The Experts below are selected from a list of 15255 Experts worldwide ranked by ideXlab platform
Frederic Paviet - One of the best experts on this subject based on the ideXlab platform.
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Modelling of an indirectly heated fixed bed Pyrolysis Reactor of wood: Transition from batch to continuous staged gasification
Fuel, 2013Co-Authors: Pierre Lamarche, Mohand Tazerout, Franck Gelix, Stefanie Koehler, Karim Mati, Frederic PavietAbstract:Gasification is today a mature technology and staged processes know an important development. The design of this kind of Reactor is still a sensitive work, and numerical simulation, as a flexible and economic tool, has to be developed. The present work concerns the first Pyrolysis stage of a staged gasification process and is organised into two parts. The first part deals with the calibration of the effective thermal conductivity of the bed. This is the key parameter in the heat transfer modelling. The calibration is obtained by comparison between experimental and modelling results in batch Reactor. The second part is the development of a transient two dimensional model of a continuous indirectly heated fixed bed Pyrolysis Reactor. The model uses a finite difference formulation to solve mass and energy balances in a cylindrical vessel. The assumptions of local thermal equilibrium, constant particle size and thermally thin particles are considered. The simulations are used to design a Pyrolysis Reactor in function of the type of biomass, the wall temperature and the direction of gas circulation. The parametric study is presented to highlight the limitations of the external heating regarding the wood conversion rate. (C) 2012 Elsevier Ltd. All rights reserved.
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Modelling of an indirectly heated fixed bed Pyrolysis Reactor of wood: Transition from batch to continuous staged gasification
Fuel, 2013Co-Authors: Pierre Lamarche, Mohand Tazerout, Franck Gelix, Karim Mati, Stefanie Köhler, Frederic PavietAbstract:Abstract Gasification is today a mature technology and staged processes know an important development. The design of this kind of Reactor is still a sensitive work, and numerical simulation, as a flexible and economic tool, has to be developed. The present work concerns the first Pyrolysis stage of a staged gasification process and is organised into two parts. The first part deals with the calibration of the effective thermal conductivity of the bed. This is the key parameter in the heat transfer modelling. The calibration is obtained by comparison between experimental and modelling results in batch Reactor. The second part is the development of a transient two dimensional model of a continuous indirectly heated fixed bed Pyrolysis Reactor. The model uses a finite difference formulation to solve mass and energy balances in a cylindrical vessel. The assumptions of local thermal equilibrium, constant particle size and thermally thin particles are considered. The simulations are used to design a Pyrolysis Reactor in function of the type of biomass, the wall temperature and the direction of gas circulation. The parametric study is presented to highlight the limitations of the external heating regarding the wood conversion rate.
C. Roy - One of the best experts on this subject based on the ideXlab platform.
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Study of Tire Particle Mixing in a Moving and Stirred Bed Vacuum Pyrolysis Reactor
The Canadian Journal of Chemical Engineering, 2008Co-Authors: Jin Yang, M. Gupta, Xavier Roy, C. RoyAbstract:The paper studies the motion of scrap tire shreds in a moving and stirred bed vacuum Pyrolysis Reactor. The Reactor configuration is a novel concept. The pattern and the residence time distribution (RTD) of the particle motion in the Reactor were investigated using tracers, for different feed rates and blade speeds. It was shown that the particle motion in the Reactor is plug flow nature with intermediate dispersion (σ2 = 0.02—0.055). The mean residence time is in the range of 7—23 min, depending on the speed of the blades and the feed rate. The ratio of mean particle speed and the speed of blades vm/vb varied between 0.03 and 0.07. Le mouvement des particules de pneus broyes dans un reacteur de pyrolyse sous vide a lit mobile et agite a ete etudie. La configuration du reacteur est un concept novateur. Le patron d'ecoulement ainsi que la distribution du temps de residence (RTD) durant le mouvement des particules dans le reacteur ont ete examines au moyen de traceurs pour differents debits d'alimentation et vitesses des racleurs. Il a ete demontre que le mouvement des particules dans le reacteur est du type ecoulement piston avec une dispersion intermediaire (σ2 = 0,02-0,055). Le temps moyen de residence se situe dans la gamme 7 a 23 min, dependant de la vitesse des racleurs et du debit d'alimentation. Le ratio entre la vitesse moyenne des particules et la vitesse des racleurs vm/vb varie entre 0,03 et 0,07.
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Flow Characterization of Moving and Stirred Bed Vacuum Pyrolysis Reactor from RTD Studies
Chemical Engineering Research and Design, 2004Co-Authors: M. Gupta, Jin Yang, S. Métral, C. RoyAbstract:Experiments were conducted in a moving and stirred bed vacuum Pyrolysis Reactor handling polydispersed softwood bark feedstock to study flow characteristics as functions of feed throughput, agitation speed, particle size and shape. A new idea of polydispersed fluorescent tracers was employed for the first time to investigate the residence time distribution (RTD), mean residence time and Reactor hold-up. A single parameter dispersed plug flow model and an identical CSTRs-in-series model have been successfully used to fit the experimental data. Correlations are proposed for mean residence time, Reactor hold-up, vessel dispersion number and number of identical CSTRs-in-series in terms of operating variable, for example feed throughput and agitation speed in the range of 20–70 kg hr –1 and 10–30 cm s –1 , respectively.
Viresh Dutta - One of the best experts on this subject based on the ideXlab platform.
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ZnO Layer onto Si Surface by Continuous Spray Pyrolysis Reactor for Solar Cell Efficiency Enhancement
Springer Proceedings in Physics, 2016Co-Authors: Hrishikesh Dhasmana, Viresh DuttaAbstract:The present investigation reports improvement of electrical parameters such as short circuit current and so efficiency of Si solar cell device by the deposition of ZnO layers onto Si surface via continuous spray Pyrolysis Reactor even under low temperature deposition conditions. In order to achieve this improvement, the ZnO layers are optimized directly on Si solar cell using kapton tape. This masking tape is helping to improve adhesion of ZnO layer along with changed surface morphology which is confirmed with respective SEM images. The report also suggests seed layer dominance in the resultant ZnO growth which is confirmed by changing precursor solution from Zinc acetate to Titanium tetraisopropoxide. The report is supported by XRD, SEM, reflectance and I-V measurements. The study suggest, if ZnO layers are suitably designed by this Reactor on Si surface, the improvement in optical coupling can be achieved in cost effective manner for existing industrial Si solar cell fabrication line.
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Size Dependent Gold Assisted ZnO Growth on Si Surface by Continuous Spray Pyrolysis Reactor for Light Suppression
Energy Procedia, 2013Co-Authors: Hrishikesh Dhasmana, Charu Dwivedi, Viresh DuttaAbstract:Colloidal Au particles of sizes 15 and 40 nm are spray deposited on polished Si surface and then the deposition of ZnO nanostructure layer using Continuous Spray Pyrolysis Reactor is performed. XRD data suggests that the larger size Au nanoparticles act as seed particles for ZnO nanostructure formation, while smaller Au nanoparticles favour (002) oriented growth. SEM measurement confirms enhancement of ZnO nanorods growth in the case of 40 nm Au assisted deposition. The reflection measurement shows higher surface plasmon resonance for larger size Au particles and hence significant light reduction up to 51% of existing value in 500-900 nm wavelength region is achieved which may ultimately help in the increase of photocurrent in Si solar cells.
Pierre Lamarche - One of the best experts on this subject based on the ideXlab platform.
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Modelling of an indirectly heated fixed bed Pyrolysis Reactor of wood: Transition from batch to continuous staged gasification
Fuel, 2013Co-Authors: Pierre Lamarche, Mohand Tazerout, Franck Gelix, Stefanie Koehler, Karim Mati, Frederic PavietAbstract:Gasification is today a mature technology and staged processes know an important development. The design of this kind of Reactor is still a sensitive work, and numerical simulation, as a flexible and economic tool, has to be developed. The present work concerns the first Pyrolysis stage of a staged gasification process and is organised into two parts. The first part deals with the calibration of the effective thermal conductivity of the bed. This is the key parameter in the heat transfer modelling. The calibration is obtained by comparison between experimental and modelling results in batch Reactor. The second part is the development of a transient two dimensional model of a continuous indirectly heated fixed bed Pyrolysis Reactor. The model uses a finite difference formulation to solve mass and energy balances in a cylindrical vessel. The assumptions of local thermal equilibrium, constant particle size and thermally thin particles are considered. The simulations are used to design a Pyrolysis Reactor in function of the type of biomass, the wall temperature and the direction of gas circulation. The parametric study is presented to highlight the limitations of the external heating regarding the wood conversion rate. (C) 2012 Elsevier Ltd. All rights reserved.
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Modelling of an indirectly heated fixed bed Pyrolysis Reactor of wood: Transition from batch to continuous staged gasification
Fuel, 2013Co-Authors: Pierre Lamarche, Mohand Tazerout, Franck Gelix, Karim Mati, Stefanie Köhler, Frederic PavietAbstract:Abstract Gasification is today a mature technology and staged processes know an important development. The design of this kind of Reactor is still a sensitive work, and numerical simulation, as a flexible and economic tool, has to be developed. The present work concerns the first Pyrolysis stage of a staged gasification process and is organised into two parts. The first part deals with the calibration of the effective thermal conductivity of the bed. This is the key parameter in the heat transfer modelling. The calibration is obtained by comparison between experimental and modelling results in batch Reactor. The second part is the development of a transient two dimensional model of a continuous indirectly heated fixed bed Pyrolysis Reactor. The model uses a finite difference formulation to solve mass and energy balances in a cylindrical vessel. The assumptions of local thermal equilibrium, constant particle size and thermally thin particles are considered. The simulations are used to design a Pyrolysis Reactor in function of the type of biomass, the wall temperature and the direction of gas circulation. The parametric study is presented to highlight the limitations of the external heating regarding the wood conversion rate.
M. Gupta - One of the best experts on this subject based on the ideXlab platform.
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Study of Tire Particle Mixing in a Moving and Stirred Bed Vacuum Pyrolysis Reactor
The Canadian Journal of Chemical Engineering, 2008Co-Authors: Jin Yang, M. Gupta, Xavier Roy, C. RoyAbstract:The paper studies the motion of scrap tire shreds in a moving and stirred bed vacuum Pyrolysis Reactor. The Reactor configuration is a novel concept. The pattern and the residence time distribution (RTD) of the particle motion in the Reactor were investigated using tracers, for different feed rates and blade speeds. It was shown that the particle motion in the Reactor is plug flow nature with intermediate dispersion (σ2 = 0.02—0.055). The mean residence time is in the range of 7—23 min, depending on the speed of the blades and the feed rate. The ratio of mean particle speed and the speed of blades vm/vb varied between 0.03 and 0.07. Le mouvement des particules de pneus broyes dans un reacteur de pyrolyse sous vide a lit mobile et agite a ete etudie. La configuration du reacteur est un concept novateur. Le patron d'ecoulement ainsi que la distribution du temps de residence (RTD) durant le mouvement des particules dans le reacteur ont ete examines au moyen de traceurs pour differents debits d'alimentation et vitesses des racleurs. Il a ete demontre que le mouvement des particules dans le reacteur est du type ecoulement piston avec une dispersion intermediaire (σ2 = 0,02-0,055). Le temps moyen de residence se situe dans la gamme 7 a 23 min, dependant de la vitesse des racleurs et du debit d'alimentation. Le ratio entre la vitesse moyenne des particules et la vitesse des racleurs vm/vb varie entre 0,03 et 0,07.
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Flow Characterization of Moving and Stirred Bed Vacuum Pyrolysis Reactor from RTD Studies
Chemical Engineering Research and Design, 2004Co-Authors: M. Gupta, Jin Yang, S. Métral, C. RoyAbstract:Experiments were conducted in a moving and stirred bed vacuum Pyrolysis Reactor handling polydispersed softwood bark feedstock to study flow characteristics as functions of feed throughput, agitation speed, particle size and shape. A new idea of polydispersed fluorescent tracers was employed for the first time to investigate the residence time distribution (RTD), mean residence time and Reactor hold-up. A single parameter dispersed plug flow model and an identical CSTRs-in-series model have been successfully used to fit the experimental data. Correlations are proposed for mean residence time, Reactor hold-up, vessel dispersion number and number of identical CSTRs-in-series in terms of operating variable, for example feed throughput and agitation speed in the range of 20–70 kg hr –1 and 10–30 cm s –1 , respectively.
