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Abstract: Wood from the leguminous tree, Leucaena diversifolia, was subjected to hydrothermal treatment (autohydrolysis) at 160–180°C for 0–30min followed by ethanol–soda–anthraquinone delignification. The liquid phase contained 18.65g of sugars per liter, and the solid phase had a gross heating value of 19.083MJ/kg, but could also be used as a source of cellulose pulp for the production of paper with tear, burst, and tensile indexes of 2.4Nm2/kg, 2.6MPam2/kg and 40.7kNm/kg, respectively. L. diversifolia lends itself readily to valorization for energy production, and also to integral, fractional exploitation by autohydrolysis and ethanol–soda–anthraquinone delignification, which can additionally bring environmental benefits to cropping zones. [Copyright &y& Elsevier]

Abstract: The influence of temperature in the hydrothermal treatment of sunflower stalks on the composition of the liquid fraction obtained was examined. The remaining solid fraction was subjected to ethanol pulping in order to obtain pulp that was used to produce paper sheets. The pulp was characterized in terms of yield, kappa index, viscosity, and cellulose, hemicellulose and lignin contents; and the paper sheets in terms of breaking length, stretch, burst index and tear index. Hydrothermal treatment of the raw material at 190°C provided a liquid phase with maximal hemicellulose-derived oligomers and monosaccharide (glucose, xylose and arabinose) contents (26.9 and 4.2g/L, respectively). Pulping the solid fraction obtained by hydrothermal treatment at 180°C, with 70% ethanol at a liquid/solid ratio of 8:1 at 170°C for 120min provided pulp with properties on a par with those of soda pulp from the sunflower stalks, namely: 36.3% yield, 69.1% cellulose, 12.6% hemicellulose, 18.2% lignin and 551ml/g viscosity. Also, paper sheets obtained from the ethanol pulp were similar in breaking length (3.8km), stretch (1.23%), burst index (1.15kN/g) and tear index (2.04mNm2/g) to those provided by soda pulp. [Copyright &y& Elsevier]

Abstract: To determine the overall efficiency of processes designed to convert lignocellulosic polysaccharides to ethanol, it is first necessary to determine the composition of the lignocellulosic substrates. Three standard methods routinely referenced in the literature for this purpose are monoethanolamine, trifluoroacetic acid and concentrated sulphuric acid-based methods. However, in the course of our studies, the suitability of these standard methods for analysis of wastepaper and wheat straw came into question. This paper details our investigations in this area, together with recommendations for appropriate modifications to one of the standard methods for reproducible and representative lignocellulosic compositional analysis of waste paper and cereal straw. [Copyright &y& Elsevier]

Abstract: The influence of temperature (150–170°C), pulping time (15–45min) and soda concentration (5–10%) in the pulping of abaca on the yield, kappa, viscosity, breaking length, stretch and tear index of pulp and paper sheets, was studied. Using a factorial design to identify the optimum operating conditions, equations relating the dependent variables to the operational variables of the pulping process were derived that reproduced the former with errors lower than 25%. Using a high temperature, and a medium time and soda concentration, led to pulp that was difficult to bleach (kappa 28.34) but provided acceptable strength-related properties (breaking length 4728m; stretch 4.76%; tear index 18.25mNm2/g), with good yield (77.33%) and potential savings on capital equipment costs. Obtaining pulp amenable to bleaching would entail using more drastic conditions than those employed in this work. [Copyright &y& Elsevier]