The United States Environmental Protection Agency offers a wealth of resources for anyone looking to learn more about the process and methods of capturing landfill methane gas for converting it to energy. Their Landfill Methane Outreach Program is a great place to start. »
Click here to download an informative presentation on the EPA Landfill Gas Program:
The following is an excerpt from the EPA page:
Methane Emissions From Landfills
Municipal solid waste (MSW) landfills are the third-largest source of human-related methane emissions in the United States, accounting for approximately 18.2 percent of these emissions in 2012. At the same time, methane emissions from landfills represent a lost opportunity to capture and use a significant energy resource. LFG is created as solid waste decomposes in a landfill. This gas consists of about 50 percent methane (the primary component of natural gas), about 50 percent carbon dioxide (CO2), and a small amount of non–methane organic compounds. To learn more about methane emissions from landfills in the United States, visit EPA’s methane emissions page. For more information on methane emissions from landfills internationally, visit EPA’s International Analyses site. Additionally, EPA issued a rule (40 CFR Part 98) in October 2009 that requires the reporting of greenhouse gases. The rule requires reporting of greenhouse gas emissions from large sources and suppliers in the United States, and is intended to collect accurate and timely emissions data to inform future policy decisions. More information on the rule may be found on the Greenhouse Gas Reporting Program page.
Converting Landfill Gas to Energy
Instead of escaping into the air, LFG can be captured, converted, and used as an energy source. Using LFG helps to reduce odors and other hazards associated with LFG emissions, and it helps prevent methane from migrating into the atmosphere and contributing to local smog and global climate change.
LFG is extracted from landfills using a series of wells and a blower/flare (or vacuum) system. This system directs the collected gas to a central point where it can be processed and treated depending upon the ultimate use for the gas. From this point, the gas can be flared, used to generate electricity, replace fossil fuels in industrial and manufacturing operations, or upgraded to pipeline–quality gas where the gas may be used directly or processed into an alternative vehicle fuel.
The generation of electricity from LFG makes up about three–fourths of the currently operational projects in the United States. Electricity for on–site use or sale to the grid can be generated using a variety of different technologies, including internal combustion engines, turbines, microturbines, and fuel cells. The vast majority of projects use internal combustion (reciprocating) engines or turbines, with microturbine technology being used at smaller landfills and in niche applications. Technologies such as Stirling and organic Rankine cycle engines and fuel cells are still in development