Dynamical modelling of an anaerobic digestion fluidized bed reactor

1997 ◽  
Vol 36 (5) ◽  
pp. 285-292 ◽  
Author(s):  
Benjamin Bonnet ◽  
Denis Dochain ◽  
Jean-Philippe Steyer
Keyword(s):  
Fluidized Bed ◽  
Solid Phase ◽  
Biofilm Reactor ◽  
Momentum Balance ◽  
Balance Equations ◽  
Biological Variables ◽  
Dynamical Simulation ◽  
Model Derivation ◽  
The Stability ◽  
Bed Expansion

One of the main difficulties in modelling a Fluidized Bed Biofilm Reactor (FBBR) is to take into account hydraulic phenomena (such as bed expansion) and its interactions with the biological variables. In this paper, we shall present a dynamical model of the process, analyse the stability of the hydrodynamics and illustrate its performances in simulation. A key feature of the model is that it combines mass balance of the process components with momentum balance equations in order to emphasise the different hydrodynamics of the liquid phase and of the solid phase, and the interactions between both phases. The model derivation finally leads to a set of partial differential equations (PDE). This model is intended to be used as a basis for the derivation of controllers and for dynamical simulation.

Numerical Analysis on the Dynamic Behaviour of Fluidized Bed Reactor

2015 ◽  
Vol 813-814 ◽  
pp. 718-722
Author(s):  
P.M. Suhaile ◽  
S. Rupesh ◽  
C. Muraleedharan ◽  
P. Arun
Keyword(s):  
Fluid Dynamics ◽  
Fluidized Bed ◽  
Volume Fraction ◽  
Solid Phase ◽  
Fluid Model ◽  
Turbulence Models ◽  
Fluidized Bed Reactor ◽  
Two Fluid Model ◽  
Bed Expansion ◽  
Phase Transport

A gas-solid multiphase flow is simulated using CFD to investigate the fluid dynamics of a fluidized bed reactor. The simulation is based on Euler-Euler two fluid model where Kinetic Theory of Granular Flow is used for predicting the solid phase transport properties. The simulation procedure is validated by reproducing and comparing hydrodynamic parameters with those available in the literature. The effect of different turbulence models on bed fluid dynamics is analyzed and k-ε RNG per-phase model is found to have better prediction accuracy compared to other models. The minimum fluidization velocity, granular temperature, bed expansion, particle velocity and volume fraction are determined by the model.

scholarly journals Computational Fluid Dynamic Simulation and Validation Bed Expansion of Three-Phase Co-Current Fluidized Bed

2018 ◽  
Vol 26 (6) ◽  
pp. 1-15
Author(s):  
Zainab Abdulameer Joodi ◽  
Zaidoon M. Shakoor ◽  
Amer A. Abdul- Rahmana
Keyword(s):  
Fluidized Bed ◽  
Computational Fluid Dynamic ◽  
Liquid Velocity ◽  
Solid Phase ◽  
Fluid Dynamic ◽  
Computational Fluid Dynamic Simulation ◽  
Ansys Fluent ◽  
Three Phase ◽  
Inner Diameter ◽  
Bed Expansion

The bed expansion of gas-liquid-solid co-current fluidized bed is studied in the present work. Experimental work is carried out using Perspex column having 0.092 m inner diameter, 2 m height. Kerosene and air are used as continuous and dispersed phases, respectively. Glass beads having 0.0038 m diameter and 2247 kg/m3 density and catalyst particles having 0.0025 m diameter and   2070 kg /m3 density, which were taken from the kerosene hydrotreating reactor that is located in Al-Daura Refinery, are used as the solid phase. The Computational fluid dynamic CFD results of dynamic characteristics were obtained based on simulation using commercial CFD codes and ANSYS FLUENT 16.0 have been used for validation, by comparing the simulation and experimental results. Eulerian approach for flow of granular multiphase is utilized to predict the performance of the three-phase co-current fluidized bed. The results are indicated that the height of the expanded bed is having a strong function of liquid velocity, which increases as the liquid velocity increases too.

Biofilm Performance of a Fluidized Bed Biofilm Reactor for Drinking Water Denitrification

1992 ◽  
Vol 26 (3-4) ◽  
pp. 555-566 ◽  
Author(s):  
V. Z. Lazarova ◽  
B. Capdeville ◽  
L. Nikolov
Keyword(s):  
Drinking Water ◽  
Fluidized Bed ◽  
Nitrate Reduction ◽  
Protein Concentration ◽  
Biofilm Reactor ◽  
Physiological Characteristics ◽  
Fluidized Bed Bioreactor ◽  
Biofilm Thickness ◽  
Residual Nitrite ◽  
Bed Expansion

The properties of two biofilms generated with different predominant organisms were studied in a laboratory-scale fluidized bed bioreactor. Bed expansion, biofilm thickness, biofilm density, protein and polysaccharide concentrations were measured and compared. A high polysaccharide concentration was observed in the less dense and more fragile biofilm of Ps. aeruginosa. The more active biofilm of Ps. stutzeri was characterized by higher protein concentration and density. The results demonstrated that the biofilm performance mostly depended on the physiological characteristics of the preponderant organism. Complete nitrate reduction was reached in both biofilms at very low biofilm thickness. Elevated residual nitrite was observed only in the biofilm of Ps. aeruginosa.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

The influence of the Stokes and Archimedes forces on the stability of a two-phase flow

2003 ◽  
Vol 3 ◽  
pp. 266-270
Author(s):  
B.H. Khudjuyerov ◽  
I.A. Chuliev
Keyword(s):  
Spectral Method ◽  
Stability Region ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Solid Phase ◽  
Stability Characteristic ◽  
Phase Flow ◽  
Two Phase ◽  
The Stability

The problem of the stability of a two-phase flow is considered. The solution of the stability equations is performed by the spectral method using polynomials of Chebyshev. A decrease in the stability region gas flow with the addition of particles of the solid phase. The analysis influence on the stability characteristic of Stokes and Archimedes forces.

scholarly journals Kinetic Modeling of Fluidized-Bed Biofilm Reactor for Lake Water Treatment.

1999 ◽  
Vol 22 (5) ◽  
pp. 389-395 ◽  
Author(s):  
Noriyo NISHIJIMA ◽  
Tetsuya TANAKA ◽  
Kouichi TSUZUKI ◽  
Takeo TAKAGI
Keyword(s):  
Water Treatment ◽  
Fluidized Bed ◽  
Kinetic Modeling ◽  
Lake Water ◽  
Biofilm Reactor

3D Numerical Simulation of Polydisperse Pressurized Gas-Solid Fluidized Bed

2011 ◽  
Author(s):  
P. Fede ◽  
O. Simonin ◽  
I. Ghouila
Keyword(s):  
Numerical Simulation ◽  
Fluidized Bed ◽  
Ethylene Polymerization ◽  
Solid Phase ◽  
Three Dimensional ◽  
Gas Velocity ◽  
Particle Segregation ◽  
3D Numerical Simulation ◽  
Model Predictions ◽  
The Mean

Three dimensional unsteady numerical simulations of dense pressurized polydisperse fluidized bed have been carried out. The geometry is a medium-scale industrial pilot for ethylene polymerization. The numerical simulation have been performed with a polydisperse collision model. The consistency of the polydisperse model predictions with the monodisperse ones is shown. The results show that the pressure distribution and the mean vertical gas velocity are not modified by polydispersion of the solid phase. In contrast, the solid particle species are not identically distributed in the fluidized bed indicating the presence of particle segregation.

On the stability of S-(alkylsulfanyl) cysteine derivatives during solid-phase synthesis

2010 ◽  
Vol 114 (1) ◽  
pp. 1-5 ◽  
Author(s):  
B. H. Rietman ◽  
R. F. R. Peters ◽  
G. I. Tesser
Keyword(s):  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Phase Synthesis ◽  
The Stability

scholarly journals Improved models for predicting bubble velocity, bubble frequency and bed expansion in a bubbling fluidized bed

2019 ◽  
Vol 141 ◽  
pp. 361-371 ◽  
Author(s):  
Cornelius Emeka Agu ◽  
Lars-Andre Tokheim ◽  
Marianne Eikeland ◽  
Britt M.E. Moldestad
Keyword(s):  
Fluidized Bed ◽  
Bubble Velocity ◽  
Bubble Frequency ◽  
Bubbling Fluidized Bed ◽  
Bed Expansion
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