scholarly journals 3-D Multi-Tubular Reactor Model Development for the Oxidative Dehydrogenation of Butene to 1,3-Butadiene

2020 ◽  
Vol 4 (3) ◽  
pp. 46 ◽  
Author(s):  
Jiyoung Moon ◽  
Dela Quarme Gbadago ◽  
Sungwon Hwang
Keyword(s):  
Oxidative Dehydrogenation ◽  
Model Development ◽  
Tubular Reactor ◽  
Maximum Error ◽  
Coolant Fluid ◽  
Reactor Performance ◽  
Reactor Model ◽  
Catalytic Reactors ◽  
Thermodynamic Conditions ◽  
Scale Design

The oxidative dehydrogenation (ODH) of butene has been recently developed as a viable alternative for the synthesis of 1,3-butadiene due to its advantages over other conventional methods. Various catalytic reactors for this process have been previously studied, albeit with a focus on lab-scale design. In this study, a multi-tubular reactor model for the butadiene synthesis via ODH of butene was developed using computational fluid dynamics (CFD). For this, the 3D multi-tubular model, which combines complex reaction kinetics with a shell-side coolant fluid over a series of individual reactor tubes, was generated using OpenFOAM®. Then, the developed model was validated and analyzed with the experimental results, which gave a maximum error of 7.5%. Finally, parametric studies were conducted to evaluate the effect of thermodynamic conditions (isothermal, non-isothermal and adiabatic), feed temperature, and gas velocity on reactor performance. The results showed the formation of a hotspot at the reactor exit, which necessitates an efficient temperature control at that section of the reactor. It was also found that as the temperature increased, the conversion and yield increased whilst the selectivity decreased. The converse was found for increasing velocities.

scholarly journals Biofilm carrier migration model describes reactor performance

2017 ◽  
Vol 75 (12) ◽  
pp. 2818-2828 ◽  
Author(s):  
Joshua P. Boltz ◽  
Bruce R. Johnson ◽  
Imre Takács ◽  
Glen T. Daigger ◽  
Eberhard Morgenroth ◽  
...  
Keyword(s):  
Plug Flow ◽  
Biofilm Reactor ◽  
Bulk Liquid ◽  
Reactor Performance ◽  
Reactor Model ◽  
Operational Conditions ◽  
Limit Model ◽  
Biofilm Model ◽  
Reactor Models ◽  
The Impact

The accuracy of a biofilm reactor model depends on the extent to which physical system conditions (particularly bulk-liquid hydrodynamics and their influence on biofilm dynamics) deviate from the ideal conditions upon which the model is based. It follows that an improved capacity to model a biofilm reactor does not necessarily rely on an improved biofilm model, but does rely on an improved mathematical description of the biofilm reactor and its components. Existing biofilm reactor models typically include a one-dimensional biofilm model, a process (biokinetic and stoichiometric) model, and a continuous flow stirred tank reactor (CFSTR) mass balance that [when organizing CFSTRs in series] creates a pseudo two-dimensional (2-D) model of bulk-liquid hydrodynamics approaching plug flow. In such a biofilm reactor model, the user-defined biofilm area is specified for each CFSTR; thereby, Xcarrier does not exit the boundaries of the CFSTR to which they are assigned or exchange boundaries with other CFSTRs in the series. The error introduced by this pseudo 2-D biofilm reactor modeling approach may adversely affect model results and limit model-user capacity to accurately calibrate a model. This paper presents a new sub-model that describes the migration of Xcarrier and associated biofilms, and evaluates the impact that Xcarrier migration and axial dispersion has on simulated system performance. Relevance of the new biofilm reactor model to engineering situations is discussed by applying it to known biofilm reactor types and operational conditions.

Heat Transfer Modeling in a Counter-Current Moving-Bed Tubular Reactor for High-Temperature Thermochemical Energy Storage

2021 ◽  
Author(s):  
Wei Huang ◽  
Eric Million ◽  
Kelvin Randhir ◽  
Joerg Petrasch ◽  
James Klausner ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Tubular Reactor ◽  
Operating Conditions ◽  
Transfer Model ◽  
Reactor Performance ◽  
Low Oxygen ◽  
Moving Bed ◽  
Oxidation Reactor ◽  
Counter Current

Abstract An axisymmetric model coupling counter-current gas-solid flow, heat transfer, and thermochemical redox reactions in a moving-bed tubular reactor was developed. The counter-current flow enhances convective heat transfer and a low oxygen partial pressure environment is maintained for thermal reduction within the reaction zone by using oxygen depleted inlet gas. A similar concept can be used for the oxidation reactor which releases high-temperature heat that can be used for power generation or as process heat. The heat transfer model was validated with published results for packed bed reactors. After validation, the model was applied to simulate the moving-bed reactor performance, through which the effects of the main geometric parameters and operating conditions were studied to provide guidance for lab-scale reactor fabrication and testing.

A Computational Study of the Thermodynamic Conditions Leading to Autoignition in Nanosecond Pulsed Discharges

2019 ◽  
Author(s):  
Vyaas Gururajan ◽  
Riccardo Scarcelli ◽  
Anand Karpatne ◽  
Douglas Breden ◽  
Laxminarayan Raja ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Computational Study ◽  
Batch Reactor ◽  
Chemical Kinetic ◽  
Electrode Erosion ◽  
Reactor Model ◽  
Modeling Tools ◽  
Thermodynamic Conditions ◽  
Streamer Propagation ◽  
Pulsed Discharges

Abstract Nanosecond pulsed discharges have attracted the attention of engine manufacturers due to the possibility of attaining distributed ignition sites that accelerate burn rates while resulting in very little electrode erosion. Multidimensional modeling tools currently capture the electrical structure of such discharges accurately, but resolving the chemical structure remains a challenging problem owing to the disparity of time-scales in streamer propagation (nanoseconds) and ignition phenomena (microseconds). The purpose of this study is to extend multidimensional results towards resolving the chemical structure in the wake of streamers (or the afterglow) by using a batch reactor model. This can afford the use of very detailed chemical kinetic information. The full non-equilibrium nature of the electrons is taken into account, along with fast gas heating, shock wave propagation, and thermal diffusion. The results shed light on ignition phenomena brought about by such discharges.

scholarly journals Treatment of milk wastewater using up-flow anaerobic packed bed reactor

2015 ◽  
Vol 17 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Kiran D. Bhuyar ◽  
Sanvidhan G. Suke ◽  
S.D. Dawande
Keyword(s):  
Rural Areas ◽  
Biogas Production ◽  
Packed Bed ◽  
Dairy Wastewater ◽  
Packed Bed Reactor ◽  
Reactor Performance ◽  
Reactor Model ◽  
Loading Rates ◽  
Empirical Relations ◽  
Low Costs

Abstract An up-flow anaerobic packed bed (UAPB) bioreactor has been designed on a laboratory-scale and used for treatment of domestic milk wastewater (MWW). The UAPB bioreactor was operated under mesophilic temperature (37-45°C) and reactor performance evaluated at various organic loading rates of MWW effluent at hydraulic retention times (HRT) of 1, 2, and 3 d based on the removal of organic matter COD, BOD, SS, pH changes and biogas production. The kinetic parameters were estimated using the experimental data to develop a reactor model. Empirical relations were generated for the characteristics like COD, BOD, and SS using modeling equations. This study proved that the UAPB reactor performance is excellent for treating domestic MWW and easily biodegradable dairy wastewater influent. Hence, this system can operate at low costs, making it suited for use in the developing countries and rural areas.

MODAL DECOMPOSITION OF A NONLINEAR TUBULAR REACTOR MODEL: A CONTROL PERSPECTIVE

2002 ◽  
Vol 35 (1) ◽  
pp. 489-494 ◽  
Author(s):  
Jennifer Brown ◽  
Denis Dochain ◽  
Michel Perrier ◽  
Fraser Forbes
Keyword(s):  
Tubular Reactor ◽  
Reactor Model ◽  
Modal Decomposition

scholarly journals Modeling and Simulation of the Hydrogenation ofα-Methylstyrene on Catalytically Active Metal Foams as Tubular Reactor Packing

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Farzad Lali ◽  
Felix-Aron Pahner ◽  
Rüdiger Lange
Keyword(s):  
Bubbly Flow ◽  
Experimental Studies ◽  
Tubular Reactor ◽  
Packed Bed ◽  
Hydrogenation Reaction ◽  
Experimental Results ◽  
Packed Bed Reactor ◽  
Orthogonal Collocation ◽  
Reactor Model ◽  
Catalytically Active

This work presents a one-dimensional reactor model for a tubular reactor packed with a catalytically active foam packing with a pore density of 30 PPI in cocurrent upward flow in the example of hydrogenation reaction ofα-methylstyrene to cumene. This model includes material, enthalpy, and momentum balances as well as continuity equations. The model was solved within the parameter space applied for experimental studies under assumption of a bubbly flow. The method of orthogonal collocation on finite elements was applied. For isothermal and polytropic processes and steady state conditions, axial profiles for concentration, temperature, fluid velocities, pressure, and liquid holdup were computed and the conversions for various gas and liquid flow rates were validated with experimental results. The obtained results were also compared in terms of space time yield and catalytic activity with experimental results and stirred tank and also with random packed bed reactor. The comparison shows that the application of solid foams as reactor packing is advantageous compared to the monolithic honeycombs and random packed beds.

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