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· I%ETHANE FROM LANDFILLS -3-
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<br />portion of the municipal solid waste for reprocessing (recycling). Metals, glass,
<br />and plastics contain no organic matter which can be digested by landfill bacteria so
<br />their collection would not reduce methane production.
<br />
<br />Paper is the major constituent of urban solid waste (roughly 40 percent by weight),
<br />and it can be broken down by landfill bacteria. However, the bacteria involved in
<br />methane production require nutrients not found in paper, in particular nitrogen and
<br />phosphorous. These nutrients can be added to solid waste in the form of sewage
<br />sludge, which is a good mater~al for methane production itself. Sludge al~ adds
<br />moisture to the landfill, improving the conditions for methane production. Removing
<br />paper from the waste stream would reduce total methane production by about 5 cubic
<br />feet of gas for each pound of paper, but would tend to improve the rate of production
<br />by making the remaining waste easier for the bacteria to digest.
<br />
<br /> Collection of methane from landfills for energy purposes is proven technology for
<br /> deep landfills. For shallow landfills, such as those typically found in the Midwest,
<br /> collection of methane is still in the experimental stages, and may or may not prove
<br />to be workable. Production of methane from solid wastes in digesters has been
<br />Odemonstrated on a small scale, but no commercial projects are in operation. Resource
<br /> recovery programs will affect the volume of methane produced from solid wastes.
<br /> However, removing some wastes may actually increase the rate or amount of methane
<br /> recovery.
<br />
<br />FOOTNOTES:
<br />
<br /> 1. Frank R. Bowerman, Naresh K. Rohatgi, Kenneth Y. Chen, and R.A. Lockwood, A Case
<br /> Study of the Los Angeles County Palos Verdes Landfill Gas Development Project,
<br /> (Cincinnati, OH: Municipal Environmental Research Laboratory, U.S. EPA, July
<br /> 1977), pp. 1-4.
<br /> 2. Gayle Meehan, Reserve Synthetic Fuels, Signall Hill, California, telephone con-
<br /> versation, March 10, 1981.
<br /> 3. Ibid.
<br /> Stephen C. James and Chris W. Rhyne, '~Methane Production, Recovery, and Utiliza-
<br /> tion from Landfills," in Energy from Biomass and Wastes, (Chicago: Institute
<br /> of Gas Technology, August 1978), pp. 317-325.
<br /> 5. Ttm Yantos, Anoka County, Minnesota, telephone conversation, February 20, 1981.
<br /> 6. Robert McCafferty, "Utilization of Landfill Gas From a Shallow Landfill," Pro-
<br /> ceedings of a symposium on the utilization of methane generated in landfills_.
<br /> (Laurel, MD: John Hopkins University, 1978), p. 15.
<br /> 7. Bruce Davis, Solid Waste Division of the Minnesota Pollution Control Agency,
<br /> Roseville, al% telephone conversation, March 30, 1981.
<br /> 8. Bowerman, et. al., op. cit., p. 9.
<br /> 9. Allan Gebhard, Vice-President, Bart Engineering Co., Minneapolis, MN, letter to
<br /> Chris Clampitt, dated March 24, 1981.
<br /> 10. Sambhunath Ghosh, Disposal of Solid Wastes with Simultaneous Energy Recovery,
<br /> (Chicago: Institute of Gas Technology, June 1980), pp. 16-19.
<br /> 11. Donald L. Klass, Anaerobic Disestion for Methane Production--A Status Report,
<br /> (Chicago: Institute of Gas Technology, April 1980), pp. 9-11.
<br /> 12. Sambhunath Ghosh, IGT, Chicago, Illinois, telephone conversation, March 9, 1981.
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