Publications of Grégoire Léonard
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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 ULiege; Giulini, Davide; Villarreal-Singer, Diego

in Computer Aided Chemical Engineering (2016), 38

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 detailDesign and evaluation of a high-density energy storage route with CO2 re-use, water electrolysis and methanol synthesis
Léonard, Grégoire ULiege; Giulini, Davide; Villarreal-Singer, Diego

Poster (2016, June)

In the context of the Energy Transition, electricity storage ranging from seconds to seasons is needed to increase the integration of variable renewables sources. The power-tofuel process uses a liquid ... [more ▼]

In the context of the Energy Transition, electricity storage ranging from seconds to seasons is needed to increase the integration of variable renewables sources. The power-tofuel process uses a liquid energy vector with high energy density for long-term energy storage. In the present work, we simulate the power-to-methanol process in Aspen Plus. Then, we use heat integration to increase the conversion efficiency from 40.1 to 53.0 %, evidencing large improvement potential thanks to process integration. Further work includes experimental design and development of control strategies. [less ▲]

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See detailReactors for CO2 utilization
Léonard, Grégoire ULiege; Toye, Dominique ULiege; Grignard, Bruno ULiege

Scientific conference (2016, January)

In this presentation, the first focus will be set on the importance of reactors in chemical and energy conversion processes and the main reactor types that are used in the industry will be presented. The ... [more ▼]

In this presentation, the first focus will be set on the importance of reactors in chemical and energy conversion processes and the main reactor types that are used in the industry will be presented. The limiting criteria for choosing the right reactor for the desired application will be listed, evidencing the fact that “one-size-fits-all” solutions are not well suited to chemical reactor engineering. The case of amine solvent degradation and experimental reactors to mimic conditions observed in CO2 capture plants will be discussed, with a special focus on the choice between batch and semi-continuous reactors (batch feed on the liquid side, continuous gas feed). The basics of reactor engineering will then be applied to CO2 chemical conversion processes, for which the main CO2 conversion pathways will be detailed, and the coupling between the CO2 re-use route and the selected reactor will be highlighted. Among others, the main CO2 chemical re-use routes include the synthesis of various organic molecules ranging from fuels for energy storage up to polymers for new materials and applications. Finally, a short description of the activities of the PEPs and CERM groups in the field of CO2 capture and re-use will be presented. In particular, activities about solvent degradation for CO2 capture and power-to-methanol as a technology for long-term (interseasonal) energy storage will be detailed. [less ▲]

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

in Computers and 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 ULiege; Bastin, David ULiege; Gaydardzhiev, Stoyan ULiege 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 detailProcess Design and Heat Integration for the Power - to - Methanol Route
Léonard, Grégoire ULiege; Giulini, Davide ULiege; Villarreal-Singer, Diego et al

Conference (2015)

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See detailElectricity storage with liquid fuels in a zone powered by 100% variable renewables
Léonard, Grégoire ULiege; François-Lavet, Vincent ULiege; Ernst, Damien ULiege 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 detailCarbon capture and storage at the University of Liège
Léonard, Grégoire ULiege

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 ULiege; Crosset, Cyril; Dumont, Marie-Noëlle ULiege 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 ULiege; Heyen, Georges ULiege; Toye, Dominique ULiege

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 ULiege

Scientific conference (2014, February)

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

in Computer Aided Chemical Engineering (2014)

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

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

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

in Industrial and Engineering Chemistry Research (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 detailModeling post-combustion CO2 capture with assessment of solvent degradation
Léonard, Grégoire ULiege; Belletante, Ségolène; Cabeza Mogador, Bruno et al

Conference (2013, October)

Post-combustion CO2 capture in power plants is one of the most mature technologies for a short-term and large-scale decrease of CO2 emissions while simultaneously addressing the growing global energy ... [more ▼]

Post-combustion CO2 capture in power plants is one of the most mature technologies for a short-term and large-scale decrease of CO2 emissions while simultaneously addressing the growing global energy demand. CO2 is chemically absorbed in an amine solvent that can be regenerated at higher temperature, producing a pure CO2 stream. However, the large impact of this technology on the power plant efficiency and the environmental penalty are the main drawbacks for large-scale implementation. In this work, an innovative approach combining process modeling and evaluation of the environmental penalty due to amine degradation is presented. Based on experimental results, the kinetics of solvent oxidative and thermal degradation is estimated and included in the process model developed in Aspen Plus. Using this model, the influence of operating parameters like the oxygen concentration in the flue gas or the solvent regeneration pressure is studied. This model is a first step for a multi-objective optimization of the CO2 capture process, assessing both energy and environmental penalties of this technology. [less ▲]

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See detailOptimal conception of a post-combustion CO2 capture unit with assessment of solvent degradation
Léonard, Grégoire ULiege; Toye, Dominique ULiege; Heyen, Georges ULiege

Poster (2013, September)

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. A kinetics model describing ... [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. A kinetics model describing solvent oxidative and thermal degradation has been developed based on experimental results. This model has been included into a global Aspen Plus model of the CO2 capture process, so that optimal operating conditions can be identified to minimize both energy and environmental impacts of the process. [less ▲]

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See detailOptimal design of a CO2 capture unit with assessment of solvent degradation
Léonard, Grégoire ULiege

Doctoral thesis (2013)

CO2 capture in power plants by absorption in amine solvents is a technology aiming at the reduction of CO2 emissions while simultaneously addressing the growth of the global energy demand. However, the ... [more ▼]

CO2 capture in power plants by absorption in amine solvents is a technology aiming at the reduction of CO2 emissions while simultaneously addressing the growth of the global energy demand. However, the energy impact of this technology on the power plant efficiency is high and amine solvent degradation induces a non-negligible environmental impact. The main innovation of this thesis is to combine both aspects within a process model based on experimental data of solvent degradation. This model leads to the identification of optimal operating conditions for the CO2 capture process, from an energetic as well as environmental point of view. [less ▲]

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