Bran of different rice cultivars produced in Portugal were used to study supercritical carbon dioxide extraction conditions of rice bran oil (RBO) and evaluate and compare antioxidant activity and fatty acid composition of the different rice bran varieties. The effect of plant loading (10–20 g), CO2 flow rate (0.5–1.5 L/min), pressure (20–60 MPa), and temperature (40–80 °C) was studied. The amount of oil extracted ranged from 11.72%, for Ariete cultivar, to 15.60%, for Sirio cultivar. The main fatty acids components obtained were palmitic (13.37%–16.32%), oleic (44.60%–52.56%), and linoleic (29.90%–38.51%). Excellent parameters of the susceptibility to oxidation of the oils were obtained and compare. RBO of Ariete and Gladio varieties presented superior DPPH and ABTS radical scavenging activities, whereas, Minima, Ellebi, and Sirio varieties had the lowest scavenging activities. Moreover, the oil obtained towards the final stages of extraction presented increased antioxidant activity.

Recently, 5‐hydroxymethyl furfural (5‐HMF) became into the spotlight as one of the most promising biorenewable platforms available from carbohydrates. Among other versatile derivatives of 5‐HMF its dimer 5,5′‐(oxy‐bis (methylene)) bis‐2‐furfural (OBMF) was recognized as a useful building block for the production of polymers and pharmaceuticals. Herein we explored the synthesis of OBMF under solvent free conditions applying vacuum as a green tool for water removal. Several readily available acidic resins, silica gel supported inorganic acid, acidic zeolites and Lewis acids were studied as promoters for this transformation. Under these conditions, SiO2/CF3SO3H exhibited the best performance allowing the synthesis of OBMF in 55 % yield in only 1 min reaction time. Similar results were achieved using Amberlyst 15 and SO2/PPA resulting in 51 % yield in 20 min and 46 % yield in 10 min, respectively.

The recycling of wastes is nowadays a priority in terms of the EU policies. This study aims at the replacement of a certain percentage of clay (natural raw material) by residues produced in a municipal solid waste incineration (MSWI) process referred as Air Pollution Control (APC) residues. The main objective of this work concerns the prediction of the quantity of the waste that can be valorized as lightweight aggregates (LWA). For this analysis the Riley diagram was considered, which consists in plotting the percentage concentration of the main oxides (SiO2, Al2O3, fluxing) in a ternary diagram. The fluxing is defined as the sum of Fe2O3+CaO+MgO+Na2O+K2O. Our results point out that no more than 5% of APC residues should be considered, since the main oxide composition of APC residues is far away from bloating area. A pre-washing treatment improved the waste characteristics being then possible to increase the amount of residue that can be incorporated in percentages below 10%. This theoretical analysis can save experimental work, since it allows the prediction of the maximum amount of wastes to be tested.

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Pulp and paper industry requires developing more sustainable production and improve technologies on biorefinery and bioproduct market areas. Based on these areas, the isolation of lignin from black liquor, obtained by Eucalyptus Globulus, is an important objective. The present study demonstrates that it is possible to recover lignin by electrolysis of the Kraft black liquor in a simple and economic way. This novel black liquor electrolyzer leads to lignin recovery by anodic electrodeposition and cathodic production of hydrogen. Physicochemical characterization of black liquor is made, with the determined values of pH, density, dry solids content and ash content being 13.0, 1111 g cm-3, 16.7 wt.%, and 8.0 wt.% (wet basis) and 40.8 wt.% (dry basis), respectively. The electrolysis experiments are conducted at room temperature on a small-scale laboratory black liquor electrolyzer using Ni plates. ATR-FTIR analysis of the obtained lignin samples is compared with previous literature reports.

The cohesion of cork agglomerates is determined by the strength of the adhesive joint established between the polymeric adhesive and the cork particles. The ability of adhesives to form good joints depends, among other factors, on the wetting of cork by the adhesives. The main objective of this research was to study the behaviour of adhesive drops deposited on cork substrates through measurements of contact angles and their time dependence. Several polyurethane prepolymers were tested to establish a correlation between the wetting characteristics and the chemical structure and physical properties of the adhesives. The effect of the morphology of cork on the interfacial properties was also investigated. The initial contact angles were related to the chemical nature of the adhesive. The kinetics of the wetting process were found to depend mainly on the viscosity of the adhesive.

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