Anaerobic digestion of municipal solid waste produced by the city of Algiers using life cycle assessment

Abstract

This study analyses the life cycle assessment of anaerobic digestion process of municipal solid waste management (MSWM) produced by Algiers city. Some keys parameters of the processes are then modified to analyze the "hot spots" and perform a sensitivity analysis to identify their influence on the results. Data for the inventory came from actual city facilities, and background process information came from Eco invent version 3.1 of SimaPro 8.1 software. The analyzed process contribution indicates that the global warming potential is affected by the anaerobic digestion because of the NOx and CO emissions from the thermal processes of biogas burning and fuel oil combustion for digesters heating. Furthermore, plastics recycling is environmentally beneficial because of net savings. The energy valorization of biogas produces the least amount of environmental damage, eliminating 403.06 kg CO2 eq/ton of waste, saving 18.2 E+09 MJ/ton of fossil fuels, and producing 2.8 E+08 kWhel/year, or 6% of the city's annual electricity consumption.