This work investigated the integration of a two-stage hydrothermal treatment for production of xylooligosaccharides (XOS), a high-value product, into the isolation process of cellulose nanofibrils (CNF) from sugarcane bagasse. Under optimized conditions, the first stage yielded a XOS-rich, high purity hydrolysate and in the second stage only a xylose-rich hydrolysate could be obtained at high purity. The resulting solid cellulosic fraction was delignified and bleached to obtain a cellulose-rich pulp, which was mechanically defibrillated by disc ultra-refining to CNF. Except for the viscosity, the sugarcane CNF showed properties (i.e., thermal stability, crystallinity and diameter size) comparable or superior to the CNF prepared from commercial bleached eucalyptus Kraft pulp. In conclusion, the integration of the two-stage hydrothermal treatment is an efficient and promising strategy to obtain hemicellulose-derived high-value co-products in the process of isolating CNF. In addition, lignin was also recovered as a co-product with yield comparable to other biomass fractionation approaches.

这项工作研究了将用于生产木糖寡糖（XOS）（一种高价值产品）的两阶段水热处理与从甘蔗渣中分离纤维素纳米原纤维（CNF）的过程的集成。在优化条件下，第一阶段产生了富含XOS的高纯度水解产物，而第二阶段则只能以高纯度获得富含木糖的水解产物。将所得的固体纤维素级分脱木质素并漂白，以获得富含纤维素的纸浆，其通过将纸盘超精制为CNF而机械除纤。除粘度外，甘蔗CNF的性能（即热稳定性，结晶度和直径大小）与由商业漂白的桉木牛皮纸浆制得的CNF相当或更好。结论，两步水热处理的集成是在分离CNF过程中获得半纤维素衍生的高价值副产物的有效且有前途的策略。另外，木质素还作为副产物被回收，收率可与其他生物质分馏方法相媲美。