CFD Simulation of Catalytic Oxidation of Ethyl Acetate over Cr-HZSM-5 Catalyst

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Aligholi Niaei ◽  
Darioush Salari ◽  
Seyed Ali Hosseini ◽  
Reza Nabavi ◽  
Azadeh Jodaei
Keyword(s):  
Ethyl Acetate ◽  
Catalytic Oxidation ◽  
Atmospheric Pressure ◽  
Cfd Simulation ◽  
Heterogeneous Reaction ◽  
Three Dimensional ◽  
Particle Diameter ◽  
Complex Catalyst ◽  
Region Temperature ◽  
Different Temperatures

This paper reports the results of a study on a three-dimensional computational fluid dynamics (CFD) simulation for a study of gas catalytic oxidation of ethyl acetate over Cr-HZSM-5 catalyst. A gaseous stream, containing N2, O2 and ethyl acetate (in which ethyl acetate concentration in mixture was 2000 ppmV) with GHSV= 32000 h-1 as the feed, was inserted into a glass reactor, charged with a required amount of Cr-HZSM-5 catalyst under atmospheric pressure. The catalytic reactions were allowed to occur at atmospheric pressure and at different temperatures. Fluent 6.2 was used for the simulation of the catalytic process. The simulation was present for the model geometry of 20 solid spheres in a tube with a tube-to-particle diameter ratio equal to 2. Results of the simulation showed a good agreement with the experimental results. It was experimentally, and by simulation, observed that the increasing of the temperature and the decreasing of the inlet mass flow rate led to the increase of ethyl acetate conversion. Velocity vector profiles of the fluid were obtained with an emphasis on the catalytic region. Temperature and pressure contours of the fluid inside the reactor were predicted by simulation. Furthermore, the surface deposition rate of oxygen (during the step of catalyst oxidation) and species concentration along the reactor were obtained. This study revealed that CFD is the best tool to study detailed homogeneous and heterogeneous reaction schemes, even for complex catalyst geometries.

Liquid–liquid equilibrium data for the systems {LTTM+benzene+hexane} and {LTTM+ethyl acetate+hexane} at different temperatures and atmospheric pressure

2013 ◽  
Vol 360 ◽  
pp. 54-62 ◽  
Author(s):  
Agustin S.B. Gonzalez ◽  
María Francisco ◽  
Guillermo Jimeno ◽  
Sara Lago García de Dios ◽  
Maaike C. Kroon
Keyword(s):  
Ethyl Acetate ◽  
Atmospheric Pressure ◽  
Liquid Equilibrium ◽  
Equilibrium Data ◽  
Different Temperatures

Numerical Simulation of a Mini-Channel Three-Way Catalytic Converter

2010 ◽  
Author(s):  
M. H. Akbari ◽  
R. Roohi ◽  
S. A. Asaee
Keyword(s):  
Conversion Efficiency ◽  
Single Channel ◽  
Heterogeneous Reaction ◽  
Catalytic Converter ◽  
Three Dimensional ◽  
Space Velocity ◽  
Kinetic Mechanism ◽  
Operating Conditions ◽  
Three Dimensional Model ◽  
Different Temperatures

A three-dimensional model is developed to simulate the behavior of a single-channel three-way catalytic converter. The flow regime is assumed to be steady and laminar, and the channel walls are considered as isothermal. A multi-step, global heterogeneous reaction mechanism with 16 reactions and 11 species is used in this investigation to enhance the accuracy of the results. The chemical reactions are assumed to occur only on the reactor walls. The developed model is validated against available experimental data for stoichiometric operating conditions. The effect of the feed temperature on the conversion efficiency of the main pollutant components is studied. The light-off temperature for the stoichiometric A/F is found to be about 530 K for CO, NO and UHC, and 425 K for H2 conversion. The model is also applied to predict the effect of reactor length and inlet mixture space velocity on the conversion efficiency at two different temperatures. By using the same kinetics a well-stirred, unsteady model is also developed to identify the sensitivity of the multi-step kinetic mechanism to the mixture composition. The effect of mole fraction variation of each species on the conversion of other mixture components is investigated.

scholarly journals CFD simulation of DC-discharge in airflow

2021 ◽  
Vol 2100 (1) ◽  
pp. 012015
Author(s):  
D A Tarasov ◽  
A A Firsov
Keyword(s):  
Atmospheric Pressure ◽  
Discharge Channel ◽  
Cfd Simulation ◽  
Fluid Model ◽  
Three Dimensional ◽  
Flow Discharge ◽  
The Core ◽  
Initial Discharge ◽  
Dc Discharge ◽  
Partial Channel

Abstract The main purpose of this work is to simulate a dynamics of DC discharge in a subsonic airflow. The calculations were performed in the FlowVision 3.12.01 software package. The single-fluid model (MHD approach) of equilibrium plasma was used while the initial discharge channel was set manually. Cylindrical coaxially arranged electrodes were located in the central part of the calculation area, in the core of the airflow. A 5A DC discharge at atmospheric pressure was considered, as well as a simple model of a re-breakdown between parts of discharge filament. In this work, three-dimensional distributions of temperature and current density were obtained during an evolution of discharge in a flow. Discharge channel extension by the airflow and partial channel decay after the re-breakdown process were shown.

scholarly journals A Three-Dimensional Numerical and Multi-Objective Optimal Design of Wavy Plate-Fins Heat Exchangers

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Chao Yu ◽  
Xiangyao Xue ◽  
Kui Shi ◽  
Mingzhen Shao
Keyword(s):  
Heat Exchangers ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Basis Functions ◽  
Approximation Model ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Colburn Factor ◽  
Heat Exchange Efficiency

This paper presents a method for optimizing wavy plate-fin heat exchangers accurately and efficiently. It combines CFD simulation, Radical Basis Functions (RBF) with multi-objective optimization to improve the performance. The optimization of the Colburn factor j and the friction coefficient f is regarded as a multi-objective optimization problem, due to the existence of two contradictory goals. The approximation model was obtained by Radical Basis Functions, and the shape of the heat exchanger was optimized by multi-objective genetic algorithm (MOGA). The optimization results showed that j increased by 17.62% and f decreased by 20.76%, indicating that the heat exchange efficiency was significantly enhanced and the fluid structure resistance reduced. Then, from the aspects of field synergy and tubulence energy, the performance advantage of the optimized structure was further confirmed.

Three-dimensional CFD simulation of anaerobic reactions in a continuous packed-bed bioreactor

2021 ◽  
Author(s):  
Sasan Zarei ◽  
Seyyed Mohammad Mousavi ◽  
Teimour Amani ◽  
Mehrdad Khamforoush ◽  
Arezou Jafari
Keyword(s):  
Cfd Simulation ◽  
Three Dimensional ◽  
Packed Bed ◽  
Packed Bed Bioreactor

Analysis of a Virtual Prototype First-Stage Rotor Blade Using Integrated Computer-Based Design Tools

2006 ◽  
Author(s):  
Michel Arnal ◽  
Christian Precht ◽  
Thomas Sprunk ◽  
Tobias Danninger ◽  
John Stokes
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Thermal Loading ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Life Assessment ◽  
Element Analysis ◽  
Pressure Losses ◽  
Cooling Channels ◽  
Internally Cooled

The present paper outlines a practical methodology for improved virtual prototyping, using as an example, the recently re-engineered, internally-cooled 1st stage blade of a 40 MW industrial gas turbine. Using the full 3-D CAD model of the blade, a CFD simulation that includes the hot gas flow around the blade, conjugate heat transfer from the fluid to the solid at the blade surface, heat conduction through the solid, and the coolant flow in the plenum is performed. The pressure losses through and heat transfer to the cooling channels inside the airfoil are captured with a 1-D code and the 1-D results are linked to the three-dimensional CFD analysis. The resultant three-dimensional temperature distribution through the blade provides the required thermal loading for the subsequent structural finite element analysis. The results of this analysis include the thermo-mechanical stress distribution, which is the basis for blade life assessment.

scholarly journals Tephra4D: A Python-Based Model for High-Resolution Tephra Transport and Deposition Simulations—Applications at Sakurajima Volcano, Japan

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 331
Author(s):  
Kosei Takishita ◽  
Alexandros P. Poulidis ◽  
Masato Iguchi
Keyword(s):  
Scale Effects ◽  
Three Dimensional ◽  
Particle Diameter ◽  
Terminal Velocity ◽  
Diameter Distribution ◽  
Velocity Variation ◽  
Small Scale ◽  
Modified Model ◽  
Sakurajima Volcano ◽  
Ash Transport

Vulcanian eruptions (short-lived explosions consisting of a rising thermal) occur daily in volcanoes around the world. Such small-scale eruptions represent a challenge in numerical modeling due to local-scale effects, such as the volcano’s topography impact on atmospheric circulation and near-vent plume dynamics, that need to be accounted for. In an effort to improve the applicability of Tephra2, a commonly-used advection-diffusion model, in the case of vulcanian eruptions, a number of key modifications were carried out: (i) the ability to solve the equations over bending plume, (ii) temporally-evolving three-dimensional meteorological fields, (iii) the replacement of the particle diameter distribution with observed particle terminal velocity distribution which provides a simple way to account for the settling velocity variation due to particle shape and density. We verified the advantage of our modified model (Tephra4D) in the tephra dispersion from vulcanian eruptions by comparing the calculations and disdrometer observations of tephra sedimentation from four eruptions at Sakurajima volcano, Japan. The simulations of the eruptions show that Tephra4D is useful for eruptions in which small-scale movement contributes significantly to ash transport mainly due to the consideration for orographic winds in advection.

Photocatalytically Active γ-WO3 Films from the Atmospheric Pressure CVD of WOCl4 with Ethyl Acetate or Ethanol.

ChemInform ◽  
2004 ◽  
Vol 35 (37) ◽  
Author(s):  
Shane O'Neill ◽  
Ivan P. Parkin ◽  
Robin J. H. Clark ◽  
Andrew Mills ◽  
Nickolas Elliott
Keyword(s):  
Ethyl Acetate ◽  
Atmospheric Pressure
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