Modelling of catalyst pellet deactivation

1985 ◽  
Vol 50 (11) ◽  
pp. 2381-2395
Author(s):  
Alena Brunovská ◽  
Ján Buriánek ◽  
Ján Ilavský ◽  
Ján Valtýni
Keyword(s):  
Experimental Data ◽  
Numerical Results ◽  
Benzene Hydrogenation ◽  
Alumina Catalyst ◽  
Temperature Changes ◽  
Catalyst Pellet ◽  
Model Equations ◽  
Catalytic Poison

The diffusion and the shell progressive models of deactivation caused by irreversible chemisorption of a catalytic poison are presented for a single catalyst pellet. The method for solution of the model equations is proposed. The numerical results are compared with experimental data obtained by measuring concentration and temperature changes due to thiophene poisoning in benzene hydrogenation over a nickel-alumina catalyst.

scholarly journals Modelling of Catalyst Pellet Deactivation: An Irreversible Chemisorption Model

1986 ◽  
Vol 3 (3) ◽  
pp. 201-215 ◽  
Author(s):  
A. Brunovská ◽  
J. Buriánek ◽  
J. Ilavský ◽  
J. Valtýni
Keyword(s):  
Experimental Data ◽  
Numerical Procedure ◽  
Experimental Results ◽  
Benzene Hydrogenation ◽  
Alumina Catalyst ◽  
Catalyst Poison ◽  
Catalyst Pellet ◽  
Temperature Time ◽  
Chemisorption Model

Deactivation caused by irreversible chemisorption of a catalyst poison of a single catalyst pellet is studied. Diffusion and shell progressive models are discussed. A numerical procedure is proposed and theoretical and experimental results are compared. Experimental data are obtained by measuring concentration and temperature time dependences due to thiophene poisoning in benzene hydrogenation over Ni/alumina catalyst in one pellet CSTR reactor.

Larger-Eddy Simulation of Velocity Fluctuation in a Mixing T-Junction

2012 ◽  
Vol 152-154 ◽  
pp. 1313-1318
Author(s):  
Tao Lu ◽  
Su Mei Liu ◽  
Ping Wang ◽  
Wei Yyu Zhu
Keyword(s):  
Experimental Data ◽  
Velocity Fluctuation ◽  
Flow Model ◽  
Numerical Results ◽  
Mean Square ◽  
Main Duct ◽  
Velocity Fluctuations ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Les Model

Velocity fluctuations in a mixing T-junction were simulated in FLUENT using large-eddy simulation (LES) turbulent flow model with sub-grid scale (SGS) Smagorinsky–Lilly (SL) model. The normalized mean and root mean square velocities are used to describe the time-averaged velocities and the velocities fluctuation intensities. Comparison of the numerical results with experimental data shows that the LES model is valid for predicting the flow of mixing in a T-junction junction. The numerical results reveal the velocity distributions and fluctuations are basically symmetrical and the fluctuation at the upstream of the downstream of the main duct is stronger than that at the downstream of the downstream of the main duct.

Modeling of Coupled Bending and Torsion in Elastic Structures

1993 ◽  
Author(s):  
H. T. Banks ◽  
C. A. Smith
Keyword(s):  
Experimental Data ◽  
Numerical Results ◽  
Computational Results ◽  
Elastic Structures ◽  
Approximation Techniques ◽  
Flexural Vibrations ◽  
And Control

Abstract In this presentation we will report on joint efforts with D.J. Inman and his colleagues at MSL, SUNY at Buffalo, to develop viable models for the analysis and control of elastic structures exhibiting coupled torsional and flexural vibrations. A model for coupled torsion and bending is developed which incorporates Kelvin Voigt damping and warping. Approximation techniques are introduced and preliminary numerical results are discussed. Experimental data is presented and used to test our computational results.

scholarly journals Modelling Macrophage Infiltration into Avascular Tumours

2002 ◽  
Vol 4 (1) ◽  
pp. 21-38 ◽  
Author(s):  
C. E. Kelly ◽  
R. D. Leek ◽  
H. M. Byrne ◽  
S. M. Cox ◽  
A. L. Harris ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Spatial Structure ◽  
Random Motion ◽  
Numerical Results ◽  
Macrophage Infiltration ◽  
Numerical Techniques ◽  
Model Predictions ◽  
Independent Experimental Data

In this paper a mathematical model that describes macrophage infiltration into avascular tumours is presented. The qualitative accuracy of the model is assessed by comparing numerical results with independent experimental data that describe the infiltration of macrophages into two types of spheroids: chemoattractant-producing (hepa-1) and chemoattractant-deficient (or C4) spheroids. A combination of analytical and numerical techniques are used to show how the infiltration pattern depends on the motility mechanisms involved (i.e. random motion and chemotaxis) and to explain the observed differences in macrophage infiltration into the hepa-1 and C4 spheroids. Model predictions are generated to show how the spheroid's size and spatial structure and the ability of its constituent cells influence macrophage infiltration. For example, chemoattractant-producing spheroids are shown to recruit larger numbers of macrophages than chemoattractant-deficient spheroids of the same size and spatial structure. The biological implications of these results are also discussed briefly.

scholarly journals Numerical and Experimental Investigation of a Rich Quench Lean Combustor Sector

1996 ◽  
Author(s):  
Johannes W. Koopman ◽  
Peter Griebel ◽  
Christoph Hassa
Keyword(s):  
Experimental Data ◽  
Experimental Investigation ◽  
Numerical Results ◽  
Detailed Knowledge ◽  
Complementary Information ◽  
Species Concentration ◽  
Flow Temperature ◽  
Nox Formation ◽  
Sector Model ◽  
Decisive Importance

The flow in a three sector model, representing a segment of an annular rich quench lean combustor for an aeroengine is investigated. Detailed knowledge of flow, temperature and species concentration distributions is of decisive importance to control the NOx formation, essential to the RQL concept. Velocities, temperatures and species concentrations are measured. They are partly used to aquire data on the inlet boundaries in the numerical calculation and partly used to compare with the numerical results. The calculation reveals many details which are not accesable in the experiment. It also shows the effects of the specific inlet dataset. Experimental data and numerical results furnish complementary information.

Comparison of Numerical Results and Experimental Data on Emission Production Processes in a Diesel Engine

2001 ◽  
Author(s):  
Hajime Ishii ◽  
Yuichi Goto ◽  
Matsuo Odaka ◽  
Andrei Kazakov ◽  
David E. Foster
Keyword(s):  
Experimental Data ◽  
Diesel Engine ◽  
Numerical Results ◽  
Production Processes

scholarly journals Calculations of the decay transitions of the modified Pöschl–Teller potential model via Bohr Hamiltonian technique

2017 ◽  
Vol 26 (11) ◽  
pp. 1750073 ◽  
Author(s):  
Nahid Soheibi ◽  
Majid Hamzavi ◽  
Mahdi Eshghi ◽  
Sameer M. Ikhdair
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Potential Model ◽  
Electric Quadrupole ◽  
Numerical Results ◽  
Transition Rates ◽  
Collective Hamiltonian

We calculate the eigenvalues and their corresponding eigenfunctions of the Bohr’s collective Hamiltonian with the help of the modified Pöschl–Teller (MPT) potential model within [Formula: see text]-unstable structure. Our numerical results for the ground state (g.s.) [Formula: see text] and [Formula: see text] band heads, together with the electric quadrupole [Formula: see text] transition rates, are displayed and compared with the available experimental data.

The Effective Use of Experimental and Numerical Data for Validating Simplified Expressions of Stiffened Steel Panel Ultimate Compressive Strength

2007 ◽  
Vol 44 (02) ◽  
pp. 93-105
Author(s):  
Jeom Kee Paik
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Numerical Data ◽  
Numerical Results ◽  
Design Code ◽  
Stiffened Panels ◽  
Collapse Mode ◽  
Effective Use ◽  
Stiffened Steel ◽  
Sophisticated Analysis

To study the accuracy of simplified formulations for prediction of the ultimate strength of longitudinally stiffened panels under uniaxial compression, the preferred approach is to compare them with available experimental data or numerical results from more sophisticated analysis procedures. Such studies are necessary in the development of both design code calibrations and reliability analysis procedures. Existing experimental data and numerical results useful for this purpose are first collected. Salient features of existing design formulations for compressive strength are then reviewed. Selected formulations are compared with the experimental data/numerical results. It is illustrated that there can be a significant amount of scatter in strength estimates by any one formulation and among formulations. The reasons for such scatter are discussed, with the emphasis on the collapse mode(s) involved, the effective width of plating, initial imperfections, and rotational restraints due to stiffening. The experimental and numerical strength data collected are documented for convenience of future use by other investigators.

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