M. Al-Rawashdeh[1,2], V. Hessel[1,2], P. Löb, and F. Schönfeld
Institut für Mikrotechnik Mainz GmbH, Mainz, Germany
Department of Chemical Engineering and
Chemistry, Eindhoven University of Technology, Eindhoven, Netherlands
Gas-liquid falling film microreactors carry out fast exothermic and mass transfer limited reactions. Since the major rate limiting steps occur on the liquid side, it is important to account for a realistic liquid film profile within the reactor simulation. Based on realistic channel geometry and liquid menisci profiles, we describe the liquid film thicknesses, flow velocities, species transport ...
I. Borsi and A. Fasano
Dipartimento di Matematica U. Dini, Università di Firenze, Firenze, Italy
In this paper we present a model to describe the process of waste water filtration based on hollow-fibre membrane filters. In particular, we deal with membranes whose pores diameter is in the range 0.01-0.1 µm. The main problem in these filtering systems is the membrane fouling. The mathematical model consists in two equations for the Darcy's flow through the filter, coupled with an ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...