Optimization of the Enzymatic Hydrolysis of Brewer’s Spent Grain Aiming at the Production of Second-Generation Ethanol
DOI:
https://doi.org/10.5281/zenodo.22949592Palavras-chave:
Enzymatic Hydrolysis, Brewer’s Spent Grain (BSG), Lignocellulosic Biomass, Process Optimization, Acid–Alkaline PretreatmentResumo
Brewer’s spent grain has high potential for application in second-generation bioprocesses due to its lignocellulosic composition. This study investigated optimization strategies for sequential acid–alkaline pretreatment and enzymatic hydrolysis, aiming at the release of fermentable sugars. Pretreatment was evaluated through a central composite rotatable design (CCRD), considering solid content, NaOH concentration, and reaction time. Solid content was identified as the most significant factor for lignin solubilization, reaching up to 5.6 g/L of total phenolics under mild conditions (12.99% solids, 1.95% NaOH, 19.8 min) with minimal sugar loss. Subsequently, another CCRD was conducted for enzymatic hydrolysis as a function of solids, enzyme loading, and time, resulting in a well-fitted model (R² = 93.4%; adj-R² = 84.8%). The optimal condition was predicted at 9.96% solids, 61.3 FPU/g, and 71.7 h, estimating up to 25 g/L of reducing sugars. Experimental validation confirmed the model trend, achieving 19.3 ± 0.8 g/L. These findings demonstrate that integrating sequential pretreatment with enzymatic hydrolysis enhances the conversion of brewer’s spent grain, reinforcing its applicability as a feedstock for bioethanol and other value-added bioproducts.
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