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Turning Garbage into Green: A Win-Win Proposition
 What if you could take three of the major concerns of the 21st century – greenhouse gases, waste disposal, and sky-rocketing energy prices, and combine them into an environmentally-friendly source of “green” energy? Sounds like a politician’s dream?
More and more cities are turning this dream into a reality. By turning to landfill gas generation, environmentally unfriendly landfills are being converted into sources of clean energy.
What is Landfill Gas?
Landfill gas is produced by the decomposition of organic waste, such as kitchen waste, inside a landfill. The resulting gas is composed primarily of methane and carbon dioxide, with traces of other gases.
Methane gas is a highly potent greenhouse gas if released into the atmosphere untreated. Landfills often have to resort to burning the methane to prevent its dispersal into the atmosphere. Other potential issues surrounding landfill gas include unpleasant odors, air quality, and the migration of explosive vapors into the soil surrounding the landfill.
Harnessing landfill gas to produce power provides a source of green energy that would otherwise have gone to waste. In addition to addressing the air quality concerns around the landfill, the power generated by the landfill lowers the consumption of fossil fuels that would otherwise have been needed to provide the equivalent amount of energy.
How is Landfill Gas Harnessed?
The process of drilling for landfill gas is done via a series of collection wells installed throughout the landfill. A network of pipes transports the collected gas from the wells to the power plant. Once at the power plant,the gas is cleaned of impurities before being sent to a reciprocating engine. Combustion of the gas in the engine powers a generator which produces electricity for the power grid.
Case Study - City of Waterloo LFG Power Plant
The city of Waterloo, Ontario has been generating electricity from its landfill site since 1999. The power plant, which is owned and operated by Toromont Energy, uses the landfill gas supplied to it to generate electricity, which is then sold to the Ontario power grid.
Originally equipped with four low-emission Caterpillar G3516F engines, the plant added a 5th engine this year, and plans to add a sixth in 2008. This will put the facility's power output at 5.55 megawatts, enough to provide electricity to about 3750 homes.
In addition to all the benefits from greenhouse gas reduction, and a clean, alternative energy source, the region of Waterloo receives royalty payments of approximately $200,000 per year. Clearly a win-win deal for all concerned!
Waterloo LFG Power Plant - An Insulation Challenge
LFG power plants are a very high temperature application. These engines generate a lot of heat, and this heat is constant. "Our plant is running 24/7", says Chris Turner, plant operations supervisor at Toromont Energy. "Plus, you get exhaust leakage in the turbo and waste gate area".
 Toromont understood that this heat would need to be contained in order to keep the plant temperature down to levels where personnel can work. But given the constant, high heat and exhaust leakage, regular insulation blankets just would not do. Chris Turner explains: "The soft style manifold blanket sections under the after cooler on the G3516 engine are prone to early failure. This is due to the heat they are subjected to and the lack of clearances between the exhaust manifold, the water manifold and the after cooler supports and the difficulty these narrow clearances create. The silicone impregnated fibreglass outer material becomes brittle with the heat and the blanket starts falling apart after 3 or 4 removals."
Toromont turned to Firwin for help. "Toromont needed a blanket that could stand up to the demands of an LFG power plant", notes Paul Herman, Firwin's president. Firwin's research and development department first proposed adding an aluminum outer coating to the company's standard blankets. However, it turned out that the continual high heat was putting too much strain on even these blankets.
"We realized that the Waterloo LFG facility required a truly unique solution", recalls Paul. "We were committed to developing a blanket that could withstand the constant heat, exhaust leaks, and would last".
 The result - a stainless steel welded blanket - was presented to Toromont, and has been in use ever since. "The hard style blanket is much easier to install due to its rigid design, and is not prone to coming apart. This new design lasts at least twice as long as the original soft-style blanket", notes Toromont's Chris Turner. "The other area where the hard style blankets stand up much better is the waste gate and exhaust elbow sections. These areas are subject to very high temperatures and are prone to exhaust leaks. The new hard style blankets in these areas are much easier to install and remove due to their design and they last much longer", adds Chris.
"We are always ready to help a customer through an insulation challenge", says Paul. "I am glad we have been able to provide Toromont with the solution they needed".
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