### Hydrogenation of aromatics: single-event microkinetic (SEMK) methodology and scale-up

Tapan Bera UGent (2012)
abstract
The present work aims at the development of a fundamental single-event microkinetic model to describe aromatics hydrogenation on a noble metal (Pt) catalyst and prepare the implementation of this model in the simulation of industrial reactor. The methodology involves developing a detailed chemistry model based on a rigorous description of the occurring elementary steps, the use of collision and transition state theory to estimate pre-exponential factors and the use of thermodynamic constraints to bound rate parameters based on equilibrium considerations and thermodynamic consistency. In order to facilitate its implementation in typical simulation software, a relumped version of the detailed model has been developed. Moreover, differences in aggregation state between laboratory kinetics determination and industrial operation need to be addressed. After having introduced the procedures in Chapter 2, Chapter 3 discusses the development of a fundamental Single-Event MicroKinetic (SEMK) model for the hydrogenation of benzene on a Pt catalyst. The reaction network used accounts for the position at which the hydrogen atoms are added to the ring. In accordance with a quantum chemical assessment of the reaction pathway it is assumed that the kinetic parameters only depend on the saturation degree of the nearest neighbor carbon atoms and the branching degree of the carbon atom involved in the hydrogen atom addition. The SEMK methodology as developed for benzene hydrogenation in Chapter 3 is further extended towards substituted monoaromatics in Chapter 4. The hydrogenation of toluene and o-xylene over a Pt catalyst is used to assess the model parameters related to tertiary carbon atoms. Relying on the single-event concept and the corresponding feed independence of the model parameters, the values obtained for hydrogen addition to secondary carbon atoms for the benzene hydrogenation studies are used without further adjustments in the regression of the toluene and o-xylene hydrogenation data set. Realizing that the complexity of s SEMK model may go beyond the purpose of present-day flowsheeting tools, a relumped single-event microkinetic (SEMK) model has been developed to describe benzene hydrogenation on a Pt catalyst in Chapter 5. Global rate expressions for the cycloalkane net production rate by hydrogenation are constructed as a sum of rate equations according to a series of potentially dominant reaction pathways. The corresponding equations account for the detailed underlying reaction network and can be implemented as a single analytical expression in complex reactor models, whereas the non relumped kinetic model constitutes a set of algebraic equations that is to be solved numerically. Chapter 6 discusses the gas versus liquid phase hydrogenation kinetics to be able to relate gas phase experimental results to liquid phase or three phase behavior for scale-up by explicitly accounting for the (i) liquid phase non ideality through the calculation of fugacity coefficients and (ii) the competitive solvent chemisorptions in the description of the liquid phase kinetics. Because of the data available for this purpose, Chapter 6 focuses on a Langmuir-Hinshelwood type of kinetic model for naphthalene hydrogenation over a commercial, sulphided NiMo/γ Al2O3 catalyst. The general conclusions are given in Chapter 7.
author
promoter
UGent and UGent
organization
alternative title
Hydrogenering van aromaten : singe-event microkinetische (SEMK) methodologie en opschaling
year
type
dissertation (monograph)
subject
keyword
Benzene, o-xylene, toluene, Aromatics hydrogenation, Single Event MicroKinetic Methodology, Platinum, Kinetics, scale up
pages
XXXIX, 200 pages
publisher
Ghent University. Faculty of Engineering and Architecture
place of publication
Ghent, Belgium
defense location
Gent : Faculteit Ingenieurswetenschappen en Architectuur (Jozef Plateauzaal)
defense date
2012-03-26 09:00
ISBN
9789085784951
language
English
UGent publication?
yes
classification
D1
I have retained and own the full copyright for this publication
id
2075612
handle
http://hdl.handle.net/1854/LU-2075612
date created
2012-03-27 17:35:29
date last changed
2012-04-12 11:08:24
@phdthesis{2075612,
abstract     = {The present work aims at the development of a fundamental single-event microkinetic model to describe aromatics hydrogenation on a noble metal (Pt) catalyst and prepare the implementation of this model in the simulation of industrial reactor. The methodology involves developing a detailed chemistry model based on a rigorous description of the occurring elementary steps, the use of collision and transition state theory to estimate pre-exponential factors and the use of thermodynamic constraints to bound rate parameters based on equilibrium considerations and thermodynamic consistency. In order to facilitate its implementation in typical simulation software, a relumped version of the detailed model has been developed. Moreover, differences in aggregation state between laboratory kinetics determination and industrial operation need to be addressed. After having introduced the procedures in Chapter 2, Chapter 3 discusses the development of a fundamental Single-Event MicroKinetic (SEMK) model for the hydrogenation of benzene on a Pt catalyst. The reaction network used accounts for the position at which the hydrogen atoms are added to the ring. In accordance with a quantum chemical assessment of the reaction pathway it is assumed that the kinetic parameters only depend on the saturation degree of the nearest neighbor carbon atoms and the branching degree of the carbon atom involved in the hydrogen atom addition. The SEMK methodology as developed for benzene hydrogenation in Chapter 3 is further extended towards substituted monoaromatics in Chapter 4. The hydrogenation of toluene and o-xylene over a Pt catalyst is used to assess the model parameters related to tertiary carbon atoms. Relying on the single-event concept and the corresponding feed independence of the model parameters, the values obtained for hydrogen addition to secondary carbon atoms for the benzene hydrogenation studies are used without further adjustments in the regression of the toluene and o-xylene hydrogenation data set. Realizing that the complexity of s SEMK model may go beyond the purpose of present-day flowsheeting tools, a  relumped single-event microkinetic (SEMK) model has been developed to describe benzene hydrogenation on a Pt catalyst in Chapter 5. Global rate expressions for the cycloalkane net production rate by hydrogenation are constructed as a sum of rate equations according to a series of potentially dominant reaction pathways. The corresponding equations account for the detailed underlying reaction network and can be implemented as a single analytical expression in complex reactor models, whereas the non relumped kinetic model constitutes a set of algebraic equations that is to be solved numerically. Chapter 6 discusses the gas versus liquid phase hydrogenation kinetics to be able to relate gas phase experimental results to liquid phase or three phase behavior for scale-up by explicitly accounting for the (i) liquid phase non ideality through the calculation of fugacity coefficients and (ii) the competitive solvent chemisorptions in the description of the liquid phase kinetics. Because of the data available for this purpose, Chapter 6 focuses on a Langmuir-Hinshelwood type of kinetic model for naphthalene hydrogenation over a commercial, sulphided NiMo/\ensuremath{\gamma} Al2O3 catalyst. The general conclusions are given in Chapter 7.},
author       = {Bera, Tapan},
isbn         = {9789085784951},
keyword      = {Benzene,o-xylene,toluene,Aromatics hydrogenation,Single Event MicroKinetic Methodology,Platinum,Kinetics,scale up},
language     = {eng},
pages        = {XXXIX, 200},
publisher    = {Ghent University. Faculty of Engineering and Architecture},
school       = {Ghent University},
title        = {Hydrogenation of aromatics: single-event microkinetic (SEMK) methodology and scale-up},
year         = {2012},
}


Chicago
Bera, Tapan. 2012. “Hydrogenation of Aromatics: Single-event Microkinetic (SEMK) Methodology and Scale-up”. Ghent, Belgium: Ghent University. Faculty of Engineering and Architecture.
APA
Bera, T. (2012). Hydrogenation of aromatics: single-event microkinetic (SEMK) methodology and scale-up. Ghent University. Faculty of Engineering and Architecture, Ghent, Belgium.
Vancouver
1.
Bera T. Hydrogenation of aromatics: single-event microkinetic (SEMK) methodology and scale-up. [Ghent, Belgium]: Ghent University. Faculty of Engineering and Architecture; 2012.
MLA
Bera, Tapan. “Hydrogenation of Aromatics: Single-event Microkinetic (SEMK) Methodology and Scale-up.” 2012 : n. pag. Print.