References of "Toye, Dominique"
     in
Bookmark and Share    
Full Text
Peer Reviewed
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 (in press)

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 ▲]

Detailed reference viewed: 40 (10 ULg)
Full Text
Peer Reviewed
See detailFungal biofilm reactor improves the productivity of hydrophobin HFBII
Khalesi, Mohammadreza; Zune, Quentin ULg; Telek, Samuel ULg et al

in Biochemical Engineering Journal (in press)

Production and purification of hydrophobin HFBII has recently been the subject of intensive research, but the yield of production needs to be further improved for a generic use of this molecule at ... [more ▼]

Production and purification of hydrophobin HFBII has recently been the subject of intensive research, but the yield of production needs to be further improved for a generic use of this molecule at industrial scale. In a first step, the influence of different carbon sources on the growth of Trichoderma reesei and the production of HFBII was investigated. The optimum productivity was obtained by using 40 g/L lactose. Carbon starvation and excretion of extracellular enzyme were determined as two main conditions for the production of HFBII. In the second phase, and according to the physiological mechanisms observed during the screening phase, a bioreactor set up has been designed and two modes of cultures have been investigated, i.e. the classical submerged fermentation and a fungal biofilm reactor. In this last set-up, the broth is continuously recirculated on a metal packing exhibiting a high specific surface. In this case, the fungal biomass was mainly attached to the metal packing, leading to a simplification of downstream processing scheme. More importantly, the HFBII concentration increased up to 48.6 ± 6.2 mg/L which was 1.8 times higher in this reactor configuration and faster than the submerged culture. X-ray tomography analysis shows that the biofilm overgrowth occurs when successive cultures are performed on the same packing. However, this phenomenon has no significant influence on the yield of HFBII, suggesting that this process could be operated in continuous mode. Protein hydrolysis during stationary phase was observed by MALDI-TOF analysis according to the removal of the last amino acid from the structure of HFBII after 48 h from the beginning of fermentation in biofilm reactor. Hopefully this modification does not lead to alternation of the main physicochemical properties of HFBII. [less ▲]

Detailed reference viewed: 71 (28 ULg)
Full Text
Peer Reviewed
See detailA fungal biofilm reactor based on metal structured packing improves the quality of a Gla::GFP fusion protein produced by Aspergillus oryzae
Zune, Quentin ULg; Delepierre, Anissa ULg; Gofflot, Sebastien et al

in Applied Microbiology and Biotechnology (2015)

Fungal biofilm is known to promote the excretion of secondary metabolites in accordance with solid-state related physiological mechanisms. This work is based on the comparative analysis of classical ... [more ▼]

Fungal biofilm is known to promote the excretion of secondary metabolites in accordance with solid-state related physiological mechanisms. This work is based on the comparative analysis of classical submerged fermentation with a fungal biofilm reactor for the production of a Gla::GFP fusion protein by Aspergillus oryzae. The biofilm reactor comprises a metal structured packing allowing the attachment of the fungal biomass. Since the production of the target protein is under the control of the promoter glaB, specifically induced in solid-state fermentation, the biofilm mode of culture is expected to enhance the global productivity. Although production of the target protein was enhanced by using the biofilm mode of culture, we also found that fusion protein production is also significant when the submerged mode of culture is used. This result is related to high shear stress leading to biomass autolysis and leakage of intracellular fusion protein into the extracellular medium. Moreover, 2D-gel electrophoresis highlights the preservation of fusion protein integrity produced in biofilm conditions. Two fungal biofilm reactor designs were then investigated further, i.e. with full immersion of the packing or with medium recirculation on the packing, and the scale-up potentialities were evaluated. In this context, it has been shown that full immersion of the metal packing in the liquid medium during cultivation allows for a uniform colonization of the packing by the fungal biomass and leads to a better quality of the fusion protein. [less ▲]

Detailed reference viewed: 18 (2 ULg)
Full Text
Peer Reviewed
See detailDPSC colonization of functionalized 3D textiles
Ortiz, Mariné; Rosales-Ibáñez, Raúl; de J Pozos-Guillén, Amaury et al

in Journal of Tissue Engineering and Regenerative Medicine (2015)

Detailed reference viewed: 8 (1 ULg)
Full Text
Peer Reviewed
See detailHYDRODYNAMICS IN A DISPOSABLE RECTANGULAR PARALLELEPIPED STIRRED BIOREACTOR WITH ELLIPTIC PENDULUM MOTION PADDLE
Collignon, Marie-Laure ULg; Droissart, Laurent; Delafosse, Angélique ULg et al

in Biochemical Engineering Journal (2015), 93

Stainless steel bioreactors increasingly fall behind to their disposable counterparts in pharma research as they do not require cleaning or sterilization. This led company ATMI LifeSciences to develop the ... [more ▼]

Stainless steel bioreactors increasingly fall behind to their disposable counterparts in pharma research as they do not require cleaning or sterilization. This led company ATMI LifeSciences to develop the “Nucleo™”. Original in design, this disposable bioreactor comprises a rectangular parallelepiped plastic bag stirred by a paddle revolving in elliptic pendulum motion. Studies covering this bioreactor showed good homogeneity of culture medium as well as good productivity for animal cell cultures. To further explain these good performances, the flow inside the “Nucleo™” had to be resolved. This paper focuses on the mean flow description, computed from stereo-PIV measurements performed in 20 verticals covering the whole volume of a 50 dm3 Nucleo™ bioreactor. As the flow is already turbulent in the chosen agitation conditions, its dimensionless mean velocity field does not vary with the paddle rotational speed. Mean flow pattern exhibits an axial symmetry – same flow is observed in opposite quarters of the tank – and can be described as a three-dimensional helix coiled on itself to form a distorted horizontal torus which covers the whole tank volume. Mean velocity value is on average doubled in the cone swept by the paddle, and its two horizontal components are twice higher than its vertical ones. However, mean velocity remains significant everywhere and, in particular, no stagnant area is observed in tank corners. Our results thus confirm previous studies observations. [less ▲]

Detailed reference viewed: 27 (9 ULg)
Full Text
Peer Reviewed
See detailInfluence of viscosity on Liquid Flow Inside Structured Packings
Bradttmöller, Christian; Janzen, Anna; Crine, Michel ULg et al

in Industrial & Engineering Chemistry Research (2015), 54

In this study, X-ray computer tomography and light-induced fluorescence were applied to investigate the morphology of liquid flow inside structured packings. Fluid dynamic parameters such as liquid holdup ... [more ▼]

In this study, X-ray computer tomography and light-induced fluorescence were applied to investigate the morphology of liquid flow inside structured packings. Fluid dynamic parameters such as liquid holdup and wetted surface were determined to study the effect of the variation of viscosity and liquid load. Flow patterns inside the packing were identified and categorized. Liquid film thickness and its distribution were analyzed on single sheets. For both methods, the measured holdup values are in good agreement, despite differences in the techniques of measurement. For the flow patterns and their relative contribution, as well as mean liquid film thickness, a strong dependency on the varied parameters was found. Furthermore, the density function of film thickness distribution changed characteristically with liquid load and viscosity. The complementary use of tomography and optical assessment allowed an improved insight into flow phenomena and the observed interdependency of physical, geometric, and operational parameters. [less ▲]

Detailed reference viewed: 13 (1 ULg)
Full Text
Peer Reviewed
See detailInvestigation of the links between mass transfer conditions, dissolved hydrogen concentration and biohydrogen production by the pure strain Clostridium butyricum CWBI1009
Beckers, L.; Masset, J.; Hamilton, C. et al

in Biochemical Engineering Journal (2015), 98

Fermentative hydrogen production has often been described as inhibited by its own gas production. In this work, hydrogen production by Clostridium butyricum was investigated in batch Biochemical Hydrogen ... [more ▼]

Fermentative hydrogen production has often been described as inhibited by its own gas production. In this work, hydrogen production by Clostridium butyricum was investigated in batch Biochemical Hydrogen Potential (BHP) tests and in a 2.5L anaerobic sequenced batch reactor (AnSBR) under different operating conditions regarding liquid-to-gas mass transfer. Through the addition of both stirring up to 400rpm and nitrogen sparging, the yields were enhanced from 1.6 to 3.1molH2molglucose -1 and the maximum hydrogen production rates from 140 to 278mLh-1. These original results were achieved with a pure Clostridium strain. They showed that hydrogen production was improved by a higher liquid-to-gas hydrogen transfer resulting in a lower dissolved hydrogen concentration in the culture medium and therefore in a lower bacterial inhibition. In addition, biohydrogen partitioning between the gas and the liquid phase did not conform to Henry's Law due to critical supersaturation phenomena up to seven-fold higher than the equilibrium conditions. Therefore, dissolved hydrogen concentration should be systematically measured instead of the headspace hydrogen partial pressure. A model was proposed to correlate H2 production yield and rate by the pure C. butyricum strain CWBI1009 with mass transfer coefficient KLa. [less ▲]

Detailed reference viewed: 22 (9 ULg)
Full Text
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 ▲]

Detailed reference viewed: 32 (2 ULg)
Full Text
Peer Reviewed
See detailInvestigation on Convective Drying of Mixtures of Sewage Sludge and Sawdust in a Fixed Bed
Li, Jie ULg; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

in Drying Technology (2014)

This work is a part of a project aiming at developing a renewable fuel for gasification purposes, through convective drying of sludge/wood mixtures. The first step consists of characterizing the behavior ... [more ▼]

This work is a part of a project aiming at developing a renewable fuel for gasification purposes, through convective drying of sludge/wood mixtures. The first step consists of characterizing the behavior of sawdust/sludge mixtures during the application of convective drying. The influence of the mixing step (no mixing against 30 s at 40 rpm), as well as the sawdust/sludge ratio (1/9, 2/8, 3/7 and 4/6 on a dry basis) and the effect of the drying temperature (50 °C, 80 °C and 110 °C) have been investigated. In this study, X-ray tomography, a non-invasive imaging technique, is used to assess changes in the volume, void and exchange surface at the beginning and the end of the drying process. Results first confirm the importance of the mixing step on the drying behavior: the drying rate of the mixed sludge is lower than that of the original sludge. Nevertheless the addition of sawdust is shown to have a positive impact on the drying process from a mass ratio of 2/8, with drying rates higher than that of the original sludge. With increasing amount of sawdust, the initial and final bed volumes, initial and final total exchange surfaces, and initial void fraction increase linearly, but the bed volume shrinkage and final void fraction decrease linearly. [less ▲]

Detailed reference viewed: 14 (4 ULg)
Full Text
Peer Reviewed
See detailCFD Comparison of hydrodynamics between BIOSTAT® Cultibag STR and standard Stirred Cell Culture Bioreactors
Calvo, Sébastien ULg; Delafosse, Angélique ULg; Crine, Michel ULg et al

Poster (2014, September 10)

Single-use bioreactors have been increasingly used for animal cell cultures on microcarriers in screening experiments. Because of their manufacturing process, the shape of these kinds of vessels such as ... [more ▼]

Single-use bioreactors have been increasingly used for animal cell cultures on microcarriers in screening experiments. Because of their manufacturing process, the shape of these kinds of vessels such as the BIOSTAT® Cultibag STR one, is limited. For example, technical constraints on weld seams limit angles to 30° and no baffle may be installed. The shape of standard re-usable vessels may thus not be exactly reproduced and the flow structure may thus significantly differs from the flow structure in standard bioreactors. [less ▲]

Detailed reference viewed: 27 (8 ULg)
Full Text
Peer Reviewed
See detailDesign of a fungal biofilm reactor for recombinant protein production from Aspergillus oryzae
Zune, Quentin ULg; Delepierre, Anissa ULg; Bauwens, Julien ULg et al

Poster (2014, September 07)

Fungi are microorganisms exhibiting high secretive power of various metabolites and have the ability to perform post-translational modifications during protein synthesis. In the field of fermentation ... [more ▼]

Fungi are microorganisms exhibiting high secretive power of various metabolites and have the ability to perform post-translational modifications during protein synthesis. In the field of fermentation industry, they are ideal hosts for secondary metabolites and recombinant protein production. At the industrial-scale, equipments usually required for solid-state or submerged fermentation of filamentous fungi have demonstrated their limitations in terms of productivity, mass transfers or products recovery (1, 2). Recently, fungal biofilm reactors were designed to combine advantages from submerged and solid-state culture and reveal their usefulness for greater secondary metabolites production relative to submerged culture conditions (3). In our work, we propose the design of a fungal biofilm reactor for a recombinant protein production from an Aspergillus oryzae strain containing a GFP reporter gene system under the control of a promoter specifically induced in solid-state conditions. The fungal biofilm reactor is composed of a metal structured packing, having the function of inert support for biofilm growth, immerged or aspersed by a liquid medium. Whereas recombinant protein production is not significantly different at the flask-scale between submerged and biofilm conditions, productivity is higher in the submerged conditions at the bioreactor-scale. Presence of recombinant proteins entrapped in the biofilm matrix highlights a diffusion constraint and a lower mass transfer in our fungal biofilm reactor. However, persistence of a free liquid biomass of low viscosity and fungal biomass retention on the support are attractive for the implementation of a continuous process in our fungal biofilm reactor. Further studies will consider a 2-D proteomic comparison of the extracellular medium from fungal biofilm reactor and submerged culture conditions in order to better understand proteins secretion and identify over-expressed proteins in biofilm conditions. [less ▲]

Detailed reference viewed: 66 (10 ULg)
Full Text
Peer Reviewed
See detailRANS and Large Eddy Simulation of the hydrodynamics inside mini-bioreactors designed for stem cell culture
Collignon, Marie-Laure ULg; Martin, Céline; Blanchard, Fabrice et al

Conference (2014, September 07)

Detailed reference viewed: 45 (7 ULg)
Full Text
See detailConvective drying of sawdust/sludge mixtures in a fixed bed: The effect of sludge origin
Li, Jie ULg; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

Scientific conference (2014, August 26)

Sludges collected from Oupeye WWTP (MS=80%), Grosses Battes WWTP (MS=85.5%), and Embourg WWTP (MS=88%) in Belgium and presenting different properties were used. The influence of the sawdust/sludge ratio ... [more ▼]

Sludges collected from Oupeye WWTP (MS=80%), Grosses Battes WWTP (MS=85.5%), and Embourg WWTP (MS=88%) in Belgium and presenting different properties were used. The influence of the sawdust/sludge ratio on convective drying was investigated in a fixed bed. X-ray tomography was used to assess changes in volume, exchange surface and void fraction. Results showed that the average drying rates were 0.062 (Oupeye), 0.079 g/s (Grosses Battes) and 0.042 g/s (Embourg) respectively, using raw sludges. For sawdust/sludge mixtures with the mass ratio of 4/6, the average drying rates of sludges were improved (Oupeye: 0.092 g/s, Grosses Battes: 0.106 g/s, Embourg: 0.049 g/s). [less ▲]

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailHow to correctly determine the kinetics of a photocatalytic degradation reaction?
Pirard, Sophie ULg; Malengreaux, Charline ULg; Toye, Dominique ULg et al

in Chemical Engineering Journal (2014), 249

Detailed reference viewed: 28 (8 ULg)
Full Text
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 ▲]

Detailed reference viewed: 45 (3 ULg)