A. Giaccherini , A. Lavacchi ,
 INSTM, Firenze, Italy
 ICCOM - CNR, Firenze, Italy
In this work we report a numerical model of a Rotating Disk Electrode (RDE) voltammetry in a finite size domain. Thus, explaining the discrepancy of the diffusion coefficient obtained from the experimental rotating speed, with respect to the literature data. We achieved a very good agreement at the limiting current and at the unexpected peak for the RDE voltammetry at 2000 rpm and different ...
K. Yadav , A. Mishra ,
 IIT Kanpur, Kanpur, Uttar Pradesh, India
Marangoni flow affects the heat and mass transfer occurring in the molten metal regions in welding and additive manufacturing processes. It originates from the surface tension gradient (∂γ/∂T) induced at the melt pool surface due to the temperature difference. The flow pattern within melt pool affects the segregation and melt-pool shape and size. The flow pattern and therefore the melt pool ...
J. Völler, M. Follmann, C. Bayer, and T. Melin
AVT Chemical Process Engineering, RWTH Aachen University, Aachen, Germany
Low temperature fuel cells require hydrogen of high purity for electricity production to avoid catalyst poisoning. To purify hydrogenrich flue gases from hydrocarbon steam reforming membrane shift reactors with a metal membranes may be utilized. A model of a tubular membrane shift reactor with a hydrogenseparating palladium membrane is modeled in the COMSOL Multiphysics® Chemical Engineering ...
M. Beckmann-Kluge, F. Ferrero, V. Schröder, A. Acikalin, and J. Steinbach
Federal Institute for Materials Research and Testing, Technical University, Berlin, Germany
Tetrafluoroethylene (TFE) is a gas widely employed in industry, which can under specific circumstances experience an exothermic dimerization to octafluorocyclobutane. If the heat generated by this reaction cannot be dissipated to the surroundings, the temperature inside the reactor will continue rising, leading to conditions where TFE can decompose in tetrafluoromethane and carbon black. This ...
Effect of Bed Diffusion and Operating Parameters on Char Combustion in the Context of Underground Coal Gasification
S. Mahajani, and G. Samdani
Indian Institute of Technology Bombay
Char combustion is one of the most important reactions in the process of Underground Coal Gasification (UCG). Experiments are performed in a boat reactor under near isothermal condition to demonstrate effects of heat and mass transfer and bed diffusion through ash layer. To obtain a complete overview of boat experiments and to further get insights, CFD analysis of boat reactor is performed using ...
J. P. Mmbaga, F. Munoz, S. Dhir, R. Gupta, R. E. Hayes, M. Toledo
University of Alberta, Edmonton, AB, Canada
Departamento de Ingenieria Mecanica, Universidad Tecnica Federico Santa Maria, Valparaiso, Chile
Pyrolysis is a key step in the conversion of carbonaceous materials into useful products. In this study, we investigate the pyrolysis of asphaltene and oil shale, both experimentally and numerically. COMSOL Multiphysics® software is used to model the combined effects of fluid flow in porous media, mass transfer of species, heat transfer, and reaction kinetics. Gas evolution and the porosity ...
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 ...
R.R. Thorat, H. Bruining
Petroleum Engineering, CiTG, TU Delft, Delft, The Netherlands
Recovery of oil by gas injection is usually inefficient due to the low viscosity of the gas, which results in bypassing of the oil. By adding surfactant solutions it is possible to get in-situ foam formation. Foam has a much higher “viscosity” and hence does not bypass the oil, leading to enhanced oil recovery. In this context, the foam propagation is studied experimentally and theoretically. We ...
D. Papasidero, F. Manenti
Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Milano, Italy
One big challenge for the food industry is to predict and optimize flavors. The Maillard reaction occurs in food matrices containing carbohydrates and proteins under specific operating conditions. The presented research couples thermal and kinetic modeling to the bread baking process, an ideal field to study this complex set of reactions responsible for many bread flavors. The thermal model ...
P. L. Mills, A. Nagaraj
Department of Chemical & Natural Gas Engineering, Texas A&M University, Kingsville, TX, USA
Department of Environmental Engineering, Texas A&M University, Kingsville, TX, USA
Introduction: Development of next-generation chemical processes that have zero emissions is a key environmental objective for sustainable development. The manufacture of H2SO4 by the air oxidation of SO2 to SO3 is an important technology where an opportunity exists for new catalyst development and process innovation by reducing emissions of unconverted SO2 in process reactor tail gases owing to ...