Trace compounds of biogas from different biogas production plants.

Household hazardous waste in municipal landfills: contaminants in leachate.

https://www.ars.usda.gov/ARSUserFiles/41695/Reprints/Scheutz_2009_409-455..pdf

Microbial methane oxidation processes and technologies for mitigation of landfill gas emissions.

Health risk assessment of BTEX emissions in the landfill environment.

The discovery of abundant natural gas resources has greatly increased the study of using methane as a feedstock to produce transportation fuels. Biogas (primarily containing methane and CO2), which is generated from waste biomass via anaerobic digestion or landfills, is regarded as a renewable source of methane, and has the potential to achieve sustainable production of transportation fuels. Since biogas also contains a significant amount of impurities (e.g., H2S, NH3, and siloxane), a cleaning procedure is generally required prior to conversion to transportation fuels. Physical approaches, mainly compression and liquefaction, have been commercially applied to upgrade biogas to bio-compressed natural gas (CNG) and liquefied biogas (LBG). For chemical approaches, catalytic reforming is the dominant method for converting methane to syngas, followed by Fischer–Tropsch synthesis (FTS) or fermentation of syngas to a variety of alcohols (e.g., methanol, ethanol, and butanol) and liquid hydrocarbon fuels (e.g., gasoline, diesel, and jet fuels). High purity hydrogen, a clean fuel, can also be produced via reforming. Methanol can be produced by direct oxidation of methane, while interest in the biological conversion of methane to methanol has grown recently due to its mild operating conditions, high conversion efficiency, and potential for using raw biogas. The derived methanol can be further converted to gasoline via a methanol to gasoline (MTG) process. This paper provides a comprehensive review of major research progress on technologies for converting biogas/methane into transportation fuels, and discusses the principles, kinetics, operating conditions, and performance of each technology. Efficient direct conversion of biogas into ethanol and higher alcohol fuels (e.g. butanol), which is envisaged to be the focus of research pursuits in the near future, is also discussed, with emphasis on the development of methane-utilizing microbes through genetic engineering.

Progress and perspectives in converting biogas to transportation fuels

The trace volatile organic compounds (VOCs) in landfill gas were examined at seven U.K. waste disposal facilities. Over 140 compounds were identified, of which more than 90 were common to all seven sites. The groups of compounds and concentrations observed were alkanes, 302−1543 mg m-3; aromatic compounds, 94−1906 mg m-3; cycloalkanes, 80−487 mg m-3; terpenes, 35−652 mg m-3; alcohols and ketones, 2−2069 mg m-3; and halogenated compounds, 327−1239 mg m-3. The observed variations in landfill gas composition were largely attributed to differ ences in the waste composition and the stage reached in the decomposition processes at each of the sites. Three sites were found to have total chlorine concentrations, derived from the organochlorine compounds in the gas, of above 250 mg m-3. Chlorine contents of this level were considered to be potentially damaging to landfill gas fueled engines used for electricity generation. Chloroethene (>0.1−87 mg m-3) was identified as the most abundant toxic component. Chloroethe...

and Alan Braithwaite

Papers

Trace organic compounds in landfill gas at seven U.K. waste disposal sites