Chalmers University of Technology, Sweden
In this paper, we perform simulations of the auto-thermal reforming of a hydrocarbon fuel in a monolithic reactor. The partial differential equations describing mass, heat and momentum transport were formulated and solved using COMSOL Multiphysics. It was found that mass transport limitations in the washcoat could also severely limit the rate of the reforming reaction. Heat transport ...
Institut für Automatisierungstechnik, Otto-von-Guericke Universität, Magdeburg, Germany
Preparative chromatography is an important separation method where the simulated moving bed (SMB) technology is an increasingly used separation process for binary mixtures. Several chromatographic columns are arranged in a ring where the feedings and drains are changed cyclically to maintain a continuous separation. For this reason, an adaptive controller is proposed to adjust the flow rates ...
Computations on the coupled heat and mass transfer during fires in bulk materials, coal deposits and waste dumps
Krause, U., Schmidt, M., Lohrer, C.
Federal Institute for Materials Research and Testing (BAM), Division II.2 “Reactive Substances and systems”, Berlin, Germany
In porous combustible matter low-rate oxidation takes place at ambient conditions. In large stockpiles of bulk goods, coal heaps, waste dumps etc. it may occur that the heat released by the oxidation reaction is not fully transmitted to the surroundings but raises the temperature within the deposit. This triggers a positive feed-back loop since the oxidation rate increases with temperature. The ...
Fundamental Three Dimensional Modeling and Parameter Estimation of a Diesel Oxidation Catalyst for Heavy Duty Trucks
A. Holmqvist and C.U.I. Odenbrand
Department of Chemical Engineering, Faculty of Engineering, LTH, Lund University, Lund, Sweden
Mathematical optimization can be used as a computational engine to generate the best solution for a given problem in a systematic and efficient way. In the context of monolithic converter systems, the parameter estimation problem (or inverse problem) is solved using Partial Differential Equations (PDE)-based models of the physical system coupled with an optimization algorithm. These problems are ...
A theoretical and experimental analysis of membrane bioreactors behavior in unsteady-state conditions
Department of Chemical Engineering and Materials University of Calabria, Rende (CS), ITALY
The behavior of hollow fiber membrane bioreactors operating in recycle configuration is characterized from both theoretical and experimental point of view. The theoretical model is based on the unsteady-state balance equations governing momentum and mass transfer within the regions that can be identified in a hollow fiber reacting system with immobilized enzyme, coupled to the unsteady-state mass ...
Study of the CO2 Transfer Rate in a Reacting Flow for the Refined Sodium Bicarbonate Production Process
C. Wylock, A. Larcy, P. Colinet, T. Cartage, and B. Haut
Université Libre de Bruxelles, Brussels, Belgium
Solvay S.A., Brussels, Belgium
This work deals with the quantification of the CO2 transfer rate from a bubble to the surrounding liquid in a bubble column. A model is successfully developed using COMSOL Multiphysics. The validated model is used to study the enhancement influence of chemical reactions on the transfer rate. Moreover, the results of this study are compared with a classical 1-D approach and excellent comparison is ...
C. K. Subramaniam, Muthuraja
School of Electronics Engineering, VIT University, Vellore, Tamil Nadu, India
The Direct Methanol Fuel Cell (DMFC) working is dependent on the concentration of methanol in water before it is introduced in the anode. DMFC has a high energy density when generating electrical power from fuel, and is an attractive power source for portable devices. A fundamental limitation in DMFC technology is methanol crossover. In this process methanol diffuses from the anode through the ...
B. Niu, W. Yan, A.A. Shapiro, and E.H. Stenby
Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
As an effective method to cope with green-house gas emission, and to enhance oil recovery, injection of carbon dioxide into oil reservoirs has obtained increasing attentions. The flooding process involves complex phase behavior among oil, brine and CO2, and geochemical reaction between CO2 and rock. COMSOL Multiphysics® was first applied to simulating two flooding processes with known ...
C. Bayer, S. Stiefel, M. Follmann, and T. Melin
AVT Chemical Process Engineering, RWTH Aachen University, Aachen, Germany
Reactive extraction of organic acids from an aqueous solution to an alkaline stripping fluid is based on a selective barrier allowing permeation of non-polar molecules, which subsequently react with the stripping agent. The shift from the organic acid to its base induced by the chemical equilibrium enhances mass transfer inside the membrane’s porous substructure. A model of the porous layer ...
G. Carrieri, M. V. De Bonis, and G. Ruocco
CFDfood - DITEC, Università degli studi della Basilicata, Potenza, Italy
Heat related processing can have various effects on food and food ingredients. Besides the intended effects to improve safety and quality of the products, undesired changes, nutritional or toxicological, can also occur. In this area, acrylamide formation occupies an important role, as this molecule has been considered as a potential cause of cancer. The possibility that this molecule may be ...