18 research outputs found

    Thermogravimetric analysis of anningre tannin resin

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    Three formulations of aningre tannin resins containing in order the paraformaldehyde powder, hexamethylenetetramine and aqueous glyoxal as hardeners were developed. Their thermogravimetric analysis have shown that they begin to decompose respectively from 135°C, 145°C and 140°C. About 24%, 40% and 39 % solid residues of their initial masses exist at the end of the analysis. Thermomechanical analysis has shown that the formulation containing paraformaldehyde powder as hardener has the best rigidity and the worst contains the hexamethylenetetramine. All formulations have different thermal degradation, differences were more significant between 400 and 900°C.The decomposition of hardeners become more significant from 400°C

    Influence of date palm-based biochar and Compost on Water Retention properties of soils with different sand contents

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    ©2024. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by/4.0/ This document is thePublished, version of a Published Work that appeared in final form in Forests. To access the final edited and published work see https://doi.org/10.3390/f15020304Generally, soils of arid and semi-arid regions have low water retention properties due to high sand and low organic carbon contents. This study aimed at quantifying the effect of date palm-based organic amendments (OAs) on the water retention properties of two soils (sandy loam and silty loam), as well as the influence of sand supplementation (0.5–2 mm) on the magnitude of the effect of OAs. Different grain size distributions were obtained by adding sand to natural soils. For this purpose, sand was added to the two soils (1/3 and 2/3) and different soil-OA combinations were tested at a dose of 3% by mass: compost alone, biochar alone and a mixture of biochar and compost (50:50 in mass), in addition to unamended control soils. Soil water contents were measured at nine matric potentials ranging from the saturation to the permanent wilting point. Biochar was more efficient than compost at improving soil water retention. The effect of organic amendments on water retention increased with sand content. In most cases, soil water content values were significantly higher for biochar-amended soils than for unamended or compost-amended soils. The weakness of the effect of compost addition (if alone) was probably due to its properties and notably its high mineral content and electrical conductivity. Soil sand supplementation led to higher differences between the OA-amended soils and unamended soils. Changes in available water capacity reached +26% and +80% in a sandy loamy soil enriched with 2/3 sand and amended with compost and with biochar, respectively, compared to the unamended soil. These results show that sand content (and more generally, soil texture) influences the effect of OA application. Thus, the application of biochar from date palm residues in soil seems to be an effective solution to improve the water retention properties of coarse textured soils and contribute to optimizing the use of water resources in irrigated areas

    Multi-step process of wood board waste enhancement

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    L’étude présentée dans ce manuscrit s’inscrit dans les contextes environnementaux de la production d’énergie renouvelable et de la valorisation des déchets à base de bois. Il s’agit de valider et d’optimiser un procédé multi-étagé pour les déchets bois de type panneaux de particules. Dans ces déchets le bois est généralement associé à des résines urée formaldéhyde et mélamine formaldéhyde, composés riches en azote qui conduisent à la production de gaz polluants (ammoniac, acides isocyanique et cyanhydrique, NOx…) lors de leur valorisation énergétique (combustion, pyrolyse, gazéification). Le procédé proposé vise dans un premier temps à éliminer l’azote contenu dans le déchet pour produire un solide de type bois chauffé ou charbon dont la valorisation est envisagée dans un second temps par différents voies. La première étape consiste en une pyrolyse basse température (250°C à 400°C) pendant 3 à 15 minutes et permet d’éliminer environ 70 % de l’azote initial pour les différentes conditions étudiées. Le traitement à 250°C permet d’obtenir un meilleur rendement en solide et donc énergétique. La pyrolyse et/ou la pyrolyse / gazéification à la vapeur d’eau du résidu de la première étape sont ensuite étudiées entre 800°C et 1000°C. Le niveau de température le plus élevé assure le meilleur rendement gazeux et permet de produire un gaz riche en hydrogène et en CO utilisable dans divers procédés de valorisation énergétique. La pyrolyse / gazéification permet de convertir l’ensemble du solide carboné optimisant ainsi l’efficacité énergétique du procédé. En revanche, la simple pyrolyse du solide conduit à une production de gaz moins importante mais permet de piéger une part de l’azote dans le charbon résiduel final. Celui-ci, après une étape d’activation, semble particulièrement bien adapté au piégeage par adsorption du phénol et des composés aromatiques en phase liquide. Ainsi, les travaux effectués montrent qu’un procédé multi-étagé est une voie intéressante pour valoriser des sous-produits bois à faible coût en leur donnant une forte valeur ajoutée.Within the environmental contexts of power generation and waste disposal, the present works deals with the validation and the optimisation of a multistage thermo chemical process of particleboard waste conversion (enhancement). These wastes are mostly associated with urea formaldehyde and melamine formaldehyde resins which contain a huge amount of nitrogen. Nitrogen causes the production of pollutants such as ammonia, isocyanic acid, cyanhydric acid and NOx… during classical thermo chemical process (combustion, pyrolysis and gasification). The process studied aims in a first time to remove nitrogen species from waste to produce a combustible solid and in a second time to convert this residual solid in a combustible gas. The first step consists in a low temperature pyrolysis (250°C to 400°C) during 3 to 15 minutes and assumes to eliminate 70 % of the initial nitrogen content for all studied conditions. The pyrolysis and/or the pyrolysis / gasification under water of the residue are then studied between 800°C and 1000°C. The higher temperature of reaction (1000°C) improves the production of gases and the energy efficiency of this second step and allow the production of hydrogen and carbon monoxide rich gases. The pyrolysis / gasification under water allows a total conversion of the solid which optimises the energy efficiency of the process. However, the pyrolysis under nitrogen produces a lower amount of gases but helps to catch a part of the nitrogen in the residual char. The char then produced is converted through an activation step, in an active char containing nitrogen functionalities with high adsorption capacities, especially for the trapping of phenol or other aromatic compounds in liquid phase. This multistage is thus a interesting way to enhance low cost raw matter like particleboard waste

    Procédé multi-étagé de valorisation de déchets bois type panneaux de particules

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    Within the environmental contexts of power generation and waste disposal, the present works deals with the validation and the optimisation of a multistage thermo chemical process of particleboard waste conversion (enhancement). These wastes are mostly associated with urea formaldehyde and melamine formaldehyde resins which contain a huge amount of nitrogen. Nitrogen causes the production of pollutants such as ammonia, isocyanic acid, cyanhydric acid and NOx... during classical thermo chemical process (combustion, pyrolysis and gasification). The process studied aims in a first time to remove nitrogen species from waste to produce a combustible solid and in a second time to convert this residual solid in a combustible gas. The first step consists in a low temperature pyrolysis (250°C to 400°C) during 3 to 15 minutes and assumes to eliminate 70 % of the initial nitrogen content for all studied conditions. The pyrolysis and/or the pyrolysis / gasification under water of the residue are then studied between 800°C and 1000°C. The higher temperature of reaction (1000°C) improves the production of gases and the energy efficiency of this second step and allow the production of hydrogen and carbon monoxide rich gases. The pyrolysis / gasification under water allows a total conversion of the solid which optimises the energy efficiency of the process. However, the pyrolysis under nitrogen produces a lower amount of gases but helps to catch a part of the nitrogen in the residual char. The char then produced is converted through an activation step, in an active char containing nitrogen functionalities with high adsorption capacities, especially for the trapping of phenol or other aromatic compounds in liquid phase. This multistage is thus a interesting way to enhance low cost raw matter like particleboard waste.L'étude présentée dans ce manuscrit s'inscrit dans les contextes environnementaux de la production d'énergie renouvelable et de la valorisation des déchets à base de bois. Il s'agit de valider et d'optimiser un procédé multi-étagé pour les déchets bois de type panneaux de particules. Dans ces déchets le bois est généralement associé à des résines urée formaldéhyde et mélamine formaldéhyde, composés riches en azote qui conduisent à la production de gaz polluants (ammoniac, acides isocyanique et cyanhydrique, NOx...) lors de leur valorisation énergétique (combustion, pyrolyse, gazéification). Le procédé proposé vise dans un premier temps à éliminer l'azote contenu dans le déchet pour produire un solide de type bois chauffé ou charbon dont la valorisation est envisagée dans un second temps par différents voies. La première étape consiste en une pyrolyse basse température (250°C à 400°C) pendant 3 à 15 minutes et permet d'éliminer environ 70 % de l'azote initial pour les différentes conditions étudiées. Le traitement à 250°C permet d'obtenir un meilleur rendement en solide et donc énergétique. La pyrolyse et/ou la pyrolyse / gazéification à la vapeur d'eau du résidu de la première étape sont ensuite étudiées entre 800°C et 1000°C. Le niveau de température le plus élevé assure le meilleur rendement gazeux et permet de produire un gaz riche en hydrogène et en CO utilisable dans divers procédés de valorisation énergétique. La pyrolyse / gazéification permet de convertir l'ensemble du solide carboné optimisant ainsi l'efficacité énergétique du procédé. En revanche, la simple pyrolyse du solide conduit à une production de gaz moins importante mais permet de piéger une part de l'azote dans le charbon résiduel final. Celui-ci, après une étape d'activation, semble particulièrement bien adapté au piégeage par adsorption du phénol et des composés aromatiques en phase liquide. Ainsi, les travaux effectués montrent qu'un procédé multi-étagé est une voie intéressante pour valoriser des sous-produits bois à faible coût en leur donnant une forte valeur ajoutée

    Procédé multi-étagé de valorisation de déchets bois type panneaux de particules

    No full text
    L étude présentée dans ce manuscrit s inscrit dans les contextes environnementaux de la production d énergie renouvelable et de la valorisation des déchets à base de bois. Il s agit de valider et d optimiser un procédé multi-étagé pour les déchets bois de type panneaux de particules. Dans ces déchets le bois est généralement associé à des résines urée formaldéhyde et mélamine formaldéhyde, composés riches en azote qui conduisent à la production de gaz polluants (ammoniac, acides isocyanique et cyanhydrique, NOx ) lors de leur valorisation énergétique (combustion, pyrolyse, gazéification). Le procédé proposé vise dans un premier temps à éliminer l azote contenu dans le déchet pour produire un solide de type bois chauffé ou charbon dont la valorisation est envisagée dans un second temps par différents voies. La première étape consiste en une pyrolyse basse température (250C à 400C) pendant 3 à 15 minutes et permet d éliminer environ 70 % de l azote initial pour les différentes conditions étudiées. Le traitement à 250C permet d obtenir un meilleur rendement en solide et donc énergétique. La pyrolyse et/ou la pyrolyse / gazéification à la vapeur d eau du résidu de la première étape sont ensuite étudiées entre 800C et 1000C. Le niveau de température le plus élevé assure le meilleur rendement gazeux et permet de produire un gaz riche en hydrogène et en CO utilisable dans divers procédés de valorisation énergétique. La pyrolyse / gazéification permet de convertir l ensemble du solide carboné optimisant ainsi l efficacité énergétique du procédé. En revanche, la simple pyrolyse du solide conduit à une production de gaz moins importante mais permet de piéger une part de l azote dans le charbon résiduel final. Celui-ci, après une étape d activation, semble particulièrement bien adapté au piégeage par adsorption du phénol et des composés aromatiques en phase liquide. Ainsi, les travaux effectués montrent qu un procédé multi-étagé est une voie intéressante pour valoriser des sous-produits bois à faible coût en leur donnant une forte valeur ajoutée.Within the environmental contexts of power generation and waste disposal, the present works deals with the validation and the optimisation of a multistage thermo chemical process of particleboard waste conversion (enhancement). These wastes are mostly associated with urea formaldehyde and melamine formaldehyde resins which contain a huge amount of nitrogen. Nitrogen causes the production of pollutants such as ammonia, isocyanic acid, cyanhydric acid and NOx during classical thermo chemical process (combustion, pyrolysis and gasification). The process studied aims in a first time to remove nitrogen species from waste to produce a combustible solid and in a second time to convert this residual solid in a combustible gas. The first step consists in a low temperature pyrolysis (250C to 400C) during 3 to 15 minutes and assumes to eliminate 70 % of the initial nitrogen content for all studied conditions. The pyrolysis and/or the pyrolysis / gasification under water of the residue are then studied between 800C and 1000C. The higher temperature of reaction (1000C) improves the production of gases and the energy efficiency of this second step and allow the production of hydrogen and carbon monoxide rich gases. The pyrolysis / gasification under water allows a total conversion of the solid which optimises the energy efficiency of the process. However, the pyrolysis under nitrogen produces a lower amount of gases but helps to catch a part of the nitrogen in the residual char. The char then produced is converted through an activation step, in an active char containing nitrogen functionalities with high adsorption capacities, especially for the trapping of phenol or other aromatic compounds in liquid phase. This multistage is thus a interesting way to enhance low cost raw matter like particleboard waste.NANCY1-Bib. numérique (543959902) / SudocSudocFranceF

    Comparison of pyrolysis behaviour results between the cone calorimeter and the fire propagation apparatus heat sources

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    The cone calorimeter and the Fire propagation apparatus are often used to carry out flammability analyses of materials. Among the numerous differences between these two devices, the impact of the heat sources has been studied by other means that time to ignition measurements as performed in past studies. In particular, visual observations, mass loss rate and temperature measurements are used to analyze the impact on the pyrolysis behavior of the two types of heaters on clear PMMA and wood samples. The mechanism, of in-depth radiation absorption and the wavelength dependency of this one are the main reasons for the different pyrolysis behavior observed

    Nitrogen Removal from Wood Laminated Flooring Waste by Low-Temperature Pyrolysis

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    International audienceThe optimisation of wood laminated flooring decontamination was studied to improve energy recovery. This work addresses the first step of a novel nitrogen-containing biomass waste-to-energy process that has been previously published. Pyrolysis in N-2 atmosphere performed at different temperatures (523-673 K) and different durations led to the removal of nitrogen contained in the material, mainly in the forms of ammonia (NH3) and isocyanic acid (HNCO), as analysed by Fourier Transform infrared spectrometry. The optimisation of this step consists in determining a [temperature, duration] of treatment parameters couple to obtain a maximum nitrogen removal coupled with the minimum energy loss in the residue. Amounts of removed nitrogen were determined through ultimate analysis, and energy available in the ``decontaminated'' residues was obtained by calorimetry. Pre-treatment at 548 K during 11 min appeared to be the most promising, with 65 % of nitrogen removed and mass and energy losses of 18.7 and 8.9 %, respectively

    Fast Pressing Composite Using Tannin-Furfuryl Alcohol Resin and Vegetal Fibers Reinforcement

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    International audienceExperimental investigations have been carried out on the potential use of tannin-furfuryl alcohol resin for biobased composites using vegetal fiber reinforcement. Results showed that a mixture containing 54% furfuryl alcohol, 45% modified quebracho extract and 0.9% paratoluenesulfonic acid as a catalyst yields a resin that can be used with a nonwoven flax fiber mat to manufacture lightweight composites with good mechanical properties and a very short curing time with a regular hot press. The panels made were tested for tensile and flexural modulus and strength, water resistance and thermo-degradation

    Thermogravimetric analysis of anningre tannin resin

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    Three formulations of aningre tannin resins containing in order the paraformaldehyde powder, hexamethylenetetramine and aqueous glyoxal as hardeners were developed. Their thermogravimetric analysis have shown that they begin to decompose respectively from 135°C, 145°C and 140°C. About 24%, 40% and 39 % solid residues of their initial masses exist at the end of the analysis. Thermomechanical analysis has shown that the formulation containing paraformaldehyde powder as hardener has the best rigidity and the worst contains the hexamethylenetetramine. All formulations have different thermal degradation, differences were more significant between 400 and 900°C.The decomposition of hardeners become more significant from 400°C
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