Methane emission quantification from municipal waste landfills: models and computer software-a case study of Long An Province, Vietnam

Abstract

Vietnam has been one of the nations strongly affected by climate change; hence, finding and promoting solutions in order to adapt and proactively respond to climate change have played an extremely significant role. A strategy of developing a low-carbon economy with eco-friendly production and consumption models, limiting the use of fossil fuels, and rising clean as well as renewable energy have been built with the aim to reduce total greenhouse gas (GHG) emissions by roughly 8% by the year 2030 compared to the business-as-usual (BAU) scenario under the Paris Agreement 2015, in particular, focusing on producing a plan to drop considerably methane (CH₄) emission and recover energy from landfill sites as the waste sector has been the third-highest GHG contributor in Vietnam. This study concentrates on forecasting and evaluating CH₄, CO, H₂S, and CH₃SH emissions for a case study in the Mekong Delta region of Vietnam: in specific, two dumping sites of Thanh Hoa and Kien Tuong according to four different scenarios so that the landfill gas (LFG) emissions are controlled under the local authority orientation of installing a gas collection system and treating captured gases by an LFG flaring approach from 2021 to 2030. Quantification of the generated LFG is carried out using a mathematical modeling method having validation with field measured data, which is a WebGIS software named EnLandFill with integrated mathematical models, environmental information, and databases allowing analysis of the main influence of two L₀ and k factors on LFG emission levels. On the one hand, based on the development planning of Long An province from 2021 to 2030, the municipal solid waste (MSW) volume is estimated at around 3.5 million tonnes and the potential waste generation index is predicted between 0.7 and 1.2 kg person^-1 day^-1. A large amount of CH₄ emissions are considered to be a remarkable contributor to GHG emissions. It can be seen that there are about 32.1-253.6 million m³ CH₄ (or equivalent to 512-589 thousand tCO₂-eq) and 1.0-5.1 million m³ CH₄ (or equivalent to 16-81 thousand tCO2-eq) created at Thanh Hoa and Kien Tuong dumping sites, respectively, under the established scenarios in the 2021-2030 period. On the other hand, the proposal of scenario 4 is found to be the optimal solution for GHG emission control and decline from this study area in the next years. Furthermore, the obtained study outcomes are considered as a basis for planning and managing the issues of MSW in Long An province until 2050 towards a circular economy.

Keywords: Dispersion; Landfill; Methane emission; Model; Municipal solid waste.