stephanie ognier - Academia.edu (original) (raw)
Papers by stephanie ognier
Journal of Hazardous Materials, 2017
MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF
Reaction Kinetics, Mechanisms and Catalysis, Dec 7, 2018
The present study focuses on the hybrid plasma catalytic process for CO 2 methanation. This plasm... more The present study focuses on the hybrid plasma catalytic process for CO 2 methanation. This plasma-catalytic process, based on the combination of a DBD plasma and Ni/CeZrO 2 catalyst, has several advantages over conventional catalysis: it operates at ambient conditions and requires no external heating. An optimization of the process considering the effect of the different operational parameters such as voltage, GHSV, catalyst mass, flow rate, discharge length, is herein presented. Moreover, a spectroscopic study, aiming to understand the mechanism of the reaction, is also showed. At temperatures around 270 °C and under adiabatic conditions, CO 2 conversion rates of about 80% were measured, with a CH 4 selectivity greater than 95%.
Water Air and Soil Pollution, Sep 11, 2018
Phenol is toxic to human and persistent in the environment. Traditional treatment methods have th... more Phenol is toxic to human and persistent in the environment. Traditional treatment methods have the disadvantages of long treatment time, large amount of agents, and secondary pollution. In this study, a novel gas-liquid two-phase dielectric barrier discharge reactor was designed to remove phenol in aqueous solution. The effects of operating conditions (applied voltage, discharge spacing, pH, and conductivity), different water matrix (deionized water, groundwater, surface water, tap water), and inorganic ions were investigated. Moreover, the reaction mechanisms and the possible degradation pathway were proposed. The removal efficiency of phenol achieved 95.5% under the optimal operating conditions (discharge voltage of 17.6 kV, discharge gap of 1 mm, air flow rate of 60 mL min −1) coupling with H 2 O 2 at 10 mM. The presence of different concentrations of inorganic ions (0.1, 1, 10, and 20 mM) could inhibit the phenol removal efficiencies. Specially, Cl − had different effects on phenol removal efficiency. The inhibition of Cl − on phenol removal was weakened when Cl − concentration was greater than 1 mM, which allows the technology that has certain advantages in treating high-salt wastewater containing high chloride concentration. In addition,˙OH was verified as the main active species in phenol removal. The possible degradation pathway was proposed according to theoretical calculation and GC-MS measurement.
International Journal of Hydrogen Energy, Mar 1, 2020
h i g h l i g h t s Ni-containing Fe-promoted hydrotalcite-derived catalysts for CO 2 methanation... more h i g h l i g h t s Ni-containing Fe-promoted hydrotalcite-derived catalysts for CO 2 methanation. Both nickel and iron were successfully introduced into hydrotalcites structure. Fe addition increased the reducibility and changed the distribution of basic sites. Fe influenced positively the catalytic activity in thermal and plasma CO 2 methanation.
Reaction Chemistry and Engineering, 2018
The present paper relates the integration of nonthermal plasma inside a biphasic gas-liquid micro... more The present paper relates the integration of nonthermal plasma inside a biphasic gas-liquid microfluidic chip. It evaluates the ability of plasma activation to become a synthetic tool in organic chemistry, operating in mild conditions (room temperature, atmospheric pressure) and without catalyst. Few preceding works on plasma chemistry involved a liquid phase and none of them was able to handle the high reactivity of plasma to achieve both high conversion rate and selective reactions. We fabricated a glass-polymer microfluidic chip comprising a one metre long serpentine channel, in which a parallel gas-liquid flow was stabilized thanks to a specific steplike cross-sectional shape. Transparent ITO electrodes, deposited on both sides of the chip and linked to a AC high voltage source, produced a dielectric barrier discharge all along the channel. We assessed the behaviour of the flow through optical observations and characterized the discharge through electrical measurements and real time intensified-CCD monitoring. We report the successful treatment of liquid cyclohexane with an oxygen plasma inside our chip. The GC analysis of the outflowing liquid revealed only a partial oxidation of cyclohexane into a mixture of cyclohexanol, cyclohexanone (both industrially known as "KA oil") and cyclohexyl hydroperoxide, with a total selectivity above 70% and conversion up to 30%. This indicates that alkanes can be activated and functionalized by means of plasma discharges, in a controlled way. In that respect, we claim to have successfully overcome some of the barriers to an industrially relevant plasma chemistry. We believe that the combined use of plasma and microfluidic technologies is essential to the development of this new field of research.
Chemical Engineering Journal, Feb 1, 2018
contaminated by fluorene using needle-plate pulsed corona discharge plasma, Chemical
De Gruyter eBooks, Aug 23, 2021
Huanjing Gongcheng Xuebao, 2017
Chemical Engineering Journal, 2016
Catalysis Communications, 2017
Chemical Engineering Journal, 2016
Reaction Chemistry & Engineering
As opposed to the in-line strategy, the automated sequential flow strategy enables multi-step che... more As opposed to the in-line strategy, the automated sequential flow strategy enables multi-step chemical processing. It takes advantage of milli-fluidic intensification while keeping the simplicity of batch mode.
Chemical Communications
Trifluoromethyl N,N-aminals were synthesized from nitrogen containing heterocycles in a R3SiCF3 s... more Trifluoromethyl N,N-aminals were synthesized from nitrogen containing heterocycles in a R3SiCF3 solution, using an argon plasma in a flow microreactor. The transformation of the trifluoromethyl N,N-aminals to N-trifluoroethylamine is also reported.
Chemical Communications
The synthesis of N-acylamines by using a plasma gas/liquid flow microreactor without any additive... more The synthesis of N-acylamines by using a plasma gas/liquid flow microreactor without any additives is reported, N-acylamines were obtained in good to excellent yields from primary and secondary amines, as well as from anilines, using different esters.
Reaction Chemistry & Engineering
The oligomerization of 1-hexene under argon plasma was investigated in a gas–liquid, continuous f... more The oligomerization of 1-hexene under argon plasma was investigated in a gas–liquid, continuous flow microreactor.
Organic Process Research & Development
Materials Science Forum
The methanation reaction has recently received considerable attention as a perspective CO2 utiliz... more The methanation reaction has recently received considerable attention as a perspective CO2 utilization technology leading to the formation of renewable natural gas methane. This reaction is favorable at low temperature, but it is hindered of slow kinetic rates, whereas below a temperature of 270°C, the CO2 conversion is practically 0, and at higher temperatures, 350-400°C, the co-existence of secondary reactions favors the formation of CO. This is the reason why new catalysts and process conditions are continuously being investigated to maximize the methane selectivity, preferably at low reaction temperatures and at atmospheric pressure. Thus, this work is focused on the use of a heterogeneous catalyst Ni/ Zirconia supports modified by rare earth metals such as Lanthanum, tungsten and Yttrium combined to a Dielectric Barrier Discharge plasma. Three catalysts were prepared by a conventional wet impregnation method, using 15 wt% of Ni loading over zirconia supports modified with diffe...
HAL (Le Centre pour la Communication Scientifique Directe), Oct 15, 2019
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Journal of Hazardous Materials, 2017
MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF
Reaction Kinetics, Mechanisms and Catalysis, Dec 7, 2018
The present study focuses on the hybrid plasma catalytic process for CO 2 methanation. This plasm... more The present study focuses on the hybrid plasma catalytic process for CO 2 methanation. This plasma-catalytic process, based on the combination of a DBD plasma and Ni/CeZrO 2 catalyst, has several advantages over conventional catalysis: it operates at ambient conditions and requires no external heating. An optimization of the process considering the effect of the different operational parameters such as voltage, GHSV, catalyst mass, flow rate, discharge length, is herein presented. Moreover, a spectroscopic study, aiming to understand the mechanism of the reaction, is also showed. At temperatures around 270 °C and under adiabatic conditions, CO 2 conversion rates of about 80% were measured, with a CH 4 selectivity greater than 95%.
Water Air and Soil Pollution, Sep 11, 2018
Phenol is toxic to human and persistent in the environment. Traditional treatment methods have th... more Phenol is toxic to human and persistent in the environment. Traditional treatment methods have the disadvantages of long treatment time, large amount of agents, and secondary pollution. In this study, a novel gas-liquid two-phase dielectric barrier discharge reactor was designed to remove phenol in aqueous solution. The effects of operating conditions (applied voltage, discharge spacing, pH, and conductivity), different water matrix (deionized water, groundwater, surface water, tap water), and inorganic ions were investigated. Moreover, the reaction mechanisms and the possible degradation pathway were proposed. The removal efficiency of phenol achieved 95.5% under the optimal operating conditions (discharge voltage of 17.6 kV, discharge gap of 1 mm, air flow rate of 60 mL min −1) coupling with H 2 O 2 at 10 mM. The presence of different concentrations of inorganic ions (0.1, 1, 10, and 20 mM) could inhibit the phenol removal efficiencies. Specially, Cl − had different effects on phenol removal efficiency. The inhibition of Cl − on phenol removal was weakened when Cl − concentration was greater than 1 mM, which allows the technology that has certain advantages in treating high-salt wastewater containing high chloride concentration. In addition,˙OH was verified as the main active species in phenol removal. The possible degradation pathway was proposed according to theoretical calculation and GC-MS measurement.
International Journal of Hydrogen Energy, Mar 1, 2020
h i g h l i g h t s Ni-containing Fe-promoted hydrotalcite-derived catalysts for CO 2 methanation... more h i g h l i g h t s Ni-containing Fe-promoted hydrotalcite-derived catalysts for CO 2 methanation. Both nickel and iron were successfully introduced into hydrotalcites structure. Fe addition increased the reducibility and changed the distribution of basic sites. Fe influenced positively the catalytic activity in thermal and plasma CO 2 methanation.
Reaction Chemistry and Engineering, 2018
The present paper relates the integration of nonthermal plasma inside a biphasic gas-liquid micro... more The present paper relates the integration of nonthermal plasma inside a biphasic gas-liquid microfluidic chip. It evaluates the ability of plasma activation to become a synthetic tool in organic chemistry, operating in mild conditions (room temperature, atmospheric pressure) and without catalyst. Few preceding works on plasma chemistry involved a liquid phase and none of them was able to handle the high reactivity of plasma to achieve both high conversion rate and selective reactions. We fabricated a glass-polymer microfluidic chip comprising a one metre long serpentine channel, in which a parallel gas-liquid flow was stabilized thanks to a specific steplike cross-sectional shape. Transparent ITO electrodes, deposited on both sides of the chip and linked to a AC high voltage source, produced a dielectric barrier discharge all along the channel. We assessed the behaviour of the flow through optical observations and characterized the discharge through electrical measurements and real time intensified-CCD monitoring. We report the successful treatment of liquid cyclohexane with an oxygen plasma inside our chip. The GC analysis of the outflowing liquid revealed only a partial oxidation of cyclohexane into a mixture of cyclohexanol, cyclohexanone (both industrially known as "KA oil") and cyclohexyl hydroperoxide, with a total selectivity above 70% and conversion up to 30%. This indicates that alkanes can be activated and functionalized by means of plasma discharges, in a controlled way. In that respect, we claim to have successfully overcome some of the barriers to an industrially relevant plasma chemistry. We believe that the combined use of plasma and microfluidic technologies is essential to the development of this new field of research.
Chemical Engineering Journal, Feb 1, 2018
contaminated by fluorene using needle-plate pulsed corona discharge plasma, Chemical
De Gruyter eBooks, Aug 23, 2021
Huanjing Gongcheng Xuebao, 2017
Chemical Engineering Journal, 2016
Catalysis Communications, 2017
Chemical Engineering Journal, 2016
Reaction Chemistry & Engineering
As opposed to the in-line strategy, the automated sequential flow strategy enables multi-step che... more As opposed to the in-line strategy, the automated sequential flow strategy enables multi-step chemical processing. It takes advantage of milli-fluidic intensification while keeping the simplicity of batch mode.
Chemical Communications
Trifluoromethyl N,N-aminals were synthesized from nitrogen containing heterocycles in a R3SiCF3 s... more Trifluoromethyl N,N-aminals were synthesized from nitrogen containing heterocycles in a R3SiCF3 solution, using an argon plasma in a flow microreactor. The transformation of the trifluoromethyl N,N-aminals to N-trifluoroethylamine is also reported.
Chemical Communications
The synthesis of N-acylamines by using a plasma gas/liquid flow microreactor without any additive... more The synthesis of N-acylamines by using a plasma gas/liquid flow microreactor without any additives is reported, N-acylamines were obtained in good to excellent yields from primary and secondary amines, as well as from anilines, using different esters.
Reaction Chemistry & Engineering
The oligomerization of 1-hexene under argon plasma was investigated in a gas–liquid, continuous f... more The oligomerization of 1-hexene under argon plasma was investigated in a gas–liquid, continuous flow microreactor.
Organic Process Research & Development
Materials Science Forum
The methanation reaction has recently received considerable attention as a perspective CO2 utiliz... more The methanation reaction has recently received considerable attention as a perspective CO2 utilization technology leading to the formation of renewable natural gas methane. This reaction is favorable at low temperature, but it is hindered of slow kinetic rates, whereas below a temperature of 270°C, the CO2 conversion is practically 0, and at higher temperatures, 350-400°C, the co-existence of secondary reactions favors the formation of CO. This is the reason why new catalysts and process conditions are continuously being investigated to maximize the methane selectivity, preferably at low reaction temperatures and at atmospheric pressure. Thus, this work is focused on the use of a heterogeneous catalyst Ni/ Zirconia supports modified by rare earth metals such as Lanthanum, tungsten and Yttrium combined to a Dielectric Barrier Discharge plasma. Three catalysts were prepared by a conventional wet impregnation method, using 15 wt% of Ni loading over zirconia supports modified with diffe...
HAL (Le Centre pour la Communication Scientifique Directe), Oct 15, 2019
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.