Hydrolysis of sugarcane bagasse in subcritical water

Abstract

In this work, a subcritical water process was used for the hydrolysis of sugarcane bagasse with the aim of producing fermentable sugars. Hydrolysis kinetics was determined using a semi-batch unit equipped with a 50mL reactor. Different sample loads (2 and 11g), flow-rates (11, 22, 33, 44 and 55mL/min) and temperatures (213, 251 and 290°C) were evaluated, while maintaining constant pressure (20MPa). The liquefaction degree of the sugarcane bagasse was not affected by water flow rate and increased with temperature; the maximum liquefaction degree was 95% for hydrolysis at 251°C and 33mL/min. The total reducing sugars recovered increased with flow rate up to 23%. The hydrolysis process was completed faster at higher temperatures, requiring 16min. Maximum monosaccharides+cellobiose+cellotriose yield was 5.6% at 213°C and 33mL/min. Approximately 60% of the sugars recovered were in the oligomeric form.