Primary Study Of Extracting Arabinose And Xylooligosaccharides From Bagasse And Bagasse Pith

In this paper, the extraction of L-arabinose from bagasse and bagasse pith by hydrolysis process was studied, and a lot of work has been done on the pre-extracting of xylooligosaccharides from bagasse for preparing dissolving pulp by alkaline cooking process.Bagasse and bagasse pith were treated with hot water in this study. By controlling the hydrolysis temperature, L-arabinose was selectively hydrolyzed from bagasse and bagasse pith, which was favorable for separation. The effect of different temperature, time and liquor ratio on the concentration of L-arabinose, xylose and glucose was discussed. Results indicated that temperature had the greatest influence on the composition of the hydrolyzate. Under the lower temperature (≤140℃), L-arabinose was markedly extracted while xylose and glucose were hardly detected, so that a lower temperature and a longer holding time were favorable for the extraction of L-arabinose, and no measurable quantities of xylose and glucose were produced. A maximum of about0.85%(on oven dry weight of material) of the sugarcane bagasse was extracted as L-arabinose at the maximum temperature of145℃, the holding time of3h, the liquor ratio of1:8, while the maximum L-arabinose of1.40%(on oven dry weight of material) was obtained from bagasse pith at the the maximum temperature of140℃, the holding time of3h, the liquor ratio of1:10, with xylose and glucose undetected in either of the process.Orthogonal experiments were adopted to get the optimum hydrolysis conditions of pre-extracting xylooligosaccharides from bagasse. The yield of xylan reached16.95%(on oven dry weight of material) at the maximum temperature of160℃, the holding time of120min, and the liquor ratio of1:8.The bagasse, treated by the optimum hydrolysis conditions, was cooked by soda and soda-AQ cooking process. The effect of temperature, alkali charge and holding time on the properties of the dissolving pulp was studied. Results showed that temperature was the greatest factor that affected the viscosity of the dissolving pulp fiber. Alkali charge and holding time were conductive to the removal of lignin and carbohydrate degradation. The viscosity of the pulp, obtained from the soda-AQ cooking process at lower temperature (<170℃) was around1000mL/g, which was adapted to prepare the higher value-added acetate fiber. The viscosity of the pulp, obtained at the maximum temperature of175℃, the alkali charge of22.5%～24.0%, and the holding time of90-120min was around500mL/g, which could be used for making viscose staple fiber.