Mathematic and Numerical Modeling of Biogas Productionin the Bioreactive Plant for Valorizing Domesctic Waste

Abstract

We consider a bioreactor as a reactive porous environment and we are interested in coupled transfers of mass and energy in order to explain the interactions between physical, thermal and biochemical processes that govern waste biodegradation. A mathematic model, based on the equation of mass conservation, energy equation, Van Genuchten empirical equations and the biological model based on Monod model, was taken to describe the real behavior of bioreactor in the methanogenic anaerobic phase. Monod model takes into account the bacterial activity, the biological behavior and considers the different concentrations of the components. We used the method of dual scan in order to solve the biological equations. Our model might also be used for simulating simultaneously the biological and hydraulic behavior of bioreactor by using the anaerobic degradation model type II coupled with the hydro-thermal model for domestic waste. We note that this mathematic model considers the role of methanogenic biomass in the production of gas, and of heat, and contributes on the best comprehension of processes which take place during the stabilization for domestic waste.