Evidence of char formation during wood heat treatment by mild pyrolysis

Inari, G. Nguila; Mounguengui, Steeve; Dumarçay, Stéphane; Pétrissans, Mathieu; Gérardin, Philippe

doi:10.1016/j.polymdegradstab.2007.03.003

Cited by 63 publications

(27 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thermo-degradation reactions result in an increase of Klason lignin content and a decrease of holocellulose content in wood (Fig. 2) as reported in the literature for other wood species (Alén et al, 2002;Boonstra et al, 2006;Hakkou et al, 2005;Nguila Inari et al, 2007;Wikberg and Maunu, 2004;Yildiz et al, 2006).…”

Section: Heat Treatment and Fungal Decaysupporting

confidence: 72%

Effect of extractives on conferred and natural durability of Cupressus lusitanica heartwood

Mohareb

Sirmah

Desharnais³

et al. 2010

Ann. For. Sci.

Self Cite

View full text Add to dashboard Cite

Abstract• Identification of extractives present in Cupressus lusitanica heartwood has been conducted using GC-MS analyses. The chromatogram of toluene/ethanol extracts indicated the presence of large amounts of benzaldehyde and numerous terpenic compounds such as cedrol, agathadiol, epimanool, bornyl acetate, α-cedrene and β-cedrene.• The effect of these extractives on the natural durability of cypress wood was investigated on heart wood blocks exposed to pure culture of Poria placenta before or after solvent extraction. Weight losses revealed severe fungal degradations on the extracted blocks compared to unextracted ones.• Efficiency of heartwood extractives as inhibitors of the growth of Poria placenta on malt/agar test confirms their contribution to cypress natural durability.• Cypress blocks were treated at 240 • C for different times to reach different levels of thermodegradation to evaluate effect of heat treatment on fungal durability. Results indicate that evaporation of volatile extractives during the first few minutes of heat treatment contribute to decreased wood durability, while longer treatment times lead to the expected improvement of durability.• This study suggests that the content of extractives, which may be modified during wood drying or weathering processes, could be the origin of the conflicting data described in the literature concerning cypress natural durability. Mots-clés :Cupressus lusitanica / durabilité / extractibles / traitement thermique / pourriture Résumé -Effet des extractibles sur la durabilité naturelle du duramen de cyprès.• Les extractibles présents dans le duramen de Cupressus lusitanica ont été analysés par GC-MS. Le chromatogramme des extraits obtenus à l'aide d'un mélange toluène/éthanol met en évidence des quantités importantes de benzaldéhyde et de nombreux composés terpéniques comme le cédrol, l'agathadiol, l'épimanool, l'acétate de bornyl, l'α-cédrène et le β-cédrène.• L'effet des extractibles sur la durabilité naturelle du cyprès a été évalué à l'aide d'essais réalisés sur des blocs préalablement extraits ou non puis exposés à Poria placenta. Les pertes de masse mettent en évidence une dégradation importante des échantillons extraits comparativement aux témoins non extraits.• L'efficacité des extractibles comme inhibiteur de croissance de Poria placenta a été évaluée. Les résultats indiquent une forte inhibition du développement fongique.• Des blocs de cyprès ont été traités à 240 • C pendant des temps variables pour atteindre différents niveaux de thermo-dégradation. L'évaporation des extractibles volatils durant la première phase du traitement thermique conduit à une diminution de la durabilité du bois aux agents de pourriture, alors que des traitements plus longs conduisent à l'augmentation de durabilité attendue.• Cette étude suggère que la teneur en extractibles, susceptible de varier suite au séchage ou aux intempéries, peut être à l'origine des observations contradictoires rapportées dans la littérature concernant la durabilité naturelle du cyprès.

show abstract

Section: Heat Treatment and Fungal Decaysupporting

confidence: 72%

Effect of extractives on conferred and natural durability of Cupressus lusitanica heartwood

Mohareb

Sirmah

Desharnais³

et al. 2010

Ann. For. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…These values are comparable with other studies, which show δ 13 C reductions of up to 1.6‰ in biomass charred in vacuo (Bird and Gröcke, 1997) and up to 2‰ in wood charcoal formed in both restricted O 2 availability and air (Turney et al, 2006). In pine charcoal, although the presence of O-alkyl C at 50-100ppm (from 13 C-CP-SSNMR) shows persistence of some cellulosic carbons at 300ºC, the loss of the C1 and C4 of cellulose demonstrates depolymerisation of the molecule by transglycosylation (Inari et al, 2007). In contrast, the relative intensity of signal from lignin-derived structures, such as the 56ppm methoxy-C peak is increased in the spectra (Figures 5 and 6; B and B1).…”

Section: δ 13 C Variations During Charcoal Formationmentioning

confidence: 98%

“…13 C-CP-SSNMR is therefore used to monitor wood structural changes during physical and chemical treatment, including heating (Evans et al, 1995;Wormald et al, 1996;Baldock and Smernik, 2002). In such studies, the effect of differing thermal stabilities between wood components is apparent, with more significant alteration of signals attributed to cellulose carbons than those of lignin (Inari et al, 2007). Characteristic changes include a reduction in intensity in the O-alkyl and di-O-alkyl regions (65-110 ppm) and an increase in aryl and O-aryl C during production of aryl and O-aryl furanlike structures (Baldock and Smernik, 2002).…”

Section: Introductionmentioning

confidence: 99%

Influence of production variables and starting material on charcoal stable isotopic and molecular characteristics

Ascough

Bird

Wormald

et al. 2008

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

We present a systematic study on the effect of starting species, gas composition, temperature, particle size and duration of heating upon the molecular and stable isotope composition of high density (mangrove) and low density (pine) wood. In both pine and mangrove, charcoal was depleted in δ 13 C relative to the starting wood by up to 1.6‰ and 0.8‰ respectively. This is attributed predominantly to the progressive loss of isotopically heavier polysaccharides, and kinetic effects of aromatization during heating. However, the pattern of δ 13 C change was dependant upon both starting species and atmosphere, with different structural changes associated with charcoal production from each wood type elucidated by Solid State 13 C Nuclear Magnetic Resonance Spectroscopy. These are particularly evident at lower temperatures, where variation in the oxygen content of the production atmosphere results in differences in the thermal degradation of cellulose and lignin. It is concluded that production of charcoal from separate species in identical conditions, or from a single sample exposed to different production variables, can result in significantly different δ 13 C of the resulting material, relative to the initial wood. These results have implications for the use of charcoal isotope composition to infer past environmental change.

show abstract

“…C CP MAS NMR studies showed that hemicelluloses are strongly degraded after thermal treatment (Wikberg and Maunu 2004;Nguila et al 2007). Cellulose, which presents a high degree of polymerisation and crystallinity, is generally considered as relatively resistant under heat treatment conditions used.…”

mentioning

confidence: 99%

New alternatives for wood preservation based on thermal and chemical modification of wood— a review

Gérardin

2015

Annals of Forest Science

Self Cite

181

126

View full text Add to dashboard Cite

Key message Increasing environmental pressures appearing over the last few years have led to important changes in the field of wood protection. In this context, new technologies, based either on thermal or chemical modifications, suggest increasing interest in prospect of programmed ban of biocide products.• Context The evolution of the regulations on the use of biocide products has led to important changes in the field of wood preservation, leading to an increasing interest for non-biocide treatments like thermal or chemical modifications to face to the programmed ban of biocide products.• Aims The paper reviews the different non-biocide alternatives developed currently on an industrial scale, highlighting their main characteristics and applications.• Results Different treatments have been developed on an industrial scale involving mainly thermal modifications and acetylation, furfurylation and DMDHEU constituting already available solutions.• Conclusion Different non-biocide alternatives already exist and will become more important in the next decades due to the increasing legislative pressure driven by environmental considerations.

show abstract

Evidence of char formation during wood heat treatment by mild pyrolysis

Cited by 63 publications

References 16 publications

Effect of extractives on conferred and natural durability of Cupressus lusitanica heartwood

Effect of extractives on conferred and natural durability of Cupressus lusitanica heartwood

Influence of production variables and starting material on charcoal stable isotopic and molecular characteristics

New alternatives for wood preservation based on thermal and chemical modification of wood— a review

Contact Info

Product

Resources

About