Mathematical modeling of the enzymatic hydrolysis process of sugarcane bagasse

Author(s)

João Moreira Neto

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2016-01-06

Examining board members

Aline Carvalho da Costa; Rubens Maciel Filho; Reginaldo Guirardello; Charles Dayan Farias de Jesus; Edvaldo Rodrigo de Morais

• Advisor: Aline Carvalho da Costa

Abstract

The goal of this work is the development and validation of a kinetic model to predict the enzymatic hydrolysis of sugarcane bagasse subjected to the hydrothermal (HB) and organosolv (OB) pretreatments. The phenomena of cellulase and ?-glucosidase enzymes adsorption on HB and OB, as well as enzyme inhibition by sugars were considered in the kinetic model. Adsorption results showed no significant adsorption of ?-glucosidase on cellulose and lignin. Increasing solids concentration had no impact on the adsorption of cellulase on the different biomasses if stirring rates higher than150 rpm are used and the adsorption equilibrium time was about 2 hours for HB and OB. Adsorption of cellulase on HB and OB samples collected at different hydrolysis times showed that the maximum enzyme adsorption on the substrate decreased during the reaction. The Lineweaver-Burk plots corresponding to the initial velocity assays have shown that the inhibition mechanism of ?-glucosidase by glucose and the inhibition mechanism of cellulase by glucose and xylose are both competitive. The simultaneous estimation of kinetic parameters of the model was performed using the PIKAIA genetic algorithm. The data used in the parameters estimation procedure and validation of the model were profiles of cellulose, cellobiose, glucose and xylose obtained from the enzymatic hydrolysis batch process with variation in the concentration of solids (4, 6, 8, 10, 12 and 15% w/v). The fitted model was able to predict accurately the set of experimental data of HB and OB (AU)

• FAPESP's process: 11/02743-5 - Mathematical modelling and optimization of the sugarcane bagasse hydrolysis process in fed-batch mode
• Grantee: João Moreira Neto
• Support Opportunities: Scholarships in Brazil - Doctorate