Quantitative assessment of the difference in free standard energy of reaction between two enantiomers of a chiral molecule and a chiral surface using a convection-diffusion model coupled to surface reactions
Bieri, M., Bürgi, T.
Université de Neuchâtel, Neuchâtel, Switzerland
Chiral surfaces and interfaces have received considerable interest in recent years due to their importance in separationand sensing of enantiomers, their application in heterogeneous enantioselective catalysis and their possibly decisive role for the origin of biochemical homochirality. In the present work, the interaction of proline with self-assembled monolayers (SAMs) of L-glutathione was ...
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 ...
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 ...
Humboldt Universität Berlin, IGB, Berlin, GERMANY
In vielen Berechnungen des Umweltschutzes, der chemischen Verfahrenstechnik, der Energietechnik und weiteren Bereichen von Wissenschaft und Technik, spielen Transport- und Reaktionsprozesse gleichermaßen eine Rolle. Aufgrund der Wechselwirkung zwischen Transport und Reaktion ist das Verständnis derartiger Systeme schwierig. In der Regel werden daher Modelle eingesetzt, um derartige Situationen ...
Simulation of Differential Ion Mobility (DMS) Principle Coupled with Mass Spectrometry in Atmospheric Pressure
F. Sinatra, T. Wu, A. Avila, E. Nazarov, T. Evans-Nguyen, J. Wang
Draper Laboratory, Tampa, FL, USA
University of South Florida, Tampa, FL, USA
Mass spectrometry is an analytical technique widely used in the scientific community to determine chemical composition of sample compounds. Typically, mass spectrometers perform their analysis under vacuum conditions, though atmospheric pressure mass spectrometers are becoming more prevalent. With the development of atmospheric pressure mass spectrometers, techniques such as FAIMS (Field ...
J. Knox, R. Coker, R. Cummings, C. Gomez, G. Schunk
NASA, Marshall Space Flight Center, Huntsville, AL, USA
Some NASA efforts are focused on improving current systems that utilize fixed beds of sorbent pellets by evaluating structured sorbents, seeking more robust pelletized sorbents, and examining alternate bed configurations to improve system efficiency and reliability. For the bulk separation of CO2 and H2O, temperature changes due to the heat of adsorption are significant, requiring modeling and ...
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 ...
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 ...
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 ...
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 ...