Co-generation potentials of municipal solid waste landfills in Serbia

Abstract

Waste management in Serbia is based on landfilling. As a result of many years of practice, a large number of municipal waste landfills has been created where landfill gas has been generated. Landfill gas, which is essentially methane (50- 55%), and CO2 (40-45%) (both green-house gases), have a great environmental impact which can be reduced by using landfill gas in cogeneration plants to produce energy. The aim of this paper is to determine economic and environmental benefits from such energy production. For that purpose, the database of cogeneration potentials of 51 landfills in Serbia was created. Amount of landfill gas generated at each municipal landfill was calculated by applying a first order decay equation which requires the data about solid waste production and composition and about some landfill characteristics. For all landfills, which have over 100,000 m3 each, a techno-economic analysis about building a combined heat and power plant was conducted. The results have shown, that the total investment in 14 combined heat and power plants with payback period of less than 7 years amounts 11,721,288 €. The total nominal power of these plants is 7 MW of electrical power and 7.9 MW of thermal power, and an average payback period is about 61 months. In addition, using landfill biogas as energy source in proposed plants would reduce methane emission for 161,000 tons of CO2 equivalent per year.