The acid hydrolysis of sugarcane bagasse hemicellulose to produce xylose, arabinose, glucose and other products

Experimental trials of the dilute acid hydrolysis of bagasse hemicellulose to produce xylose, arabinose, glucose, acid-soluble lignin (ASL) and furfural were conducted using a temperature-controlled digester. The reaction conditions varied were; temperature (80-200degreesC), mass ratio of solid to liquid (1:5-1:20), type of bagasse material (i.e. bagasse or bagacillo), concentration of acid (0.25-8 wt% of liquid), type of acid (hydrochloric or sulphuric) and reaction time (10-2000 min). Kinetic modelling of the global rates of formation of products was performed. The most accurate kinetic model of the global reaction for the decomposition of xylan was a simple series hydrolysis of xylan to xylose followed by xylose decomposition. Similar schemes were used to model the production of arabinose, glucose and furfural from the hemicellulose. The production of ASL was modelled by a first-order decomposition of lignin to ASL followed by a reversible decomposition of ASL. Yields of up to 220 mg xylose/g solid were achieved, i.e. about 80% of the theoretical xylose available from the bagasse. The bagasse particle size was found to negligibly affect the rate of hydrolysis. Hydrochloric acid was found to be less active for the degradation of xylose compared to sulphuric acid. (C) 2002 Elsevier Science Ltd. All rights reserved.