Modelling the potential biogas productivity range from a MSW landfill for its sustainable exploitation

A model of biogas generation was modified and applied to the case of a sanitary landfill in Italy. The modifications considered the role of the temperature field normally established within each layer of waste. It must be pointed out the temperature affects the anaerobic biodegradation kinetics. In order to assess the effect of moisture on the waste biodegradation rate, on the bacteria process and then on the methane production, the model was compared with the LandGEM one. Information on the initial water content came from data concerning waste composition. No additional information about the hydrological balance was available. Thus, nine sets of kinetic constants, derived by literature, were adopted for the simulations. Results showed a significant variability of the maximal hourly biogas flows on a yearly basis, with consequences for the collectable amount during the operating period of a hypothetical engine. The approach is a useful tool to assess the lowest and highest biogas productivity in order to analyze the viability of biogas exploitation for energy purposes. This is useful also in countries that must plan for biogas exploitation from old and new landfills, as a consequence of developments in the waste sector.