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Abstract: The aim of this work was to chemically characterize orange tree prunings and use it in pulping and combustion processes. Soda-anthraquinone pulping of the main fraction of orange pruning (stems with a diameter >0.5cm) was simulated with polynomial and neurofuzzy models, that predicted pulp properties as a function of operating variables (155–185°C, 40–90min, soda concentration, 10–16%) with errors less than 20%. The heating values (16,870kJ/kg), the flame temperature (1150–2150°C) and dew point temperature of fuel gas (47–53°C) for the residual fraction from orange pruning (stems diameter <0.5cm and leaves) was determined and compared with other non-wood lignocellulosic materials. As a consequence the price of kJ obtained by combustion of this residual fraction is less than other lignocellulosic materials, much lower than those of fossil fuels. [Copyright &y& Elsevier]

Abstract: The influence of the hydrothermal treatment conditions of rice straw (temperature – 150–190°C , time – 0–20min after reaching the operation temperature – and liquid/solid ratio – 6–8), on the composition of liquid and solid fractions was studied. Polynomial models were found for to reproduce the experimental results with errors less than 6%. Operating to 190°C, 15min and 9 liquid/solid ratio was obtained high values of glucose (1.92g/L), xylose (3.97g/L), arabinose (0.99g/L) and acetic acid (1.96g/L), what allows to save capital when not operating with the maximum time and/or liquid/solid ratio; yield in the solid fraction is 88.1% and lignin content 24.43%. If what it is required to obtain good values of yield (96.46%) and lignin content, is necessary to operate to 150°C, obtaining lower concentrations glucose (1.11%), xylose (2.78%), arabinose (0.56%) and acetic acid (0.39%). Ethanolamine pulping of solid fraction of hydrothermal treatment provides pulp with higher or similar properties to those obtained of pulping rice straw with ethanolamine or soda. [Copyright &y& Elsevier]

Abstract: The influence of operational variables in the pulping of vine shoots by use of ethylene glycol [viz. temperature (155–185°C), cooking time (30–90min) and ethylene glycol concentration (50–70% v/v)] on the properties of the resulting pulp (viz. yield, kappa number and viscosity) and paper sheets (breaking length, stretch, burst index, tear index and brightness) was studied. A central composite factorial design was used in conjunction with the software ANFIS Edit Matlab 6.5 to develop fuzzy neural model that reproduced the experimental results of the dependent variables with errors less than 5%. The model is therefore effective with a view to simulating the ethylene glycol pulping process. [Copyright &y& Elsevier]

In order to identify faster-growing non-woody species usable for biomass and paper production, four Leucaena species (L. diversifolia, L. colinsii, L. salvadorensis and three varieties of L. leucocephala) were tested. All the Leucaena species showed a good soil and climatic adaptation to Spain Southwest except for L. salvadorensis. Studied Leucaena species showed biomass productivity ranges from 67.14 to 9.44tha−1 (o.d.b.) and 43.6 to 11.4tha−1 under Mediterranean conditions for the first and second year sprouts, respectively. The quantity of solubles and extractives shows similar values when compared with wood materials. Relatively lower lignin content in Leucaena (from 15.7% to 21.4%) species has been found with respect to other vegetal species. The α-cellulose contents (39.4–45.3%) are in the range of the normal values expected for the other non-wood raw materials. The study confirms the feasibility of organocell yield pulping process to Leucaena species. Organocell process provides an efficient delignification (kappa number 12.4 and pulp yield 42.2%) for L. leucocephala and suitably physical characteristics of paper sheet (tensile index 20.3kNm/kg for L. diversifolia). [Copyright &y& Elsevier]

Abstract: In order to identify faster-growing non-woody species usable for biomass and paper production, four Tagasastes (Chamaecytisus proliferus) from different origins are tested. All the Tagasaste species (T. Huelva, T. Australia, T. New Zealand and T. La Palma island) show a good soil and climatic adaptation to Southwest Spain. The studied Tagasaste provenances shows biomass productivity ranges from 1.0tha−1 yr−1 to 3.4tha−1 yr−1 (o.d.b.) and 25.3tha−1 yr−1 to 49.4tha−1 yr−1 under Mediterranean conditions for first and second year sprouts, respectively. The quantity of solubles and extractives shows similar values when compared with wood materials. A relatively lower lignin content in Tagasaste (from 13.7% to 17.1%) species has been found with respect to other vegetal species. The α-celullose contents (43.6–45.3%) were in the range of the normal values expected for the other non-wood raw materials. The study confirms the feasibility of the organocell yield pulping process to Tagasaste provenances. Organocell processes provide an efficient delignification (kappa index from 7.2 to 10.9 and pulp yield from 43.6% to 54.1%). The best results are obtained for the physical properties of paper sheets for Tagasaste from Australia in the second year, with values of tensile index of 16.0kNm/kg, burst index of 1.12MPam2/kg and tear index of 0.55Nm2/kg. [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: We characterized vine shoots, cotton stalks, Leucaena leucocephala and Chamaecytisus proliferus as pulping raw materials and found C. proliferus and cotton stalks to be the best for the intended purpose on the grounds of their increased contents in holocellulose (79.73% and 72.86%) and α-cellulose (45.37% and 58.48%), and their decreased contents in ethanol–benzene extractables (2.64% and 1.42%), hot water solubles (2.79% and 3.33%) and 1% soda solubles (16.67% and 20.34%). These properties resulted in increased pulp yields and hence in efficient use of these two types of raw material. The previous raw materials were pulped by using an ethyleneglycol concentration of 65% at 180°C for 75min, followed by beating at 1500 revolutions in a PFI refiner. The paper sheets obtained were characterized and those from C. proliferus found to be the best overall as they exhibited an increased breaking length (4644m), stretch (2.87%), burst index (2.46kN/g) tear index (0.33mNm2/g) and brightness (49.92% ISO); in addition C. proliferus pulp was obtained with a high-yield (62.88%). On the other hand, vine shoots provided the poorest results among the studied raw materials. [Copyright &y& Elsevier]

Abstract: This paper examines the influence of the degree of refining of different pulps, produced from olive trimmings and eucalyptus wood, on various physical properties. Corresponding pulps were obtained by means of different cooking processes. Pulp from olive trimmings was obtained by means of an organosolv process and pulp from eucalyptus was obtained by means of a kraft process. Pulp from olive trimmings exhibited a lower specific surface area, water retention volume, breaking length, stretch and burst index, but a higher porosity, than eucalyptus pulp. On the other hand, the same degree of refining was achieved with less energy for olive pulp than for eucalyptus pulp. Mixed pulp from olive trimmings and eucalyptus provided paper sheets with acceptable physical properties but with reduced refining energy costs relative to eucalyptus pulp alone. [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]

The influence of the operating conditions used in the bleaching of olive wood trimmings pulp (viz. hydrogen peroxide concentration and time) on the yield, kappa index and viscosity of the resulting pulp and on strength-related properties of paper sheets was studied to determine the optimal bleaching conditions of this pulp. Hydrogen peroxide bleached pulps at different sequences (oxygen, ozone, chlorine dioxide and alkaline extractions) were compared. Hydrogen peroxide bleaching proved to be suitable for this pulp. Considerable improvements in viscosity were obtained with respect to other bleaching sequences such as oxygen, ozone and chlorine dioxide. Hydrogen peroxide bleaching decreased the kappa index 51.3% less than ozone bleaching, 25.0% less than chlorine dioxide (D) and 6.3% less combined chlorine dioxide-alkaline extraction (DE). To obtain kappa indices 50.9% and 37.9% lower than the index achieved by hydrogen peroxide, oxygen (LaOp) and ozone (LaO(LaZ)R) sequences respectively were needed. Lower-medium levels of hydrogen peroxide concentrations (1–3%) and high reaction times (210 min) proved to be suitable for bleaching of pulp olive trimming residues. This approach could be used on this residue to produce adequately bleached pulp. [Copyright &y& Elsevier]