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13 results on '"Sylvie Valin"'

1. Design and thermal characterization of an induction-heated reactor for pyrolysis of solid waste

Author

Sylvain Salvador, Sébastien Thiery, Oscar Sosa Sabogal, Sylvie Valin, Université Grenoble Alpes (UGA), Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Induction heating, Steady state, Materials science, 020209 energy, General Chemical Engineering, Tar, 02 engineering and technology, General Chemistry, 7. Clean energy, Solid waste, [CHIM.GENI]Chemical Sciences/Chemical engineering, 020401 chemical engineering, Chemical engineering, Fluidized bed, Thermal, Heat transfer, 0202 electrical engineering, electronic engineering, information engineering, Fluidized bed reactor, 0204 chemical engineering, Pyrolysis, Refuse-derived fuel, Gasification
Abstract

International audience; A small-scale induction heated reactor (IHR) was specifically developed to study fast pyrolysis, here investigated as the first step of gasification process, representing some of the reaction conditions encountered in a fluidized bed reactor. First, the thermal response of the system was characterized at transient and steady state, and CFD calculations were performed to have a complete description of the temperature profiles inside the reactor. The novel device can handle a few grams of solid at temperatures up to 900 °C, allowing high heating rates (near 80 °C/s) and a uniform distribution of temperature in the sample. Secondly, the pyrolysis of a solid recovered fuel (SRF) sample was carried out at 800 °C, and the distribution and composition of reaction products were analyzed and compared with tests performed in a pilot scale fluidized bed reactor (FBR). The results obtained in the IHR showed a good reproducibility. The same main gas and tar species were measured in the IHR and FBR, with however some differences in gas and tar composition that were attributed to the extent of secondary reactions, enhanced by higher heat transfer rates and the presence of bed material in the FBR.

Published
2021
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2. Pyrolysis of solid waste and its components in a lab scale induction-heating reactor

Author

Oscar Sosa, Sylvain Salvador, Sébastien Thiery, Sylvie Valin, Université Grenoble Alpes (UGA), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Environmental Engineering, Municipal solid waste, Induction heating, Materials science, 020209 energy, 02 engineering and technology, 010501 environmental sciences, 7. Clean energy, 01 natural sciences, chemistry.chemical_compound, [CHIM.GENI]Chemical Sciences/Chemical engineering, Waste derived fuel, 0202 electrical engineering, electronic engineering, information engineering, Environmental Chemistry, Waste Management and Disposal, Refuse-derived fuel, 0105 earth and related environmental sciences, cardboard, Polyethylene, Solid waste, Chemical engineering, chemistry, Fluidized bed, visual_art, Yield (chemistry), visual_art.visual_art_medium, Pyrolysis, Gasification
Abstract

The present study investigates the thermochemical conversion of Solid Recovered Fuel (SRF), represented by selected “model materials”. A laboratory-scale induction heated device was specifically developed to achieve fast pyrolysis conditions close to those encountered in a fluidized bed reactor. The novel device can handle up to 5 grams of solid, allowing fast heating rates (near 70°C/s) and a homogeneous distribution of temperature all along the reactor. Pyrolysis tests of a SRF sample and four model materials (Polyethylene, Polyethylene Terephthalate, beech wood, cardboard) were performed at 800°C. The yield and composition of the produced gas for each sample were determined. Experimental results will help to elucidate the relation between the initial components of waste derived fuels and the obtained reaction products.

Published
2021
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3. Biomass fast pyrolysis in a drop tube reactor for bio oil production: Experiments and modeling

Author

Marine Peyrot, Joseph Billaud, Sylvie Valin, Chamseddine Guizani, Sylvain Salvador, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Materials science, 020209 energy, General Chemical Engineering, Organic Chemistry, Modeling, Energy Engineering and Power Technology, Tar, Biomass, 02 engineering and technology, Residence time (fluid dynamics), 7. Clean energy, Fast-pyrolysis, Cracking, Drop tube reactor, Fuel Technology, Chemical engineering, 13. Climate action, 0202 electrical engineering, electronic engineering, information engineering, Particle, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Particle size, Char, Experiments, Pyrolysis
Abstract

International audience; Woody biomass fast pyrolysis in Entrained Flow Reactor (EFR) is studied both with experiments in a lab-scale drop tube reactor (DTR) and simulations with a 1-D model. The parameters of the study are temperature (450-600 degrees C), woody biomass particle size (370-640 mu m) and gas residence time (12.6-20.6 s). The most critical phenomena affecting the bio-oil yield are considered in the model: heating of the biomass particles, slip velocity of the biomass particles varying with biomass/char properties, biomass pyrolysis and tar cracking. The analyses of all products - char, bio-oil and gas - also brought information on the advancement of the pyrolysis and cracking for the different tests. The reactor temperature and particle size were found to have a major influence on the pyrolysis product distribution. The production of bio-oil reaches a maximum of 62.4 wt.% at 500 degrees C for the 370 mm particles. The particle conversion advancement is then estimated at 94% at the reactor exit. The bio-oil yield is lower at higher temperatures for a constant particle size due to tar cracking. At 550 degrees C, increasing the particle size from 370 mm to 640 mu m induces a decrease of the bio-oil yield from 48.3 to 34.8 wt.%, which was shown to be due to incomplete pyrolysis of the particles, because of a too short residence time as well as a too long heating time of particles. The pyrolysis conditions - temperature, particle size - were not found to have any significant influence on the bio-oil properties, such as acidity.

Published
2017
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4. Fluidized bed air gasification of solid recovered fuel and woody biomass: Influence of experimental conditions on product gas and pollutant release

Author

Serge Ravel, Philippe Pons de Vincent, Sébastien Thiery, Sylvie Valin, Hélène Miller, Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Pollutant, 020209 energy, General Chemical Engineering, Organic Chemistry, Energy Engineering and Power Technology, Tar, Biomass, 02 engineering and technology, Pulp and paper industry, 7. Clean energy, [SPI]Engineering Sciences [physics], Fuel Technology, 020401 chemical engineering, 13. Climate action, Fluidized bed, visual_art, 0202 electrical engineering, electronic engineering, information engineering, visual_art.visual_art_medium, Environmental science, Sawdust, Char, 0204 chemical engineering, Pyrolysis, Refuse-derived fuel
Abstract

The aim of this work is to study the air gasification of solid recovered fuel (SRF), and to compare it to the gasification of woody biomass (beech wood sawdust, and waste wood). This study focuses on the influence of several operating parameters: temperature – between 800 and 910 °C –, O2/C ratio – between 0 (pyrolysis conditions) and 0.34, and addition of steam. Experiments are performed in a bubbling fluidized bed at 1.5 bar, with a solid feeding rate of 1–3 kg/h. The yield and composition of the product gas is particularly looked at, together with the repartition of carbon into the different types of products (gas species, tar molecules). Sulphur release to the gas phase is also investigated. Temperature has mainly an influence on H2 and CO yields, which is attributed to char gasification enhancement. The addition of steam in fluidising gas induces an increase in oxygenated gas species yields (CO + CO2), related to char gasification improvement. It does not have any reforming influence on light hydrocarbon and tar, with even a slight inhibiting effect. Woody biomass and SRF show significant differences in product yields, which are qualitatively explained by the initial elemental composition and material content of each type of fuel. From a process point of view, the conversion efficiency improvement by varying the gasification conditions for SRF is limited compared to the higher efficiency obtained with woody biomass. Co-gasification of biomass – possibly waste wood – and SRF, could be a way to improve the overall efficiency, and limit pollutant content.

Published
2019
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5. Analysis and comparison of bio-oils obtained by hydrothermal liquefaction and fast pyrolysis of beech wood

Author

Suzanne Anouti, Maxime Déniel, Geert Haarlemmer, Anne Roubaud, Chamseddine Guizani, Sylvie Valin, Département Technique Conversion et Hydrogène (DTCH), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), ARC-Nucleart CEA Grenoble (NUCLEART), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Fuel quality, 020209 energy, General Chemical Engineering, Energy Engineering and Power Technology, Biomass, 02 engineering and technology, 7. Clean energy, Hydrothermal circulation, [SPI]Engineering Sciences [physics], chemistry.chemical_compound, Beech wood, 0202 electrical engineering, electronic engineering, information engineering, Refining (metallurgy), Organic Chemistry, Pulp and paper industry, Hydrothermal liquefaction, Fuel Technology, chemistry, Sodium hydroxide, Yield (chemistry), Scientific method, Environmental science, Fast pyrolysis, Pyrolysis, Analysis
Abstract

International audience; There are many different ways to convert biomass into liquid fuels, mostly referred to as bio-oils. This paper presents the analysis of bio-oils produced by hydrothermal liquefaction and fast pyrolysis of beech wood. Both processes have a wide panel of parameters that can be optimised influencing the oil quality. Results of the analysis show that both oils have high acidities. Iodine values indicate a high degree of unsaturations. These two qualities seem to be inversely proportional in the case of pyrolysis oils. In the case of hydrothermal conversion, additives to adjust the pH such as sodium hydroxide increase oil yields, lower its viscosity but do little to further improve the quality of the oils. For pyrolysis oils, increasing the severity does reduce acidity but at the expense of more unsaturations and a loss in yield. The results show that without extensive upgrading or refining, commercial fuel standards cannot be met. Specific norms and standards are being elaborated for pyrolysis used in specific installations. This paper shows how detailed analysis can help to optimise process parameters with an objective that goes beyond the mass or energy yield.

Published
2016
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6. The Heat Treatment Severity Index: A new metric correlated to the properties of biochars obtained from entrained flow pyrolysis of biomass

Author

Sylvie Valin, Sylvain Salvador, Mejdi Jeguirim, Chamseddine Guizani, Marine Peyrot, Aalto University, Institut de Science des Matériaux de Mulhouse (IS2M), Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), ARC-Nucleart CEA Grenoble (NUCLEART), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de L'Energie Solaire (INES), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Thermogravimetric analysis, Work (thermodynamics), Materials science, 020209 energy, General Chemical Engineering, Biochar properties, Energy Engineering and Power Technology, Biomass, 02 engineering and technology, Thermal treatment, Entrained flow pyrolysis, [CHIM.GENI]Chemical Sciences/Chemical engineering, 020401 chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, Heat Treatment Severity, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, 0204 chemical engineering, ta216, Chemical composition, Heat Treatment Severity Index, Organic Chemistry, Index, Fuel Technology, Chemical engineering, 13. Climate action, Elemental analysis, Scientific method, Pyrolysis
Abstract

International audience; The properties of biochars produced in biomass pyrolysis processes highly depend on the pyrolysis conditions, specifically the pyrolysis temperature and thermal treatment duration. The higher the temperature and the duration, the more severe is the heat treatment. The present work proposes a new Heat Treatment Severity Index (HTSI) for the quantification of the heat treatment severity during the pyrolysis reaction. This metric takes into account both effects of reactor temperature and heat treatment time inside the reactor. The relevance of this HTSI is assessed through analyzing the evolution of some properties of biochars obtained after pyrolysis of 370 µm beech wood particles in an entrained flow reactor. These biochars were characterized for their chemical composition (elemental analysis), structure (Raman spectroscopy) and reactivity towards oxygen (thermogravimetric analysis). These properties were well correlated with the HTSI following remarkable mathematical relationships. This finding demonstrates the possibility to engineer biochars with controlled properties by a careful mastering of the experimental conditions of the pyrolysis process in terms of temperature and heat treatment time.

Published
2019
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7. Steam gasification of char from wood chips fast pyrolysis: Development of a semi-empirical model for a fluidized bed reactor application

Author

S. Septien, F.J. Escudero Sanz, Sylvain Salvador, Sylvie Valin, Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Materials science, 020209 energy, Diffusion, Thermodynamics, Context (language use), 02 engineering and technology, 7. Clean energy, Endothermic process, Modelling, Isothermal process, [CHIM.GENI]Chemical Sciences/Chemical engineering, Effectiveness factor, 020401 chemical engineering, Fluidized bed reactor, 0202 electrical engineering, electronic engineering, information engineering, Char, 0204 chemical engineering, Waste Management and Disposal, Woodchips, Char gasification, Renewable Energy, Sustainability and the Environment, Forestry, Fluidized bed, Thermogravimetry, Particle, Agronomy and Crop Science, Pyrolysis
Abstract

International audience; This study, performed in the context of GAYA project, focuses on the development of a simple predictive model about steam gasification of char from woodchips fast pyrolysis. A semi-empirical model was developed through experiments in a macro thermogravimetric analyzer which owns the peculiar ability of fast heating, as well as to deal with macro-size particles and higher mass loads compared to conventional TGA. The experimental results show that gasification is controlled by chemical kinetics and internal transfer phenomena. During gasification, char particles can be considered as isothermal in a given range of temperatures and particle sizes, more likely for low values. The gasification model was based on the effectiveness factor, which involves the chemical kinetics and diffusion rate. The chemical kinetics were expressed by a classical Arrhenius law, whereas empirical expressions from mathematical fitting of the experimental data were established for the diffusion coefficient and surface function. The diffusion coefficient from this work is suspected to probably include supplementary rate limiting phenomena, apart from steam porous diffusion, such as H2 inhibition and/or the decrease of temperature within char particles because of the endothermic character of gasification. The model globally predicts with accuracy the gasification rate in typical operating conditions of a fluidized bed reactor. For its simplicity and reliability, this approach can be used for the modelling of char gasification in the conditions of interest.

Published
2015
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8. The effect of pyrolysis heating rate on the steam gasification reactivity of char from woodchips

Author

Sylvain Salvador, Sylvie Valin, F.J. Escudero Sanz, S. Septien, Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and This work was supported by the ADEME (Grant number 0901C0124)

Subjects
Materials science, 020209 energy, Context (language use), 02 engineering and technology, Industrial and Manufacturing Engineering, Modelling, Reaction rate, Chemical kinetics, 0202 electrical engineering, electronic engineering, information engineering, Fluidized bed reactor, Organic chemistry, Reactivity (chemistry), [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Char, Electrical and Electronic Engineering, Civil and Structural Engineering, TGA, Woodchips, Char gasification, Mechanical Engineering, Building and Construction, Heating rate, Pollution, General Energy, Chemical engineering, 13. Climate action, Fluidized bed, Pyrolysis
Abstract

International audience; This work, performed in the context of Gaya project, focuses on the characterization and modelling of the effect of the pyrolysis heating rate on the steam gasification of char from woodchips. An experimental work was performed based on thermogravimetry and solid characterization of char samples prepared under different conditions. The results showed that gasification apparent reactivity increased with the increase of heating rate. The faster chemical kinetics of char prepared under high heating rate could be related to its higher catalytic inorganic content together with a more reactive carbonaceous structure. The increase of heating rate favours porosity development and the enlargement of pores, which would have a positive effect on gasification reaction rate by enhancing gas diffusion within the solid. The effect of heating rate on char gasification was included in a model previously developed, by correlating the chemical kinetics, particle density and diffusion rate to the char yield, which was selected as a suitable indicator of the heating rate. The new version of the model, considering the variability of heating rate during char formation, was validated through accurate predictions of the experimental results.

Published
2018
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9. Characterization of char and soot from millimetric wood particles pyrolysis in a drop tube reactor between 800°C and 1400°C

Author

Marine Peyrot, Sylvain Salvador, S. Septien, Sylvie Valin, and Capucine Dupont

Subjects
Materials science, 020209 energy, General Chemical Engineering, Organic Chemistry, Tube reactor, Energy Engineering and Power Technology, 02 engineering and technology, medicine.disease_cause, Soot, Characterization (materials science), Thermogravimetry, Matrix (chemical analysis), Fuel Technology, 020401 chemical engineering, Chemical engineering, Scientific method, 0202 electrical engineering, electronic engineering, information engineering, medicine, Organic chemistry, Char, 0204 chemical engineering, Pyrolysis
Abstract

Char and soot characterization was performed for samples obtained from beech particles pyrolysis in a drop tube reactor at various temperatures and residence times. Firstly, an experimental study was performed and highlights the variation of char and soot composition and reactivity with operating conditions. A structure ordering with temperature for soot samples was also experimentally put into evidence. These variations are believed to be consequence of structural changes during char thermal annealing and soot formation process, affecting both carbonaceous matrix and mineral matter. Secondly, a semi-empirical model was developed and validated with thermogravimetry experiments. This model was then used for conversion time estimation in conditions representative of an entrained flow reactor, and shows that a complete conversion of char and soot is possible in a few seconds under severe operating conditions.

Published
2014
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10. Influence of steam on gasification of millimetric wood particles in a drop tube reactor: Experiments and modelling

Author

Sylvie Valin, Bertrand Spindler, S. Septien, Marine Peyrot, Sylvain Salvador, ARC-Nucleart CEA Grenoble (NUCLEART), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Materials science, 020209 energy, General Chemical Engineering, Energy Engineering and Power Technology, 02 engineering and technology, 010501 environmental sciences, medicine.disease_cause, 01 natural sciences, 7. Clean energy, Modelling, Steam reforming, [CHIM.GENI]Chemical Sciences/Chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, medicine, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Biomass, Char, 0105 earth and related environmental sciences, Superheated steam, Organic Chemistry, Tar, Soot, Steam, Drop tube reactor, Fuel Technology, Chemical engineering, 13. Climate action, Particle, Particle size, Pyrolysis, Gasification
Abstract

International audience; Wood particle conversion in a drop tube reactor was studied between 1000 °C and 1400 °C, both with experiments and simulations using a comprehensive model. Particular attention was paid to the influence of steam on the gasification process, and to the wood particle size. The model included a description of the different phenomena involved in biomass conversion: pyrolysis, gas phase reactions, soot formation and carbonaceous solid gasification. Satisfactory results were obtained in comparison with experiments. The addition of steam in the atmosphere influenced char, tar, soot and gas yields, especially at 1200°C and 1400°C. These changes were linked to char and soot steam gasification, and to gas phase reactions, among which hydrocarbons steam reforming and water-gas shift. At 1400°C, with 25 mol% H$_2$O and after a residence time of 4.4 s, the char seems to be completely gasified, while the soot yield still represents about 5 wt% of the initial dry biomass. Wood particle size in the range 0.35-0.80 mm was experimentally shown to have no influence on products yields for a residence time of a few seconds.

Published
2013
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11. Influence of H2O, CO2 and O-2 addition on biomass gasification in entrained flow reactor conditions: Experiments and modelling

Author

Marine Peyrot, Joseph Billaud, Sylvie Valin, Sylvain Salvador, Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), ARC-Nucleart CEA Grenoble (NUCLEART), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Département Technique Conversion et Hydrogène (DTCH), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Thermodynamic equilibrium, 020209 energy, General Chemical Engineering, Energy Engineering and Power Technology, Biomass, 02 engineering and technology, Combustion, medicine.disease_cause, 7. Clean energy, Modelling, chemistry.chemical_compound, [CHIM.GENI]Chemical Sciences/Chemical engineering, 020401 chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, medicine, Organic chemistry, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Char, 0204 chemical engineering, Entrained flow reactor, Organic Chemistry, Tar, Soot, Fuel Technology, Drop tube reactor, chemistry, Chemical engineering, 13. Climate action, Carbon dioxide, Pyrolysis, Gasification
Abstract

International audience; Biomass gasification in Entrained Flow Reactor (EFR) is both studied with experiments in a drop tube reactor and modelling with a 1-D model (GASPAR). Operating conditions are chosen thanks to results of a preliminary modelling of an industrial EFR. Influence of addition of steam (0.55 g/g db), carbon dioxide (0.87 g/g db) and oxygen (Equivalent Ratio: 0-0.61) is investigated between 800 and 1400 degrees C with beech wood particles sieved between 315 and 450 mu m as feedstock. The model takes into account pyrolysis reaction, gas phase reaction with a detailed chemical scheme (176 species, 5988 reactions), char gasification by steam and CO2 and soot formation. H2O or CO2 addition has no influence on gasification product yields at 800 and 1000 degrees C, while at 1200 and 1400 degrees C the char gasification is significantly enhanced and soot formation is certainly inhibited by OH radical which reacts with soot precursors. The modification of output gas phase composition is mostly due to WGS reaction which reaches thermodynamic equilibrium from about 1200 degrees C. As expected, O-2 has a significant influence on gas and tar yields through combustion reactions. Char and soot yields decrease as ER increases. The GASPAR model allows a good prediction of gas and char and gives relevant evolution of soot and tar yields on the large majority of conditions studied.

Published
2016
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12. Effect of particle size and temperature on woody biomass fast pyrolysis at high temperature (1000-1400 degrees C)

Author

Sylvie Valin, Capucine Dupont, S. Septien, Marine Peyrot, Sylvain Salvador, Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement (RAPSODEE), Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
020209 energy, General Chemical Engineering, Energy Engineering and Power Technology, 02 engineering and technology, medicine.disease_cause, [CHIM.GENI]Chemical Sciences/Chemical engineering, 020401 chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, medicine, Hydrocarbon consumption, Organic chemistry, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Tube furnace, Char, 0204 chemical engineering, Soot formation, Chemistry, Organic Chemistry, Tar, Decomposition, Soot, Fuel Technology, Drop tube reactor, Chemical engineering, 13. Climate action, Gas, Yield (chemistry), Particle size, Pyrolysis, Fast pyrolysis
Abstract

International audience; Fast pyrolysis of wood was conducted in a drop tube furnace to study the influence of temperature (1000-1200-1400 degrees C) and particle size (0.35-0.80 mm) for a particle residence time of some seconds. No effect of particle size has been observed on final pyrolysis products. At 1000 degrees C, much more gas and tar are produced than char (yield of 96% versus 4%); hydrocarbons, including light species and tar, present a considerable yield of 26%. From 1200 degrees C, the drastic hydrocarbons decomposition, emphasized with temperature, leads to high yields in soot, H-2 and CO. At 1200 degrees C, no tar are detected; at 1400 degrees C only low amounts of CH4 and C2H2 still remain. Under the explored conditions, char and soot gasification with H2O and CO2, species produced during pyrolysis, is kinetically blocked. However, even if carbonaceous solids do not seem to be considerably affected by gasification, they suffer some changes when temperature is increased.

Published
2012
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13. Mechanisms and kinetics of methane thermal conversion in a syngas

Author

Anthony Dufour, Sébastien Thiery, Sylvie Valin, Guillaume Boissonnet, Pierre-Alexandre Glaude, André Zoulalian, Pierre Castelli, Laboratoire des Sciences du Génie Chimique (LSGC), Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS), Research and Development Division (GdF), GDF, CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Etude et de Recherche sur le Matériau Bois (LERMAB), Université de Lorraine (UL), Département de Chimie Physique des Réactions (DCPR), and ANR-06-BIOE-0009,ANAPUR,Analyses et traitements de composés traces dans un gaz de synthèse issu de procédés de pyrolyse/gazéification de la biomasse pour la production catalytique de biocarburants(2006)

Subjects
020209 energy, General Chemical Engineering, Radical, Inorganic chemistry, Kinetics, chemistry.chemical_element, 02 engineering and technology, medicine.disease_cause, Mole fraction, 7. Clean energy, Industrial and Manufacturing Engineering, Methane, chemistry.chemical_compound, 020401 chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, medicine, Organic chemistry, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, 0204 chemical engineering, Thermal decomposition, General Chemistry, Soot, chemistry, 13. Climate action, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Carbon, Syngas
Abstract

International audience; In order to optimize H2 and CO production from biomass gasification, the thermal decomposition of methane in a reconstituted syngas was investigated in a tubular reactor at 130 kPa, for a gas residence time of 2 s and as a function of temperature (1000-1400 °C), CH4 (7, 14%), H2 (16, 32%), and H2O (15, 25, 30%) initial mole fractions. H2 showed an inhibiting effect on CH4 conversion whereas H2O had few effects. Three detailed elementary mechanisms were used to predict the methane conversion rate and to identify the key reaction pathways. Flow rate analyses showed that carbon oxidation occurs mainly by addition of OH radicals on C2 compounds. OH radicals are mainly produced by CO2 (CO2 + H ) CO + OH). The inhibiting role of H2 on CH4 conversion is explained by a competition between the OH radicals consumption channels (H2 + OH ) H2O + H). The competition between thermal conversion of methane and reforming of unsaturated C2 explains the soot formation.

Published
2009
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