68 research outputs found
Development and Utilization of an E-learning Course on Heat Exchangers at ENSIC
No full textInternational audienceThis paper deals with the development and utilization of an e-learning course at ENSIC in France. Some definitions and examples of problem based learning (PBL) or e-learning utilizations in the world of chemical engineering are first given. This survey results from discussions held in the frame of the Working Party on Education of the European Federation of Chemical Engineering. The e-learning course developed at ENSIC is described and its use, according to an original pedagogy mixing e-learning and PBL, is detailed. The results show that this new pedagogy does not reduce the time of training but induces much more active learning, a better comprehension of technology and the possibility for the students to progress at their own rhythm. Author(s): E. Schaer 1, *, | C. Roizard 2, | N. Christmann 3, | A. Lemaitre
Data supporting the validation of a simulation model for multi-component gas separation in polymeric membranes
No full textAbstractThe article describes data concerning the separation performances of polymeric hollow-fiber membranes.The data were obtained using a model for simulating gas separation, described in the research article entitled “Interplay of inlet temperature and humidity on energy penalty for CO2 post-combustion capture: rigorous analysis and simulation of a single stage gas permeation process” (L. Giordano, D. Roizard, R. Bounaceur, E. Favre, 2016) [1]. The data were used to validate the model by comparison with literature results. Considering a membrane system based on feed compression only, data from the model proposed and that from literature were compared with respect to the molar composition of permeate stream, the membrane area and specific energy requirement, varying the feed pressure and the CO2 separation degree
REMOVED: CO2 Selective Membrane Materials on the Basis of Poly(Vinyltrimethylsilane)-graft-poly(Ethylene Glycol)
No full textThis article has been removed: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been removed at the request of the Executive Publisher.This article has been removed because it was published without the permission of the author(s)
Photoinduced Electron Transfer as a Trigger for Molecular and Supramolecular Metamorphism
No full textInternational audienceThe key elements in the development of nanoscience are to observe, modify and control mater at the nanoscale. One strategy proposed to meet these immense challenges is to develop responsive molecular or supramolecular systems for which a structural reorganization is obtained when exposed to an external stimulus: this phenomenon is known as metamorphism. Systems that endure structural changes leading to major modification of macroscopic properties are of great interest for the controlled capture and release of guest molecules, the development of molecular machines and molecular electronics. The strategy developed at the Chemistry Laboratory of ENS Lyon is to exploit the switching and assembly properties of π-conjugated organic radicals that can be generated in-situ by electrical or light excitation.[1–3] This concept is based on molecular or supramolecular engineering strategies aiming at promoting the formation of -dimers in solution under usual conditions of temperature and concentration. A first approach consists in favoring the formation of π-dimers inside cavitands molecules such as cucurbituril in order to control the reversible association/dissociation of molecular building blocks into 2D-supramolecular assembly.[1] Another approach consists in connecting viologen subunits by labile coordination bond or with mobile covalent linker in order to guide and facilitate an electron-transfer triggered switching.[2,3] These strategies are very promising for the development of new soft-materials such as gels with switchable properties.[3–5]References[1] S. Chowdhury, Y. Nassar, L. Guy, D. Frath, F. Chevallier, E. Dumont, A. P. Ramos, G. J.-F. Demets, and C. Bucher, Electrochim. Acta, 316, 79–92 (2019).[2] C. Kahlfuss, S. Chowdhury, A. F. Carreira, R. Grüber, E. Dumont, D. Frath, F. Chevallier, Eric-Saint-Aman, and C. Bucher, Inorg. Chem., 60, 3543–3555 (2021).[3] C. Kahlfuss, T. Gibaud, S. Denis-Quanquin, S. Chowdhury, G. Royal, F. Chevallier, E. Saint-Aman, and C. Bucher, Chem. Eur. J., 24, 13009–13019 (2018).[4] S. Chowdhury, Q. Reynard-Feytis, C. Roizard, D. Frath, F. Chevallier, C. Bucher, and T. Gibaud, J. Phys. Chem. B, 125, 12063–12071 (2021).[5] C. Roizard, V. Andrieux, S. Al Shehimy, S. Chowdhury, Q. Reynard-Feytis, C. Kahlfuss, E. Saint-Aman, F. Chevallier, C. Bucher, T. Gibaud, and D. Frath, ECS Adv., 1, 020502 (2022)
Preparation and study of crosslinked polyurethane films to fractionate toluene–n-heptane mixtures by pervaporation
No full text
Surface asperity flattening in sheet metal forming — A 3-D relocation stylus profilometric study
No full textPotentials of pervaporation to assist VOCs' recovery by liquid absorption
No full textInternational audienceGas treatment by liquid absorption is a well-known process to remove volatile organic compounds (VOCs) from industrial waste gases. Usually the liquid is an organic solvent of high boiling point; however, after VOCs' absorption it must be regenerated for the possible reuse and this step is classically achieved by heating the liquid. The paper presents the work directed to investigate an alternative regeneration step based on a liquid–vapour membrane separation, i.e. pervaporation. Because most of the energy required in pervaporation processes is consumed to remove the minor component from the initial mixture by selective permeation through the membrane, one can expect a significant energy cut in the operational costs linked to the regeneration of the liquid if the pervaporation step can substitute the heating one. The results reported here show that the technological possibility to use pervaporation is first governed by the stability of the membrane in the absorption liquid. The viability of the overall process is actually controlled by the mutual affinity between the VOCs, the solvent phase and the polymeric material. As a matter of fact, whereas VOCs have to exhibit strong affinities to both the solvent and the membrane material, the polymer has to be well resistant and even repellent to the solvent to avoid the possible sorption in the membrane that would drastically depress the pervaporation efficiency. In other words the membrane transport properties must be specific for the VOCs. This goal was reached following several experimental approaches, going from membrane modifications to the selection of suitable heavy protic solvents. Hence it has been shown for the case of dichloromethane (DCM) that low molecular weights polyalcohols (e.g. glycols) appeared to be suitable media to allow in particular the specific transport of DCM. On the other hand, polydimethylsiloxane (PDMS) based membranes were selected for their stability in these polyglycols and for their marked affinity for DCM. The simulation of the hybrid gas treatment process at pilot-scale was also achieved by a simple model relying on experimental data for both vapour liquid equilibria and permeation flux. A simple comparison of the energy needed to regenerate the heavy solvent by each possible step has also been made
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