Papers by Angélique Leonard
• Agricultural products: the use of specific data could really improve the results • Influence on... more • Agricultural products: the use of specific data could really improve the results • Influence on background data (impact of the database used) • Influence of the raw material used in starch production for ECOSE® These analyses will allow comparison between ECOSE and traditional binders. This comparison should be realized at the application level (glass wool, wood panel, etc.) because the implementation of the binder can be different. Besides, the comparison between binders is only relevant when the change of binder does not change intrinsic product properties.
The aim of this study is to have a good understanding of the environmental impact of glucose prod... more The aim of this study is to have a good understanding of the environmental impact of glucose production to be able to study material produce from glucose. Glucose is general-ly produced from corn or wheat. Since agricultural processes are known to be difficult to evaluate by LCA, the results obtained with two different LCA databases, Gabi and EcoIn-vent, are compared in this work. The production of glucose from raw materials can be divided in two steps: the agricul-tural step allowing the plant production, and the conversion step including the extraction of the starch from the plant and its hydrolysis into glucose. Preliminary results underline the high impact of the agricultural step, so a special attention has been paid to these data. Specific Belgian data collected by the Walloon Agricultural Research Centre (CRA-W) (2014) [1] have been used as primary data (yield, amount of fertilizers, etc.), either using EcoInvent or Gabi datasets background data to model fertilizers, diesel consumption, etc. A third model was built using only data available in Ecoinvent for corn and wheat cultures. For the conversion step, literature data have been used along with some industrial data. As few studies are available in the literature concerning starch hydrolysis, the focus has been placed on data validation (mass balance checks, cross-reference information, etc.). Based on these multiple sources, it is possible to compare the LCA results for the pro-duction of 1 kg of glucose for three different cases, summarized in the following table. Table 1: Summary of modelled cases Agricultural step Conversion steps Primary data Dataset Primary data Dataset Case 1 Belgian GaBi Literature + Industry GaBi Case 2 Belgian Ecoinvent Literature + Industry Ecoinvent Case 2 Ecoinvent Literature + Industry Ecoinvent The results obtained using these three models will be presented, at both the inventory and impact assessment steps. They show significant differences and highlight the need to understand in depth the involved assumptions when developing the datasets, in addition to the ones adopted for the inventory. These differences in results lead to higher uncer-tainties, allowing only to have a range of possible values as a result. We make the choice to only communicate this range of value and not an absolute value when communicating the results of this study but this leads to some disadvantages such as difficulties in com-parison, etc.Peer reviewe
The aim of this paper is to present the teaching approach which has been followed concerning the ... more The aim of this paper is to present the teaching approach which has been followed concerning the Life Cycle Assessment methodology (LCA). This course was launched three years ago by the Chemical Engineering Department, being aware of the potential of this methodology but also the pressure demand of LCA in industries.
Impact categories Unit GaBi Simapro chemicals energy Crops chemicals energy Crops Freshwater eutr... more Impact categories Unit GaBi Simapro chemicals energy Crops chemicals energy Crops Freshwater eutrophication kg P eq 6.63E-3 2.36E-4 1.27E-1 1.65E-2 2.89E-2 1.74E-1 Water resource depletion kg m3 1.04 2.80 6.61E-1 2.34E-1 9.54E-2 7.84E-1 Mineral, fossil & ren resource depletion kg Sb eq 9.77E-5 5.72E-4 7.24E-4 2.07E-3 5.05E-3 2.99E-2 Conclusions A change in the used database, even among the most used ones, can have an large influence the results. Especially on agricultural processes, even when the practises are modelled similarly by the users in the two databases. For example, the infrastructure could have large contribution. The differences are even larger when the generic database for agricultural process are compared with countries specific data. Comparison of agricultural products between each others, but also with fossil-based product should be realized with high caution. Moreover, some differences are difficult to explain, even with a detailed analysis.
B6c-Sart Tilman-B-4000 Liège (Belgique) http://www.chimapp.ulg.ac.be Rapport final Résumé Analyse... more B6c-Sart Tilman-B-4000 Liège (Belgique) http://www.chimapp.ulg.ac.be Rapport final Résumé Analyse du cycle de l'eau produite, distribuée et épurée en Wallonie Analyse du cycle de l'eau de pluie
Frontiers in Bioengineering and Biotechnology, 2021
Surfactin is a lipoheptapeptide produced by severalBacillusspecies and identified for the first t... more Surfactin is a lipoheptapeptide produced by severalBacillusspecies and identified for the first time in 1969. At first, the biosynthesis of this remarkable biosurfactant was described in this review. The peptide moiety of the surfactin is synthesized using huge multienzymatic proteins called NonRibosomal Peptide Synthetases. This mechanism is responsible for the peptide biodiversity of the members of the surfactin family. In addition, on the fatty acid side, fifteen different isoforms (from C12 to C17) can be incorporated so increasing the number of the surfactin-like biomolecules. The review also highlights the last development in metabolic modeling and engineering and in synthetic biology to direct surfactin biosynthesis but also to generate novel derivatives. This large set of different biomolecules leads to a broad spectrum of physico-chemical properties and biological activities. The last parts of the review summarized the numerous studies related to the production processes op...
This paper focuses on the dewatering efficiency of activated sludge from waste water treatment pl... more This paper focuses on the dewatering efficiency of activated sludge from waste water treatment plant using biobased coagulants in addition with classical flocculant and compares the results with those obtained with a sole classical coagulant. For this work, a standard compression-expression cell is used and an experimental design is develop to highlight the effect of the biobased coagulants
Drying Technology, Feb 12, 2019
Thermal drying is an important treatment method for sewage sludge. Sludges from Oupeye, Grosses B... more Thermal drying is an important treatment method for sewage sludge. Sludges from Oupeye, Grosses Battes, and Embourg wastewater treatment plants (WWTPs) were chosen for study. The effect of the mass fraction of sawdust (10%, 20%, 30%, and 40%) on sludge drying in a fixed bed dryer was investigated. A universal testing machine was used to determine the stiffness of the samples. X-ray tomography was employed to measure the structural properties of sample beds including the volume, total exchange surface, and void fraction. Both a lower moisture content of sludge and a higher mass fraction of sawdust lead to higher stiffness. The initial void fraction, bed volume, and total exchange surface of the sample bed are all related to sludge matrix and sawdust addition; however, the maximum drying rate is proportional to the initial total exchange surface, which is independent of the sludge matrix. This proves that sawdust addition is a positive means of sludge drying because of the increase in the initial total exchange surface.
Drying Technology, May 27, 2015
ABSTRACT Drying appears as a major step prior to valorization of sludge from wastewater treatment... more ABSTRACT Drying appears as a major step prior to valorization of sludge from wastewater treatment plant. This study uses an experimental design on different sludges to highlight the drying behavior according to drying conditions, storage and extrusion. This research is performed with industrial view, but on a single cylinder sample, and focuses on five responds: maximum drying flux, time to reach 95% of dry matter, final volume, critical moisture and slowing-down coefficient.
Desalination and Water Treatment, Jul 8, 2015
Chemical Engineering Communications, Nov 13, 2015
The main objective is studying the fundamental aspect, by the mean of the drying kinetics, the ap... more The main objective is studying the fundamental aspect, by the mean of the drying kinetics, the application of forced convective drying of wastewater sludge with determination of the optimum drying conditions. The drying system is composed of two units; small samples of 2.5 g are dried in the first unit and bed of sludge weighting 250 g is dried the second unit. The experiments are performed under air temperatures varying between 80°C and 200°C. The range of the air velocity and its humidity is 1-2 m/s and 0.005-0.05 kg water /kg dry air , respectively. The experiments are performed for two different sludges; activated sludge (AS) and thermalized and digested sludge (TDS). Usually, three main drying phases are observed during drying of bed of sludge. These phases are reduced to only two for small samples. Determination of the influent parameters shows that temperature of the drying air and sludge origin can profoundly influence the drying kinetic of the sludge. The exergy analysis of the two units of the drying system allows selecting 140 °C, 2 m/s, 0.05 kg water /kg dry air as optimum drying condition with an exergy efficiency reaching 90%.
This paper investigated the influence of Polyaluminium chloride (PAX) co-conditioning with a high... more This paper investigated the influence of Polyaluminium chloride (PAX) co-conditioning with a high linear weight polymer on the dewatering performance and the drying behavior of sludge. The CT linear polymer with a high molecular weight was used combined with PAX for sludge flocculation prior to mechanical dewatering and drying. It was found that sludge conditioned with the couple PAX/ CT led to better flocculation/dewatering process regarding size flocs and specific resistance to filtration. Concerning drying, it appeared that this chemicals combination led to improved drying rates with effect of a reduction of the drying time, when compared to polyelectrolyte used without PAX adding.
Drying appears as a major step prior to valorization of sludge from wastewater treatment plant. T... more Drying appears as a major step prior to valorization of sludge from wastewater treatment plant. This study uses an experimental design on different sludges to highlight the drying behavior according to drying conditions, storage and extrusion. This research is performed with industrial view, but on a single cylinder sample, and focuses on five responds: maximum drying flux, time to reach 95% of dry matter, final volume, critical moisture and slowing-down coefficient.Peer reviewe
Annual production of sewage sludge in Europe is estimated at more than eleven million tons of dry... more Annual production of sewage sludge in Europe is estimated at more than eleven million tons of dry matter [1]. Use in agriculture and incineration are the main ways of valorization. In this context, drying of residual sludge appears as an essential step after mechanical dewatering. It reduces the costs of storage, transport and allows the sludge stabilization. However, this process is highly energy consuming and still needs to be optimized as it constitutes an important economic and environmental issue [2].
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Papers by Angélique Leonard