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Landfill gas is a complex mix of different gases created by the action of microorganisms within a landfill. Landfill gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Trace amounts of other volatile organic compounds comprise the remainder (<1%). These trace gases include a large array of species, mainly simple hydrocarbons.〔Hans-Jürgen Ehrig, Hans-Joachim Schneider and Volkmar Gossow "Waste, 7. Deposition" in Ullmann's Encyclopedia of Industrial Chemistry, 2011, Wiley-VCH, Weinheim. 〕 ==Production of landfill gases== Landfill gas are the result of three processes:〔 *evaporation of volatile organic compounds (e.g., solvents) *chemical reactions between waste components *microbial action, especially methanogenesis. The first two depend strongly on the nature of the waste. The dominant process in most landfills is the third process whereby anaerobic bacteria decompose organic waste to produce biogas which consists of methane and carbon dioxide together with traces of other compounds.〔(【引用サイトリンク】publisher = U.S. Energy Information Administration )〕 Despite the heterogeneity of waste, the evolution of gases follows well defined kinetic pattern. Formation of methane and CO2 commence about six months after depositing the landfill material. The evolution of gas reaches a maximum at about 20 years, then declines over the course of decades.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「landfill gas」の詳細全文を読む スポンサード リンク
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