Article

Use of butanol-water mixtures for making wheat straw pulp

Wood Science and Technology (Impact Factor: 1.87). 03/1999; 33(2):97-109. DOI: 10.1007/s002260050102

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.

0 Bookmarks
 · 
80 Views
  • Source
  • [Show abstract] [Hide abstract]
    ABSTRACT: Fractionation of hemp hurds into its three main components, cellulose, hemicellulose, and lignin, was carried out using organosolv pretreatment. The effect of processing parameters, such as temperature, catalyst concentration, reaction time, and methanol (MeOH) concentration, on the dissolution and recovery of hemicellulose and lignin was determined. More than 75 % of total hemicellulose and 75 % of total lignin was removed in a single step with low amounts of degradation products under the following conditions: 165 °C, 3 % H2SO4, 20 min reaction time, and 45 % MeOH. Enzymatic hydrolysis of the residual pretreated biomass yielded up to 60 % of cellulose-to-glucose conversion. The maximum recovery of the main components was obtained at a combined severity factor value of around one. Characterization of pretreated biomass and isolated lignin was carried out with FTIR and 2D 13C–1H correlation HSQC NMR spectroscopy, the latter technique providing detailed structural information about the obtained methanol organosolv lignin (MOSL). Results suggested that xylopyranoside is the major carbohydrate associated with hemp lignin. The chemical properties of MOSL samples in terms of their phenolic group content and antioxidant capacity were also investigated. The results showed that MOSL samples have a high phenolic group content and antioxidant capacity relative to Klason lignin.
    ChemSusChem 07/2014; 7(7). DOI:10.1002/cssc.201301396 · 7.48 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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.
    01/2015; 99. DOI:10.1016/j.jmrt.2014.12.006