Optimización de la producción de biomasa en procesos fermentativos del mucílago de cacao CCN – 51 aplicando la ecuación logística integrada y el modelo de Andrew y Levenspiel, bajo diferentes condiciones de operación

Abstract

The main objective of this study was: optimize the variables involved in the biomass production process from cocoa mucilage CCN – 51 in batch ethanol fermentation with S. cerevisiae; and from optimum results perform kinetic modeling through integrated logistic equation and Andrew and Levenspiel model. The operating conditions were determined by factorial design with two levels and three variables (23): temperature, pH and yeast’s concentration. Fermentations were performed in a stirred tank bioreactor further biomass was quantified by the method of dry weight. Later models to experimental data were adjusted, minimizing the discrepancy between model predictions and experimental, corresponding to the optimum operating conditions data, using MATLAB (Version 8.3). The results of temperature, pH and optimum concentration of yeast were 35 °C, 4 and 3 g/L respectively, with a final concentration of biomass 90,9880 g/L were obtained after 34,5 hours of fermentation. The logistic model described yeast growth depending on the initial concentration of biomass, fermentation time, the specific growth rate and maximum final biomass concentration; while the Andrew and Levenspiel model represented limitation and substrate inhibition and ethanol inhibition. The results showed that the models satisfactorily fit the experimental data (R2>0,90), proving be suitable for process modeling.