The surface tension of aqueous binary solutions of 1-amino-2-propanol and 3-amino-1-propanol and aqueous ternary solutions of these amines with diethanolamine, triethanolamine, and 2-amino-2-methyl-1-propanol was measured at temperatures from 298.15 K to 323.15 K. For binary mixtures, the concentration range was 0-100 mass percent alkanolamine, and for ternary mixtures, the concentration range for each amine was 0-50 mass percent. The experimental values for binary mixtures were correlated with mole fraction by an empirical equation (the maximum deviation was in both cases always less than 0.2%).

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The biofuels production from alternative and renewable raw materials is mandatory to achieve sustainable growth based on a bioeconomy. Eucalyptus bark is a waste generated during the chemical manufacturing of Eucalyptus pulp that can be used as an alternative source of biomass, suitable for the production of biofuels. In this work, Eucalyptus nitens bark (ENB) was fractionated by organosolv treatment for ethanol production. For that, a Doehlert experimental design was carried out to evaluate the dependent variables: temperature (170-200°C), time (30-90 min) and ethanol-water percentage (50-80 %) on delignification of Eucalyptus bark. Organosolv process was suitable for the fractionation of E. nitens bark. After treatment, 74-93 % of glucan was recovered and 25-52 % of delignification was achieved. Delignified ENB was subjected to simultaneous saccharification and fermentation process for bioethanol production. The results showed that the variables temperature and time of organosolv process had significant influence on ethanol production. The organosolv pretreatment improved the ethanol yield from 32 to 99%. This work shows a suitable process for the valorization of Eucalyptus bark into bioethanol.

Density and kinematic viscosity of (2-methyl-1-butanol + ethanol), (2-methyl-2-butanol + ethanol), and (3methyl-1-butanol + ethanol) binary solutions were measured over the entire composition range and at seven different temperatures (293.15, 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15) K, at atmospheric pressure. Redlich-Kister-type polynomial equations were used to fit the calculated excess molar volumes and viscosity deviations.