Sugarcane bagasse (SCB) is a widely available biomass feedstock currently used for ethanol production in various parts of the world. Here, we carried out a combined liquid hot water and neutral/alkaline sulfonation pretreatments of SCB at relatively low temperatures to maximize enzymatic hydrolysis yields. To describe multi-step pretreatments severities, analytical equations for modified combind severity factors (CSF´_m) were introduced. Although the chemical composition of SCB after the liquid hot water pretreatment alone has not been significantly changed under tested conditions, this pretreatment led to an increase in the efficiency of its enzymatic hydrolysis. Furthermore, a combination of liquid hot water pretreatment (at 120 °C for 1 h) and sulfonation of SCB (at 120 °C for 2 h) resulted in excellent enzymatic hydrolysis yields. After alkaline sulfonation, glucose yields reached 99.6 ± 0.21% for autoclaved and alkaline sulfonated bagasse (AASB) and 97.47 ± 0.75% for boiled and alkaline sulfonated bagasse (BASB), whereas xylose yields were 86.9 ± 1.9% and 88.0 ± 1.8% for AASB and BASB, respectively. High enzymatic hydrolysis yields are in line with elevated CSF´_m of the latter pretreatments. X-ray diffraction, confocal laser scanning microscopy, and solid-state ¹³C NMR spectroscopy analyses showed that the structural desorganization of bagasse after liquid hot water pretreatment associated to chemical modifications of lignin and its massive removal promoted by alkaline sulfonation led to efficient separation of carbohydrates and lignin, revealing underlying structural reasons of the observed efficient enzymatic hydrolysis.

甘蔗渣 (SCB) 是一种广泛可用的生物质原料，目前在世界各地用于乙醇生产。在这里，我们在相对较低的温度下对 SCB 进行了液体热水和中性/碱性磺化预处理的组合，以最大限度地提高酶水解产率。为了描述多步预处理的严重性，修改后的组合严重性因素的分析方程 (CSF´ _m) 进行了介绍。尽管在测试条件下单独使用液体热水预处理后 SCB 的化学成分没有发生显着变化，但这种预处理导致其酶水解效率提高。此外，液体热水预处理（120°C 1 小时）和 SCB 磺化（120°C 2 小时）的组合产生了优异的酶水解产率。碱性磺化后，高压灭菌和碱性磺化甘蔗渣 (AASB) 的葡萄糖产量达到 99.6 ± 0.21%，煮沸和碱性磺化甘蔗渣 (BASB) 的葡萄糖产量达到 97.47 ± 0.75%，而 AASB 的木糖产量分别为 86.9 ± 1.9% 和 88.0 ± 1.8%和 BASB，分别。_{高酶水解产率与升高的 CSF´ m}一致后者的预处理。X 射线衍射、共聚焦激光扫描显微镜和固态¹³ C NMR 光谱分析表明，液体热水预处理后甘蔗渣的结构解构与木质素的化学改性有关，而碱性磺化促进了其大量去除，从而有效分离了碳水化合物和木质素，揭示了观察到的有效酶水解的潜在结构原因。