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Qualidade de black pellets de finos de carvão vegetal produzidos com diferentes umidades e tempo de secagem
Publication . Carvalho, Felipe Barbosa; Martins, Caio Cesar Nemer; Peres, Letícia Costa; Surdi, Paula Gabriella; Lima, Laura Vitória Lopes; Zanuncio, Antônio José Vinha; Carneiro, Angélica de Cássia Oliveira; Castro, Vinícius Resende de; Araújo, Solange; Demuner, Iara Fontes
Charcoal fines are co-products of the wood carbonization process, unwanted because they reduce
the gravimetric yield of the main product, charcoal. It can be produced due to the carbonization
process, during the storage and transport of charcoal. Pelletizing charcoal fines increases the
energy density of this material, producing a homogeneous fuel with lower moisture content,
enabling burning in equipment with high energy efficiency, in addition to desirable properties
in energy products such as high fixed carbon content and low moisture content. This study
evaluated the effect of moisture content and drying time on the production of black pellets from
charcoal fines bound with rice starch (Oryza sativa) on the physicochemical and mechanical
characteristics. Black pellets were produced using two proportions of water (10 or 20%) and a
drying time of 4 or 6 hours. Black pellets were evaluated for their proximate analysis, elemental
composition, moisture content, size, apparent density, calorific value and energy density. The
addition of water did not affect the content of volatile matter, ash, and fixed carbon, while the
treatment with addition of 20% water and four hours of drying showed a higher moisture content
(3.34%). The addition of water allowed for better heat conduction and particle arrangement,
producing pellets with a durability greater than 98%. The better arrangement promoted by the
addition of 20% water also increased the density of the pellets, resulting in greater energy
density. Black pellets can be considered an alternative for residential heating, with T3 treatment
(20% - 4h) with a high energy density and better performance in terms of desirable properties
for use and commercialization according to the standard EN 14961-6.
Chemical composition of heartwood and sapwood of Tectona grandis characterized by CG/MS‑PY
Publication . Castro, Vinicius Resende; Surdi, Paula Gabriella; Fernandes, Sérgio António; Berger, Matheus da Silva; Zanuncio, António José Vinha; Zanuncio, José Cola; Araújo, Solange
Teak wood has chemical compounds that can be used for pharmaceutical and textile industries,
in addition, this compounds are related to resistance to biodeterioration, color and modification
processes. Heartwood and sapwood of T. grandis (teak), 15 years-old, were characterized by
Py-CG/MS analysis and syringyl (S)/guaiacyl (G) ratio was evaluated. Heartwood and sapwood
were pyrolyzed at 550 °C and 62 and 51 compounds were identified from them, respectively. The
acetic acid (10%) and levoglucosan (26.65%) were the most abundant compound in the sapwood
and heartwood, respectively. The high acetic acid content enhances the use of teak wood to
production of artificial essences for perfumery, paints, dyes. While levoglucosan can be used in the
manufacture of epoxy resins, antiparasitic and insecticides. The organic compounds identified include
2-methylanthraquinone as one of the main component responsible for the resistance of the teak wood
to biological factors (fungi and termites). The syringyl (S)/guaiacyl (G) ratio of heartwood and sapwood
was 0.51 and 0.50, respectively
Drying of Eucalyptus Logs from plantations with different spacing between trees
Publication . Silva, Willian Martins da; Zanuncio, Antonio José Vinha; Carvalho, Amélia Guimarães; Castro, Vinícius Rezende de; Carneiro, Angélica de Cassia Oliveira; Araújo, Solange
The adoption of dense plantations can reduce the drying time of the logs, by optimizing this step. This study evaluated the drying of eucalyptus wood from plantations with different spacing (3 × 4; 3 × 3; 2 × 3; 1 × 3 m). Five trees were selected per treatment. Logs were removed from the base and at 50% and 100% of commercial height for drying evaluation for 60 days. The diameters of the eucalyptus trees from plantations with wider spacing were bigger, and the productivity per hectare was not affected by the spacing between trees. The planting spacing did not affect the initial moisture, which was higher for those removed from the top of the trees. The logs from the base from the denser spacing showed a drying rate 2.5 times higher than the same logs from the treatment with greater spacing, reducing the final moisture from 37.2 to 18.8%. The logs removed from the top of the trees reached the equilibrium moisture after the drying period. The reduction in the planting spacing reduced the wood moisture and the difference in this parameter between the logs removed from the base and top of the eucalyptus trunks.
Tannin extracts as a preservative for pine thermomechanically densified wood
Publication . Niela de Lima, Nídia; Castro, Vinícius Resende de; Lopes, Nayara Franzini; Nunes, Ítalo Lima; Andrade, Frances Alves; Zanuncio, Antonio José Vinha; Carneiro, Angélica de Cassia Oliveira; Araújo, Solange
Thermo-mechanical densification modifies wood to produce a more dense and resistant lignocellulosic material and may degrade extractives that contribute to the increased susceptibility of wood to attack by xylophagous organisms. This study evaluated the efficiency of tannin extracts of Acacia mearnsii in the treatment of thermo-mechanical densified pine wood in relation to physical, mechanical, and biological resistance (Cryptotermes brevis) properties. Pinus elliottii samples were pretreated with oxalic acid in a Parr reactor, then treated by diffusion in tannin solutions at concentrations 5, 10, and 15%, and finally hot pressed. The apparent density of the modified wood was 87.8% greater than that of the in natura wood (control) with tannins at 15%. The mechanical strength increased, especially the parallel compressive strength, which had an average increase of 169% for the wood with tannins at 10 and 15%, compared with the in natura wood. There was an increase in termite mortality and a reduction in damage for the modified wood treated with 15% tannins, obtaining the best results in mechanical and biological resistance and for the physical parameters. Thermal densification pine wood and preserved with tannin extractives proved to be a potential alternative as a high performance material
Properties of Pinus sp. pellets prepared after In-line pre-compaction with torrefaction
Publication . Lima, Laura V. L.; Castro, Vinícius R. de; Surdi, Paula G.; Zanuncio, Antônio J. V.; Zanuncio, José C.; Carneiro, Angélica de C. O.; Gominho, Jorge; Araújo, Solange
Pelletizing and torrefaction increase biomass energy density, generating
a more homogeneous fuel with lower moisture, enabling it to burn in
equipment with high energy efficiency. This work evaluated the quality of
pellets made from wood particles that had been densified and torrefied in
an extruder-type system. Particles of the Pinus sp. wood were torrefied at
200, 250, and 300 °C for six minutes and then compacted to produce
pellets. The physical, chemical, and mechanical properties of these pellets
were evaluated and compared with standard ones. Torrefaction modified
the pellets properties by increasing ash, fixed carbon, higher heating
value, and the energy density, while reducing the volatile matter and
equilibrium moisture content. The mechanical durability of the pellets was
lower than that defined by the European, German, and American
standards. The torrefaction pre-compaction route with torrefied particles at
a temperature of 300 °C was the most efficient for energetic use,
compared to the in natura biomass. The latter has negative aspects such
as great variation in size (length and diameter) and density besides high
moisture content
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
DL 57/2016
Número da atribuição
DL 57/2016/CP1382/CT0018