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- Global warming is one of the most pressing issues that confronts our
society today. Global warming is the phenomenon of increasing global
temperatures. Several gases, called "greenhouse gases" are contributing factors
to global warming. They're called greenhouse gases because they absorb and send
ultraviolet radiation back to the earth, as in a greenhouse. Scientists believe
that an increasing level of these gases is causing an increased warming of the
earth's surface, complicating our climatic system. Water vapor, carbon dioxide,
methane, nitrous oxide, ozone, perfluorocarbons, hydrofluorocarbons, and sulphur
hexafluoride are the gases scientists believe are responsible.
- Landfill gas, or methane, a hydrocarbon, naturally exists in wetlands, gas
hydrates, permafrost, termite activity, and salt and fresh bodies of water, just
to name a few. Human-related activities, such as mining operations, rice
cultivation, biomass burning, livestock operations (manure), and landfill
operations release significant quantities of methane into the atmosphere.
Landfills are the largest single human source of methane emissions in the United
States, accounting for nearly 34 percent of all methane sources. Of all
greenhouse gases, landfill gas and carbon dioxide emissions must be controlled
to lessen the environmental detriment of global warming.
- Industry, worldwide, recognizes the importance of reducing landfill gas
emissions. Here in the United States, many companies have engaged in voluntary
efforts with the U.S. Environmental Protection Agency to reduce landfill gas and
other emissions.
- Landfill gas is emitted from landfills and is the result of the
decomposition of trash. In the past, it was flared-off and essentially
wasted into the atmosphere. Utilizing landfill gas is smart business and
environmentally sound. PEI Power Corporation burns landfill gas from two
nearby landfills in its combustion turbines and its boiler to produce steam,
which is then used to produce electricity. The electricity that PEI
generates from LFG offsets electricity that would have otherwise been
generated from other higher-polluting fossil fuels such as coal or fuel oil.
- Using LFG for energy is a win/win opportunity. Landfill gas utilization
projects involve citizens, non-profit organizations, local governments, and
industry in sustainable community planning and create partnerships. These
projects go hand-in-hand with community and corporate commitments to cleaner
air, renewable energy, economic development, improved public welfare and safety,
and reductions in greenhouse gases.
- Producing electricity using landfill gas involves several components. A series
of wells are drilled throughout the landfill area and perforated plastic pipes
are inserted into the wells to collect the gas. The area around the piping is
filled with gravel to prevent pluggage. All of the wells are connected to a main
collection header. Vacuum blowers are connected to the piping, which helps
evacuate the gas from the landfill. The vacuum blowers transport the gas to a
processing station where filters are used to remove particulate. Moisture that
may have condensed in the system is also extracted.
- From the processing station, the gas is transported to a gas turbine or a
boiler where the gas is ignited and used to produce steam, which is ultimately
used to produce electricity. During combustion, analyzers monitor the flue gas
to ensure the facility is within emission compliance.
Source: U.S. Environmental Protection Agency
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