References of "Léonard, Angélique"
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See detailX-ray microtomography: A new tool to follow soft material shrinkage during convective drying
Léonard, Angélique ULg; Blacher, Silvia ULg; Marchot, Pierre ULg et al

in 2nd World Congress on Industrial Process Tomography : Hannover, Germany 29-31 août 2001 (2014)

X-ray microtomography is proposed as a new tool to investigate the shrinkage of soft material which occurs during convective drying. Reliable shrinkage curves are obtained with samples of wastewater ... [more ▼]

X-ray microtomography is proposed as a new tool to investigate the shrinkage of soft material which occurs during convective drying. Reliable shrinkage curves are obtained with samples of wastewater treatment sludge. We develop a four zones model to describe the drying kinetics based of the experimental data provided by X-ray microtomography. The observation of the drying and shrinkage curves allows us to determine 3 critical water content values, which define different drying zones where extragranular, intragranular or mixed limitations prevail. When drying is externally controlled, the decrease of the drying rate observed during experiments can be related to the reduction of the external area of the sample. © 2014 International Society for Industrial Process Tomography. [less ▲]

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See detailLife Cycle Analysis (LCA) of photovoltaic panels: A review
Gerbinet, Saïcha ULg; Belboom, Sandra ULg; Léonard, Angélique ULg

in Renewable and Sustainable Energy Reviews (2014), 38

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See detailCharacterization of multi-walled carbon nanotube dispersion in resorcinol-formaldehyde aerogel
Haghgoo, Majid; Yousefi, Ali Akbar; Zohouriaan Mehr, Mohammad Jalal et al

in Microporous and Mesoporous Materials (2014), 184

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See detailErratum: Characterization of multi-walled carbon nanotube dispersion in resorcinol-formaldehyde aerogels (Microporous and Mesoporous Materials (2014) 184 (97-104))
Haghgoo, M.; Yousefi, A. A.; Zohouriaan Mehr, M. J. et al

in Microporous and Mesoporous Materials (2014), 195

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See detailCharacterization of dry and wet sawdust porous beds
Parmentier, Nicolas; Plougonven, Erwan ULg; Léonard, Angélique ULg et al

in Powder Technology (2014), 264

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See detailExperimental arguments concerning a hydraulic connection layer during limestone convective drying
Prime, Noémie ULg; Housni, Z.; Fraikin, Laurent ULg et al

in Proceedings of the 6th International Conference on Unsaturated Soils, UNSAT 2014 (2014)

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See detailImportance of LUC and ILUC on the carbon footprint of bioproduct: case of bio-HDPE
Belboom, Sandra ULg; Léonard, Angélique ULg

in Matériaux et Techniques (2014), 102(2),

Suite à la diminution des ressources fossiles et à l’augmentation des émissions des gaz à effet de serre, des solutions sont nécessaires pour remplacer les produits issus du pétrole. Cela a pour ... [more ▼]

Suite à la diminution des ressources fossiles et à l’augmentation des émissions des gaz à effet de serre, des solutions sont nécessaires pour remplacer les produits issus du pétrole. Cela a pour conséquence une constante augmentation du nombre de produits biobasés développés à partir de ressources agricoles. Cette étude évalue l’empreinte carbone du polyéthylène haute densité (PEHD) produit à partir de canne à sucre brésilienne ou de betterave belge. Le but de cette étude est de comparer l’empreinte carbone du bio-PEHD avec le PEHD fossile en considérant l’effet du changement d’affectation des sols. Les frontières communes des systèmes agricoles regroupent l’étape de culture de la canne à sucre et de la betterave, avec toutes les consommations associées d’énergie et d’engrais, le transport depuis le champ jusqu’à l’unité industrielle, la transformation des plantes sucrières en bioéthanol hydraté, la valorisation des sous-produits, la polymérisation et l’incinération du PEHD. Le scénario fossile comprend la production d’éthylène, sa polymérisation et l’incinération du PEHD. La comparaison du cycle de vie entier des PEHD biobasé et fossile montre des émissions de GES plus faibles avec le produit biobasé, ce qui est l’effet voulu. Ce résultat est uniquement valide s’il n’y pas de changement direct ou indirect d’affectation des sols. Pour évaluer l’impact environnemental de la déforestation ou de la transformation d’un pâturage en champ, les lignes directrices de l’Union Européenne ont été suivies afin de calculer les émissions de CO2 en fonction de divers paramètres. Pour la canne à sucre, le changement direct d’affectation des sols (LUC) est défini par la transformation de pâturages en champs dans la région de Sao Paulo au Brésil. Trois scénarios ont été développés, basés sur différentes pratiques agricoles pour les pâturages et les champs (labour et engrais) : le meilleur, le pire et le moyen. Le meilleur cas engendre un gain environnemental supplémentaire pour le produit biobasé. Le pire et le moyen amènent des émissions complémentaires. Un temps de retour, considérant le temps nécessaire pour récupérer à nouveau un gain environnemental comparativement au produit fossile, a été calculé pour le scenario moyen et s’élève à 12 ans. Le changement indirect d’affectation des sols pour la canne à sucre est modélisé comme étant la transformation d’une forêt en champ induite par les effets du changement direct décrit ci-avant. Le taux de déforestation peut varier entre 16 et 100%, dépendant des statistiques utilisées et entrainant un temps de retour de respectivement 26 et 101 ans. Pour la betterave, aucun changement direct n’est considéré. En effet, aucune expansion des terres agricoles ne peut être envisagée en Belgique au vu des faibles surfaces disponibles. Si une augmentation en termes de production de bioplastiques a lieu, la Belgique devra importer de la betterave provenant des pays voisins, ce qui peut induire un changement indirect d’affectation des sols. Dans cette étude, la betterave est supposée provenir des Pays-Bas. Celle-ci est cultivée sur des pâturages préalablement transformés en champs. Ce scénario moyen induit un temps de retour de 8 ans. Cette étude a mis en évidence l’importance du changement direct et indirect d’affectation des sols, spécialement pour les cultures énergétiques dédiées au remplacement des produits fossiles. Cet effet peut renverser les résultats attendus et engendrer de longs temps de retour. [less ▲]

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See detailVisible-light photo-activity of alkali metal doped ZnO
Benhebal, Hadj; Chaib, Messaoud; Malengreaux, Charline ULg et al

in Journal of the Taiwan Institute of Chemical Engineers (2014), 45(1), 249-253

In order to utilize visible light more efficiently in the field of photocatalysis, Li, Na and K-doped ZnO nanoparticles were prepared using a sol–gel method. The obtained samples were characterized by BET ... [more ▼]

In order to utilize visible light more efficiently in the field of photocatalysis, Li, Na and K-doped ZnO nanoparticles were prepared using a sol–gel method. The obtained samples were characterized by BET surface area measurements, X-ray diffraction, scanning electron microscopy and UV–vis analysis. The photocatalytic activity of the photocatalysts was evaluated for the degradation of p-nitrophenol (p-NP) under visible light irradiation. It has been observed that these photocatalysts could be a promising photocatalyst for degradation of organic molecules as compared to transition metal doped ZnO under visible light. Li-doped ZnO is the most active photocatalyst and shows high photocatalytic activity for the degradation of p-nitrophenol (p-NP). The enhanced photocatalytic activity of Li-doped ZnO is mainly due to the electron trapping by lithium metal ions, small particle size, large surface area, and high surface roughness of the photocatalysts. [less ▲]

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See detailModeling and Simulation of Heat and Mass Transfer During Convective Drying of Wastewater Sludge with Introduction of Shrinkage Phenomena
Bennamoun, Lyes ULg; Fraikin, Laurent ULg; Léonard, Angélique ULg

in Drying Technology (2014), 32(1), 13-22

Wastewater sludge is dried in a convective dryer using air temperatures varying from 80°C to 200°C, velocities changing from 1 m · s−1 to 2 m · s−1, and humidities ranging from . The convective dryer is ... [more ▼]

Wastewater sludge is dried in a convective dryer using air temperatures varying from 80°C to 200°C, velocities changing from 1 m · s−1 to 2 m · s−1, and humidities ranging from . The convective dryer is equipped with a camera and an infrared pyrometer to follow respectively the external surface and the temperature of the product. The experimental results show that drying kinetic can be divided into three phases: two short first phases, called adaptation and constant drying phases, and a long third phase, called falling drying rate phase. As the moisture content decreases, the camera confirms simultaneous shrinkage effect with the volume reduction of the product of about 30–45% of the initial volume. Moreover, an increase of the product temperature towards air temperature was measured with the infrared pyrometer. In a second step of this study, the experimental results are modeled and simulated using heat and mass balances applied to the product and the heated air. The drying curve is rightly expressed with fourth-degree polynomial model with a correlation coefficient that approximates the unity and with low calculated errors. An outstanding determination of the heat transfer coefficient has permitted calculating the product temperature with good agreement with experimental results. The heat transfer coefficient expressed by means of Nusselt number is presented as a function of Reynolds and Prandlt numbers, changeable with air and product characteristics taking into account shrinkage effect. Moreover, as the applied air temperatures are sufficiently high, transfer by radiation is not neglected and is introduced in the mathematical model. [less ▲]

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See detailModeling of Wastewater Sludge Drying with Determination of Diffusivity Moisture
Bennamoun, Lyes ULg; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

in Journal of Residuals Science and Technology [=JRST] (2013), 10(4), 165

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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; Collard, Valérie ULg et al

Poster (2013, November 15)

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 [1]. 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 [1]. Parmi les différents polymères biosourcés et biodégradables déjà utilisés pour la fabrication de scaffolds, l’acide polylactique (PLA) a été choisi [2]. 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 [3]. 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 detailUse of Life Cycle Assessment to support in the Eco-Design of a glass-wool process
Gerbinet, Saïcha ULg; Renzoni, Roberto ULg; Briard, Vincent et al

Poster (2013, November 15)

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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 detailConvective drying of cherry tomato: Study of skin effect
Khama, Réda; Aissani, F.; Alkama, R. et al

Poster (2013, October 03)

A whole single cherry tomato is dried in a forced convective micro-dryer. The experiments are carried out under temperatures of 50, 60, 70 °C and a constant air flow and humidity. In order to study the ... [more ▼]

A whole single cherry tomato is dried in a forced convective micro-dryer. The experiments are carried out under temperatures of 50, 60, 70 °C and a constant air flow and humidity. In order to study the effect of the skin two sets of experiments were performed using original tomatoes or after skin was handly removed. The drying kinetics show the existence of two main phases, which are: adaptation phase and falling drying rate phase with an increase of the drying rate with the temperature increase. The observation of the product behavior shows that shrinkage effect is largely happening during the process. It is possible to follow this effect represented by variation of the product volume with its moisture content using X-ray microtomography. This non destructive imaging technique has been proved to find interesting applications in the drying field. In a second part, mathematical modeling using diffusion equation based on Fick’s law is studied. Consequently and using the analytical solutions proposed by Crank (1975), the diffusion coefficient is determined and written as function of the drying air temperature under Arrhenius form permitting by this way the calculus of the activation energy. The skin effect is clearly determined as the calculated diffusion coefficient of an original tomato with skin is largely smaller than the one without skin. [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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