References of "Léonard, Grégoire"
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See detailIntegrated Project with Focus on Energy Transition and Circular Economy for Developing Engineering Students' Soft Skills
Léonard, Grégoire ULg; Pfennig, Andreas ULg; Toye, Dominique ULg et al

Poster (2016, September 05)

The present work reports the experience of an integrated project developed at the University of Liege for master students in chemical engineering. The goals are to promote the acquisition of soft skills ... [more ▼]

The present work reports the experience of an integrated project developed at the University of Liege for master students in chemical engineering. The goals are to promote the acquisition of soft skills and to consolidate technical knowledge by integrating and linking chemical engineering disciplines usually taught separately. A case study was selected to address some of the challenges related to energy transition: students had to design the energy system of a remote island and make it as energy independent and CO2-neutral as possible by 2030. The course of action during the academic year, the assessment of soft skills, and the tools offered to ease the mentoring and encourage the acquisition of soft skills are described. Not all implemented techniques performed equally well, and this project finally appeared to be a challenge for the teaching team as well. 1 Introduction and background Over the last few years, University authorities, industrial partners as well as national and international experts that evaluated the education quality of our Department (AEQES, CTI) strongly suggested that opportunities should be offered to students to increase their soft skills as part of their curriculum. Moreover, many developments in chemical engineering are related to energy transition and circular economy, which are both transdisciplinary to conventional lectures. In this paper, we present methods and mentoring tools developed to teach students technical and soft skills for multi-disciplinary topics. 2 Description of the integrated project Objectives and constraints were defined at the onset of the project for both technical and soft skills. The technical objective was to propose an energy system that would make Reunion Island as energy independent and CO2-neutral as possible by 2030. This idea originated in the challenge set by the Eurecha 2015 student contest[1], for which students had to design facilities for a sheikhdom: electricity, water recycling, production of fertilizers… In our case, Reunion Island (~850 000 inhabitants) was considered as a case study as it is remote, has large biomass resources and high potential for renewable energies. Besides the objectives mentioned above and in order to force students to look at chemical engineering processes, the treatment of wastewater was imposed as well as the use of a synthetic liquid fuel as energy carrier. The targeted soft skills included working in large groups of minimum 4 students, efficient communication of results in English - both written and oral -, ability to integrate knowledge from various disciplines, development of critical mind and demonstration of independent and creative thinking. 3 Course of actions A team of 8 professors and senior scientists mentored the project and contributed to its assessment. The 10-ECTS project was divided in two parts. In the fall semester, students made global energy balances to design the energy system that would fulfill the objectives. As a result, a Sankey diagram of the energy flows on Reunion Island by 2030 was produced to allow for an overview of the available Island’s resources and needs, as well as of processes that can make the link between resources and needs. In the spring semester, two processes identified in the first part, namely the synthesis of bio-ethanol and bio-methanol, were modelled in more details using commercial software. Different tools were used to encourage student initiatives and work: • The use of a shared on-line portfolio for students to gather their documents improved their internal communication, but this remained a marginal channel for communication with teachers • In the fall semester, students orally presented progress reports every two weeks. After a feedback to students, the teaching team met to discuss the achievements and set the objectives for the next two weeks. This was very positive for the communication inside the teaching team. However, presentations every fortnight implied a work overload for students that had to constantly focus on preparing the presentations. • From the beginning, students were strongly encouraged to reach out to field experts whose contacts were provided. However, they preferred to rely mostly on Internet as their main source of information and reached out only rarely for help and usually very late. • In the fall semester, students had to designate new team leaders in turn every fortnight. This was abandoned as it prevented the establishment of clear structures in the group, reducing its efficiency. • In the spring semester, work tables allowed students to work directly with the teacher specialized in their task. This was appreciated by students and teachers, and it needs to be further encouraged. • Help in the group organization and interactions was provided by the PSGO (psychology of groups and organizations). This also included videoscopy, i.e. filming the students during their presentations and analyzing the records with them. This help was appreciated by students. The assessment was based on technical results for 60%, and soft skills for 40%. The evaluation of technical skills was done partly by all teachers equally and partly by teachers whose expertise was the closest to the technical sub-tasks. For soft skills, efficient communication, creativity in the work and results and links with conventional lectures were assessed. Critical thinking was evaluated through the relevance of qualitative and quantitative results and discussions. Group work was assessed by the teachers as well as by students through mutual evaluation. 4 Conclusions and perspectives The integrated project gave students a first opportunity to improve their soft skills along with their technical knowledge. It also improved their communication skills and their fluency in English. The teaching team proposed different mentoring techniques to encourage efficient work, with varying results. Finally, as the assessment ignored soft skills improvements, it may be modified by evaluating soft skills all year long so both the final result and the observed improvements contribute to the grade. Reference Eurecha, The European Committee for the Use of Computers in Chemical Engineering Education, 2015. Announcement for student contest problem competition 2015. http://bari.upc.es/eurecha/. [less ▲]

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See detailUtilisation of CO2 from an Industrial source for Methanol production
Font-Palma, Carolina; Douven, Sigrid ULg; Léonard, Grégoire ULg

Conference (2016, September)

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See detailDesign and Evaluation of a High-Density Energy Storage Route with CO2 Re-Use, Water Electrolysis and Methanol Synthesis
Léonard, Grégoire ULg; Giulini, Davide; Villarreal-Singer, Diego

in Proceedings of the 26th European Symposium on Computer Aided Process Engineering - ESCAPE 26 (2016, June)

The energy transition corresponding to more electricity generation from variable and decentralized renewable energy sources requires the development of electricity storage technologies ranging from ... [more ▼]

The energy transition corresponding to more electricity generation from variable and decentralized renewable energy sources requires the development of electricity storage technologies ranging from seconds to seasons. The power-to-fuel process provides a way to store electricity as a liquid energy vector, leading to high energy density and cheap long-term storage at ambient conditions. In the present work, we study the powerto- methanol process combining CO2 capture, water/CO2 co-electrolysis and methanol synthesis. An Aspen Plus model focussing on the electrolysis and methanol synthesis sub-processes is presented. The energy conversion efficiency is improved from 40.1 to 53.0 % thanks to heat integration using the pinch method. Further works include the experimental demonstration of this technology as well as the development of control strategies for its regulation. [less ▲]

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See detailInfluence of process operating conditions on solvent thermal and oxidative degradation in post-combustion CO2 capture
Léonard, Grégoire ULg; Crosset, Cyril; Toye, Dominique ULg et al

in Computers & Chemical Engineering (2015), 83

The CO2 post-combustion capture with amine solvents is modeled as a complex system interconnecting process energy consumption and solvent degradation and emission. Based on own experimental data ... [more ▼]

The CO2 post-combustion capture with amine solvents is modeled as a complex system interconnecting process energy consumption and solvent degradation and emission. Based on own experimental data, monoethanolamine degradation is included into a CO2 capture process model. The influence of operating conditions on solvent loss is validated with pilot plant data from literature. Predicted solvent consumption rates are in better agreement with plant data than any previous work, and pathways are discussed to further refine the model. Oxidative degradation in the absorber is the largest cause of solvent loss while thermal degradation does not appear as a major concern. Using a single model, the process exergy requirement decreases by 10.8% and the solvent loss by 11.1% compared to our base case. As a result, this model provides a practical tool to simultaneously minimize the process energy requirement and the solvent consumption in post-combustion CO2 capture plants with amine solvents. [less ▲]

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See detailCOPPER LEACHING FROM WASTE ELECTRIC CABLES BY BIOHYDROMETALLURGY
Lambert, Fanny ULg; Bastin, David ULg; Gaydardzhiev, Stoyan ULg et al

in Minerals Engineering (2015)

This study examines the leaching of copper from waste electric cables by chemical leaching and leaching catalysed by Acidithiobacillus ferrooxidans in terms of leaching kinetics and reagents consumption ... [more ▼]

This study examines the leaching of copper from waste electric cables by chemical leaching and leaching catalysed by Acidithiobacillus ferrooxidans in terms of leaching kinetics and reagents consumption. Operational parameters such as the nature of the oxidant (Fe3+, O2), the initial ferric iron concentration (0-10 g/L) and the temperature (21-50°C) were identified to have an important influence on the degree of copper solubilisation. At optimal process conditions, copper extraction above 90% was achieved in both leaching systems, with a leaching duration of 1 day. The bacterial leaching system slightly outperformed the chemical one but the positive effect of regeneration of Fe3+ was limited. It appears that the Fe2+ bio-oxidation is not sufficiently optimised. Best results in terms of copper solubilisation kinetics were obtained for the abiotic test at 50°C and for the biotic test at 35°C. Moreover, the study showed that in same operating conditions, a lower acid consumption was recorded for the biotic test than for the abiotic test. [less ▲]

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See detailElectricity storage with liquid fuels in a zone powered by 100% variable renewables
Léonard, Grégoire ULg; François-Lavet, Vincent ULg; Ernst, Damien ULg et al

in Proceedings of the 12th International Conference on the European Energy Market - EEM15 (2015)

In this work, an electricity zone with 100% renewables is simulated to determine the optimal sizing of generation and storage capacities in such a zone. Using actual wind output data, the model evaluates ... [more ▼]

In this work, an electricity zone with 100% renewables is simulated to determine the optimal sizing of generation and storage capacities in such a zone. Using actual wind output data, the model evaluates the economic viability of a power-to-fuel storage technology that combines water electrolysis, CO2 capture and methanol synthesis. The main advantage of using methanol as an energy carrier is that liquid fuels are suitable for (long-term) energy storage thanks to their high energy density. The levelized electricity cost projection by 2050 equals 83.4 €/MWh in the base case configuration. The effects of storage round-trip efficiency and the storage unit lifetime are quantified and their impacts on the electricity cost discussed. Additional benefits of using methanol as a fuel substitute may be taken into account in further work. [less ▲]

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See detailProcess Design and Heat Integration for the Power - to - Methanol Route
Léonard, Grégoire ULg; Giulini, Davide ULg; Villarreal-Singer, Diego et al

Conference (2015)

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See detailAir Capture and Power-to-Fuel to Close the Carbon Loop
Léonard, Grégoire ULg; Giulini, Davide ULg; Villarreal-Singer, D et al

Conference (2015)

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See detailAir Capture and Power-to-Fuel to Close the Carbon Loop
Léonard, Grégoire ULg; Villarreal-Singer, D; Lackner, K S

Poster (2015)

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See detailCarbon capture and storage at the University of Liège
Léonard, Grégoire ULg

Scientific conference (2014, November 05)

The objective of this presentation was to discuss the main technologies of CO2 capture, re-use and storage, with their respective characteristics (costs, challenges...), advantages and drawbacks. Then ... [more ▼]

The objective of this presentation was to discuss the main technologies of CO2 capture, re-use and storage, with their respective characteristics (costs, challenges...), advantages and drawbacks. Then, the second part of the presnetation highlights the main research results that have been achieved at the University of Liège in this field. [less ▲]

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See detailDesigning large-scale CO2 capture units with assessment of solvent degradation
Léonard, Grégoire ULg; Crosset, Cyril; Dumont, Marie-Noëlle ULg et al

Poster (2014, October)

Solvent degradation is a major drawback for the large-scale implementation of post-combustion CO2 capture due to amine consumption and emission of degradation products. In the present work, we refine a ... [more ▼]

Solvent degradation is a major drawback for the large-scale implementation of post-combustion CO2 capture due to amine consumption and emission of degradation products. In the present work, we refine a previous kinetic model for describing solvent oxidative and thermal degradation based on experimental results. The CO2 capture process is then modeled in Aspen Plus with assessment of solvent degradation. As a result, this work provides a useful tool for the identification of optimal operating conditions that minimize both the energy and environmental impacts of the process. [less ▲]

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See detailAssessment of Solvent Degradation within a Global Process Model of Post-Combustion CO2 Capture
Léonard, Grégoire ULg; Heyen, Georges ULg; Toye, Dominique ULg

Conference (2014, June 17)

Solvent degradation may be a major drawback for the large-scale implementation of post-combustion CO2 capture due to amine consumption and emission of degradation products. However, its influence on the ... [more ▼]

Solvent degradation may be a major drawback for the large-scale implementation of post-combustion CO2 capture due to amine consumption and emission of degradation products. However, its influence on the process operations has rarely been studied. In the present work, a kinetics model describing solvent oxidative and thermal degradation has been developed based on own experimental results for the benchmark solvent, i.e. 30 wt% monoethanolamine (MEA) in water. This model has been included into a global Aspen Plus model of the CO2 capture process. The selected process modelling approaches are described in the present work. Using the resulting simulation model, optimal operating conditions can be identified to minimize both the energy requirement and the solvent degradation in the process. This kind of process model assessing solvent degradation may contribute to the design of large-scale CO2 capture plants to consider not only the process energy penalty, but also its environmental penalty. Indeed, both aspects are relevant for the large-scale deployment of the CO2 capture technology. [less ▲]

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See detailCapture, utilisation et stockage du CO2
Léonard, Grégoire ULg

Scientific conference (2014, February)

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See detailExperimental study and kinetic model of monoethanolamineoxidative and thermal degradation for post-combustion CO2 capture
Léonard, Grégoire ULg; Toye, Dominique ULg; Heyen, Georges ULg

in International Journal of Greenhouse Gas Control (2014), 30

In the present work, a kinetic model is proposed for the prediction of amine solvent degradation in the post-combustion CO2 capture process. Solvent degradation combined to the emission of degradation ... [more ▼]

In the present work, a kinetic model is proposed for the prediction of amine solvent degradation in the post-combustion CO2 capture process. Solvent degradation combined to the emission of degradation products represents one of the main operational drawbacks of this process. It induces additional costsand it impacts the process efficiency and its environmental balance. In the present work, degradation isstudied under accelerated conditions for the case of monoethanolamine solvent (MEA). The influence of the temperature and of the O2 and CO2 concentrations in the gas feed are studied, and their effect on theMEA loss and the emission of degradation products is quantified. Based on the experimental results, a kinetic model for both oxidative and thermal degradation of MEA is proposed and compared to previous attempts to model MEA degradation. The present kinetic model may be further used to develop a practical tool assessing solvent degradation in large-scale capture plants. [less ▲]

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See detailInfluence of dissolved metals and oxidative degradation inhibitors on the oxidative and thermal degradation of monoethanolamine in post-combustion CO2 capture
Léonard, Grégoire ULg; Voice, Alexander; Toye, Dominique ULg et al

in Industrial and Engineering Chemistry Reseach (2014), 53(47), 18121

In the present work, the influence of metal ions and oxidative degradation inhibitors on the stability of monoethanolamine solvents (MEA) is studied. Solvent degradation induces additional costs and ... [more ▼]

In the present work, the influence of metal ions and oxidative degradation inhibitors on the stability of monoethanolamine solvents (MEA) is studied. Solvent degradation induces additional costs and impacts the environmental balance of the CO2 capture process as well as its efficiency. The two main degradation pathways of MEA are studied under accelerated conditions: oxidative degradation with continuous gas feed and thermal degradation in batch reactors. It is confirmed that metal ions (resulting from solvent impurities and wall leaching) enhance the oxidative degradation of MEA, while they do not impact its thermal degradation. Moreover, different oxidative degradation inhibitors are tested with varying results according to the inhibitor. It appears that at the selected concentration, radical scavengers like Inhibitor A and DMTD (2,5-dimercapto-1,3,4-thiadiazole) are more efficient than chelating agents like HEDP (1-hydroxyethylidene diphosphonic acid) at inhibiting oxidative degradation. Furthermore, attention must be paid to the influence of oxidative degradation inhibitors on the thermal degradation of MEA. Indeed, some inhibitors like DMTD, DTPA (diethylenetriaminepentaacetic acid), and DTDP (3,3′-dithiodipropionic acid) appeared to decrease the MEA thermal stability, which cannot be accepted in industrial applications. Finally, a further drawback of DTPA is its high affinity for metal ions, leading to a more corrosive solution, so its use is not recommended for CO2 capture applications. [less ▲]

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See detailRelevance of accelerated conditions for the study of monoethanolamine degradation in post-combustion CO2 capture.
Léonard, Grégoire ULg; Toye, Dominique ULg; Heyen, Georges ULg

in Canadian Journal of Chemical Engineering (2014), 93(2), 348

Solvent degradation represents one of the main operational drawbacks of the post-combustion CO2 capture process. Degradation not only induces additional costs for solvent make-up, it also impacts the ... [more ▼]

Solvent degradation represents one of the main operational drawbacks of the post-combustion CO2 capture process. Degradation not only induces additional costs for solvent make-up, it also impacts the process efficiency and its environmental penalty due to the emission of various degradation products. There is still a gap of knowledge about the influence of process operating conditions on degradation, making it currently impossible to predict the solvent degradation rate in CO2 capture plants. Morever, the reaction mechanisms corresponding to solvent degradation are very slow, significantly complicating its study in industrial units. In the present work, appropriate experimental equipment and analytical methods are developed for accelerating the degradation of monoethanolamine solvents (MEA). The relevance of accelerated conditions is established by comparing artificially degraded solvent samples with degraded solvent samples from industrial CO2 capture pilot plants. Two approaches are evaluated implying either discontinuous or continuous gas feed, this latest being the most representative of industrial degradation. The respective influences of the gas feed composition and the gas-liquid transfer are evidenced and quantified. Finally, the present study leads to a better understanding of solvent degradation in the CO2 capture process with MEA. More generally, it also evidences that accelerated conditions at laboratory-scale may provide relevant information for the study of slow phenomena taking place in large-scale industrial processes. Further works include the development of a kinetic model for MEA solvent degradation and the extension of this methodology to other promising solvents in order to facilitate the operation and large-scale deployment of CO2 capture. [less ▲]

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See detailDesigning large-scale CO2 capture units with assessment of solvent degradation
Léonard, Grégoire ULg; Crosset, Cyril; Dumont, Marie-Noëlle ULg et al

in Energy Procedia (2014), 63

Solvent degradation is one of the main operational drawbacks of post-combustion CO2 capture with amine solvents. Although the different degradation mechanisms have been largely studied in recent years, it ... [more ▼]

Solvent degradation is one of the main operational drawbacks of post-combustion CO2 capture with amine solvents. Although the different degradation mechanisms have been largely studied in recent years, it is still impossible to predict the solvent losses and the emissions of degradation products that may occur in a CO2 capture plant depending on its size and on its operating conditions. In the present work, we experimentally study the degradation of MEA monoethanolamine) under accelerated conditions implying high temperature, continuous gas feed and vigorous agitation. A special focus is set on the oxidative degradation of MEA, which is studied in the absence of CO2. Based on the experimental results, we propose a kinetic model to describe both MEA oxidative and thermal degradation pathways. The degradation kinetics is then included into a global model of the CO2 capture process, enabling solvent losses and emissions of degradation products to be predicted as a function of the process operating conditions. The predicted MEA loss is in the same order of magnitude as reported in degradation measurements from pilot plants, although lower by a factor 3. This kind of model assessing solvent degradation could and should be used for the design of large-scale CO2 capture plants in order to simultaneously consider the energy consumption of the process and its environmental impact related to the emissions of degradation products and amine solvent. Further developments shall consider the effect of SOx, NOx and dissolved metals on MEA degradation. [less ▲]

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