Danish Technological Institute, Aarhus C, Denmark
The use of the finite element method for understanding and analyzing the freezing and drying processes of food products is in focus in this paper. The objective of this study is to develop a model that can predict temperature distribution and weight loss of food products during the freezing and drying processes. The problem was solved by utilizing heat, mass transfer and moving mesh model. In ...
S. Curcio and M. Aversa
Department of Engineering Modeling, University of Calabria, Arcavacata di Rende, CS, Italy
The aim of the present work is the formulation of a theoretical model describing the transport phenomena involved in food drying process. The attention has been focused on the simultaneous transfer of momentum, heat and mass occurring in a convective drier where hot dry air flows, in turbulent conditions, around the food sample. The proposed model does not rely on the specification of interfacial ...
T. C. Zhu, B. Liu
University of Pennsylvania, Philadelphia, PA, USA
Singlet oxygen (1O2) is the major cytotoxic agent that kills cells during photodynamic therapy (PDT). Based on a previously-developed model, the distance-dependent reacted 1O2 can be numerically calculated using finite-element method. We improved the model to include microscopic kinetic equations of oxygen diffusion from uniformly distributed blood vessels to the adjacent tissue. The blood vessel ...
L. Z. Tong
Keisoku Engineering System Co., Ltd., Tokyo, Japan
The plasmas generated in water involve various physical phenomena such as flows agitated by bubbles, high electric fields for breakdown, discharges in bubbles with size variation, and so on. In this paper, studies have been made on the simulation of plasmas generated in bubbles with size variation. The species taken in account include electrons, three kinds of ions, and ten kinds of neutral ...
Numerical Modeling and Performance Optimization Study of a Dehumidification Process in Nuclear Waste Storage
Sogin Spa, Rome, Italy
One of the main parameters to consider during the nuclear waste storage design phase is the drum corrosion risk. The humid-air corrosion models available in literature predict that, for carbon steel, the phenomena start to become appreciable for relative humidity (RH) values close to 65%. In general, the corrosion rate increases exponentially with relative humidity above the RH threshold. To ...
A COMSOL Multiphysics®-based Model for Simulation of Methane-Hydrate Dissociation by Injection of Superheated Carbon Dioxide
M. Gharasoo, C. Deusner, N. Bigalke, M. Haeckel
Department of Marine Geosystems, GEOMAR - Helmholtz Centre for Ocean Research, Kiel, Germany
Immense amounts of methane are stored as gas-hydrate deposits in deep layers of marine sediments. This has raised considerable interest to develop strategies for producing natural gas from marine hydrates. One potential production strategy is the injection of supercritical CO2 into methane hydrate-bearing sand layers to release the CH4 as a gas and sequester the CO2 as hydrate. We used COMSOL ...
Sulfur Deactivation Effects on Catalytic Steam Reforming of Methane Produced by Biomass Gasification
P. Sadooghi, R. Rauch
Vienna University of Technology, Vienna, Austria
Sulfur, which is incorporated in the biomass structure, is released into the product gas during gasification as hydrogen sulfide. Hydrogen sulfide is known to deactivate nickel based steam reforming catalysts by chemisorption on the metal surface during steam reforming process. Desulfurization has a negative effect on the process efficiency therefore steam reforming has to be run without ...
W. Beckert, M. Dannowski, L. Wagner, J. Adler
Fraunhofer IKTS, Dresden, Germany
The 3D unit cell model approach offers an efficient tool to analyze the influences of geometrical design (channel shape and arrangement, filter length, wall thickness) and filter material properties (permeability, soot loading characteristics) on the performance of ceramic particle filter structure in the soot loading process, assessed by pressure loss and soot loading capacity. It does correctly ...
Kinetics of Carbon Dioxide Absorption into Mixed Aqueous Solutions of MDEA and MEA using Laminar Jet Apparatus and Numerically Solved Absorption-Rate/Kinetic Model
M. Edali1, A. Aboudheir2, and R. Idem1
1Process Systems Engineering, University of Regina, Regina, SK, Canada
2HTC Purenergy, Regina, SK, Canada
The experimental kinetic data obtained with a laminar jet apparatus for the absorption of carbon dioxide (CO2) in CO2 loaded mixed solutions of mixed MDEA and MEA were interpreted with the aid of a comprehensive numerically-solved absorption rate/kinetic model. The partial differential equations in this model were solved by two numerical techniques; the finite difference method (FDM) based on an ...
A. Nardi, E. Abarca, F. Grandia, J. Molinero
Amphos 21, Barcelona, Spain
The capture and storage of CO2 in deep geological formations is one of the proposed solutions to reduce CO2 emissions to the atmosphere. CO2 is injected as a supercritical fluid deep below a confining geological formation that prevents its return to the atmosphere. In general, four trapping mechanisms are expected, which are of increasing importance through time: (1) structural, (2) residual ...