Study of the energy potential of the biogas produced by an urban waste landfill in Southern Spain

Sanitary landfills have been and continue to be one of the most common ways to dispose of urban waste although such landfills inevitably generate waste management problems. Landfills are an important source of anthropogenic CH4 emissions. In this sense the European Union has passed regulations regarding the effective management of biogas within the framework of an EU policy for renewable energies. The sealed landfill analyzed in this study is an example of energy recovery, but in this case the biogas generated by the landfill is being re-used to produce electrical energy. This article presents the results of the economic viability study, which was carried out previous to the construction of the installation. The results based on the use of empirical and theoretical models show the biogas to have a 45% proportion of methane and an overall flowrate ranging from 250 to 550 N m3/h. It is presently being used to produce electricity amounting to approximately 4,500, 000 kW h/year. The economic viability of the installation was estimated by means of the Internal Recovery Rate (IRR) for an exploitation period of 7 years.