Bagasse, a major by-product of sugarcane-processing industries, has potential to play a significant role as feedstock for production of cellulosic ethanol, platform chemicals, and bio-based commodities. Pretreatment is essential for efficient processing of lignocellulosic feedstocks by biochemical conversion. In this work, auto-catalyzed (A-HTP) and dilute sulfuric-acid-catalyzed (SA-HTP) hydrothermal pretreatment of sugarcane bagasse was investigated, setting the temperature (175−205 °C) and the time (4−51 min) in such a way that the severity factor (SF) was always maintained at one of three predetermined values (2.8, 3.8, and 4.8). The investigation covered the effects of different operational pretreatment conditions on (i) the formation of sugars and water-soluble bioconversion inhibitors, including newly discovered inhibitors such as formaldehyde and p-benzoquinone, in the pretreatment liquid, (ii) the chemical composition and recovery of constituents in the solid phase, as determined using two-step treatment with sulfuric acid, Py-GC/MS, and solid-state NMR, (iii) pseudo-lignin formation, (iv) furan aldehydes in condensates from the gas phase, (v) enzymatic digestibility of pretreated solids, (vi) enzyme inhibition by pretreatment liquids, and (vii) fermentability of pretreatment liquids using Saccharomyces cerevisiae yeast. Glucose and xylose were the predominant sugars in pretreatment liquids from SA-HTP and A-HTP, respectively. For A-HTP, the enzymatic digestibility of the pretreated solids was proportional to the SF, while for SA-HTP no clear trend was observed. The best enzymatic digestibility (above 80%) was achieved for A-HTP performed at SF 4.8. The highest total yields of glucose and xylose, the predominant sugars, were achieved for A-HTP at SF 3.8 and temperatures of 190 °C and 205 °C. The fermentability of the pretreatment liquids by Saccharomyces cerevisiae was lower for SA-HTP than for A-HTP. The investigation suggests that hydrothermal pretreatment of sugarcane bagasse can be performed with good results without addition of sulfuric acid, but that the conditions must be just harsh enough to almost quantitatively solubilize the hemicelluloses.

甘蔗加工行业的主要副产品蔗渣具有作为纤维素乙醇，平台化学品和生物基商品生产原料的巨大潜力。预处理对于通过生化转化有效加工木质纤维素原料至关重要。在这项工作中，对甘蔗渣的自动催化（A-HTP）和稀硫酸催化（SA-HTP）水热预处理进行了研究，设定了温度（175-205°C）和时间（4-51分钟） ），以使严重程度因子（SF）始终保持在三个预定值（2.8、3.8和4.8）之一。调查涵盖了不同操作预处理条件对（i）在预处理液中形成糖和水溶性生物转化抑制剂，包括新发现的抑制剂，例如甲醛和对苯醌，（ii）固相的化学组成和成分回收，采用两步法确定用硫酸，Py-GC / MS和固态NMR进行处理，（iii）假木质素形成，（iv）气相冷凝物中的呋喃醛，（v）预处理固体的酶消化率，（vi）酶预处理液的抑制作用，以及（vii）使用酿酒酵母的预处理液的发酵能力酵母。葡萄糖和木糖分别是来自SA-HTP和A-HTP的预处理液中的主要糖。对于A-HTP，预处理后的固体的酶消化率与SF成正比，而对于SA-HTP，未观察到明显的趋势。在SF 4.8下进行的A-HTP具有最佳的酶消化率（80％以上）。在SF 3.8和190°C和205°C的温度下，A-HTP可获得最高的葡萄糖和木糖（主要糖）总产量。酿酒酵母对预处理液的发酵能力SA-HTP低于A-HTP。研究表明，无需添加硫酸即可对甘蔗渣进行水热预处理，且效果良好，但条件必须足够苛刻，以至于几乎可以定量溶解半纤维素。