scholarly journals Enhancement of Feed Gas Distribution of Heterogeneous Catalytic Fixed-bed Reactor

2016 ◽  
Vol 2 (4) ◽  
pp. 595-600
Author(s):  
Ji Hyun Lee ◽  
Beom-Ju Kim ◽  
No-Sang Kwak ◽  
Jung Hyun Lee ◽  
Su Hyun Shin ◽  
...  
2019 ◽  
Vol 35 (2) ◽  
pp. 139-190 ◽  
Author(s):  
Nico Jurtz ◽  
Matthias Kraume ◽  
Gregor D. Wehinger

Abstract In 2006, Dixon et al. published the comprehensive review article entitled “Packed tubular reactor modeling and catalyst design using computational fluid dynamics.” More than one decade later, many researchers have contributed to novel insights, as well as a deeper understanding of the topic. Likewise, complexity has grown and new issues have arisen, for example, by coupling microkinetics with computational fluid dynamics (CFD). In this review article, the latest advances are summarized in the field of modeling fixed-bed reactors with particle-resolved CFD, i.e. a geometric resolution of every pellet in the bed. The current challenges of the detailed modeling are described, i.e. packing generation, meshing, and solving with an emphasis on coupling microkinetics with CFD. Applications of this detailed approach are discussed, i.e. fluid dynamics and pressure drop, dispersion, heat and mass transfer, as well as heterogeneous catalytic systems. Finally, conclusions and future prospects are presented.


Author(s):  
Pious Okekunle ◽  
Akinola Ogunsola ◽  
Oluwapelumi Babayemi ◽  
Emmanuel Abodunrin ◽  
Olanrewaju Daramola

1995 ◽  
Vol 31 (9) ◽  
pp. 137-144 ◽  
Author(s):  
T. Miyahara ◽  
M. Takano ◽  
T. Noike

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.


1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.


1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.


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