Mathematical Modeling of the Kinetics of Glucose Production by Batch Enzymatic Hydrolysis from Algal Biomass

Abstract

The processing of Kappaphycus alvarezii algae to obtain carrageenan (polysaccharide) generates a residue composed mainly of glucans and galactans that can be converted to monosaccharides, making these algae a renewable feedstock that can be used to produce biofuels. This residue was subjected to batch enzyme hydrolysis with different commercial enzymatic cocktails, achieving, after 72 h of reaction time, a complete conversion of glucan to glucose for all the cocktails used. A simple mathematical model, based on a semi-empirical approach, was proposed to describe the behavior of the experimental data. The temporal profile of glucose concentration was obtained by direct analytical integration of the mathematical model, resulting in an explicit equation as a time function. Estimation of the model parameters was carried out by non-linear regression, using the least squares criterion, together with the Levenberg–Marquardt method. The quality of the model fit was evaluated by specific statistical criteria, including Fisher’s F test, the R2 value, and the p-value test. The accuracy of the model was considered acceptable (p-value < 0.05 and R2 ≥ 0.98), enabling its use in subsequent studies aimed at improving the enzymatic hydrolysis process under similar experimental conditions.