Enhancing landfill gas recovery

The landfilling of municipal solid waste (MSW) may cause potential environmental impacts like global warming (GW), soil contaminations, and groundwater pollution. The degradation of MSW in anaerobic circumstances generates methane emissions, and can hence contribute the GW. As the GW is nowadays considered as one of the most serious environmental threats, the mitigation of methane emissions should obviously be aimed at on every landfill site where methane generation occurs. In this study, the treatment and utilization options for the generated LFG at case landfills which are located next to each other are examined. The yearly GHG emission balances are estimated for three different gas management scenarios. The first scenario is the combined heat and power (CHP) production with a gas engine. The second scenario is the combination of heat generation for the asphalt production process in the summer and district heat production by a water boiler in the winter. The third scenario is the LFG upgrading to biomethane. The estimation results illustrate that the LFG collection efficiency affects strongly on the magnitudes of GHG emissions. According to the results, the CHP production gives the highest GHG emission savings and is hence recommended as a gas utilization option for case landfills. Furthermore, aspects related to the case landfills' extraction are discussed.