posted on Mar, 1 2005 @ 05:29 AM
"Methane generated by rotting rubbish in landfill dumps could make a far greater contribution to the world's energy supply. A new way of harvesting
the gas should mean that many landfill dumps that till now were thought to be too small to produce usable amounts of the gas will be able to provide a
In Europe alone, landfill has the potential to generate as much as 94 billion cubic metres of methane each year. Yet according to the European
Commission's energy directorate only about 1% of this is being tapped. The rest of it goes to waste, as landfill operators burn it off to prevent a
build-up of dangerous quantities of the flammable gas.
As well as wasting energy, flaring off methane pumps pollutants into the environment. These are caused by impurities in the methane and the low
temperature of the flare, says Greg Miller, who set up a firm called SusBus in 1998 in Durham, UK, to look for ways to use methane from landfill gas
as fuel for buses.
Methane forms in landfill when organic waste decomposes in the absence of oxygen. At some landfills the gas is collected and used to power vehicles or
to heat nearby buildings. Till now this has been practical only for landfills that produce large volumes of methane. But Viktor Popov at the Wessex
Institute of Technology, in Southampton, UK, says simple modifications to existing landfills will make it possible to extract methane from any site.
No oxygen required
Methane is usually extracted by sinking pipes or wells into the landfill and sucking the gas out. But if the surroundings are not airtight, sucking
out methane also sucks in air. This is not only difficult to separate from the methane; it also means methane production slows down. "You don't want
oxygen in there because that would prevent anaerobic digestion," says Popov. As a result the only landfill sites suitable for methane extraction are
those that are large and deep enough to restrict the entry of air."
How many barrels of oil could be saved if this technology was fully utilized. How great it would be to tell the middle east they are now irrelevant.