M.S. Thesis: Recovering Energy From Waste

By Natali Ganfer

Department of Earth and Environmental Engineering
Fu Foundation School of Engineering & Applied Science
Columbia University

August 2011

Part A: MSW Management in the City of Buenos Aires, Argentina and Potential for a Waste-To-Energy Plant
Advisor: Prof. Nickolas J. Themelis, Columbia University

Solid Waste Management (SWM) is a major concern for most Argentinean municipalities. The population of most Argentinean municipalities is constantly increasing. As a result of the increase, the cities’ borders constantly expand and this results to ever increasing land prices in areas closer to the city. These factors coupled with a population who refuse to have waste management facilities located near their houses (phenomenon known as “not in my backyard”), results in landfills located further and further away from population centers. The City of Buenos Aires (CBA or the City) and its metropolitan area were selected as the subject of the present analysis on SWM for its critical role in Argentinean MSW disposal. This area generates 40% of the total MSW of the country. The Accesso Norte III landfill is utilized to dispose of 90% of this waste i.e. 36% of the country’s MSW is expected to reach its full
capacity in 2012.

Part B: Upgrading Low BTU Fuels to Reduce Emissions in Internal Combustion Engines

Advisor: Prof. Marco J. Castaldi, Columbia University

Landfills are the most common method utilized to dispose of municipal solid waste in the American Continent. Their emissions of landfill gas, the gas emitted from the anaerobic decomposition of the municipal solid waste, are composed of CO2 and CH4. Therefore, this gas has a high global warming potential (CH4’s global warming potential is 21 times that from CO2). However, the landfill gas also embodies a free source of low BTU fuel.

It is common practice to collect landfill gas and destroy it, mitigating the greenhouse gas emissions associated with it. There are numerous existing technologies to carry this destruction, with different levels of complexity. One of the most commonly used destruction technologies that takes advantage of the energy content of the landfill gas at the same time as the waste’s destruction is internal combustion engines. This is the preferred technology because of its cost-benefit ratio. However, these engines produce pollutants as a subproduct of the combustion including NOx, CO, and UHC (unburned hydrocarbons) emissions. This not only represents a threat to the environment, but in many cases will keep the internal combustion engines from installation because of their resulting inability to comply with stricter regulations that establish low emissions limits of those pollutants.

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