Diffusion and Reaction in Fe-Based Catalyst for Fischer-Tropsch Synthesis Using Micro Kinetic Rate Expressions - new
A. Nanduri, P. L. Mills
Department of Chemical & Natural Gas Engineering, Texas A&M University, Kingsville, TX, USA
Fischer-Tropsch synthesis (FTS) is a highly exothermic polymerization reaction of syngas (CO+H2) in the presence of Fe/Co/Ru-based catalysts to produce a wide range of paraffins, olefins and oxygenates, often known as syncrude. Multi-Tubular Fixed Bed Reactors (MTFBR) and Slurry Bubble Column Reactors (SBCR) are widely employed for FTS processes. The scale-up of MTFBR is complicated by the ...
V. Runkana, S. Maheshwari, S. Cherlo, RSR Thavva
Tata Research Development and Design Centre, Tata Consultancy Services Ltd., Pune, Maharashtra, India
Polymer hydrogels are commonly used as carriers or vehicles for the controlled release of drugs, primarily because of their bio-compatibility and because rates of drug release can be controlled by manipulating polymer properties like molecular weight, cross linking ratio, etc. Drugs can be released for prolonged periods of time through polymer hydrogels [1, 2]. Sustained drug release may ...
J. W. McTernan, I. Abu-Mahfouz
Buell Division of Fisher-Klosterman Inc., Lebanon, PA, USA
Pennsylvania State University - Harrisburg, Middletown, PA, USA
Fluidized Catalytic Cracking (FCC) regenerators utilize a fluidized bed to facilitate catalyst regeneration. Cyclones are used to separate the catalyst from the gas stream and return the catalyst to the fluidized bed; as the gas progresses through the system for further processing. This is accomplished by centrifugal forces that force the particles to dislodge from the fluid flow. The fluid exits ...
Modeling of Packed Bed Reactors: Hydrogen Production by the Steam Reforming of Methane and Glycerol - new
A. Dixon, B. MacDonald, A. Olm
Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA, USA
The conventional route to hydrogen production is by steam reforming of methane (MSR) in a multitubular packed bed. With the increasing use of biodiesel as a renewable fuel, interest has grown in steam reforming of the excess glycerol produced as a side product (GSR). We use COMSOL Multiphysics® software to model a tubular packed bed reactor, solving a single pellet model at each point. The ...
Simulation of the Temperature Profile During Welding with COMSOL Multiphysics® Software Using Rosenthal's Approach - new
A. Lecoanet, D. G. Ivey, H. Henein
Department of Chemical & Materials Engineering, University of Alberta, Edmonton, AB, Canada
A 3D finite element analysis is carried out, using COMSOL® software, to reproduce the thermal profile obtained with Rosenthal’s equation. The implemented heat transfer equation has been modified as a means to approximate Rosenthal’s solution. An analysis of the differences between the simulation and Rosenthal’s solution, when the geometry of the domain and the source are changed, has been ...
J. T. Andrews, R. Choubey, O P Choudhary, N. Malviya, A. Patel, M. Kumar, S. Chouksey, J. Solanki
National MEMS Design Center, Department of Applied Physics, Shri G S Institute of Technology & Science, Indore 452003 MP, India
A logic gate performs a certain Boolean logic operation on one or more logical inputs and produces a single logical output. The logic values are either “true” or “false.” Logic gates are bistable devices, that is, they may yield one of these two possible stable outputs. The NAND logic is a universal gate; any logic operation can be performed with various combinations of NAND logics. Many ...
Y. T. Habtemichael, R. T. Kiflemariam, H. R. Fuentes
Department of Civil & Environmental Engineering, Florida International University, Miami, FL, USA
Department of Mechanical & Materials Engineering, Florida International University, Miami, FL, USA
Seawater intrusion into coastal aquifers is usually modeled by using transport models that include account for the effect of variable-density on flow. Variable-density models can be validated with the Henry and Elder benchmark problems. However, when mixed convective flow is simulated under variable density conditions, it is susceptible to physical and numerical instabilities. The purpose of this ...
M. Tehler, and S. Jonsson
Materials Science and Engineering, Royal Institute of Technology, Stockholm, Sweden
The present work describes the first steps in creating a robust material model able to predict volume changes due to thermal expansion and phase transformations.A dilatometer test is simulated starting from room temperature, with an original microstructure constituting a mixture of ferrite and pearlite. During heating, the structure transforms to austenite, which upon quenching will transform ...
Simulation and Performance of Pulsed Pipe Flow Mixing in Non-Newtonian Liquid Dispersion Media - new
T. Koiranen, J. Tamminen, A. Häkkinen
LUT Chemtech, Lappeenranta University of Technology, Lappeenranta, Finland
A non-newtonian oil dispersion in a pulsed flow pipe system was mixed in a circulation loop pipe with custom-made static mixers. The rotor-pump was used in a non-pulsed flow circulation, and diaphragm pump for pulsed flow circulation. Modeling was done using COMSOL Multiphysics® 4.3b. The simulations were performed using single-phase laminar flow model in steady-state and in time-dependent modes ...
M. Mattheakis, C. Athanasopoulos, G. P. Tsironis
University of Crete, Heraklion, Greece
We present numerical simulations for the propagation of surface plasmon polaritons in a dielectric-metal-dielectric waveguide using COMSOL Multiphysics® software. We show that the use of an active dielectric with gain that compensates metal absorption losses enhances substantially plasmon propagation. Furthermore, the introduction of the active material induces, for a specific gain value, a ...