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    Calorific Power Improvement of Wood by Heat Treatment and Its Relation to Chemical Composition
    (Mdpi, 2020) Domingos, Idalina; Ayata, Umit; Ferreira, Jose; Cruz-Lopes, Luisa; Sen, Ali; Sahin, Sirri; Esteves, Bruno
    Chemical composition influences the calorific power of wood, mainly due to the calorific power of structural compounds and extractives. Heat treatment changes the chemical composition of treated wood. This work studies the relationship between chemical composition and calorific power improvement by heat treatment. Samples were heat-treated by the ThermoWood process for 1 h and 2 h. High heating value (HHV) and chemical composition; lignin, cellulose, hemicelluloses and extractives in dichloromethane, ethanol, and water were determined. The HHV of untreated wood ranged between 18.54-19.92 MJ/kg and increased with heat treatment for all the tested species. A positive linear correlation was found between HHV and Klason lignin (R-2 = 0.60). A negative trend was observed for holocellulose, cellulose, and hemicelluloses content against HHV, but with low determination coefficients for linear regression. The best adjust for polysaccharides was found for hemicelluloses content. A positive correlation could be found for dichloromethane extractives (R-2 = 0.04). The same was obtained in relation to ethanol extractives with R-2 = 0.20. For water and total extractives, no clear positive or negative trends could be achieved. The results showed that the HHV of wood increased with heat treatment and that this increase was mainly due to the increase in lignin content.
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    CHANGES IN THE CONTENT AND COMPOSITION OF THE EXTRACTIVES IN THERMALLY MODIFIED TROPICAL HARDWOODS
    (Univ Bio-Bio, 2022) Esteves, Bruno; Ayata, Umit; Cruz-Lopes, Luisa; Bras, Isabel; Ferreira, Jose; Domingos, Idalina
    Chemical composition of wood is known to change during thermal treatments. Two species grown in Turkey, afrormosia (Pericopsis elata) and duka (Tapirira guianensis) were heat treated according to Thermowood (R) method. Lignin, cellulose, hemicelluloses and extractives in dichloromethane, ethanol and water were determined. Wood extracts were analysed by gas chromatography with mass detection and existing compounds were identified by NIST17 database. Results show that hemicelluloses and cellulose content decreased for both heat-treated woods along the treatment while lignin percentage increased. The analysis of extractives has shown several compounds normally associated to lignin thermal degradation that increased along the treatment. At the same time several compounds associated to carbohydrate thermal degradation were found in all the extracts for both heat-treated woods. These founding have allowed the understanding of the degradation pattern of wood during thermal modification. There was not much difference between afrormosia and duka woods structural compounds behaviour along thermal modification. However, the variation of the amount of extractives along the treatment depended on the species.
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    Land Use Impact of Maritime Pine and Eucalypt: A Life Cycle Assessment Study
    (North Carolina State Univ Dept Wood & Paper Sci, 2021) Ferreira, Jose; Esteves, Bruno; Ayata, Umit; Cruz-Lopes, Luisa; Domingos, Idalina
    The forestry sector faces important challenges worldwide in the climate change scenario. The major challenges are the sustainability of forest resources and the conservation of biological diversity. Due to climate change, an increase in the incidence of fires and the action of pathogens has been observed in recent years. The forestry sector in Portugal has a high economic, social, and environmental value. In economic 'Willis, in 2015, its gross value added (GVA) represented more than 10 billion euros, corresponding to 13% of industrial GVA and 3% of national gross domestic ABSTRACT The forestry sector in Portugal faces important challenges, resulting in an increased incidence of fires and the action of pathogens, which puts the sustainability of forest resources at risk. Due to the economic, social, and environmental importance of forests, this work assessed the land use environmental impact of maritime pine and eucalypt standing in Portuguese forests. SimaPro software was used to translate the inventory table results into land use impact category. The ILCD 2011 Midpoint+ method was chosen to assess the land use environmental impact that focuses on soil quality and its indicator (kg carbon deficit), which describes the changes in soil organic matter associated with land interventions. The results showed that for the first rotation time, the land use impact category per cubic meter of maritime pine is 18423 kg C deficit and 23430 kg C deficit for eucalypt, which means that the land use impact category of eucalypt is 27% higher than the impact of maritime pine.