A comparison of greenhouse gas emissions and potential electricity recovery from conventional and bioreactor landfills

As methane constitutes about 50% of landfill biogas, reduction of methane emissions from municipal solid waste (MSW) landfills results in climate change mitigation. As such, it is important for a landfill lifetime model to properly reflect the manner in which biogas is managed. The goal of this research is to compare landfill biogas management in a conventional landfill with a bioreactor landfill during a 100-year time horizon. This comparison concentrates on the greenhouse gas (GHG) emissions balances and electricity generation potential from recovered biogas using reciprocating internal combustion engines (RICE), which leads to avoiding GHG emissions due to fossil fuel displacement. The results estimated that the total amount of GHG emissions released to atmosphere, including fugitive methane emissions and the avoided effect of electrical energy production, was 668 and 803 kg carbon dioxide (CO2) equivalents (CO2E) per metric ton (t) of landfilled MSW for the conventional and the bioreactor landfill, respectively. This study underscores the importance of installing an aggressive gas collection system early for bioreactor landfills, and for investigating methods of improving gas collection efficiency during active landfilling.