Use of butanol-water mixtures for making wheat straw pulp
ABSTRACT A central composite design was used to investigate the influence of the cooking conditions (time, temperature and butanol
concentration) for wheat straw with butanol-water mixtures on the properties of the pulp obtained (yield and holocellulose,
α-cellulose, lignin and ethanol-benzene extractives contents) and the pH of the resulting waste water. A second-order polynomial
model consisting of three independent process variables was found to accurately describe the organosolv pulping of wheat straw.
The equations derived predict the yield, the holocellulose, α-cellulose, lignin and ethanol-benzene extractives contents of
the pulp, and the pH of the waste water with multiple-R, R2, adjusted-R2 and Snedecor' F values of 0.99, 0.99, 0.99 and 310.33; 0.98, 0.97, 0.95 and 56.63; 0.91, 0.84, 0.74 and 9.14; 0.99, 0.98,
0.96 and 70.52; 0.97, 0.94, 0.92 and 40.42; and 0.98, 0.95, 0.93 and 49.33, respectively.
The process variables must be set at low values in order to ensure a high yield and pH. On the other hand, if a high holocellulose
content and low lignin and ethanol-benzene extractives contents are to be obtained, then the process variables must be set
at high values. Finally, obtaining pulp with a high α-cellulose content entails using a long cooking time and a high temperature,
as well as a low butanol concentration.
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- "Therefore, non-wood fiber will play important roles in papermaking as substitutes or complements to wood. Examples of non-wood fiber resources available for paper production are wheat-straw   , rice-straw  , sugarcane straw , reeds , bamboo , bagasse  , kenaf , palm oil , and jute . Non-wood material, particularly wheat straw, was successfully exploited as the main raw material for papermaking in China because of the limited wood resource with forest coverage of only 13.94% . "
ABSTRACT: The main objective of this study is to evaluate the implementation of acetone as a pulping agent for pineapple leaves. Mixtures of water and acetone with concentration of 1%, 3%, 5%, 7%, and 10% were used. The effects of soaking and delignification time on the paper properties were investigated. Thermal and physical properties of paper sheet were studied using thermogravimetric analysis (TGA) and tearing resistance test respectively. The morphological properties were observed using microscope at 200× magnification. The paper sheet produced from pulping with 3% acetone concentration shows the highest mechanical properties. Papers strength was improved by increasing the delignification time. The delignification time was reduced by cooking the pineapple leaves at a temperature of 118 °C under applied pressure of 80 kPa which has remarkable effect on paper strength.Journal of Materials Research and Technology 01/2015; 99. DOI:10.1016/j.jmrt.2014.12.006
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- "These empirical models are to be preferred to theoretical ones as the latter are rather complex when more than two independent variables are involved. The potential of organosolv pulping in this context has been examined by authors such as Parajó et al. , Tjeerdsma et al. , Vázquez et al. , Vega et al. , Gilarranz et al.   and Jiménez et al.       , using alcohols, organic acids and other organic solvents; however , ethanolamine/soda mixtures have never previously been tested for this purpose. For this reason, in this work we used a central composite design to examine the influence of the independent cooking variables (viz. "
ABSTRACT: This paper reports on the influence of independent variables in the pulping of olive wood trimmings [viz. cooking temperature (165–195 °C) and time (30–90 min), ethanolamine concentration (5–15%), soda concentration (2.5–7.5%) and liquid/solid ratio (4–6)], on the yield and kappa number of the pulps and breaking length, burst index and tear index of the resulting paper sheets.By using a central composite factorial design, equations that relate each dependent variable to the different independent variables were obtained that reproduced the experimental results for the dependent variables with errors less than 15%. These equations could be used to find the suitable operations conditions, so that operating with not too high values of operating variables (with the consequent minor costs of capital and of operation) pulps could be obtained by acceptable strength properties.Optimizing pulp yield, the kappa number and the strength properties of the resulting paper sheets entails using rather different conditions in each case.Obtaining acceptably strong paper sheets while saving on immobilized capital through the use of smaller facilities and less chemical reagents entails using a medium soda concentration and low values of all other independent variables. In this way, the yield is 22.2% lower, the kappa number 42.5% higher, and the breaking length, burst index and tear index 6.2, 29.1 and 29.6%, respectively, lower than their optimum values; in any case, the strength properties increase although the pulp was suitably refining.Biochemical Engineering Journal 04/2008; 39(2-39):230-235. DOI:10.1016/j.bej.2007.09.006 · 2.37 Impact Factor
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ABSTRACT: Summary form only given. II-VI based blue-green laser and LEDs suffer from the problem of short operating lifetimes. We show that this is related to microstructural degradation that takes place in the active region during operation and originates from pre-existing defects