Power Generation from Landfill Gas and a Case Study

Abstract

Municipal solid waste is a pool of various solid wastes by towns and cities from different types of household activities. All over the world, municipal solid wastes are dumped in permitted landfills. Landfill gas is a mixture of methane and carbon dioxide which is emitted from the dumping sites of municipal wastes. Methane is a flammable toxic greenhouse gas more damaging to the climate than carbon dioxide. Instead of discharging into the atmosphere and becoming a greenhouse gas which is harmful to the environment, methane can be collected in every landfill and used to produce useful energy. This paper outlines the basic procedure for estimation of methane from landfill site. The Landfill Gas Emissions Model (Landgem) is an automated estimation tool with a Microsoft Excel interface which is available from the EPA's Clean Air Technology Center. It can be used to estimate emissions rate of methane from municipal solid waste landfills. Based on the methane emission rate obtained from Landgem output and the heating value of methane, the net heat input available and hence the potential for generation of electric power can be computed. A typical case study on the evaluation of methane emission rate from a landfill site at Namibia and its potential for generation of electric power as well as the cost estimates are presented. It is found that the power plant would be able to provide 142 streetlights in the city with electrical energy every day.