Methane Gas From Landfills Can Be Used for Fuel, Heat, Electricity
By Nancy L. Pontius
U.S.-Indian Team Investigates Alternative Energy Source in IndiaLittleton, Colorado - To tap into a new energy source, U.S. and Indian organizations are exploring ways to use methane gas from Indian landfills for fuel, heating and electricity.
"Energy scarcity in all its forms is a big issue in India. Any attempt to get [new] energy sources, particularly unconventional sources, is most welcome," Rakesh Kumar, deputy director of the National Environmental Engineering Research Institute, told America.gov. NEERI - a multidiscipline, environmental research laboratory - is an Indian partner in this investigation.
In landfills, decomposing food and paper release gas, including methane gas, which has good and bad consequences. On the negative side, because methane is 23 times as effective in trapping heat in the atmosphere as carbon dioxide, methane gas escaping into the atmosphere can contribute to climate change, according to the U.S. Environmental Protection Agency (EPA). On the positive side, methane is the primary component of natural gas, which is used as a fuel and energy source.
"The trick is to capture the methane before it leaves the landfill and escapes into the atmosphere so that its energy can be harnessed for positive uses," Joe Zietsman, project manager of one Indian landfill investigation, told America.gov. Zietsman is director of the Center for Air Quality Studies at the Texas Transportation Institute, which is part of Texas A&M University.
Zietsman's group is leading a study in Mumbai, India, to investigate the feasibility of converting landfill gas to vehicle fuel or energy sources. Other partners in the study include NEERI, the Texas State Energy Office and Mack Trucks Inc.
The investigations are funded by EPA as part of the agency's Methane to Markets partnership - an international initiative advancing cost-effective methane recovery and use as a clean energy source. (See "International Partners Reduce Methane Greenhouse Gas Emissions ( http://www.america.gov/st/env-english/2008/December/20081202153251lcnirellep0.3222925.html ).")
"India is one of 27 partner governments, plus the European Commission, who have joined the partnership to voluntarily reduce methane emissions," Rachel Goldstein, EPA team leader for the landfill methane outreach program, told America.gov.
WORKSHOP IN AHMEDABAD
Goldstein conducted a two-day workshop in Ahmedabad, India, in early April to highlight beneficial uses for landfill gas. The workshop, co-sponsored by the Indian Ministry of Urban Development and EPA, included a tour of the existing Ahmedabad dumpsite and its new sanitary-engineered landfill under construction.
"Clearly, the government in India supports this effort because with the ministry's support 50 municipal commissioners and engineers attended the workshop," Goldstein said.
Lessons learned in Texas have benefited the study in India. Funding from the Texas State Energy Conservation Office (SECO) helped develop a methodology for evaluating the use of methane recovered at landfills in Texas as a source of liquid natural gas fuel for refuse trucks, Mary-Jo Rowan, Texas SECO program manager, told America.gov.
"It made perfect sense to collaborate with India when given the chance to do so," Rowan said. "The project with India has given credibility to the methodologies developed here in Texas and shown that the formulas can be used worldwide."
BENEFICIAL USES OF METHANE GAS
To assess the cost effectiveness of capturing and harnessing the methane gas continually generated by landfills, researchers consider four uses for the gas:
. Convert the gas into fuel for trucks and buses.
. Generate electricity by using the gas to run an electricity-producing turbine.
. Convert the gas into natural gas and sell it for residential heating and industrial use.
. Burn the gas in a flare at the landfill to destroy the gas, which keeps methane out of the atmosphere and lets the landfill owner receive carbon-emission credits.
Producing fuel for vehicles is an attractive choice. "In India, many city buses currently run on compressed natural gas, and the city of Mumbai is interested in this option," Zietsman said.
To generate fuel, the raw gas is cleaned in a chemical plant on site, then converted to liquid natural gas (LNG) or compressed natural gas. Existing vehicles can be converted to run on either fuel, or new vehicles designed for these alternative fuels can be purchased, Zietsman said.
According to Kumar, operating vehicles with LNG would reduce vehicular emissions considerably. This option "could be more relevant for cities like Mumbai, which has a large population and generates about 6,000 metric tons of waste per day."
EPA's Goldstein said the next step "is for each municipality running a landfill to assess their options," including estimating the revenue anticipated from generating electricity and selling the gas.
For one Mumbai landfill, the choice has been made. "The Gorai dumpsite will soon be the first landfill in India, as far as we know, to begin flaring [burning off] landfill gas, when this begins at the end of April," Goldstein said.
Worldwide, millions of tons of municipal solid waste are discarded daily into sanitary landfills and dumpsites. Landfills are the third-largest human-induced source of methane gas, accounting for about 12 percent of global emissions.
EPA's Methane to Markets partnership is working to reduce global methane emissions, enhance economic growth, strengthen energy security, improve air quality, improve industrial safety and reduce emissions of greenhouse gases. The partnership brings together interested parties from governments and the private sector to facilitate methane-project development around the world.
More information is available at EPA's Methane to Markets Partnership Web site ( http://www.methanetomarkets.org/index.htm ).
(This is a product of the Bureau of International Information Programs, U.S. Department of State. Web site: http://www.america.gov)
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