Acid hydrolysis of wheat straw: A kinetic study

Abstract

Biotechnological xylitol production can be enhanced if the needed xylose solutions can be obtained from hydrolysis of low-cost lignocellulosic wastes. The hydrolysis of wheat straw 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 wheat straw by sulphuric acid hydrolysis at 130 degrees C. Several mass fraction of acid (1, 2, 3, 4 or 5\%) were evaluated. Kinetic models were developed to explain the variation with time of xylose, glucose, arabinose, furfural, 5-(hydroxymethyl)-2-furaldehyde and acetic acid in the hydrolysates. Optimal conditions found were a H2SO4 mass fraction of 2\% at 130 degrees C for 29 min, which yielded a solution with xylose, 18.9 kg m (3); glucose, 3.5 kg m (3); arabinose, 3.1 kg m(-3); furfural, 0.6 kg m(-3); 5-(hydroxymethyl)-2-furaldehyde, 0.3 kg m (3) and acetic acid, 2.3 kg m(-3). In these conditions, 99\% of the hemi-celluloses and 11\% of the glucan were hydrolysed. (C) 2011 Elsevier Ltd. All rights reserved.