The objective of this work was to determine the properties of particleboard panels made of “in natura” sugarcane bagasse particles, heated at 250 °C for 5 minutes. Various particle proportions were utilized to produce the panels and their properties were compared with that of a panel made of Pinus sp. The panels were produced with 8% tannin formaldehyde adhesive, and 0.5% paraffin emulsion, being pressed at 32 kgf.cm-2 for 10 minutes at 180 ° C. It was determined the basic density of the “in natura” and heat-treated particles, their chemical composition, as well as the compression ratio necessary to obtain panels with density equal to 0.75 g.cm-3. The basic density of the panels, hygroscopic equilibrium humidity, thickness swelling, linear expansion, water vapor adsorption, modulus of elasticity and rupture, perpendicular traction, screw pullout, and Janka hardness were determined. The basic densities of Pinus particles and sugarcane bagasse without and with heat treatment were 0.46, 0.27 and 0.30 g.cm-3, respectively. The average specific mass of the panels was 0.74 g.cm-3 with no significant difference between them. Generally, panels made of sugarcane particles were less hygroscopic and dimensionally more stable than panels made of Pinus particles. However, the perpendicular tensile strength, screw pullout and Janka hardness of these panels were higher than for the Pinus panels. The heat treatment of sugarcane bagasse particles resulted in better mechanical properties of perpendicular traction and Janka hardness. In general, the panels are within the limits set by ANSI A208.1. It is therefore possible to replace panels made of Pinus particles for the ones made of sugarcane bagasse, provided that at least 25% of the particles are heat treated for 5 minutes at 250 ° C.

Abstract Dissolving pulps could be considered as the future biorefineries, which normally generate liquor during the wood chip pre-hydrolysis (PHL). PHL has high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Mills do not have efficient means for disposal of PHL, being in general burned in the recovery boiler with a high cost due to its low consistency. The objectives of this work were to evaluate i) the biotreatability of PHL and the effects it would have on a kraft mill effluent biological treatment plant and ii) the use of ultrafiltration (UF) membrane to treat the PHL prior to biological treatment. PHL was generated into lab with a hydrothermal process and was mixed with kraft pulp mill effluent in different proportions and added to sequencing batch reactors (SBRs). The SBRs achieved high rates of COD removal (>75 %). However, treated effluent COD increased with the increase in PHL dose. This treatment using UF membranes reduced the COD load. Biotreatability of the UF permeate was higher than that of PHL. UF retentate, with 28 % of the volume and a much higher solids content than the initial PHL, would have a significantly lower evaporation energy demand if sent to the black liquor evaporators.

The uses of kraft lignin (KL), obtained from the black liquor (BL) in the pulping process, allow the production of activated carbon (AC), a product with high added value in the pulp mill. The AC can be used in three different sectors in a cellulose pulp mill: sectorial treatment of the cellulosic pulp bleaching filtrates; wastewater treatment; and in the treatment of water received by the mill. Thus, this article considers the steps in the production of AC, their types, and the advantages and challenges of its use in the kraft cellulose pulp mill as well as in other industries.