Features of using the landgem model to determine methane emissions from municipal solid waste disposal sites

Abstract

This article focuses on the current scientific and practical area of estimating and forecasting the production of biogas and its components, in particular methane, from municipal solid waste disposal sites. Despite a significant number of scientific studies and developed models for assessing methane generation from waste disposal sites, there are many uncertainties in the tasks of theoretical modelling and assessment of its generation. The results presented reveal the specific features of applying one of the models for calculating methane generation, the Landfill Gas Emission Model, developed by the US Environmental Protection Agency. The aim of the study is to assess the applicability of the model for estimating the generation of methane and other biogas components from landfills and waste disposal sites in Ukraine. The other methane generation models – the National Multi-Component Model based on the third-level detail decay method and the IPCC Waste Model – are also used in the study, as well as methods for the statistical analysis of results. The main results of the study consist in identifying the specific features of applying the Landfill Gas Emission Model to address the task of inventorying emissions of methane and other biogas components from Ukrainian landfills and dumps. The parameters of the calculation model that most closely approximate national conditions have been determined, namely: a methane generation constant of 0.098 year⁻¹, corresponding to conditions of rapid waste decomposition; and a content of biodegradable organic carbon at a level of 0.24 MgC/Mg of waste.
It is necessary to take into account the landfill conditions (0.729) and the methane burn-off factor (0.8) to ensure the results as accurate as possible; however, applying these conditions does not guarantee complete consistency between results obtained using different methodologies. Thus, the total methane emissions over 50 years from the annual mass of landfilled municipal waste, calculated using the Landfill Gas Emission Model, will be 37% higher than those calculated using the National Model. Further adaptation of the model’s results is promising, as is the application of the Landfill Gas Emission Model principles for determining other biogas components within the framework of the National Model. The scientific and practical significance of this study lies in the validation of the components of the Landfill Gas Emission Model for the most accurate application in Ukraine.