Numerical simulation of enzymatic hydrolysis in a bionic intestinal segmentation reactor

Abstract

Enzymatic hydrolysis plays a critical role in the microbial conversion of lignocellulosic biomass, which has been widely performed in continuous stirred-tank reactors (CSTRs). However, low hydrolysis efficiency in CSTRs hinders the industrial application of lignocellulose to produce biofuels. A bionic intestinal segmentation reactor (BISR) was proposed for efficient enzymatic hydrolysis. In BISR, the dynamic reactor's wall with enzyme secretion led to a 2.0-fold improvement in the conversion of cellobiose as a model substrate compared to the control with a static one. Meanwhile, the reaction rate reached 0.89 mmol/l/s, which was increased by 6.7-fold. Flow fields further illustrated that secondary flow during the segmentation facilitated radial mass transfer between cellobiose and enzyme. Dimensionless secondary flow intensity Sem increased from 0.93 to 2.35 with amplitude, while decreasing from 2.86 to 2.26 with period. More importantly, the analysis of dimensionless Péclet number (Pe) and Damköhler number (Da) indicated that secondary flow could significantly enhance the hydrolysis process controlled by mass transfer.