The impact of landfill operation factors on improving biogas generation in Brazil

The systems for recovering energy from biogas in landfills represent a solution for solid waste treatment and the growing demand for renewable energy. However, landfill biogas recovery in Brazil is not efficient considering that the impact of the operational factors is unknown. To cope with this problem, this study presents a model to measure the impact of the various factors of landfills in the production of biogas. The study focused on improving the generation of methane. The modelling of the impact factors was supported by the Analytic Hierarchy Process (AHP), which was employed to build the strategic map of the cause-and-effect relationship between the factors and the biodegradation. To complement the diagnostic, the performance of biogas companies was evaluated using the Key Performance Indicators (KPI). The results showed that the operational factor that most impacted the methane generation system was the coating process (23.8%), followed by the gas drainage (23.3%) and liquid management (19.6%). On the other hand, site characteristics such as landfill extension and depth had the lowest impact, about five times smaller than that of the coating system. Meanwhile, the factors that most impacted the biodegradation were the moisture content and the fraction of organic carbon. Combined, these two factors had an impact of nearly 40% on the biodegradation process. One of the companies evaluated presented a fully satisfactory performance (80.6%), while the others achieved potentially satisfactory performance concerning the level of achievement of the operational factors. The difference among the companies’ performance was found up to 12.5%. •Coating system was the operational factor that most impact biogas generation.•Moisture content had the greatest impact on the biodegradation of solid waste.•The site characteristics represented the least impact on biogas generation.•The factors with greatest impact can be changed daily in the landfill operation.