Kinetic model for glycan hydrolysis and formation of monosaccharides during dilute acid hydrolysis of sugarcane bagasse.

Sugarcane bagasse was hydrolyzed with 0.4-5 wt.% sulfuric acid at 97-126 °C. A novel kinetic model was proposed to describe glycan solubilization and formation of monosaccharides. Based on the multilayered structure of plant cell wall, the concept of "potential hydrolysis degree" (h(d))" was introduced into kinetic models for the hydrolysis of biomass glycans. It was found that during xylan hydrolysis, xylo-oligomers were apparently present in the liquid phase, particularly at low temperature. Therefore, to accurately determine the rate constants of xylan hydrolysis, residual xylan content in the solid phase, xylo-oligomers and xylose concentrations in liquid phase should be measured. Similarly, the concept of "potential hydrolysis degree" was applicable for araban and cellulose hydrolysis. The kinetic relationships between rate constant or h(d) and reaction severity (dilute acid concentration and temperature) were determined according to experimental data. The results showed that the model was reliable (determination coefficients (R(2)) in the range of 0.95-0.995) to describe the kinetic behavior of dilute acid hydrolysis of sugarcane bagasse.