Coupled Fluid-Dynamics and Population-Balance Kinetic Models for Enzymatic Hydrolysis of Biomass

A population-balance kinetic model developed previously for the enzymatic hydrolysis of lignocellulosic biomass is extended to include fluid mixing and transport.  The kinetic model is focused on the depolymerization of insoluble cellulose chains by an endoglucanase and an exoglucanase. Population-balance models combined with a continuous-distribution representation provide computational efficiency, which is critical when considering the addition of fluid-mixing effects.  The resulting coupled equations are solved with a high-order open-source computational fluid dynamics (CFD) package.  The CFD model is validated against experimental and analytical data for a simple vane mixer.  Preliminary results examining the effects of fluid mixing on dilute enzymatic hydrolysis are presented and compared to existing experimental data.  This work provides a foundation for future efforts to model pilot- and commercial-scale bioconversion-reactors.