References of "Léonard, Angélique"
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See detailEnvironmental Product Declaration of purified and defluorinated phosphoric acid – difficulties and limitations of the methodology
Belboom, Sandra ULg; Scözs, Carl; Léonard, Angélique ULg

Poster (2013, November)

The awareness of environment and the development of environmental product declarations (EPDs) are increasing through years. EPD becomes a need for producers in both B to B and B to C relations. EPD ... [more ▼]

The awareness of environment and the development of environmental product declarations (EPDs) are increasing through years. EPD becomes a need for producers in both B to B and B to C relations. EPD elaboration process is not without difficulties. Such a declaration requires a considerable amount of time and information, a full comprehension of the applied methodology but it also causes confidentiality problems. All these difficulties can lead to the use of simpler tools, as Carbon Footprint, which only focuses on a single impact and misses a part of the message. This case study is based on the production of phosphoric acid in Belgium using PCR for inorganic chemicals. It takes into account the use of raw materials as phosphate rocks or chemicals, their transportation to site and the manufacturing of defluorinated and purified phosphoric acid. This process also requires steam, electricity, demineralised water and sulphuric acid. These inputs are produced on site and their modelling is taken into account in this study. The first step of this process is the production of weak phosphoric acid with transformation of phosphate rocks into 30% phosphoric acid using sulphuric acid attack. The particularity of this process is the production, in this company, of a recoverable coproduct, called gypsum. The amount of this product is about 1.6 t per t of weak acid. A stoichiometric relation connects both products and is used as allocation factor, as recommended by the PCR. Through next concentration steps, fluosilicic acid is produced, also linked to the production of phosphoric acid by a stoichiometric relation. For facilities production plant, repartition of impact between coproducts is not so easy. As mentioned before, the production of steam, electricity, demineralised water and sulphuric acid are performed on site. Sulphuric acid is produced by the combustion of liquid sulphur provided by oil refineries. Two different units produce both sulphuric acid and steam through the combustion of liquid sulphur but only one of them transforms a part of steam into electricity. Repartition of impact between sulphuric acid and steam can be achieved using a physical relation based on thermodynamic values which can be transformed into mass relation. For repartition between electricity, steam and sulphuric acid, the main difficulty is that electricity does not have a weight and a transformation into steam shall be achieved to use the same relationship that previously. This way of allocating is not very obvious for producers, even if it is the one recommended by the PCR. As electricity and steam are coproduced, an energetic allocation is also relevant and gives completely opposite results for repartition of impact of each product. In that case, sulphuric acid impact achieves a non-negligible part of the impact which modifies greatly results of phosphoric acid production. This is a problem when you know that environmental product declarations are used to compare products on environmental criteria, using mainly values of climate change or energy impacts. Producers are then reticent to publish such a value which can lead to a loss of customer confidence, even more when they occupy a leading position on the market and taking into account that a comparison with other producers is quite impossible. More specific guidelines should be set to indicate the best way to perform an environmental product declaration in specific fields using a specific way of allocation. [less ▲]

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See detailDoes Belgian bioethanol comply with European Renewable Energy Directive ?
Belboom, Sandra ULg; Bodson, Bernard ULg; Léonard, Angélique ULg

Poster (2013, November)

The craze for biofuels has increased in recent years mainly to reduce greenhouse gas emissions and fossil fuel consumptions. The European Renewable Energy Directive (RED), published in 2009, defined ... [more ▼]

The craze for biofuels has increased in recent years mainly to reduce greenhouse gas emissions and fossil fuel consumptions. The European Renewable Energy Directive (RED), published in 2009, defined guidelines to assess carbon footprint of a biofuel depending on biomass source. It also provided generic values of GHG emissions relative to each step of the life cycle taking into account all steps from the cultivation to the end-of-life. These values are used to evaluate the sustainability of European biofuels depending on the used crops and the used transformation technology. This study, based on local crops cultivated in Belgium (sugar beet and wheat), compares specific Belgian values with European generic ones. Belgium yields for both crops are among the best of the continent. Specific Belgian values for fertilizers and pesticides are used. The transformation of wheat into bioethanol is modelled using industrial data. As recommended by the RED, no land use change is taken into account for Belgium. Greenhouse gas emissions induce by the life cycle of Belgium sugar beet bioethanol are similar to the ones mentioned in the European directive but impact repartition is different. In our case, the transformation step achieves a higher part of the impact. That can be explained by the higher cultivation yield. Belgian wheat bioethanol obtains better results than those mentioned by the European directive with a 9% higher reduction. Cultivation step is the major step for this impact. Importance of fertilizers consumptions and associated emissions are highlighted. The comparison of both bioethanols impacts for climate change category, using an energy basis, shows that wheat allows a higher reduction of GHG emissions than sugar beet. If the comparison is performed on a cultivated area basis, results are reversed and sugar beet achieves a twofold reduction compared with wheat. Sensitivity analyses are performed on the importance of N fertilizers and associated emissions and on energy consumptions relative to the transformation step. These analyses reveal non-negligible impact variations. A range of GHG reduction that can be reached using Belgian sugar beet and wheat bioethanol are then calculated. In any case, sugar beet does not achieve the amount of reduction given by the RED, while the opposite effect is shown for wheat with a reduction at least as high as the RED default value. These results indicate the importance of make use of specific values to assess the sustainability of bioethanol for a specific country using a specific crop and a specific technology. Further measurements and research about emission factors due to fertilizers application could improve the accuracy of our results. [less ▲]

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See detailLe « génie orienté produit » appliqué à l’élaboration de matrices poreuses pour l’ingénierie tissulaire.
de Bien, Charlotte ULg; Ounally, Thameur ULg; Collard, Valérie ULg et al

in Récents Progrès en Génie des Procédés (2013, October 08)

Ce travail vise à appliquer une approche « génie-orienté produit » à la fabrication de matrices poreuses synthétiques (scaffolds) susceptibles d’être utilisées en ingénierie tissulaire. Parmi les ... [more ▼]

Ce travail vise à appliquer une approche « génie-orienté produit » à la fabrication de matrices poreuses synthétiques (scaffolds) susceptibles d’être utilisées en ingénierie tissulaire. Parmi les différents polymères biosourcés et biodégradables déjà utilisés pour la fabrication de scaffolds, l’acide polylactique (PLA) a été choisi. Des matrices poreuses ont été obtenues par un procédé de moussage par lyophilisation puis leur microstructure 2D/3D a été caractérisée par microtomographie à rayons X avant d’être mise en lien avec les conditions d’élaboration testées. La diminution de la porosité ainsi que l’augmentation de l’épaisseur des parois avec l’augmentation de rapport polymère/solvant ont été confirmées. [less ▲]

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See detailImpact of sludge storage duration on its dewatering and drying ability
Pambou, Yvon-Bert; Salmon, Thierry ULg; Fraikin, Laurent ULg et al

Poster (2013, October)

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See detailBehavioural study of  chemical  products during vacuum agitated contact drying
Bennamoun, Lyes; Léonard, Angélique ULg

Poster (2013, October)

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See detailBaker's yeast behavior during vacuum agitated contact drying
Bennamoun, Lyes ULg; Afzal, Muhammad; Léonard, Angélique ULg

in Chemical Engineering and Technology (2013), 36(10), 1795-1800

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See detailDifferent phases of water transfer during rock drying
Prime, Noémie ULg; Housni, Zakarya; Fraikin, Laurent ULg et al

Conference (2013, September 10)

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See detail"Product-oriented engineering" applied to the development of porous scaffolds for tissue engineering.
de Bien, Charlotte ULg; Ounally, Thameur ULg; Collard, Valérie ULg et al

in Procedia Engineering (2013, September 02)

This work applies a “product-oriented engineering” approach to the development of porous scaffolds for tissue engineering. Polylactic acid scaffolds were obtained by a freeze-drying process. Their 2D/3D ... [more ▼]

This work applies a “product-oriented engineering” approach to the development of porous scaffolds for tissue engineering. Polylactic acid scaffolds were obtained by a freeze-drying process. Their 2D/3D microstructure was characterized by X-ray microtomography and related to the operating conditions used. Two types of scaffold end-use properties were characterized in relation to their microstructure: the mechanical and the transport properties. Scaffold young's modulus was computed from data measured on tension-compression devices. To evaluate the permeability, Darcy’s experiments were carried out. The obtained results allowed highlighting the quantitative relationships existing between elaboration conditions, microstructure and end use properties of the fabricated PLA scaffolds. [less ▲]

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See detailHeat and mass transfer coefficient analysis during rock convective drying
Prime, Noémie ULg; Housni, Zakarya; Fraikin, Laurent ULg et al

Conference (2013, August)

This paper presents some experimental investigations about convective drying of rocks. Cylindrical samples made of limestone are dried from one their bases submitted to an air flow, while the other ... [more ▼]

This paper presents some experimental investigations about convective drying of rocks. Cylindrical samples made of limestone are dried from one their bases submitted to an air flow, while the other surfaces are hermetically covered. All other factors being equal, the influence of two parameters is looked after: the cylinder height, equivalent to the volume/surface ratio of the samples, and the direction of the air flow. The tests are interpreted both from the drying curves and from the values of water and heat transfer coefficients. Results first highlight that air flow incidence on the dried surface changes the kinetics and the transfer coefficient values. It can thus be supposed that the air flow direction would modify the thickness of the transfer limit layer at the surface and/or would make invalid the hypothesis of such a limit layer model for some flow configurations. Besides, the volume/surface ratio is shown to be correlated to the evaporation flux on the constant drying phase, and thus to the transfer coefficients. Nonetheless, this link tends to disappear from sufficiently high values of the volume/surface ratio since, in this case, the transfer coefficients reach constant values. This effect, in addition to other observations made on the drying curves, well fits with the hypothesis of a hydraulically connected layer below the drying surface, which would maintain during the constant drying rate phase. In the present case, this layer would have a thickness of around 20 to 30 mm. [less ▲]

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See detailConvective drying of wastewater sludge: Introduction of shrinkage effect in mathematical modeling
Bennamoun, Lyes ULg; Crine, Michel ULg; Léonard, Angélique ULg

in Drying Technology (2013), 31(6), 643-654

Drying of two kinds of wastewater sludge was studied. The first part was an experimental work done in a discontinuous cross-flow convective dryer using 1 kg of wet material extruded in 12-mm-diameter ... [more ▼]

Drying of two kinds of wastewater sludge was studied. The first part was an experimental work done in a discontinuous cross-flow convective dryer using 1 kg of wet material extruded in 12-mm-diameter cylinders. The results show the influence of drying air temperature for both sludges. The second part consisted of developing a drying model in order to identify the internal diffusion coefficient and the convective mass transfer coefficient from the experimental data. A comparison between fitted drying curves, well represented by Newton's model, and the analytical solutions of the equation of diffusion, applied to a finite cylinder, was made. Variations in the physical parameters, such as the mass, density, and volume of the dried product, were calculated. This allowed us to confirm that shrinkage, which is an important parameter during wastewater sludge drying, must be taken into account. The results showed that both the internal diffusion coefficient and convective mass transfer coefficient were affected by the air temperature and the origin of the sludge. The values of the diffusion coefficient changed from 42.35 × 10−9 m2 · s−1 at 160°C to 32.49 × 10−9 m2 · s−1 at 122°C for sludge A and from 33.40 × 10−9 m2 · s−1 at 140°C to 28.45 × 10−9 m2 · s−1 at 120°C for sludge B. The convective mass transfer coefficient changed from 4.52 × 10−7 m · s−1 at 158°C to 3.33 × 10−7 m · s−1 at 122°C for sludge A and from 3.44 × 10−7 m · s−1 at 140°C to 2.84 × 10−7 m2 · s−1 at 120°C for sludge B. The temperature dependency of the two coefficients was expressed using an Arrhenius-type equation and related parameters were deduced. Finally, the study showed that neglecting shrinkage phenomena resulted in an overestimation that can attain and exceed 30% for the two coefficients. [less ▲]

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See detailUse of Life Cycle Assessment in view of Eco-Design for a glass wool process
Gerbinet, Saïcha ULg; Renzoni, Roberto ULg; Briard, Vincent et al

Conference (2013, April 25)

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See detailL’Analyse du Cycle de vie : quoi, pourquoi, comment ?
Léonard, Angélique ULg

Scientific conference (2013, March 22)

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See detailACV et Ecoconception: illustration de la démarche au sein de Knauf Insulation.
Gerbinet, Saïcha ULg; Briard, Vincent; Léonard, Angélique ULg

Conference (2013, March 22)

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See detailDetermination of Moisture Diffusivity During Drying of Mortar Cement: Experimental and Modeling Study
Bennamoun, Lyes ULg; Kahlerras, Loubna ULg; Michel, Frédéric ULg et al

in International Journal of Energy Engineering (2013), 3(1), 1-6

The aim of this study is the experimental characterization of the behaviour of a mortar during convective drying. We focalise on mortar that has a rate water-cement of 0.5. The drying tests are developed ... [more ▼]

The aim of this study is the experimental characterization of the behaviour of a mortar during convective drying. We focalise on mortar that has a rate water-cement of 0.5. The drying tests are developed in a micro-convective dryer that can use samples weighing from 0 to 8g. The advantage of these experiments is to reproduce the natural conditions that can be found during the treatment of the mortar-atmosphere problems. The response of the drying curve or the drying kinetic depends on the applied drying conditions. So, the temperature of the air varies from 60°C to 130°C, the velocity of the air is changed from 2 m.s-1 to 5 m. s-1and the relative humidity is kept less than 1.7%. The comparison between the experimental results and the proposed analytical solutions of the equation of diffusion represented by Fick’s law, applied for a finite shape, allows determination of the values of the diffusion coefficient. It has a value of 1.71×10-10 m2.s-1 at 60°C, 13.69×10-10 m2.s-1 at 90°C and 16.27×10-10 m2.s-1 at 130°C. Calculation of the activation energy and the D0 constant are also possible. [less ▲]

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See detailThe effect of collagenated space filling materials in sinus bone augmentation: a study in rabbits
LAMBERT, France ULg; Léonard, Angélique ULg; Drion, Pierre ULg et al

in Clinical Oral Implants Research (2013), 24(5),

Aim: The inclusion of biomaterial particles used for alveolar bone regeneration in a carrier or in binding agents such as collagen gel or fibers is of interest as a means to help with surgical handling ... [more ▼]

Aim: The inclusion of biomaterial particles used for alveolar bone regeneration in a carrier or in binding agents such as collagen gel or fibers is of interest as a means to help with surgical handling. However, the possible influence of collagen on bone tissue response to biomaterials is poorly studied. The objective of the present study was to investigate, in a sub-sinus bone augmentation model in rabbits, the effect of collagen at different stages of the osteogenesis process. Histologic, histomorphometric and volumetric analyses were performed. Materials and methods: Rabbits underwent a double sinus lift procedure using bovine hydroxyapatite (BHA), collagenated bovine hydroxyapatite (BHAColl), and prehydrated and collagenated porcine hydroxyapatite (PHAColl). Animals were sacrificed at 1 week, 5 weeks or 6 months. Samples were subjected to X-ray micro-tomography and histology. Qualitative analysis was performed on the non-decalcified sections and quantitative histomorphometric analyses were conducted using scanning electron microscopy (SEM). Volume variations of bone augmentations were calculated at different time points. Results: The three biomaterials allowed an optimal bone formation and were able to equally withstand sinusal reexpansion. A comparable percentage of new bone, as well as 3D volume stability, was found between the groups at each time point. However, the PHAColl resorption rate was significantly higher than the rates in other groups (P = 0.0003), with only 3.6% of the particles remaining at 6 months. At 1 week, both collagenated groups displayed the presence of inflammatory cells although BHA did not show any sign of inflammation. At 5 weeks and 6 months, the inflammatory process had disappeared completely in the BHAColl groups, whereas some inflammatory-like cells could still be observed around the remaining particles of PHAColl. Conclusions and clinical implications: Within the limitations of this study in rabbits, the findings showed the presence of inflammatory-like cells at the early stage of bone regeneration when collagenated xenogenic biomaterials were used compared to xenogenic granules alone. Nevertheless, similar bone formation occurred and comparable 3D volumes were found at 6 months in the different groups. [less ▲]

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