Stability analysis of some nonlinear anaerobic digestion models

The paper deals with local asymptotic stability analysis of some mass balance dynamic models (based on one and on two-stage reaction schemes) of the anaerobic digestion (AD) in CSTR. The equilibrium states for models based on one (with Monod, Contois and Haldane shapes for the specific growth rate) and on two-stage (only with Monod shapes for both the specific growth rate of acidogenic and methanogenic bacterial populations) reaction schemes have been determined solving sets of nonlinear algebraic equations using Maples. Their stability has been analyzed systematically, which provides insight and guidance for AD bioreactors design, operation and control.