Mathematical modeling of batch bioethanol generation from carob extract in the suspended-cell stirred-tank bioreactor

In this study, various functions were evaluated and utilized to forecast observed values and kinetic parameters of the batch ethanol fabrication from carob extract in the suspended-cell stirred tank reactor (SCSTR). The best model was detected with the model comparison parameters (root-mean-square-error [RMSE], mean-absolute-error [MAE], and R²). The results indicated that the model Stannard (ST) successfully predicted biomass production data (RMSE = 0.26 g L⁻¹, MAE = 0.18 g L⁻¹, and R² = 0.9910), ethanol fabrication data (RMSE = 2.44 g L⁻¹, MAE = 1.88 g L⁻¹, and R² = 0.9809), and sugar depletion data (RMSE = 2.82 g L⁻¹, MAE = 2.17 g L⁻¹ and R² = 0.9938). Nevertheless, the lowest value of the objective function (Φ-factor) was also yielded as 0.041 using the model ST. Additionally, in the estimation of the kinetic data, the model ST also gave well-directed results. Besides, when an independent set of the observed values was utilized to confirm the mathematical functions, the satisfactory consequences were achieved in terms of both the experimental and kinetic values. Consequently, the model ST can work as a universal function in predicting observed values and kinetics of batch ethanol generation from carob extract in an SCSTR.