Optimization of Paulownia Fortunei L. Autohydrolysis−Organosolv Pulping as a Source of Xylooligomers and Cellulose Pulp

Abstract

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 conditionss viz., ethanol concentration (20%-60%), temperature (150-180 °C), and pulping time (30-90 min)son 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 °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 °C), short pulping time (30 min), and low ethanol concentration (20%).

Fractionation of Hemicelluloses and Lignin from Rice Straw by Combining Autohydrolysis and Optimised Mild Organosolv Delignification

“…Glucan yields are in agreement with those obtained by direct delignification of raw wheat straw . In other studies (Caparros et al 2007;Romani et al 2011) with a similar hydrothermal pretreatment before organosolv delignification, glucan yields were lower (ranging 70 to 87%).…”

Paulownia as a raw material for the production of pulp by soda–anthraquinone cooking with or without previous autohydrolysis

“…1,16,17 These compounds could cause problems related to pitch: pitch deposits in the manufacturing of pulp is a complex phenomenon, which has increased in recent years 25 and could cause problems by adhering to machinery and by reducing the quality of pulp. 26 The cellulose content in Paulownia trihibrid, 19 is 6.0-17.6% (expressed as glucan), lower than those found for Eucalyptus globulus, but higher (22.2-14.9%) than those found for Paulownia Fortunei, whereas lignin content is 17.6-28.2%, higher than that for Eucalyptus.…”

“…12 Also, this plant could be susceptible to producing xylooligomers under a hydrolytic process, as well as provide a low degraded lignocellulosic residue to the pulping process, which is justified by some Paulownia characteristics, such as its growth and physicochemical properties. 16,17 Ethanol for delignification of Paulownia fortunei was used by these last authors after extraction of sugars and oligosaccharides by autohydrolysis. Kraft pulp with kappa number 25, tensile index of 106 Nm g −1 , burst index 6.47 kPa m 2 g −1 and tear index 2.67 mN m 2 g −1 was obtained by Rai et al (2000).…”

Improvements in Pulp Properties by Alkali Pre-Extraction and Subsequent Kraft Pulping With Controlling H-Factor and Alkali Charge

“…Generally, treatment of the chips with hot water or steam is conducted in the first stage for dissolving pulp grade production in order to remove most of the hemicelluloses (Lora and Wayman 1978). This is usually called 'autohydrolysis', and there have been several studies about its effects on the chemical composition of wood chips (Caparrós et al 2007;Leschinsky et al 2009). Pre-extraction using hot water causes acidic conditions due to the release of acetic acid formed during autohydrolysis of the acetyl groups in the hemicelluloses (Song et al 2008;Tunc and van Heiningen 2008;Yoon and van Heiningen 2008b), and this acidity may accelerate the degradation of the cellulose at high temperatures, resulting in a significant loss in the pulp yield (Yoon et al 2010).…”