Modelamiento de la producción de bioetanol a partir de la holocelulosa obtenida mediante refinamiento catalítico de cáscara de cacao y su posterior hidrólisis enzimática y fermentación alcohólica

Abstract

In this study, a process was developed for the production of bioethanol from holocellulose extracted from cacao husk (Theobroma cacao L.), employing a catalytic pretreatment based on the Lignin-First approach, followed by enzymatic hydrolysis and alcoholic fermentation. The main objective was to evaluate the efficiency of catalytic refinement in sugar conversion and to optimize the enzymatic hydrolysis conditions. Three experimental runs were carried out using different concentrations of cellulases from Trichoderma reesei (Celluclast) (0.1, 0.2, and 0.3 mL/g) and hemicellulases from Aspergillus niger H2125 (0.1 and 0.3 g/g). The highest sugar release was achieved at the highest enzyme concentrations, reaching 489.967 mg/g, while the fermentation efficiency was 88.62%, resulting in a bioethanol yield of 3.36 g/L, equivalent to 112 g/kg of dry biomass. Although no significant differences in sugar release were observed compared to non-catalyzed samples during the hydrolysis stage, the catalytic treatment significantly enhanced the fermentability of the substrate. Furthermore, the kinetic behavior of the fermentation process was modeled using the modified Gompertz equation, yielding a determination coefficient (R2) of 0.97, thus validating the consistency between the experimental data and the simulation performed in MATLAB. The results confirm that catalytic pretreatment is a viable strategy to increase the efficiency of bioethanol production from lignocellulosic biomass; however, further optimization is recommended to reduce losses and minimize the formation of inhibitory compounds.