Kinetic study of the acid hydrolysis of sugar cane bagasse

Abstract

Economic interest in xylitol production can be enhanced if the needed xylose solutions can be obtained from the hydrolysis of low-cost lignocellulosic wastes. Sugar cane bagasse is a renewable, cheap and widely available waste in tropical countries. The hydrolysis of sugar cane bagasse to obtain xylose solutions has a double consequence, the elimination of a waste and the generation of a value-added product. The objective of this work was to study the xylose production from sugar cane bagasse by sulphuric acid hydrolysis at several temperatures (100, 122 and 128 °C) and concentrations of acid (2%, 4% and 6%). Kinetic models were developed to explain the variation with time of xylose, glucose, acetic acid and furfural generated in the hydrolysis. Optimal conditions found were 2% H 2SO 4 at 122 °C for 24 min, which yielded a solution with 21.6 g xylose/l, 3 g glucose/l, 0.5 g furfural/l and 3.65 g acetic acid/l. In these conditions, ≈90% of the hemicelluloses was hydrolysed.