Elevated Temperature Landfill Reactions and Triggering Mechanisms

Municipal solid waste landfill (MSW) waste composition is mostly compromised of biogenic materials, such as wood, paper, and food waste, but also contains plastics, metals, and synthetic textiles. Biogenic materials in a normally operating landfills decompose in an oxygen-free environment and produce landfill gas that is approximately 50% methane and 50% carbon dioxide at temperatures between approximately 35 and 55˚C. However, in the last decade, there have been reports of landfills reaching 80 to 100 ˚C, which are referred to as Elevated Temperature Landfills (ETLFs). The increased temperature in an ELTF is typically accompanied by an increase in the ratio of carbon dioxide composition in landfill gas and rapid subsidence of MSW cells. Rapid subsidence can damage landfill cover systems and gas collection wells, creating significant cost for operators and cause environmental concerns. Better understanding of the phenomenon is needed to assist operators in reducing the risk of ETLF occurrence.

This study will seek to better understand the reactions involved in ETLFs and possible triggering mechanisms of ELTF conditions. A laboratory reactor vessel will be used to study the various pressure, temperature, and stress conditions of a typical MSW sample to observe ETLF conditions. This will be coupled with metaphysical modelling of MSW landfills to simulate ETLF reactions to better understand possible triggering mechanisms.