Abstract:
This paper examines landfill gas (LFG) emissions at a large inactive waste disposal site to evaluate the viability of investment in LFG recovery through the clean development mechanism (CDM) initiative. For this purpose, field measurements of LFG emissions were conducted and the data were processed by geospatial interpolation to estimate an equivalent site emission rate which was used to calibrate and apply two LFG prediction models to forecast LFG emissions at the site. The mean CH4 flux values calculated through tessellation, inverse distance weighing and kriging were 0.188±0.014, 0.224±0.012 and 0.237±0.008lCH4-m2hr, respectively, compared to an arithmetic mean of 0.24l-m2hr. The flux values are within the reported range for closed landfills (0.06-0.89l-m2hr), and lower than the reported range for active landfills (0.42-2.46l-m2hr). Simulation results matched field measurements for low methane generation potential (L0) values in the range of 19.8-102.6m3-ton of waste. LFG generation dropped rapidly to half its peak level only 4yrs after landfill closure limiting the sustainability of LFG recovery systems in similar contexts and raising into doubt promoted CDM initiatives for similar waste. © 2012 Elsevier Ltd.