Laboratory assessment of a flux chamber to determine landfill gas emissions

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:353639

Gowing, A; Farquhar, G J ^[1]

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1. Univ. of Waterloo, Ontario (Canada). Dept. of Civil Engineering

Landfill gas (LFG) is one of the by-products of decomposing municipal solid waste (MSW). The composition of LFG is approximately 50% V/V carbon dioxide and 50% V/V methane with a small percentage (generally less than 1%) of non-methane organic compounds (NMOCs). The LFG components contribute to ozone production, greenhouse gases, fire and explosive hazards, and the potential for cancer and other health problems. The flux chamber provides a nonintrusive technique which can be simple, accurate, and flexible for measuring real time emissions of the LFG components from the landfill surface. This research involved developing a flux chamber to be operated under different LFG flux conditions and different sweep gas flow rates. These parameters together with negative and positive pressure differentials were evaluated to determine the extent to which they affect LFG capture efficiencies. The flux chamber system was designed with a process controller attached to a pressure transducer and variable speed pump to regulate the pressure within chamber. The chamber was tested under laboratory conditions which included a multimedia, simulated landfill surface. A source of LFG was maintained below the simulated surface. The pressure control system was able to maintain average pressure differentials at values less than 0.04 mm H{sub 2}O under different LFG flux rates and sweep gas flow rates. Excellent capture efficiencies were achieved; capture ratios of expected to measured LFG flux rates through the soil surface ranged from 0.95 to 1.02 with an average of 0.99. Relatively small pressure differentials of {+-}1.8 mm H{sub 2}O reduced capture efficiency dramatically producing capture ratios ranging from 0.06 to 2.59.

• OSTI ID: 353639
• Report Number(s): CONF-970677--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR POLLUTION MONITORING
BENCH-SCALE EXPERIMENTS
CARBON DIOXIDE
EMISSION
ENVIRONMENTAL IMPACTS
MEASURING INSTRUMENTS
METHANE
MUNICIPAL WASTES
OZONE
SANITARY LANDFILLS