Thermogravimetric study of high temperature treatment of aspen: effect of treatment parameters on weight loss and mechanical properties

Kocaefe, Duygu; Chaudhry, Bushra; Poncsák, Sándor; Bouazara, Mohamed; Pichette, André

doi:10.1007/s10853-006-0054-3

Cited by 45 publications

(28 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Los tratamientos térmicos provocan una descomposición de la hemicelulosa por hidrólisis, formándose ácidos orgánicos que acidifican la madera (Poblete 1983, Kocaefe et al 2007). …”

Section: Y Vestigios De Productos Biológicos (Figueroa Y Moraes 2009)unclassified

Propiedades químicas, color y humectabilidad de partículas de Laureliopsis philippiana (tepa) con y sin tratamiento térmico

H³

et al. 2013

Maderas, Cienc. tecnol.

View full text Add to dashboard Cite

El propósito de este trabajo fue determinar el efecto de un tratamiento térmico, en una atmósfera saturada de vapor de agua, en partículas de madera de la especie Laureliopsis philippiana. Las partículas fueron tratadas en autoclave a 150 ºC por 90 minutos y a una presión de 430 kPa, la cual se generó durante el proceso por la evaporación del agua en el autoclave herméticamente cerrado. Se determinaron la cantidad de extraíbles en soda, etanol tolueno, agua caliente y fría, así también, los porcentaje de celulosa, holocelulosa y lignina, el valor pH, los porcentajes de ácidos volátiles y solubles en agua, y la capacidad tampón, tanto para partículas sin tratamiento como con tratamiento. Para las partículas con tratamiento térmico, se encontró un aumento en el porcentaje de extraíbles, de celulosa, y de ácidos volátiles y lavables, así como también, un aumento de la acidez y de una mayor capacidad tampón, en comparación con las partículas sin tratamiento. El tratamiento térmico produjo un cambio de color en las partículas y una reducción de la humectabilidad. Debido a los cambios químicos encontrados en las partículas tratadas, estas presentarían ventajas en la fabricación de tableros de partículas, favoreciendo el fraguado de la ureaformaldehído. Palabras claves:Composición química, acidez, Laureliopsis philippiana, tratamiento térmico, tableros de partículas. ABSTRACTThe purpose of this work was to determine the effect of a thermal treatment in a vapor water saturated atmosphere, on wood particles of Laureliopsis philippiana. The particles in autoclave at 150 ºC for 90 minutes and with a pressure of 430 kPa were thermally treated, the pressure generated by the evaporation of water in the sealed autoclave. The amount of extractives in soda, ethanol-toluene, cold and hot water, as well as, the percentages of cellulose, holocellulose and lignin, the pH value, the percentages of volatiles and washables acids, and buffer capacity, for both particles without and with treatment, were determined. In thermally treated particles an increase in the percentage of extractives, cellulose and volatiles and water soluble acids was found, as well as, in thermally treated particles an increment of acidity and a higher buffer capacity was found, in comparison with the particles without treatment. The thermal treatment produced a color change in the particles and a reduction in their wettability. Due to the chemical changes found in the treated particles they could present advantages in the particleboard production, allowing a better ureaformaldehyde polymerization.

show abstract

“…Los tratamientos térmicos provocan una descomposición de la hemicelulosa por hidrólisis, formándose ácidos orgánicos que acidifican la madera (Poblete 1983, Kocaefe et al 2007). …”

Section: Y Vestigios De Productos Biológicos (Figueroa Y Moraes 2009)unclassified

Propiedades químicas, color y humectabilidad de partículas de Laureliopsis philippiana (tepa) con y sin tratamiento térmico

H³

et al. 2013

Maderas, Cienc. tecnol.

View full text Add to dashboard Cite

show abstract

“…Depending on the treatment parameters such as the maximum treatment temperature, the heating rate, the holding time at the maximum temperature or the nitrogen gas humidity, cracks can appear and the cell structure can be partially degraded as well (Poncsak et al 2006;Kocaefe et al 2007). Temperature has a greater effect on many wood properties than does treatment time (Kartal et al 2007).…”

Section: Universidad Del Bío -Bíomentioning

confidence: 99%

THE DENSITY, COMPRESSION STRENGTH AND SURFACE HARDNESS OF HEAT TREATED HORNBEAM (Carpinus betulus L.) WOOD

Gündüz

Korkut

Aydemir

et al. 2009

Maderas, Cienc. tecnol.

View full text Add to dashboard Cite

The heat treatment of wood is an environment-friendly method for wood preservation. The heat treatment process only uses steam and heat, and no chemicals or agents are applied to the material during the process. Tests have shown no harmful emissions are apparent when working with the material. This process improves wood's resistance to decay and its dimensional stability. In this study, the density, compression strength and hardness of heat treated hornbeam (Carpinus betulus L.) wood were investigated. Wood specimens that had been conditioned at 65% relative humidity and 20 ºC were subjected to heat treatment at 170, 190, and 210 ºC for 4, 8, and 12 hrs. After heat treatment, compression strength and hardness were determined according to TS 2595 and TS 2479. The results showed that the decreases of compression strength and hardness were related to the extent of density loss. Both compression strength and hardness decreased with the increasing temperatures and durations of the heat treatment. While the maximum density loss observed was 16.12% at 210 ºC and 12 hour, at these heat-treatment conditions, the compression strength approximately decreased 30% and hardness values in tangential, radial, and longitudinal directions approximately decreased by 55%, 54%, and 38%, respectively. Hence, it was concluded that there might be a relationship between changes of these wood properties.

show abstract

“…While the beneficial effects of thermal treatment on wood properties were brought to light several centuries ago, industrial exploitation of this phenomenon is quite recent and it is only in the last 20 years that this question has been scientifically investigated (Bourgois et al, 1989;Branca and Di Blasi, 2003;Tjeerdsma et al, 1998). Recent studies have highlighted the technological importance of controlling the heating rate as well as the final temperature and its duration (Kocaefe et al, 2006;Rapp, 2001). The interaction between these three parameters results in more or less complete reactions of vaporization, decomposition and condensation involving the various wood components (Funaoka et al, 1990;Rousset et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Effect of severe thermal treatment on spruce and beech wood lignins

Rousset¹,

Lapierre

Pollet

et al. 2009

Ann. For. Sci.

View full text Add to dashboard Cite

Ann. For. Sci. 66 (2009) Abstract• The structure, proportion and mode of assembly of lignin, celluloses and hemicelluloses have marked effects on the reaction mechanisms during thermal treatment and therefore have a strong influence on the quality of the final product. The effect of treatment conditions, including severe conditions (up to 553 K) and treatment duration (up to 8 h) on the structure of native spruce and beech lignins was studied.• Lignin content was determined by the Klason method and lignin structure was evaluated by thioacidolysis.• The results highlighted the strong reactivity of the native spruce and beech lignins towards severe heat treatments. The distinct susceptibility of syringyl (S) and guaiacyl (G) units towards thermal treatment is confirmed by comparing the data for beech and spruce samples. The most severe treatment of spruce wood (280• C) induced a dramatic enrichment in lignin content together with the almost complete disappearance of G lignin units, whereas a more moderate treatment substantially changed lignin structure by degradation reactions that affect the p-hydroxyphenyl (H) and G lignin units similarly.• Thioacidolysis revealed that the thermal treatment induces the appearance of vinyl ether structures in spruce lignins. The decreased yield of the G and S thioacidolysis monomers reflects the progressive disappearance of G and S lignin units only involved in β-O-4 bonds and the formation of condensed linkages in proportions related to treatment severity. In severe conditions, β-O-4 linked S units are more degraded than their G homologues. Mots-clés :lignine / traitement thermique / thioacidolyse / épicéa / hêtre Résumé -Effet d'un traitement thermique sévère sur les lignines du bois d'épicéa et de hêtre.• La structure, la proportion et le mode de montage de la lignine, des celluloses et des hémicelluloses ont eu des effets marqués sur les mécanismes de la réaction au cours du traitement thermique et, par conséquent, ont eu une forte influence sur la qualité du produit final. L'effet des conditions de traitement, y compris des conditions sévères (jusqu'à 553 K) et la durée du traitement (jusqu'à 8 h) sur la structure de lignines de l'épicéa et du hêtre ont été étudiés.• La teneur en lignine a été déterminée par la méthode Klason et la structure de la lignine a été évaluée par thioacidolyse.• Les résultats ont mis en évidence la forte réactivité des lignines de l'épicéa et du hêtre vis-à-vis des traitements thermiques sévères. La sensibilité des différentes unités syringyl (S) et guaiacyl (G) vis-à-vis du traitement thermique est confirmée par comparaison des données obtenues avec les échantillons du hêtre et de l'épicéa. Le traitement le plus sévère (280• C) du bois d'épicéa a induit un enrichissement spectaculaire en lignine ainsi que la quasi-disparition des unités de la lignine G, alors qu'un traitement plus modéré a sensiblement modifié la structure de la lignine par des réactions de dégradation qui affectent les p-hydroxyphényl (H ) et les unités de lignine G.• La thio...

show abstract

Thermogravimetric study of high temperature treatment of aspen: effect of treatment parameters on weight loss and mechanical properties

Cited by 45 publications

References 7 publications

Propiedades químicas, color y humectabilidad de partículas de Laureliopsis philippiana (tepa) con y sin tratamiento térmico

Propiedades químicas, color y humectabilidad de partículas de Laureliopsis philippiana (tepa) con y sin tratamiento térmico

THE DENSITY, COMPRESSION STRENGTH AND SURFACE HARDNESS OF HEAT TREATED HORNBEAM (Carpinus betulus L.) WOOD

Effect of severe thermal treatment on spruce and beech wood lignins

Contact Info

Product

Resources

About