Kinetic study on the dilute acid catalyzed hydrolysis of waste mushroom medium

In this study, kinetic modeling for the acid hydrolysis of waste mushroom medium was investigated. Sulfuric and oxalic acid were used as catalyst, under 140-160 degrees C at 50 mM acid concentration for 80 min. Glucose was the most abundant sugar in the hydrolysate for both acid catalysts. The production of glucose and xylose increased in proportion to reaction time until 150 degrees C. However, the sugar concentration increased in the initial stages at 160 degrees C and it has not increased after 10 min of reaction time, due to the degradation of sugars to furfural and 5-hydroxymethylfurfural (HMF) at high temperature and long reaction time. The activation energies for the degradation of xylan and glucan to xylose and glucose on oxalic acid catalyst were 59.1 and 38.7 kJ/mol, respectively, which were lower values than that of sulfuric acid. The degradation reactions of xylose (105.4 kJ/mol) and glucose (128.2 kJ/mol) to furfural and HMF have high activation energies, compared to those of xylan (69.1 kJ/mol) and glucan (50.0 kJ/mol) degradation on sulfuric acid catalyst. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.