Sciences

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Section: Scaling Of Reacting Flow In Fluidized Bed Gasification Reactormentioning

confidence: 99%

Heat transfer optimization in a fluidized bed biomass gasification reactor

Thapa¹,

Halvorsen²

2014

WIT Transactions on Engineering Sciences

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“…[1][2][3][4][5][6] It was traditionally thought that no hot spot would appear in a uidized bed, since the strong back mixing in it would lead to the uniform distribution of temperature. 1,7 However, when faced with a highly exothermic reaction, signicant temperature gradients and hot spots may occur where the heat generated in a conned space is far more than that which can be transferred. These uncontrollable hot spots will destroy the catalyst, lower the conversion and selectivity and lead to risks of explosion and re.…”

Section: Introductionmentioning

confidence: 99%

The analysis of hot spots in large scale fluidized bed reactors

et al. 2017

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The influence of gas velocity and bed diameter on temperature and hot spot profile in gas-solid fluidized beds is studied based on a 2D pseudo homogeneous phase model. A dimensionless number, the fluidized Prater number b f , is introduced into fluidized bed reactors to estimate the temperature gradient and hot spot profile based on various operating parameters and a quantitative relationship is established.Contrary to fixed beds, in fluidized beds, with low gas velocity and small bed diameter, there tend to be large temperature gradients and hot spots. With the increase of gas velocity in the turbulent regime and decrease in the bed diameter, b f , the hot spot gradually disappears and the temperature profile tends to be more uniform. The hot spot in highly exothermic reactions in fluidized beds can be effectively minimized by increasing gas velocity in the turbulent regime and enlarging the bed diameter. An operating map for the industrial hydrogenation of nitrobenzene reaction is provided to estimate the possible axial temperature gradient from operating parameters. This method can be applied to other similar reactions for selecting operating parameters and methods to eliminate hot spots and produce a uniform temperature gradient.

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“…Scaling laws have been used to construct a small scale model which produces identical hydrodynamic behavior as the large scale fluidized bed system [6][7][8]. For this purpose, scaling methods were developed based on different approaches.…”

Section: Introductionmentioning

confidence: 99%

Application of Scaling-Law and CFD Modeling to Hydrodynamics of Circulating Biomass Fluidized Bed Gasifier

et al. 2016

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Two modeling approaches, the scaling-law and CFD (Computational Fluid Dynamics) approaches, are presented in this paper. To save on experimental cost of the pilot plant, the scaling-law approach as a low-computational-cost method was adopted and a small scale column operating under ambient temperature and pressure was built. A series of laboratory tests and computer simulations were carried out to evaluate the hydrodynamic characteristics of a pilot fluidized-bed biomass gasifier. In the small scale column solids were fluidized. The pressure and other hydrodynamic properties were monitored for the validation of the scaling-law application. In addition to the scaling-law modeling method, the CFD approach was presented to simulate the gas-particle system in the small column. 2D CFD models were developed to simulate the hydrodynamic regime. The simulation results were validated with the experimental data from the small column. It was proved that the CFD model was able to accurately predict the hydrodynamics of the small column. The outcomes of this research present both the scaling law with the lower computational cost and the CFD modeling as a more robust method to suit various needs for the design of fluidized-bed gasifiers.

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Scale-up of bubbling fluidized bed reactors — A review

Cited by 184 publications

References 76 publications

Heat transfer optimization in a fluidized bed biomass gasification reactor

Heat transfer optimization in a fluidized bed biomass gasification reactor

The analysis of hot spots in large scale fluidized bed reactors

Application of Scaling-Law and CFD Modeling to Hydrodynamics of Circulating Biomass Fluidized Bed Gasifier

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