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 ...
M. Brundu, V. Guida
Procter & Gamble Italia, Pomezia, Roma, Italy
The challenge with the use of Sodium Carbonate Peroxyhydrate (Na2CO3*1.5H2O2) as a bleach source in dry detergent formulations is its lower stability in comparison with other materials, and the risk of quality losses of the product over the shelf life. The issue can be solved with the understanding and modeling of the decomposition mechanism of the powder. It is well known that the decomposition ...
K.O. Lund, C.M. Lord
Kurt Lund Consulting, Del Mar, CA, USA
Lord Engineering Corp., Encinitas, CA, USA
Pressure-drop experiments were conducted for the turbulent, compressible flow of air in a small, slender tube, and modeled with COMSOL heat transfer module, and analytically. A scalar integration variable is introduced which integrates the mass velocity [kg/m²s] over the inlet area and iteratively equates this to the input mass flow [kg/s]. For computation, the temperature specification is ...
Two-Dimensional Modelling of a Non-Isothermal PrOx Reactor with Water Cooling for Fuel Cell Applications
H. Beyer, B. Schönbrod, C. Siegel, M. Steffen, and A. Heinzel
Zentrum für BrennstoffzellenTechnik GmbH, Duisburg, Germany
Institut für Energie und Umweltverfahrenstechnik, University of Duisburg-Essen, Duisburg, Germany
This work treats of a preferential oxidation reactor, which is simulated by a two-dimensional axial symmetric model. The reactor serves as purification of hydrocarbon reformat and converts the CO mole fraction from up to 1 % in the feed gas down to a few ppm at the outlet to deliver a hydrogen rich feed gas for a PEM fuel cell. The model combined chemical kinetic expressions, which were ...
M. Ghadrdan, and H. Mehdizadeh
Department of Chemical Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
Department of Chemical Engineering, Tarbiat Modares University, Tehran, Iran
Interest in the production of hydrogen from hydrocarbons has grown significantly recently. In order to achieve high surface to volume ratio with reasonable pressure drop, monolithic reactors are used. The goal of this work is to develop a two-phase (gas & solid) transient catalytic combustor model using a simplified flow field inside a single channel to test the advantages of the COMSOL ...
Simulation of a Diesel Oxidation Catalyst Used in a NOx Storage and Reduction system for Heavy Duty Trucks
C. Odenbrand, and E. Senar Serra
Department of Chemical Engineering, Lund University, Lund, Sweden
This work concerns the performance of an oxidation catalyst used in a NOx storage and reduction system. The oxidation of NO is the main objective of this study, where the presence of CO and propene has also been taken into account. Experimental data has been determined on a monolithic oxidation catalyst mounted after a heavy duty diesel engine in a rig. The conversion of hydrocarbons is predicted ...
D. Dalle Nogare and P. Canu
Department of Chemical Engineering Principles and Practice, University of Padova, Padova, Italy
This work investigates the effects of boundary conditions on the species profiles in heterogeneous catalysis, with low Péclet systems. Hydrogen combustion in Helium was chosen because of the high diffusivities. Furthermore, already at T=300°C over a Pt catalyst, kinetics is very fast and the composition gradients at the inlet extremely steep. The issue is analyzed with 1D models, ...
Numerical Simulations of Methane Aromatization with and without a Ceramic Hydrogen Separation Membrane
Z. Li, C. Kjølseth, S. Hernandez Morejudo, R. Haugsrud
University of Oslo, Department of Chemistry, FERMiO, Oslo, Norway
Protia, Oslo, Norway
University of Oslo, Department of Chemistry, InGAP, Oslo, Norway
Oxygen-free methane aromatization has been attracting growing attention due to a potential means for producing high valuable products such as aromatics and hydrogen. Many studies have been focused on catalysts screening and characterization, and elementary thermodynamic steps of the reaction. However, little attention has been paid to fluid dynamics which are important for an industrial ...
M. Yang, A. Young, and B. Crittenden
Department of Chemical Engineering University of Bath, Bath, United Kingdom
A small batch stirred cell which is operated at temperatures up to 400 °C and pressures up to 30 bar is used to study fouling behaviors of selected crude oils. COMSOL Multiphysics package is used for the CFD (Computational Fluid Dynamics) and heat transfer modeling for this stirred cell system. The simulation results are validated against the measured temperature data at various axial ...
IFP, Lyon, Vernaison, France
In a search of concepts for innovative reactors allowing CO2 capture in gas turbine, monolith based chemical looping combustion has been identified as a promising concept. A precise simulation of the chemical looping combustion in a channel of monolith is developed to define the design rules and the material specifications. The objective is also to evaluate this innovative process in terms of ...