Industrial & Engineering Chemistry Research, Vol.46, No.2, 623-631, 2007
Optimization of Paulownia fortunei L. autohydrolysis-organosolv pulping as a source of xylooligomers and cellulose pulp
This paper will consider the influence of the autohydrolysis pretreatment on Paulownia fortunei L. woods to obtain a liquid phase (which can be used as a commercial source of organic reagents) and also a solid phase (which is valuable as raw material for pulping processes). Moreover, the influence of the operating conditionsviz., ethanol concentration (20%-60%), temperature (150-180 degrees C), and pulping time (30-90 min)on the organosolv pulping (the initial liquor-to-solid ratio was 8:1, with 10% of soda and 0.5% of anthraquinone) of the obtained Paulownia fortunei L. solid after the autohydrolysis process has been considered to determine the best pulping conditions and characteristics of the solid phase. In that form, the yield, kappa number, glucan and lignin contents, and tensile index values of the resulting pulps and paper sheets have been studied. The optimum of solubilized components has been obtained at 190 degrees C (0.92 g/L glucose, 1.61 g/L xylose, 0.60 g/L arabinose, 0.93 g/L acetic acid, 0.047 g/L 5-hydroxymethylfurfural, 0.141 g/L furfural, and 14.66 g/L oligomers). Under these conditions, a suitable chemical composition of pulps and acceptable yield (38%), kappa number (45), and tensile index (28.87 N m/g) could be obtained through operation at high temperature (180 degrees C), short pulping time (30 min), and low ethanol concentration (20%).