Development
Waste Fuel-to-Energy
Since much of the popular debate over greenhouse gases (GHG) is focused on the damaging effects carbon dioxide has on the atmosphere, methane gas is often considered a secondary concern. However, according to the Environmental Protection Agency (EPA), methane gas is over 20-times more effective at trapping heat in the atmosphere than carbon dioxide. Like carbon dioxide, a large proportion of the methane gas in the atmosphere is produced by naturally occurring events--but man-made sources of methane continue to pose a sizable problem to those concerned about climate change.
In addition to being a greenhouse gas, methane can also be used as a valuable fuel source. A primary component of natural gas (methane accounts for 87% of content by volume), it can be harnessed to provide electricity and thermal energy in a way that both lessens its detrimental impact on the environment and helps decrease reliance on traditional fossil fuel sources.
Sources of Methane
The two primary sources of man-made methane gas are farm animal waste and landfills. Methane is produced as a byproduct of the break down process of organic materials. On large farms, livestock create a large amount of methane through regular biological functions. The effect is multiplied by the large concentration of animals in a small area resulting in mass releases of methane into the atmosphere. While methane from livestock accounts for 37% of all man-made methane, it is landfills that are the largest contributor of this greenhouse gas. As organic waste breaks down in a landfill, pockets of methane form underneath the surface. The environmental impact of this methane as a greenhouse gas is known. An additional danger is posed as methane is combustible and, if not properly vented, can pose serious risks of ignition.
From Waste to Energy
Unlike attempts to limit carbon dioxide emissions, it is unlikely that methane emissions can be significantly reduced in modern society as the need for livestock and waste processing is a necessary byproduct of growth. However, by harnessing the useful properties of methane as a source of fuel, its effects on the environment can be mitigated while producing much-needed renewable energy. In a landfill gas to energy project, wells are drilled into the landfill which, through a system of gas collection piping, tap into the methane being produced in the landfill. The methane is then piped to either a direct use application, such as a boiler, or to a natural gas pipeline, or to a power generating plant where it can be combusted in either a reciprocating piston engine or a turbine to produce electric and thermal energy. In this fashion, a landfill can serve dual purposes, as both a waste management center and an energy provider. Endurant Energy, in partnership with the Winnebago County Landfill in Rockford, Illinois, has created such a system, providing 6.4 MW of clean, renewable energy at the Winnebago Energy Center