Department of Bioproducts and Biosystems, Aalto University, PO BOX 16300, 00076 Aalto, Finland; VTT Technical Research Centre of Finland Ltd, PO BOX 1000, 02044 VTT, Finland.
RISE Bioeconomy, PO Box 5604, 11486 Stockholm, Sweden.
Carbohydr Polym. 2018 Jun 15;190:212-221. doi: 10.1016/j.carbpol.2018.02.064. Epub 2018 Feb 24.
Hydrothermal treatments of birch wood and kraft pulp were compared for their ability to extract the xylan and produce viscose-grade pulp. Water post-hydrolysis of kraft pulp produced a high-purity cellulosic pulp with lower viscosity but higher cellulose yield than traditional pre-hydrolysis kraft pulping of wood. Post-hydrolysis of pulp also increased the crystallite dimensions and degree of crystallinity in cellulose, and promoted a higher extent of fibril aggregation. The lower specific surface area in post-hydrolyzed pulps, derived from their larger fibril aggregates, decreased the accessibility of OH groups. However, this lower accessibility did not seem to decrease the pulp reactivity to derivatizing chemicals. In the aqueous side-stream, the xylose yield was similar in both pre- and post-hydrolysates, although conducting post-hydrolysis of pulp in a flow-through system enabled the recovery of high purity and molar mass (∼10 kDa) xylan for high-value applications.
桦木和硫酸盐浆的水热处理被比较，以评估它们提取木聚糖和生产粘胶级浆的能力。硫酸盐浆水解后的水相可产生高纯度的纤维素浆，其粘度较低，但纤维素得率高于传统的木材预水解硫酸盐法制浆。纸浆水解后还增加了纤维素的微晶尺寸和结晶度，并促进了纤维原纤的更高程度聚集。较大纤维原纤聚集导致后水解浆的比表面积降低，降低了 OH 基团的可及性。然而，这种较低的可及性似乎并没有降低纸浆对衍生化学品的反应性。在水的副产物中，预水解和后水解产物中的木糖收率相似，尽管在流动系统中进行纸浆后水解可以回收高纯度和高摩尔质量（约 10 kDa）的木聚糖，用于高价值应用。
