Comparison of carbon footprint of different waste treatment systems in Hanoi - Vietnam

Abstract

Municipal solid waste (MSW) treatment requires complex integration of several technologies which is most suitable to handle different material fraction, for example: combustible material, organic fraction, recyclables, etc. Waste material can be utilized more efficiently and contribute to energy production as well. As energy sector is one of major carbon emission producers, Waste-2-Energy potentially can reduce carbon emissions by replacing energy produced from fossil fuel. However, combining technologies for treating MSW is time and financial demanding which lead to difficult decision makings process for investors, operators, and authorities. Selection of most suitable solutions may benefit from application of Life Cycle Assessment and Life Cycle Costing methodologies during developing phase of new waste treatment projects. These two methods produce results that can be linked together via life cycle perspective that providing useful information for decision making process that can be understood and utilized by several stakeholders. This thesis compares the application of anaerobic digestion (AD) in two hypothetical scenarios with the treatment system in Vietnam which landfills the organic fraction of MSW (OFMSW). Two hypothetical scenarios compare the different approaches to produce energy from biogas as electricity via combustion process and biomethane via upgrading process using Pressure Swing Adsorption technology. LCA section focuses on carbon footprint of each system due to information available during the time of this thesis. LCC evaluation based on the expected lifetime of waste treatment project in Vietnam at minimum 30 years. The results of the study indicate that i) application of AD for OFMSW and utilizing biogas and biosoil from digestion process will reduce carbon footprint of waste treatment plant by 16-17%; ii) investment and operational cost of waste treatment plant using AD is significantly higher than current system but revenues also increase and result in net positive cash flow.