Optimization of the second-generation ethanol production process using simultaneous saccharification and fermentation from mixtures of lignocellulosic residues

• Autor(a) principal: Sánchez Acosta, Deyanira Nohely
• Data de Publicação: 2022
• Outros Autores: Villavicencio Vera, Lezzie Valeria, Andrade Díaz, Christhel, Rosero Delgado, Ernesto Alonso
• Tipo de documento: Artigo
• Idioma: spa
• Título da fonte: Sapienza (Curitiba)
• Texto Completo: https://journals.sapienzaeditorial.com/index.php/SIJIS/article/view/510
• topic: Lignocelulose, sacarificação e fermentação simultânea, otimização, etanol de segunda geração; Lignocellulose, saccharification and simultaneous fermentation, optimization, second generation ethanol; Lignocelulosa, sacarificación y fermentación simultánea, optimización, etanol de segunda generación

Ecuador is positioned as the first exporter of fine aroma cocoa, representing more than 62% of the world production of this fruit, which favors an abundant availability of recoverable residues from this plant. The lignocellulosic composition of these residues gives them the ability to be processed and transformed into bioethanol. In this research, cocoa shell, stem and leaf residues were conditioned (dried and powdered) and subjected to a simultaneous saccharification and fermentation process for the production of second-generation bioethanol. The conditioned biomass was subjected to a pretreatment of alkaline hydrolysis (3% NaOH) with steam explosion at 121ºC for 90 min at 1 atm. The hydrolyzed biomass was subjected to an enzymatic hydrolysis process using the cellulase enzyme from Aspergillus niger from Sigma Aldrich and Safale S-04 yeast was used simultaneously for the fermentation of sugars to bioethanol. The treated samples were filtered and centrifuged and the alcohol content was quantified by gas chromatography. Simultaneous saccharification and fermentation conditions were optimized through a multilevel factorial design, using the response surface methodology. The design included nine base runs (all in triplicate), where three enzyme concentrations (5, 15 and 25 FPU/g) were evaluated for the five grams of initial load of dry solid material (DSM) and three temperatures (27, 37 and 47°C). The maximum production of bioethanol (0.00240 μL/g) was reached with the optimal conditions of 23.5 FPU and 31.7 °C. A final run was carried out using the optimal conditions for a higher biomass load (20 g), reaching a maximum concentration of second-generation bioethanol of 0.11 mL/L.