The role of spatio-temporal effects in anaerobic digestion of solid waste

Abstract

Using methods of mathematical modelling and computer simulation, we study the effect that spatial distribution of material has on the process duration of anaerobic digestion of solid waste. The need for a spatio-temporal model is demonstrated by analysis of the solutions of an ODE model in dependence of model parameters and initial data. The spatio-temporal model is obtained by inclusion of mass transfer processes. This leads to a semi-linear diffusion–reaction system, the transient behavior of which we study numerically. Our focus is on the temporal spreading of so-called methanogenic pockets in bounded domains. These are regions, in which the qualitative behavior of the model solution is different than in their neighborhood.