Bioresource Technology, Vol.250, 197-203, 2018
Kinetic and thermodynamic analysis of dilute acid hydrolysis of sugarcane bagasse
This study has investigated kinetic and thermodynamic features of dilute acid (2% v/v H2SO4, 1: 30 w/v) hydrolysis of sugarcane bagasse. Time profiles of xylose formation in range of 100 degrees-130 degrees C and treatment period of 0-120 min have been analysed with modified biphasic Saeman model. Generation of glucose, arabinose and inhibitory products (furfural, 5-HMF and acetic acid) have also been analysed. Easy-to-hydrolyse fraction of hemicellulose increased with temperature. Activation energies for hydrolysis and xylose degradation were 60.3 and 83.4 kJ/mol, respectively. Although maximum xylose yield (0.81 g/g hemicellulose) was obtained at 130 degrees C, significant fraction of xylose was converted to inhibitory products. Thermodynamic analysis revealed Delta H=57.06 kJ/mol and Delta S=-1.05 kJ/mol for hydrolysis. Moreover, xylose formation is thermodynamically more favoured (Delta G=468.53 kJ/mol) than degradation (Delta G=482.17 kJ/mol). Optimum conditions for hydrolysis are: temperature=120 degrees C, time=30 min, xylose yield=0.76 g/g hemicellulose.