Collection of Thermal Energy Available from a Biogas Plant for Leachate Treatment in an Urban Landfill: A Sicilian Case Study

The landfill of Bellolampo is located in northern Sicily and serves the greater area of Palermo (Sicily). In the recent past, the landfill has been progressively renovated in order to align the waste disposal process with the state-of-the-art technology. During the past years, the site had been equipped with seven biogas engines, fuelled with the biogas produced at the oldest part of the landfill. More recently, another two engines of the same type have been installed for a total of 9 MW electrical power installed at the landfill. The landfill of Bellolampo faces a significant leachate disposal problem. Some 250 m of contaminated leachate are produced daily and transported by ships and trucks to an area about 1000 km away before being treated and disposed. The disposal of this extremely polluting fluid causes significant nuisance in the integrated waste management process and significant disposal expenses (in excess of € 60 per ton of fluid disposed and € 4.5 mln per year). Furthermore, the recent legislation strongly suggests the landfill manager to activate fully integrated systems and 100% landfill auto-sustainability. On the other hand, the above mentioned biogas engines produce a great quantity of unused thermal energy yearly. This study demonstrates that this energy could be effectively and efficiently used to enable the sustainable in-house treatment of the leachate. The treatment is aimed to significantly reduce leachate volume in order to reduce fluid disposal costs. A thorough economical analysis is also performed. The study demonstrates that a medium sized landfill can sustainably and cost-effectively be managed through a fully integrated system thus producing substantial economies.