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carine julcour

Institut National Polytechnique de Toulouse, Laboratoire de Genie Chimique, Faculty Member

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I obtained Engineer degree (1996) and PhD (1999) in Chemical Engineering at Toulouse INP (Institut National Polytechnique). I worked as teaching and research assistant at ENSIACET Toulouse (1999-2000) and ENS Cachan (2000-2001). Since 2001 I have hold a CNRS researcher position at Laboratoire de Génie Chimique (Toulouse). My scientific interests concern Chemical Reaction Engineering and include more specifically the characterization and modelling of three phase (catalytic) reactors and the development of non-conventional (hybrid) processes for environment (waste and water treatment, CO2 mitigation).

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Papers by carine julcour

Guiding Mineralization Process Development with Geochemical Modelling

SSRN Electronic Journal, 2019

Amphiphilic core-cross-linked micelles functionalized with bis(4-methoxyphenyl)phenylphosphine as catalytic nanoreactors for biphasic hydroformylation

Polymer, 2015

Core-cross-linked micelles (CCM) functionalized at the core with covalently linked bis(pmethoxyph... more Core-cross-linked micelles (CCM) functionalized at the core with covalently linked bis(pmethoxyphenyl)phenylphosphine (BMOPPP) ligands have been synthesized by a three-step one-pot radical polymerization in emulsion, using the polymerization-induced self-assembly (PISA) strategy and reversible addition-fragmentation chain transfer (RAFT) as the controlling method. The CCM are obtained by chain extending in water poly(methacrylic acid-copoly(ethylene oxide) methyl ether methacrylate) (P(MAA-co-PEOMA), degree of polymerization of 30, MAA/PEOMA units molar ratio of 50:50) synthesized in a first step by RAFT with a 95:5 molar mixture of styrene and 4-[bis(p-methoxyphenyl)phosphino]styrene (BMOPPS) units. The resulting micelles exhibiting a core composed of P(S-co-BMOPPS) segments with a degree of polymerization of 300 are then crosslinked in a third step with a mixture of di(ethylene glycol) dimethacrylate (DEGDMA) and styrene. The resulting BMOPPP@CCM exhibit a narrow size distribution (PDI = 0.16) with an average diameter of 81 nm in water and swell in THF or by addition of toluene to the latex. The addition of [Rh(acac)(CO)2] to the toluene-swollen latex results in metal coordination to the phosphine ligands. 31 P{ 1 H} NMR spectroscopy shows that the Rh centers undergo rapid intraparticle phosphine ligand exchange. Application of these nanoreactors to the aqueous biphasic hydroformylation of 1-octene shows excellent activity and moderate catalyst leaching.

Ultrasonic sludge pretreatment under pressure

Ultrasonics Sonochemistry, 2013

Selective hydrogenation in trickle-bed reactor: experimental and modelling including partial wetting

Catalysis Today, 2003

A steady state model of a trickle bed reactor is developed for the consecutive hydrogenation of 1... more A steady state model of a trickle bed reactor is developed for the consecutive hydrogenation of 1,5,9-cyclododecatriene on a Pd/Al 2 O 3 catalyst. Various experiments have shown that the selectivity of this reaction towards the product of interest is much lower in co-current down-flow (trickle-bed) than in up-flow. This is due to uneven liquid distribution and to partial wetting of the catalyst surface at low liquid flow rates. The non-isothermal heterogeneous model proposed here takes into account the partial wetting of the catalyst, as well as the resistances to heat and mass transfer at the gas-liquid, liquid-solid and solid-gas interfaces. It assumes that the catalyst particles can be divided into two distinct concentration zones corresponding to the wetted and dry catalyst surfaces; mass transfer between these two zones is described by a simplified diffusion mechanism. Compared to previous models assuming a uniform concentration of liquid-phase components inside the catalyst particles, this model improves the prediction of the outlet concentrations of hydrogenation products.

Dynamics of internal diffusion during the hydrogenation of 1,5,9-cyclododecatriene on Pd/Al2O3

Catalysis Today, 1999

Dynamic and pseudo-steady state diffusion-reaction models were simulated for the three phase cons... more Dynamic and pseudo-steady state diffusion-reaction models were simulated for the three phase consecutive hydrogenation of 1,5,9-cyclododecatriene on a shell Pd/Al 2 O 3 catalyst in order to examine the time evolution of concentration profiles inside the catalyst pellet: a model accounting only for the dynamics of the active layer and a model taking also into account the inert part of the catalyst were compared. In the conditions of the semibatch experiments (T = 433 K, p H2 = 1.2 MPa), all the models lead to the same bulk concentration-time curves, but the hydrocarbon concentration profiles in the pores are dependent on the model. The influence of the diffusion in the inert part of the catalyst on the bulk concentrations becomes non negligible only when the external liquid volume (out of the catalyst) is reduced. The transient evolution of the concentration profiles in the pores show that hydrogen concentration reaches its steady state within a few seconds, while the evolution of the organic concentration profiles is slower. Furthermore, the reaction rate has been found to be only affected by the hydrogen diffusion. The diffusion of organics can control the reaction rate only for low values of organic concentration and higher pressure in hydrogen.

Regeneration of activated carbon by fenton and photofenton oxidation for the treatment of phenol wastewater

Advanced Oxidation Processes have emerged as promising technologies for the recovery of carbons s... more Advanced Oxidation Processes have emerged as promising technologies for the recovery of carbons saturated with aromatic molecules, owing to their potency to degrade a wide range of organic pollutants by the generation of very reactive and non selective free hydroxyl radicals. The purpose of this work is to study the adsorption of phenol on activated carbons (ACs) and the consecutive in-situ regeneration of carbon by Fenton oxidation. Two different processes have been carried out:-the first one is based on a complete batch system in order to investigate the influence of Fe 2+ and H2O2 concentrations;-the second one consists in a continuous fixed bed adsorption, followed by a batch circulation of the Fenton's reagent through the saturated AC bed, to examine the efficiency of the real process. Two different activated carbons have been also studied: a both micro-and mesoporous AC (L27) and an only microporous one (S23). In the batch reactor containing a 1 g/L phenol solution, the optimal conditions found for pollutant mineralization in the homogeneous Fenton system (Fe 2+ = 10 mmol/L, [H2O2] = 1000 mmol/L, corresponding to 6.5 times the stoechiometric amount for complete mineralization) are not the best for AC regeneration: a continuous reduction of adsorption capacity of L27 from 100% to 23% is observed after 3 oxidations, due to the decrease of both AC weight and surface area. Higher concentration of Fe 2+ (20 mmol/L) and lower concentration of H2O2 (2 times the stoechiometry) lead to a 50% recovery of the initial adsorption capacity during at least 4 consecutive cycles for L27, while about 20% or less for S23. In the consecutive continuous adsorption/batch oxidation process, the regeneration efficiency reaches 30% to 40% for L27 after two cycles whatever the feed concentration (0.1 g/L or 1 g/L of phenol) and less than 10% for S23 (0.1 g/L of phenol). During oxidation step, Total Organic Carbon removal is found to reach a limit, probably due to the formation of Fe 3+ /organic acid complex, hindering Fe 2+ regeneration. Such complexes are stable in usual Fenton conditions, but can be destroyed by UV radiation. A photo-Fenton test performed on L27 indeed shows almost complete mineralization and improved recovery of AC adsorption capacity although not complete (56% after two cycles).

Partial Wetting in Trickle Bed Reactors: Measurement Techniques and Global Wetting Efficiency

Industrial & Engineering Chemistry Research, 2007

Three very different techniques for measuring the catalyst wetted fraction-or wetting efficiency-... more Three very different techniques for measuring the catalyst wetted fraction-or wetting efficiency-in trickle bed reactors have been carried out and compared. The first one based on pressure drop data performed successively in single gas then liquid phase, then in gas-liquid phase is experimentally very simple but did not result in meaningful wetting efficiency estimation. The other ones, based on RTD analysis and on dye adsorption on wetted surfaces, gave similar results, and were used to investigate different parameters: liquid velocity and gas molecular weight and pressure by RTD, liquid-solid interaction or affinity (contact angle) and particle shape and diameter by dye fixation. The main operating parameter is the liquid velocity while the effect of gas flow is very weak. Higher solid-liquid affinity (heptane versus water) improves wetting efficiency only at very low liquid velocity (<2•10-3 m/s).

Microkinetic Modeling of Acetylene Hydrogenation Under Periodic Reactor Operation

ChemCatChem, 2022

Dynamic reactor operations will gain interest with the increase of intermittent electricity from ... more Dynamic reactor operations will gain interest with the increase of intermittent electricity from renewable sources. Periodic operation of catalytic reactors can also be used for kinetic studies with better parameter estimation than steady-state operation. This methodology is exemplified for the case of acetylene hydrogenation over Pd/α-Al 2 O 3 using small amplitude flow oscillations. It allows the evaluation of several elementary kinetic parameters from one set of dynamic data for a reaction mechanism based on a single catalytic site. The optimized transient model is able to reproduce the time-evolution of the reactant and product molar fractions at the outlet of a fixed bed operated with modulations of different amplitudes and frequencies. It further shows that the acetylene conversion is controlled by two steps, the hydrogen adsorption step and the hydrogenation of the surface vinyl intermediate into adsorbed ethylene.

Effet d'une phase solide finement dispersée sur le transfert gaz-liquide en réacteur autoclave et en colonnes à bulles

On a cherche a quantifier et comprendre l’effet de particules microniques sur le transfert de mat... more On a cherche a quantifier et comprendre l’effet de particules microniques sur le transfert de matiere gaz-liquide. Les mesures ont ete realisees a la fois en colonne a bulles et en reacteur agite par une turbine a induction de gaz pour des suspensions de nature (charbons, silices hydrophiles et hydrophobisees), de taille (de 4 a 32 μm) et de concentrations variees. En colonne a bulles, la vitesse de transfert entre l’air et l’eau est essentiellement liee a l’hydrodynamique, et aucun des solides etudies n’a permis d’ameliorer ni la retention gazeuse, ni le coefficient de transfert. Au contraire, a partir de 5 g/l, l’ajout des plus fines particules de silice hydrophile a eu un effet negatif. En reacteur agite, la nature du gaz a egalement ete etudiee, mais la encore le transfert gaz-liquide n’est que peu modifie, avec le plus souvent des variations inferieures a 15% par rapport au cas diphasique, mais jusqu’a +50% pour les silices hydrophobisees aux plus fortes vitesses d’agitation.

Core-Cross-Linked Micelles and Amphiphilic Nanogels as Unimolecular Nanoreactors for Micellar-Type, Metal-Based Aqueous Biphasic Catalysis

Effects of Nanoconﬁnement on Catalysis, 2017

Biphasic homogeneous protocols are attractive for catalyzed transformations in industry, especial... more Biphasic homogeneous protocols are attractive for catalyzed transformations in industry, especially when conducted with water as the catalyst phase as exemplified by the large-scale Rhone-Poulenc/Ruhrchemie hydroformylation process, but can only be applied when the substrate is sufficiently soluble in the aqueous phase to sustain sufficiently fast mass transport . Different solutions to reduce mass transport limitations include the use of additives to increase the substrate solubility in water or increase the water/organic interface, anchoring the catalyst onto a lower critical solution temperature (LCST) polymer to implement thermomorphic behavior, and anchoring the catalyst to the hydrophobic part of surfactants or amphiphilic block copolymers that self-assemble in the form of micelles in water. The use of catalytic micelles appears as the most attractive approach but is limited by the potential formation of stable emulsions and by loss of free macromolecules during separation. These limitations are removed by cross-linking the macromolecules into a unimolecular nanoreactor. This chapter covers the emerging area of unimolecular catalytic nanoreactors, focusing on transition metal-based catalytic applications. It will also present the synthesis of new types of catalytic unimolecular nanoreactors developed in our laboratories, conceived to function on the basis of the micellar catalysis principle. These nanoreactors consist of either core-cross-linked micelle (CCM) or amphiphilic functionalized nanogels (NG). The proof of principle of their catalytic performance in the aqueous biphasic hydroformylation of 1-octene will also be presented. The catalyst confinement objective which is highlighted in this chapter is process optimization in terms of the catalyst phase recovery and recycling.

Periodic reactor operation for parameter estimation in catalytic heterogeneous kinetics. Case study for ethylene adsorption on Ni/Al2O3

Chemical Engineering Science, 2018

Periodic reactor operation for parameter estimation in catalytic heterogeneous kinetics. Case stu... more

Hydrodynamic study of a monolith-type reactor for intensification of gas-liquid applications

Chemical Engineering and Processing: Process Intensification, 2017

study of a monolith-type reactor for intensification of gas-liquid applications. (2017) Chemical ... more

Preparation of Polymer Supported Phosphine Ligands by Metal Catalyzed Living Radical Copolymerization and Their Application to Hydroformylation Catalysis

ChemCatChem, 2013

A series of well defined polystyrene supported tertiary phosphine ligands were prepared by copper... more A series of well defined polystyrene supported tertiary phosphine ligands were prepared by copper catalyzed atom transfer radical polymerization (ATRP), involving direct copolymerization of styrene and 4-styryldiphenylphosphine (SDPP). Copolymerization of the two monomers at different molar ratios showed a decreasing level of control as the SDPP molar fraction (fSDPP) increased, with a satisfactory level of control being achieved for fSDPP ≤ 0.25 (constant concentration of growing "living chains", linear Mn growth with conversion and low dispersity). Copper-free polymers with different chain lengths were prepared and tested as polymeric ligands in the Rh-catalyzed hydroformylation of 1-octene. The polymeric ligands yielded higher linear/branched selectivity and lower activity relative to PPh3 at the same P/Rh ratio. The selectivity increased slightly as a function of the polymer chain length.

Improving sewage sludge ultrasonic pretreatment under pressure by changing initial pH

Journal of Environmental Management, 2013

OATAO is an open access repository that collects the work of Toulouse researchers and makes it fr... more

Preparation of phosphine-functionalized polystyrene stars by metal catalyzed controlled radical copolymerization and their application to hydroformylation catalysis

Dalton Transactions, 2013

Well defined star copolymers have been prepared by copper-catalyzed atom transfer radical copolym... more Well defined star copolymers have been prepared by copper-catalyzed atom transfer radical copolymerization of styrene and styryldiphenylphosphine starting from a modified Boltorn TM H30 multifunctional initiator. These polymers and an analogue obtained by debromination of the arm ends with nBu3SnH have been used in combination with [Rh(acac)(CO)2] for the homogeneous phase hydroformylation of 1-octene.

Etude Hydrodynamique d'une Colonne á Bulles 2D en Presence d'Additifs Faiblement Concentres

fe.up.pt

... Utilizador: Senha: Validar. Mapa do Campus. Etude Hydrodynamique d&#x27;une Colonne á Bul... more

Observation of the depassivation effect of attrition on magnesium silicates' direct aqueous carbonation products

Frontiers in Climate

The main obstacle to the aqueous carbonation of non-serpentinised magnesium silicates is the form... more The main obstacle to the aqueous carbonation of non-serpentinised magnesium silicates is the formation of surface passivation layers, which severely limits the reaction rate and thus the overall efficiency of the process. A technological solution to overcome this problem is to perform the carbonation process inside a stirred bead mill, which aims to continuously remove the surface by-product layers by attrition. In this work, the aqueous carbonation of ferronickel slag, a mineralogically complex mining waste composed of a Mg/Si rich amorphous phase and a crystalline ferrous forsterite, was studied at 150°C and under 10 bar of CO2 with different operating configurations: carbonation alone (C mode), attrition followed by carbonation (A-C mode) and concomitant attrition and carbonation (AC mode). By careful observation of the mineralogy and the surface of the secondary phases formed using complementary analytical techniques, the article allows a better understanding of the passivation ...

Thermo-kinetic modelling of the acidic leaching of anorthosite: Key learnings toward the conception of a sustainable industrial process

Minerals Engineering, 2022

Degradation of ibuprofen by photo-based advanced oxidation processes: exploring methods of activation and related reaction routes

International Journal of Environmental Science and Technology, 2021

Degradation of ibuprofen by photo-based advanced oxidation processes: exploring methods of activa... more

Sunflower oil hydrogenation mechanisms and kinetics

Chemical Engineering Journal, 2021

A kinetic model for sunflower oil hydrogenation on a palladium catalyst is proposed based on Hori... more A kinetic model for sunflower oil hydrogenation on a palladium catalyst is proposed based on Horiuty-Polanyi type mechanism and considering either a dissociative or associative adsorption of hydrogen. The derived kinetic laws allow to explain the distinct dependency of saturation and isomerization reactions on hydrogen pressure. Kinetic parameters are identified based on batch slurry hydrogenations carried out at 60-160 • C and 2-31 bar with a powdered Pd/Al 2 O 3 catalyst. A statistical analysis is used to select the most suitable adsorption mechanism for H 2. Evaluation of the Weisz-Prater modulus reveals that limitations to intraparticle diffusion occur despite the particle diameter does not exceed 40 μm.

Guiding Mineralization Process Development with Geochemical Modelling

SSRN Electronic Journal, 2019

Amphiphilic core-cross-linked micelles functionalized with bis(4-methoxyphenyl)phenylphosphine as catalytic nanoreactors for biphasic hydroformylation

Polymer, 2015

Core-cross-linked micelles (CCM) functionalized at the core with covalently linked bis(pmethoxyph... more Core-cross-linked micelles (CCM) functionalized at the core with covalently linked bis(pmethoxyphenyl)phenylphosphine (BMOPPP) ligands have been synthesized by a three-step one-pot radical polymerization in emulsion, using the polymerization-induced self-assembly (PISA) strategy and reversible addition-fragmentation chain transfer (RAFT) as the controlling method. The CCM are obtained by chain extending in water poly(methacrylic acid-copoly(ethylene oxide) methyl ether methacrylate) (P(MAA-co-PEOMA), degree of polymerization of 30, MAA/PEOMA units molar ratio of 50:50) synthesized in a first step by RAFT with a 95:5 molar mixture of styrene and 4-[bis(p-methoxyphenyl)phosphino]styrene (BMOPPS) units. The resulting micelles exhibiting a core composed of P(S-co-BMOPPS) segments with a degree of polymerization of 300 are then crosslinked in a third step with a mixture of di(ethylene glycol) dimethacrylate (DEGDMA) and styrene. The resulting BMOPPP@CCM exhibit a narrow size distribution (PDI = 0.16) with an average diameter of 81 nm in water and swell in THF or by addition of toluene to the latex. The addition of [Rh(acac)(CO)2] to the toluene-swollen latex results in metal coordination to the phosphine ligands. 31 P{ 1 H} NMR spectroscopy shows that the Rh centers undergo rapid intraparticle phosphine ligand exchange. Application of these nanoreactors to the aqueous biphasic hydroformylation of 1-octene shows excellent activity and moderate catalyst leaching.

Ultrasonic sludge pretreatment under pressure

Ultrasonics Sonochemistry, 2013

Selective hydrogenation in trickle-bed reactor: experimental and modelling including partial wetting

Catalysis Today, 2003

A steady state model of a trickle bed reactor is developed for the consecutive hydrogenation of 1... more A steady state model of a trickle bed reactor is developed for the consecutive hydrogenation of 1,5,9-cyclododecatriene on a Pd/Al 2 O 3 catalyst. Various experiments have shown that the selectivity of this reaction towards the product of interest is much lower in co-current down-flow (trickle-bed) than in up-flow. This is due to uneven liquid distribution and to partial wetting of the catalyst surface at low liquid flow rates. The non-isothermal heterogeneous model proposed here takes into account the partial wetting of the catalyst, as well as the resistances to heat and mass transfer at the gas-liquid, liquid-solid and solid-gas interfaces. It assumes that the catalyst particles can be divided into two distinct concentration zones corresponding to the wetted and dry catalyst surfaces; mass transfer between these two zones is described by a simplified diffusion mechanism. Compared to previous models assuming a uniform concentration of liquid-phase components inside the catalyst particles, this model improves the prediction of the outlet concentrations of hydrogenation products.

Dynamics of internal diffusion during the hydrogenation of 1,5,9-cyclododecatriene on Pd/Al2O3

Catalysis Today, 1999

Dynamic and pseudo-steady state diffusion-reaction models were simulated for the three phase cons... more Dynamic and pseudo-steady state diffusion-reaction models were simulated for the three phase consecutive hydrogenation of 1,5,9-cyclododecatriene on a shell Pd/Al 2 O 3 catalyst in order to examine the time evolution of concentration profiles inside the catalyst pellet: a model accounting only for the dynamics of the active layer and a model taking also into account the inert part of the catalyst were compared. In the conditions of the semibatch experiments (T = 433 K, p H2 = 1.2 MPa), all the models lead to the same bulk concentration-time curves, but the hydrocarbon concentration profiles in the pores are dependent on the model. The influence of the diffusion in the inert part of the catalyst on the bulk concentrations becomes non negligible only when the external liquid volume (out of the catalyst) is reduced. The transient evolution of the concentration profiles in the pores show that hydrogen concentration reaches its steady state within a few seconds, while the evolution of the organic concentration profiles is slower. Furthermore, the reaction rate has been found to be only affected by the hydrogen diffusion. The diffusion of organics can control the reaction rate only for low values of organic concentration and higher pressure in hydrogen.

Regeneration of activated carbon by fenton and photofenton oxidation for the treatment of phenol wastewater

Advanced Oxidation Processes have emerged as promising technologies for the recovery of carbons s... more Advanced Oxidation Processes have emerged as promising technologies for the recovery of carbons saturated with aromatic molecules, owing to their potency to degrade a wide range of organic pollutants by the generation of very reactive and non selective free hydroxyl radicals. The purpose of this work is to study the adsorption of phenol on activated carbons (ACs) and the consecutive in-situ regeneration of carbon by Fenton oxidation. Two different processes have been carried out:-the first one is based on a complete batch system in order to investigate the influence of Fe 2+ and H2O2 concentrations;-the second one consists in a continuous fixed bed adsorption, followed by a batch circulation of the Fenton's reagent through the saturated AC bed, to examine the efficiency of the real process. Two different activated carbons have been also studied: a both micro-and mesoporous AC (L27) and an only microporous one (S23). In the batch reactor containing a 1 g/L phenol solution, the optimal conditions found for pollutant mineralization in the homogeneous Fenton system (Fe 2+ = 10 mmol/L, [H2O2] = 1000 mmol/L, corresponding to 6.5 times the stoechiometric amount for complete mineralization) are not the best for AC regeneration: a continuous reduction of adsorption capacity of L27 from 100% to 23% is observed after 3 oxidations, due to the decrease of both AC weight and surface area. Higher concentration of Fe 2+ (20 mmol/L) and lower concentration of H2O2 (2 times the stoechiometry) lead to a 50% recovery of the initial adsorption capacity during at least 4 consecutive cycles for L27, while about 20% or less for S23. In the consecutive continuous adsorption/batch oxidation process, the regeneration efficiency reaches 30% to 40% for L27 after two cycles whatever the feed concentration (0.1 g/L or 1 g/L of phenol) and less than 10% for S23 (0.1 g/L of phenol). During oxidation step, Total Organic Carbon removal is found to reach a limit, probably due to the formation of Fe 3+ /organic acid complex, hindering Fe 2+ regeneration. Such complexes are stable in usual Fenton conditions, but can be destroyed by UV radiation. A photo-Fenton test performed on L27 indeed shows almost complete mineralization and improved recovery of AC adsorption capacity although not complete (56% after two cycles).

Partial Wetting in Trickle Bed Reactors: Measurement Techniques and Global Wetting Efficiency

Industrial & Engineering Chemistry Research, 2007

Three very different techniques for measuring the catalyst wetted fraction-or wetting efficiency-... more Three very different techniques for measuring the catalyst wetted fraction-or wetting efficiency-in trickle bed reactors have been carried out and compared. The first one based on pressure drop data performed successively in single gas then liquid phase, then in gas-liquid phase is experimentally very simple but did not result in meaningful wetting efficiency estimation. The other ones, based on RTD analysis and on dye adsorption on wetted surfaces, gave similar results, and were used to investigate different parameters: liquid velocity and gas molecular weight and pressure by RTD, liquid-solid interaction or affinity (contact angle) and particle shape and diameter by dye fixation. The main operating parameter is the liquid velocity while the effect of gas flow is very weak. Higher solid-liquid affinity (heptane versus water) improves wetting efficiency only at very low liquid velocity (<2•10-3 m/s).

Microkinetic Modeling of Acetylene Hydrogenation Under Periodic Reactor Operation

ChemCatChem, 2022

Dynamic reactor operations will gain interest with the increase of intermittent electricity from ... more Dynamic reactor operations will gain interest with the increase of intermittent electricity from renewable sources. Periodic operation of catalytic reactors can also be used for kinetic studies with better parameter estimation than steady-state operation. This methodology is exemplified for the case of acetylene hydrogenation over Pd/α-Al 2 O 3 using small amplitude flow oscillations. It allows the evaluation of several elementary kinetic parameters from one set of dynamic data for a reaction mechanism based on a single catalytic site. The optimized transient model is able to reproduce the time-evolution of the reactant and product molar fractions at the outlet of a fixed bed operated with modulations of different amplitudes and frequencies. It further shows that the acetylene conversion is controlled by two steps, the hydrogen adsorption step and the hydrogenation of the surface vinyl intermediate into adsorbed ethylene.

Effet d'une phase solide finement dispersée sur le transfert gaz-liquide en réacteur autoclave et en colonnes à bulles

On a cherche a quantifier et comprendre l’effet de particules microniques sur le transfert de mat... more On a cherche a quantifier et comprendre l’effet de particules microniques sur le transfert de matiere gaz-liquide. Les mesures ont ete realisees a la fois en colonne a bulles et en reacteur agite par une turbine a induction de gaz pour des suspensions de nature (charbons, silices hydrophiles et hydrophobisees), de taille (de 4 a 32 μm) et de concentrations variees. En colonne a bulles, la vitesse de transfert entre l’air et l’eau est essentiellement liee a l’hydrodynamique, et aucun des solides etudies n’a permis d’ameliorer ni la retention gazeuse, ni le coefficient de transfert. Au contraire, a partir de 5 g/l, l’ajout des plus fines particules de silice hydrophile a eu un effet negatif. En reacteur agite, la nature du gaz a egalement ete etudiee, mais la encore le transfert gaz-liquide n’est que peu modifie, avec le plus souvent des variations inferieures a 15% par rapport au cas diphasique, mais jusqu’a +50% pour les silices hydrophobisees aux plus fortes vitesses d’agitation.

Core-Cross-Linked Micelles and Amphiphilic Nanogels as Unimolecular Nanoreactors for Micellar-Type, Metal-Based Aqueous Biphasic Catalysis

Effects of Nanoconﬁnement on Catalysis, 2017

Biphasic homogeneous protocols are attractive for catalyzed transformations in industry, especial... more Biphasic homogeneous protocols are attractive for catalyzed transformations in industry, especially when conducted with water as the catalyst phase as exemplified by the large-scale Rhone-Poulenc/Ruhrchemie hydroformylation process, but can only be applied when the substrate is sufficiently soluble in the aqueous phase to sustain sufficiently fast mass transport . Different solutions to reduce mass transport limitations include the use of additives to increase the substrate solubility in water or increase the water/organic interface, anchoring the catalyst onto a lower critical solution temperature (LCST) polymer to implement thermomorphic behavior, and anchoring the catalyst to the hydrophobic part of surfactants or amphiphilic block copolymers that self-assemble in the form of micelles in water. The use of catalytic micelles appears as the most attractive approach but is limited by the potential formation of stable emulsions and by loss of free macromolecules during separation. These limitations are removed by cross-linking the macromolecules into a unimolecular nanoreactor. This chapter covers the emerging area of unimolecular catalytic nanoreactors, focusing on transition metal-based catalytic applications. It will also present the synthesis of new types of catalytic unimolecular nanoreactors developed in our laboratories, conceived to function on the basis of the micellar catalysis principle. These nanoreactors consist of either core-cross-linked micelle (CCM) or amphiphilic functionalized nanogels (NG). The proof of principle of their catalytic performance in the aqueous biphasic hydroformylation of 1-octene will also be presented. The catalyst confinement objective which is highlighted in this chapter is process optimization in terms of the catalyst phase recovery and recycling.

Periodic reactor operation for parameter estimation in catalytic heterogeneous kinetics. Case study for ethylene adsorption on Ni/Al2O3

Chemical Engineering Science, 2018

Periodic reactor operation for parameter estimation in catalytic heterogeneous kinetics. Case stu... more

Hydrodynamic study of a monolith-type reactor for intensification of gas-liquid applications

Chemical Engineering and Processing: Process Intensification, 2017

study of a monolith-type reactor for intensification of gas-liquid applications. (2017) Chemical ... more

Preparation of Polymer Supported Phosphine Ligands by Metal Catalyzed Living Radical Copolymerization and Their Application to Hydroformylation Catalysis

ChemCatChem, 2013

A series of well defined polystyrene supported tertiary phosphine ligands were prepared by copper... more A series of well defined polystyrene supported tertiary phosphine ligands were prepared by copper catalyzed atom transfer radical polymerization (ATRP), involving direct copolymerization of styrene and 4-styryldiphenylphosphine (SDPP). Copolymerization of the two monomers at different molar ratios showed a decreasing level of control as the SDPP molar fraction (fSDPP) increased, with a satisfactory level of control being achieved for fSDPP ≤ 0.25 (constant concentration of growing "living chains", linear Mn growth with conversion and low dispersity). Copper-free polymers with different chain lengths were prepared and tested as polymeric ligands in the Rh-catalyzed hydroformylation of 1-octene. The polymeric ligands yielded higher linear/branched selectivity and lower activity relative to PPh3 at the same P/Rh ratio. The selectivity increased slightly as a function of the polymer chain length.

Improving sewage sludge ultrasonic pretreatment under pressure by changing initial pH

Journal of Environmental Management, 2013

OATAO is an open access repository that collects the work of Toulouse researchers and makes it fr... more

Preparation of phosphine-functionalized polystyrene stars by metal catalyzed controlled radical copolymerization and their application to hydroformylation catalysis

Dalton Transactions, 2013

Well defined star copolymers have been prepared by copper-catalyzed atom transfer radical copolym... more Well defined star copolymers have been prepared by copper-catalyzed atom transfer radical copolymerization of styrene and styryldiphenylphosphine starting from a modified Boltorn TM H30 multifunctional initiator. These polymers and an analogue obtained by debromination of the arm ends with nBu3SnH have been used in combination with [Rh(acac)(CO)2] for the homogeneous phase hydroformylation of 1-octene.

Etude Hydrodynamique d'une Colonne á Bulles 2D en Presence d'Additifs Faiblement Concentres

fe.up.pt

... Utilizador: Senha: Validar. Mapa do Campus. Etude Hydrodynamique d&#x27;une Colonne á Bul... more

Observation of the depassivation effect of attrition on magnesium silicates' direct aqueous carbonation products

Frontiers in Climate

The main obstacle to the aqueous carbonation of non-serpentinised magnesium silicates is the form... more The main obstacle to the aqueous carbonation of non-serpentinised magnesium silicates is the formation of surface passivation layers, which severely limits the reaction rate and thus the overall efficiency of the process. A technological solution to overcome this problem is to perform the carbonation process inside a stirred bead mill, which aims to continuously remove the surface by-product layers by attrition. In this work, the aqueous carbonation of ferronickel slag, a mineralogically complex mining waste composed of a Mg/Si rich amorphous phase and a crystalline ferrous forsterite, was studied at 150°C and under 10 bar of CO2 with different operating configurations: carbonation alone (C mode), attrition followed by carbonation (A-C mode) and concomitant attrition and carbonation (AC mode). By careful observation of the mineralogy and the surface of the secondary phases formed using complementary analytical techniques, the article allows a better understanding of the passivation ...

Thermo-kinetic modelling of the acidic leaching of anorthosite: Key learnings toward the conception of a sustainable industrial process

Minerals Engineering, 2022

Degradation of ibuprofen by photo-based advanced oxidation processes: exploring methods of activation and related reaction routes

International Journal of Environmental Science and Technology, 2021

Degradation of ibuprofen by photo-based advanced oxidation processes: exploring methods of activa... more

Sunflower oil hydrogenation mechanisms and kinetics

Chemical Engineering Journal, 2021

A kinetic model for sunflower oil hydrogenation on a palladium catalyst is proposed based on Hori... more A kinetic model for sunflower oil hydrogenation on a palladium catalyst is proposed based on Horiuty-Polanyi type mechanism and considering either a dissociative or associative adsorption of hydrogen. The derived kinetic laws allow to explain the distinct dependency of saturation and isomerization reactions on hydrogen pressure. Kinetic parameters are identified based on batch slurry hydrogenations carried out at 60-160 • C and 2-31 bar with a powdered Pd/Al 2 O 3 catalyst. A statistical analysis is used to select the most suitable adsorption mechanism for H 2. Evaluation of the Weisz-Prater modulus reveals that limitations to intraparticle diffusion occur despite the particle diameter does not exceed 40 μm.