Effects of operational conditions on auto-catalyzed and sulfuric-acid-catalyzed hydrothermal pretreatment of sugarcane bagasse at different severity factor

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