Simulation of coke and metal deposition in catalyst pellets using a non-steady state fixed bed reactor model

2006 ◽  
Vol 61 (22) ◽  
pp. 7463-7478 ◽  
Author(s):  
Bas M. Vogelaar ◽  
Rob J. Berger ◽  
Bas Bezemer ◽  
Jean-Paul Janssens ◽  
A. Dick van Langeveld ◽  
...  
Keyword(s):  
Steady State ◽  
Fixed Bed ◽  
Metal Deposition ◽  
Fixed Bed Reactor ◽  
Reactor Model ◽  
Catalyst Pellets

Evaluation of stability of a catalytic fixed-bed reactor from a steady-state model

1993 ◽  
Vol 48 (21) ◽  
pp. 3677-3681 ◽  
Author(s):  
Venkata R. Khandavalli ◽  
V.Dharma Rao ◽  
M.V. Ramakanth ◽  
Kirankumar V. Athota
Keyword(s):  
Steady State ◽  
Fixed Bed ◽  
State Model ◽  
Fixed Bed Reactor ◽  
Steady State Model

Methane Dry Reforming over Ni-Co/Al2O3: Kinetic Modelling in a Catalytic Fixed-bed Reactor

2017 ◽  
Vol 15 (6) ◽  
Author(s):  
Yacine Benguerba ◽  
Mirella Virginie ◽  
Christine Dumas ◽  
Barbara Ernst
Keyword(s):  
Catalyst Deactivation ◽  
Kinetic Modelling ◽  
Fixed Bed ◽  
Dry Reforming ◽  
Fixed Bed Reactor ◽  
Coke Deposition ◽  
Dry Reforming Of Methane ◽  
Reactor Model ◽  
Reverse Water Gas Shift ◽  
Different Temperatures

Abstract The dry reforming of CH4 was investigated in a catalytic fixed-bed reactor to produce hydrogen at different temperatures over supported bimetallic Ni-Co catalyst. The reactor model for the dry reforming of methane used a set of kinetic models: The Zhang et al model for the dry reforming of methane (DRM); the Richardson-Paripatyadar model for the reverse water gas shift (RWGS); and the Snoeck et al kinetics for the coke-deposition and gasification reactions. The effect of temperatures on the performance of the reactor was studied. The amount of each species consumed or/and produced were calculated and compared with the experimental determined ones. It was showed that the set of kinetic model used in this work gave a good fit and accurately predict the experimental observed profiles from the fixed bed reactor. It was found that reaction-4 and reaction-5 could be neglected which could explain the fact that this catalyst coked rapidly comparatively with other catalyst. The use of large amount of Ni-Co will lead to carbon deposition and so to the catalyst deactivation.

Steady State Model for Heat Transfer in a Packed Bed Reactor of Elliptic Cylindrical Shape

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Laércio G. Oliveira ◽  
Ramdayal Swarnakar ◽  
Antonio G. B. de Lima
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Fixed Bed ◽  
Packed Bed ◽  
Numerical Results ◽  
Packed Bed Reactor ◽  
Fixed Bed Reactor ◽  
Dimensionless Temperature ◽  
Cylindrical Shape ◽  
Temperature Profiles

The fixed-bed reactors of circular cylindrical geometry with heated or cooled walls are frequently used to carry out heterogeneous reactions of solid-gas type in engineering applications. The design of a fixed bed reactor requires an extensive knowledge of heat transfer characteristics within the packed bed. In this sense, this work presents a three-dimensional mathematical model to predict the heat transfer inside a fixed bed elliptical cylinder heat exchanger. The model considers uniform velocity and temperature profiles of the fluid phase at the entrance of the reactor, and constant thermo-physical properties. The surface of the equipment convective boundary condition is assumed to be constant. The energy equation, written in the elliptical cylindrical coordinates, was discretized using a finite-volume method considering a fully implicit formulation, and WUDS interpolation scheme. Numerical results of the dimensionless temperature profiles inside the packed bed reactor at a steady state are presented and temperature distribution is interpreted. To validate the model, numerical results obtained for the circular cylinder are compared with analytical results from literature and a good agreement was obtained.

A Trickle Fixed-Bed Recycle Reactor Model for the Fischer-Tropsch Synthesis

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Kyle M. Brunner ◽  
Joshua C. Duncan ◽  
Luke D. Harrison ◽  
Kyle E. Pratt ◽  
Robson P. S. Peguin ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Prandtl Number ◽  
Fixed Bed ◽  
Effective Diffusivity ◽  
Tropsch Synthesis ◽  
Fixed Bed Reactor ◽  
Maximum Temperature ◽  
Reactor Model ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis

A trickle fixed-bed reactor model for the Fischer-Tropsch synthesis applicable to both cobalt and iron catalysts which accounts for gas and liquid recycle is described. A selection of kinetic models for both iron and cobalt catalysts (4 each) is included in the reactor model and their effect on model predictions is compared. While the model is 1-D and reaction rates are determined for quasi-average radial bed temperatures, a correlation is used to account for radial thermal conductivity and radial convective heat transfer. Traditional pressure drop calculations for a packed column were modified with a correlation to account for trickle-flow conditions. In addition to describing the model in detail and showing validation results, this paper presents results of varying fundamental, theoretically-based parameters (i.e. effective diffusivity, Prandtl number, friction factor, etc.). For example, the model predicts that decreasing effective diffusivity from 7.1E-09 to 2.8E-09 m2/s results in a lower maximum temperature (518 K vs. 523 K) and a longer required bed length to achieve 60% conversion of CO (8.5 m vs. 5.7 m). Using molar averages of properties to calculate the Prandtl number for the gas phase (recommended by the authors) results in average bed temperatures up to 10 K higher and reactor lengths 17-45% shorter than assuming a Prandtl number of 0.7. Using the Tallmadge equation to estimate friction losses, as recommended by the authors, results in a pressure drop 40% smaller than using the Ergun equation. Validation of the model was accomplished by matching published full-scale plant data from the SASOL Arge reactors.

scholarly journals Validation of a Fixed Bed Reactor Model for Dimethyl Ether Synthesis Using Pilot-Scale Plant Data

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1522
Author(s):  
Daesung Song ◽  
Sung Yong Cho ◽  
Thang Toan Vu ◽  
Yen Hoang Phi Duong ◽  
Eunkyu Kim
Keyword(s):  
Dimethyl Ether ◽  
Fixed Bed ◽  
Pilot Scale ◽  
Fixed Bed Reactor ◽  
Average Error ◽  
Reactor Model ◽  
Feed Pressure ◽  
Co Conversion ◽  
Dimethyl Ether Synthesis ◽  
The One

The one-dimensional (1D) mathematical model of fixed bed reactor was developed for dimethyl ether (DME) synthesis at pilot-scale (capacity: 25–28 Nm3/h of syngas). The reaction rate, heat, and mass transfer equations were correlated with the effectiveness factor. The simulation results, including the temperature profile, CO conversion, DME selectivity, and DME yield of the outlet, were validated with experimental data. The average error ratios were below 9.3%, 8.1%, 7.8%, and 3.5% for the temperature of the reactor, CO conversion, DME selectivity, and DME yield, respectively. The sensitivity analysis of flow rate, feed pressure, H2:CO ratio, and CO2 mole fraction was investigated to demonstrate the applicability of this model.

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