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Simo-Tagne M.,LERMaB | Zoulalian A.,University of Lorraine | Remond R.,University of Lorraine | Rogaume Y.,University of Lorraine | Bonoma B.,P.A. College
Maderas: Ciencia y Tecnologia | Year: 2017

This paper presents a modeling of an instrumental indirect solar wood dryer less expensive functioning in a Cameroonian climate applied to the climate of Yaoundé. The dryer is easy to build and electric energy is only used for the fan. Applications are done on Iroko wood (Chlorophora excelsa), a tropical wood 50mm thick most utilized in Africa. A satisfactory agreement between experimental and numerical results was found. Influences of thickness, wood initial water content and airflow rate were studied.

Bilot N.,ONF R and D pole de Dole | Bilot N.,French National Institute for Agricultural Research | Andre L.S.,French National Institute for Agricultural Research | Rogaume Y.,LERMaB | And 3 more authors.
Chemical Engineering Transactions | Year: 2014

In the context of increasing energy demand, forest timber residues and leaves are a potential resource for fuel. How renewable are these resources? What are their qualities as a fuel? These issues can be answered through parallel works in two research fields: forest sciences considering nutrients cycles between plants and soil and growth and yield dynamics of the trees, and energy sciences considering the qualities of fuel such as heating value, and ash content. This interdisciplinary interaction leads to the balanced thinking between nutrient dynamics (harvesting forest residues while maintaining soil fertility and wood production) and energy interests. In a previous work, a study was presented that intended to bridge the two research fields by predicting the ash content and higher heating value in trees from a model developed by biogeochemists for predicting elemental composition distributed in several tree compartments. The models developed were applied on predictions of characteristics of forest products. These characteristics were outputted from a growth and yield simulator developed by forest research. This application added energy characterization to the wood biomass described biochemically. This connexion was the first step for the development of a simulation package which aims at characterizing the production chain of energy wood from forest growth and yield simulations (developed by forest sciences), through energy characterization (use of the interdisciplinary model), to harvesting and transformation chain characterization (energy and engineering sciences). Here, we quickly describe the models connecting biochemistry to fuel characterization of forest biomass; then we describe the simulation package and how these models are connected to biochemists models in the simulation package and finally we explain why the use of such a package is an important tool toward the improvement of the biomass production chain quality. Copyright © 2014,AIDIC Servizi S.r.l.

Meyer J.,MAP | Duchanois G.,MAP | Bignon J.-C.,MAP | Bouali A.,LERMAB
CAADRIA 2015 - 20th International Conference on Computer-Aided Architectural Design Research in Asia: Emerging Experiences in the Past, Present and Future of Digital Architecture | Year: 2015

The research presented in this paper revolves around the experimental development of the morpho-structural potential of folded architectural structures made of wood. The aims are to develop an innovative system for timber used in sustainable construction and to increase the inventory of wood architectural tectonics. Laminated timber panels associated with "digital production line" approach have opened up new perspectives for the building industry in creating prefabricated wooden structures. This article provides a characterization of the digital chain associated to the development of non-standard folded structures which consist of wood panels by way of a full-scale experimental pavilion. The purpose is the study of architectural design process from parametric modeling (through CNC machining) and assembly operations to production. Towards the completion of the pavilion, a number of analytical experiments have been performed. © 2015 All rights reserved and published by The Association for Computer-Aided Architectural Design Research in Asia (CAADRIA), Hong Kong.

Amaral-Labat G.,CNRS Jean Lamour Institute | Grishechko L.,CNRS Jean Lamour Institute | Grishechko L.,RAS Institute of Chemistry and Chemical Technology | Szczurek A.,CNRS Jean Lamour Institute | And 4 more authors.
Green Chemistry | Year: 2012

The first organic aerogels natural at the 91% level, based on soy and tannin, are reported. Such materials were prepared from denatured soy protein which was formylated, crosslinked with flavonoid tannin at different pHs, gelled and cured at 85 °C, and finally dried with supercritical CO 2. The resultant aerogels presented both low bulk density and high mesopore volumes. Morphology, pore texture, chemical structure and thermal performances have been investigated by SEM, envelope and helium pycnometry, nitrogen adsorption at 77 K, FTIR, elemental analysis, XPS, NMR and hot disk transient plane source methods, respectively. We show that soy-tannin aerogels are among the "greenest" organic aerogels combining low cost, renewable character, highly developed mesopore texture and good thermal performances. © 2012 The Royal Society of Chemistry.

Amaral-Labat G.,CNRS Jean Lamour Institute | Sahimi M.,University of Southern California | Pizzi A.,LERMAB | Fierro V.,CNRS Jean Lamour Institute | Celzard A.,CNRS Jean Lamour Institute
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

The mechanical properties of a class of cellular material were measured. The composition of the material was progressively modified, while its pore structure was kept unchanged. Rigid foam, prepared from a thermoset resin, was gradually converted into reticulated vitreous carbon foam by pyrolysis at increasingly higher heat-treatment temperatures (HHT). The corresponding changes in the Young's modulus Y and the compressive strength σ of the materials were measured over a wide range of porosities. The materials exhibit a percolation behavior with a zero percolation threshold. At very low densities the Young's modulus and the compressive strength appear to follow the power laws predicted by percolation theory near the percolation threshold. But, whereas the exponent τ associated with the power-law behavior of Y appears to vary significantly with the material's density and the HHT, the exponent associated with σ does not change much. The possible cause of the apparent and surprising nonuniversality of τ is discussed in detail, in the light of the fact that only the materials' composition varies, not the structure of their pore space that could have caused the nonuniversality. © 2013 American Physical Society.

Jana P.,French National Center for Scientific Research | Fierro V.,French National Center for Scientific Research | Pizzi A.,LERMAB | Celzard A.,French National Center for Scientific Research
Society of Plastics Engineers - 12th International Conference on Foam Materials and Technology, FOAMS 2014 | Year: 2014

Carbon foams with improved thermal conductivity and mechanical properties were prepared from a tanninbased resin and exfoliated graphite used as filler. Organic foams were first prepared by suspending exfoliated graphite in an aqueous solution of tannin, furfuryl alcohol, formaldehyde, diethyl ether and para-toluene-4-sulphonic acid at room temperature. Spontaneous foaming started after a short induction time, and the resultant dark brown, hard, foams were carbonized at 1173 K. The addition of exfoliated graphite in the foam matrix increased the thermal conductivity by more than one order of magnitude, passing from 0.11 W m-1 K-1 for pure tanninbased carbon foams to 3.65 W m-1 K-1 for composite foams. In the same time, compressive strength and elastic modulus increased from 3.6 to 6.9 MPa and from 30.1 to 61 MPa, respectively. Such biomass-derived carbon foams are suitable porous structures for hosting phase change materials for seasonal storage applications.

Lagel M.-C.,French National Center for Scientific Research | De Yuso A.M.,French National Center for Scientific Research | Basso M.-C.,Indunor Group | Giovando S.,SilvaChimica | And 4 more authors.
Society of Plastics Engineers - 12th International Conference on Foam Materials and Technology, FOAMS 2014 | Year: 2014

Tannins are plant extracts combining many advantages: low cost, "green" character, absence of toxicity, chemical reactivity, and availability. Their phenolic nature allows them to be very efficient substitutes of toxic, more expensive and non-renewable, molecules such as phenol and resorcinol. High-quality resins can indeed be formulated from tannins, with which different materials can be prepared, among them thermoset foams. Such foams have similar properties as those of commercial phenolic foams, and can be prepared from tannins extracted from different plants. In the present work, the characteristics of the foams made from Mimosa (Acacia mearnsii), Pine (Pinus radiata) and Quebracho (Schinopsis sp) tannins are presented and compared, in relation to their chemical structures. Finally, all these foams are shown to be extremely valuable precursors of carbon foams having the same density and the same structure, but presenting a new panel of properties of valuable interest for energy and environmental applications.

Dufour A.,LERMAB | Dufour A.,French National Center for Scientific Research | Masson E.,CRITTBois | Girods P.,LERMAB | And 2 more authors.
Energy and Fuels | Year: 2011

Tar reduction and monitoring is the major stake for gasification processes. Pyrolysis is the precursor mechanism of the gasification of solid fuels and tar production. The evolution of gas and tar composition produced from wood chips pyrolysis was investigated in a tubular reactor as a function of its wall temperature (700-1000 °C, with gas mean residence times of 1.1-2.7 s). High thermal severities lead to the "gasification" regime, promoting gas production from tar conversion. Tar (benzene, toluene, o- and m-xylenes, phenol, indene, o-, m-, and p-cresols, naphthalene, 1- and 2-methylnaphthalenes, acenaphthylene, and phenanthrene) were quantified by gas chromatography/mass spectrometry (GC/MS) analysis using deuterated internal standards. Closed mass balances were obtained. A simplified chemical scheme of secondary tar conversion is proposed. Under the investigated range of thermal severity, CH 4 production is mainly controlled by aromatic tar demethylation. Linear relations were observed between the molar production of benzene and CH 4 and between all quantified tars and C 2H 4 (ethene). CH 4 and C 2H 4 could thus be analyzed by direct online methods and used as indicators of the tar content and speciation for gasifier monitoring. The validity of these relations depends upon the thermal conditions of reactors and biomass composition. These relations could be suitable for dual-fluidized-bed gasifiers because H 2O has very few chemical effects on hydrocarbon thermal conversion. © 2011 American Chemical Society.

Authier O.,Électricité de France | Cluet B.,LERMAB | Cluet B.,French National Center for Scientific Research | Delebarre A.,French National Center for Scientific Research | Mauviel G.,French National Center for Scientific Research
Chemical Engineering Transactions | Year: 2014

The fast devolatilization of biomass is the first step of thermochemical conversion in fluidized bed boilers or gasifiers. Some advanced devolatilization models applicable to a wide range of biomasses and process conditions have been developed on the basis of a detailed description of the physico-chemical mechanisms and of biomass standard analysis. In this study, the results of a biomass devolatilization model taking into account the main physical and chemical phenomena are reported. Attention is focused on biomass thermal properties derived from its composition and density. The kinetic scheme is based on the lumped kinetic model of (Ranzi et al., 2008) and its further development. Predictions of the complete devolatilization time of biomass thick particles are compared with experimental results obtained in different high-temperature fluidized bed reactors. Experimental results obtained with biomass pellets under image furnace conditions are also used to assess the dynamic release of volatile matter predicted in transient state. The great interest of predictive model able to reduce the number of input parameters for any biomass type is finally underlined. Copyright © 2014,AIDIC Servizi S.r.l.

Simo-Tagne M.,LERMaB | Remond R.,University of Lorraine | Rogaume Y.,University of Lorraine | Zoulalian A.,University of Lorraine | Bonoma B.,University of Yaounde I
International Journal of Thermal Sciences | Year: 2016

We have developed a model on drying of two tropical woods of ayous (Triplochiton Scleroxylon) and frake (Terminalia Superba) coming from Cameroon forests. Some thermophysical parameters used in the model were experimentally obtained in this work while the remaining properties were from literature. A comparison is doing between numerical results of our model, these given by the Luikov's model and experimental data. Numerical simulation results from the developed model give close agreement with experimental results. We note that Luikov's model not gives a satisfaction results in the non-hygroscopic domain in the case of frake. The present model can be used to explain the drying phenomenon of these two tropical species and can be applied to others species when necessary thermophysical parameters of these species are known. In a future work, it is important to integrate the influence of anatomical direction on our numerical and experimental results. © 2016 Elsevier Masson SAS

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