Temporal exergy analysis in fed-batch enzymatic hydrolysis: Assessing irreversibilities and sustainability in lignocellulosic biomass conversion

Abstract

Although not yet widely industrialized, biofuels from lignocellulosic biomass show promise in enhancing industrial sustainability, with potential for a reduced carbon footprint and alignment with renewable energy goals. In this context, enzymatic hydrolysis assumes a fundamental position, being essential to make these biofuels viable. This study investigates the performance and thermodynamic sustainability of enzymatic hydrolysis in a fed-batch bioreactor, employing exergy analysis. The total exergy potential available to the system was 1239.93 kJ, with 30% of this exergy being destroyed at the end of the operation. The system achieved an overall exergy efficiency of 70.04%, while the rational efficiency reached 37.33% at the end of the process. Furthermore, the process sustainability indicator (PSI) reached a value of 1.67 and the system achieved a value for thermodynamic sustainability of 3.34. This study provides insights into the optimization of enzymatic hydrolysis processes, focusing on the reduction of irreversibilities, the improvement of exergy efficiency, and the enhancement of sustainability.