Biogas modeling for the analysis of its exploitability in a MSW sanitary landfill

An existing biogas generation model was modified to take into account the influence of the temperature field that normally is established within each layer of waste and that controls, in its turn, the biodegradation kinetics of waste. The model was applied to a municipal landfill in the North of Italy, in order to calculate an estimation of the potential biogas productivity and assess the feasibility of its exploitation for energy purposes. Moisture is the most important factor influencing the biodegradation rate of the waste. Information about the initial water content was obtained from data regarding the waste composition, but no additional information about the hydrological balance was available. Therefore, on the basis of several studies, 9 sets of kinetic constants were adopted for the simulation of scenarios. The calculated maximal hourly biogas flows on yearly average showed a large variability, with repercussions on the maximal collectable volume during the operating period of a hypothetical generator and, hence, on the cost-benefit balance of biogas exploitation.