Acid hydrolysis of corn stover using hydrochloric acid: Kinetic modeling and statistical optimization

The hydrolysis of corn stover using hydrochloric acid was studied. The kinetic parameters of the mathematical models for predicting the yields of xylose, glucose, furfural and acetic acid were obtained, and the corresponding xylose generation activation energy of 100 kJ/mol was determined. The characterization of corn stover using different techniques during hydrolysis indicated an effective removal of xylan and slight alterations of the structures of cellulose and lignin. A 2³five-level central composite design (CCD) was used to develop a statistical model for the optimization of process variables including acid concentration, pretreatment temperature and time. The optimum conditions determined by this model were found to be 108 C for 80 min with acid concentration of 5.8%. Under these conditions, the maximised results were the following: xylose 19.93 g/L, glucose 1.2 g/L, furfural 1.5 g/L and acetic acid 1.3 g/L. The validation of the model indicated good agreement between the experimental results and the predicted values.