Study of high solid loading enzymatic hydrolysis of sodium bisulphite pretreated corncob residue and kinetic modeling.

In this study, sodium bisulfite (NaHSO3) pretreatment was employed to overcome the limitations of corncob residue in high solid loading enzymatic hydrolysis by introducing hydrophilic sulfonic acid groups (-SO3H) into lignin aromatic rings via sulfonation reactions, which significantly enhanced substrate accessibility. Furthermore, to enhance the precision of glucose concentration prediction during high solid loading enzymatic hydrolysis of NaHSO3 pretreated corncob residue, we developed a novel kinetic model. It introduced a substrate characteristic parameter (b) and revised the traditional fractal parameters h and k. This model demonstrated noteworthy prediction capabilities across a broad spectrum of solid loadings (2%-24%), enzyme dose gradients (5-20 FPU/g), and shaking speeds (100-200 rpm). Compared with the traditional fractal model, it not only achieved a higher R2 (>0.9927) but also reduced the prediction error substantially, especially under high solid loading conditions. A variety of lignocellulosic biomasses were pretreated using NaHSO3, NaOH/H2O and NaOH/ethanol, and the model predicted glucose concentration in these pretreated solids with a high degree of accuracy. The findings demonstrated that the model was a valuable instrument for the precise control of lignocellulosic biorefinery processes, thereby enhancing the controllability and economic efficiency of high solid loading enzymatic processes.