Co-Production of Furfural, Xylo-Oligosaccharides, and Reducing Sugars from Waste Yellow Bamboo Through the Solid Acid-Assisted Hydrothermal Pretreatment

Lignocellulosic waste biomass, a versatile natural resource derived from plants, has gained significant attention for its potential in the sustainable production of biobased chemicals. Furfural (FAL), xylo-oligosaccharides (XOSs), and reducing sugars are important platform chemicals, which can be obtained through the valorization of lignocellulosic solid biomass in a green and sustainable way. Waste yellow bamboo (YB) is one kind of abundant, inexpensive, and renewable lignocellulosic biomass resource. In order to improve the high-value utilization rate of raw YB, biochar-based solid acid catalyst (AT-Sn-YB) was utilized to assist the hydrothermal pretreatment for the valorization of YB in water. Under the optimal reaction conditions (200 °C, 60 min, and AT-Sn-YB dosage of 5.4 wt%), the FAL yield reached 60.8%, and 2.5 g/L of XOSs was obtained in the pretreatment system. It was observed that the surface structure of YB became rough and loose, exposing a significant number of pores. The accessibility increased from 101.8 mg/g to 352.6 mg/g after combined treatment. The surface area and hydrophobicity of lignin were 70.7 m2/g and 2.5 L/g, respectively, which were significantly lower than those of untreated YB (195.4 m2/g and 4.1 L/g, respectively). The YB solid residues obtained after treatment were subjected to enzymatic saccharification, achieving an enzymatic hydrolysis efficiency of 47.9%. Therefore, the hydrothermal pretreatment assisted by the AT-Sn-YB catalyst shows potential application value in FAL production and bamboo utilization, providing important references for other biomass materials.