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Pterogyne nitens is commonly known in northeastern Brazil as a lesser-known fast-growing species in the Caatinga biome, which is a difficult place for tree development due to the low natural fertility soils and low availability of water. Due to the importance of expanding information about the anatomical wood properties of Caatinga native species, the aim of this work was to characterize the anatomical elements, to macroscopically describe the wood and make inferences about its possible end-uses. Maceration was performed which enabled measuring fiber dimensions, pore frequency and the following technological indexes: cell wall fraction, slenderness ratio, Runkel index and flexibility coefficient. Histological sections enabled describing the arrangements of the cellular elements in different observation sections and to determine the pore diameter. P. nitens wood has anatomical arrangements characterized by confluent axial parenchyma, being diffuse-porous with the presence of tylosis and heterogeneous/stratified rays (biseriate). The fibers were classified as very short (length 0.81 mm), not flexible and Runkel index 0.82. The pores were few in number with a frequency of 32.9 pores/mm2, distributed in a diffuse format and many were obstructed by tylosis. Based on the anatomical results and considering other technological studies, P. nitens wood is most suitable for charcoal production. [ABSTRACT FROM AUTHOR]

The objective of this work was the quantification of above ground total biomass of the Eucalyptus forest at cutting age, divided into its main parts and to quantify the biomass loss during the steps of cutting, extraction, drying, transport and transformation of wood into charcoal. For this, a Eucalyptus urophylla x Eucalyptus grandis stand, at the 79 months age, was evaluated. Sixty trees were selected to be scaled, and samples of leaves and branches collected; of these 60 trees, 15 were selected for wood and bark basic density determination. To determine the bark loss 100 logs of 3 m long were selected at 3 different logs movement stages: the field edge, the courtyard of CPU and the oven. The biomass stock of the Eucalyptus forest was 145.99 t ha −1 , and 11.67% was in the form of harvest waste, and presents potential for use mainly for heat and electricity generation. The total bark loss was 25.7%, and the first step that generated the greatest loss of bark, when the wood is still on the edge of the field. [ABSTRACT FROM AUTHOR]

• Thorough characterization of eucalypt kraft lignin aiming biorefinery application. • Strategies for evaluating technical lignins by PY-GC–MS. • Changes in the lignin S/G ratio of heat-treated lignins. • Thermal treatment on black liquor from eucalypt kraft pulping as an alternative for modifying technical lignins. Kraft lignin is considered a potential valuable by-product in the pulp industry within the biorefinery concept. However, kraft lignin is characterized by a complex chemical structure, having a low reactivity and a high heterogeneity. Technical options to increase the reactivity of eucalypt kraft lignin are important for the manufacture of lignin based products. This study evaluates the effect of thermal treatment on the chemical composition of extracted kraft lignin from eucalypt kraft black liquor. The black liquor was heat-treated at temperatures of 175, 200 and 225 °C at reaction times of 30, 90 and 150 min. The lowest process yield (93 %) was found for the most drastic treatment conditions (225 °C and 150 min), with a minimum thermal degradation of the liquor, analyzed by TG/DTG curves. The lignins from the original liquor and the heat-treated liquors were extracted and characterized by their chemical composition, elemental analysis, heating value and Py-GC–MS to evaluate the changes caused by the thermal treatment. The thermal treatment promoted demethylation and demethoxylation on the eucalypt kraft lignin. A reduction in soluble lignin, oxygen and hydrogen content as well as an increase in insoluble lignin and carbon content were observed when higher temperature and retention time in the thermal treatment were applied. A reduction in the lignin S/G ratio of heat-treated lignins and an increase in the catechol and methoxycatechol content for the treatment of 225 °C and 150 min were also observed when compared to the reference. The eucalypt kraft lignin isolated from the heat-treated liquor may be more reactive than the original lignin due to changes in its chemical composition and molecular structure. This lignin should be considered in the production of high value-added lignin-based products. [ABSTRACT FROM AUTHOR]