Dependency of landfill gas generation parameters on waste composition based on large-size laboratory degradation experiments

Abstract

Landfill gas (LFG) is a product of the biodegradation of municipal solid waste (MSW) under anaerobic conditions. LFG primarily consists of methane (CH 4 ) (40–60%) and carbon dioxide (CO 2 ) (40–60%), both greenhouse gases. Methane has high energy potential that remains largely untapped as a national energy source. In order to recover LFG for energy generation purposes, a reliable estimate of gas generation at landfill sites is necessary. To that end, numerous LFG generation models have been developed with different assumptions made. In this study, three gas generation models – two first order decay (LandGEM and IPCC) and one sigmoidal model (Modified-Gompertz) are considered. The cumulative methane yield prediction of these models is fitted against three degradation experiments on well-characterized MSW specimens with significantly different waste composition ranging from “waste-rich” to “soil-rich”. The results indicate that the sigmoidal model better captures the evolution of methane yield compared to first order decay model and majority of the model parameters follow a systematic trend as a function of waste composition.