Model-Based Experimental Analysis of a Fixed-Bed Reactor for Catalytic SO2Oxidation

2009 ◽  
Vol 48 (11) ◽  
pp. 5165-5176 ◽  
Author(s):  
J. C. Schöneberger ◽  
H. Arellano-Garcia ◽  
G. Wozny ◽  
S. Körkel ◽  
H. Thielert
Keyword(s):  
Experimental Analysis ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Model Based

scholarly journals Analysis and Model-Based Description of the Total Process of Periodic Deactivation and Regeneration of a VOx Catalyst for Selective Dehydrogenation of Propane

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1374
Author(s):  
Andreas Brune ◽  
Andreas Seidel-Morgenstern ◽  
Christof Hamel
Keyword(s):  
Catalyst Deactivation ◽  
Process Development ◽  
Coke Formation ◽  
Fixed Bed ◽  
Reaction Network ◽  
Fixed Bed Reactor ◽  
Side Reactions ◽  
Model Based ◽  
Total Process

This study intends to provide insights into various aspects related to the reaction kinetics of the VOx catalyzed propane dehydrogenation including main and side reactions and, in particular, catalyst deactivation and regeneration, which can be hardly found in combination in current literature. To kinetically describe the complex reaction network, a reduced model was fitted to lab scale experiments performed in a fixed bed reactor. Additionally, thermogravimetric analysis (TGA) was applied to investigate the coking behavior of the catalyst under defined conditions considering propane and propene as precursors for coke formation. Propene was identified to be the main coke precursor, which agrees with results of experiments using a segmented fixed bed reactor (FBR). A mechanistic multilayer-monolayer coke growth model was developed to mathematically describe the catalyst coking. Samples from long-term deactivation experiments in an FBR were used for regeneration experiments with oxygen to gasify the coke deposits in a TGA. A power law approach was able to describe the regeneration behavior well. Finally, the results of periodic experiments consisting of several deactivation and regeneration cycles verified the long-term stability of the catalyst and confirmed the validity of the derived and parametrized kinetic models for deactivation and regeneration, which will allow model-based process development and optimization.

scholarly journals Ammonia synthesis fundamentals for a model-based HAZOP study

2015 ◽  
Vol 8 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Ján Janošovský ◽  
Juraj Labovský ◽  
Ľudovít Jelemenský
Keyword(s):  
Process Model ◽  
Ammonia Synthesis ◽  
Fixed Bed ◽  
Steady States ◽  
Hazard Identification ◽  
Fixed Bed Reactor ◽  
Multiple Steady States ◽  
Nonlinear Behaviour ◽  
Model Based ◽  
Operation Conditions

Abstract Hazard and operability (HAZOP) analysis is a highly disciplined process hazard analysis (PHA) technique based on the exploration of the effects of process variables deviations. Inconveniences of a conventional HAZOP study are its time-consuming character and high cost. The principal objective of this paper is to present a new methodology for hazard identification of a selected chemical production process. Model-based HAZOP study is a very robust tool for predicting a systems response to deviations from design or operation conditions. An approach based on the mathematical modelling of a process can help to identify sources of hazard that could be overlooked by conventional PHA techniques. A case study focused on the multiple steady states phenomenon in an ammonia synthesis reactor is presented. The process simulation was performed using the Aspen HYSYS v8.4 process modelling environment. Nonlinear behaviour of the investigated fixed-bed reactor system was confirmed by an accident in an industrial ammonia synthesis reactor. The analysed system exhibited the feed temperature and pressure dependence of various operation parameters. This fact indicates the presence of multiple steady states. From the safety analysis point of view, switching between steady states can lead to process hazards.

scholarly journals Model-Based Catalyst Selection for the Oxidative Coupling of Methane in an Adiabatic Fixed-Bed Reactor

2018 ◽  
Vol 57 (48) ◽  
pp. 16295-16307 ◽  
Author(s):  
Laura Pirro ◽  
Ana Obradović ◽  
Bart D. Vandegehuchte ◽  
Guy B. Marin ◽  
Joris W. Thybaut
Keyword(s):  
Oxidative Coupling ◽  
Fixed Bed ◽  
Oxidative Coupling Of Methane ◽  
Fixed Bed Reactor ◽  
Model Based ◽  
Selection For ◽  
Catalyst Selection

Role of filter media in an anaerobic fixed-bed reactor

1995 ◽  
Vol 31 (9) ◽  
pp. 137-144 ◽  
Author(s):  
T. Miyahara ◽  
M. Takano ◽  
T. Noike
Keyword(s):  
Anaerobic Bacteria ◽  
Fixed Bed ◽  
Methanogenic Bacteria ◽  
The Other ◽  
Fixed Bed Reactor ◽  
Filter Media ◽  
Fixed Bed Reactors ◽  
Attached Bacteria ◽  
The Relationship

The relationship between the filter media and the behaviour of anaerobic bacteria was studied using anaerobic fixed-bed reactors. At an HRT of 48 hours, the number of suspended acidogenic bacteria was higher than those attached to the filter media. On the other hand, the number of attached methanogenic bacteria was more than ten times as higher than that of suspended ones. The numbers of suspended and deposited acidogenic and methanogenic bacteria in the reactor operated at an HRT of 3 hours were almost the same as those in the reactor operated at an HRT of 48 hours. Accumulation of attached bacteria was promoted by decreasing the HRT of the reactor. The number of acidogenic bacteria in the reactor packed sparsely with the filter media was higher than that in the closely packed reactor. The number of methanogenic bacteria in the sparsely packed reactor was lower than that in the closely packed reactor.

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