Modelling the methane generation potential and decay constant for a tropical landfill

This study modelled the methane (CH4) generation for a landfill in a tropical climate in Brazil, adjusting the values of the parameters of methane generation potential (L-o) and decay constant (k), using the Intergovernmental Panel on Climate Change numerical model and LandGEM and Biogas (CETESB) software. Adopting published data from cell 6 (C6) of the Metropolitan Center Sanitary Landfill, 15 combinations of k and L-o were carried out to determine the range of values that best represented the generation of methane. The results of the study allowed to conclude that values of k between 0.1 and 0.15 year, and L-o between 60 and 70 m(3)/t, resulted in simulations with good capacity to predict methane for the chosen landfill, obtaining errors lower than 30%. Furthermore, these intervals identified a better representation of methane generation for values of k equal to 0.15/year and L-o equal to 60 m(3)/t. This combination showed estimation errors smaller than 6% when compared to methane measured at C6 between 2004 and 2009, showing the importance of having experimental values of k and L-o to adjust the simulations and calibrate the used tools.