ASABE Technical Library - Abstract

Abstract.The conversion of lignocellulosic biomass to bioethanol is impacted by several uncertainties, necessitating their systematic consideration for robust process design, optimization, and control. This work includes stochastic analysis of biomass pre-treatment followed by enzymatic hydrolysis. An integrated stochastic kinetic model of acid pre-treatment in batch mode was developed up to 300 minutes batch time. The output composition of the prescribed model is used to perform the stochastic analysis of enzymatic hydrolysis. Stochastic simulations were performed by considering variability in feedstock composition, model kinetic parameters, and operational parameters for both processes individually. The results showed that output concentration profiles varied significantly due to these uncertainties with potential impact on optimal batch time. Subsequently, global sensitivity analysis for these uncertain parameters was performed for acid pre-treatment. The results identified cellulose and xylan fractions to be important for sugar yield, and could be used to optimize input biomass composition. The analysis on kinetic parameters identified reaction activation energies to be important, and analysis on the operating parameters identified temperature as the most important parameter for optimization or control.