A great deal on research is currently being done on alternative energy, and one of the major sources of this energy is methane commonly known as natural gas. Though a very potent greenhouse gas, contributing immensely to global-warming, the gas is in high demand as a result of its fueling attributes and its abundance on earth (the most abundant organic compound on earth). Methane is found pretty much everywhere, being one of the results of decomposition of former life, it is in fairly significant amounts in the soil and atmosphere and of course land fill sites. A land fill is a site where trash is dumped and processed; usually an open area of land divided into different sections and the trash goes through quite a few processes. One of the processes and our main focus here is the Methane Collection System.
Landfills, due to anaerobic bacterial activity, contain a gas, commonly called landfill gas. This gas is majorly carbon dioxide and methane in an approximate 50-50 split but it also contains some impurities like oxygen and nitrogen. The process of the production of methane in the anaerobic conditions is known as methanogenesis. Not too long ago this landfill gas was considered potentially harmful, constituting about a third of greenhouse gas emission in the US and so most of the gas had to be burnt, constituting quite a nuisance for the people unfortunate enough to live near a landfill site. Fairly recently the gas has been considered a valuable source of fuel in form of methane gas. This energy source is quite new and is far from developed in most countries. The process of extraction of methane gas from these landfill sites is quite cost efficient and seems to be an economically viable process of obtaining cheap fuel.
A network of pipes is embedded within the landfill to trap the valuable gas in the extraction process. The collected gas is then refined to separate it into its constituents (mainly via fractional distillation). The methane gas is then usually sold off to be used as fuel elsewhere. The uses of this methane gas vary widely, it can be sent directly to buildings through central networks to run utility systems like internal heating and cooling, purified into natural gas (which is what we burn out of our gas cookers) or compressed into liquid to power garbage trucks and city buses.
The removal of methane from landfills has also been taken advantage of by companies as a way of generating income. As the gas is considered a potential greenhouse gas, its removal earns carbon credits which are traded off to generate capital to fund the process of conversion to electricity. This energy source can be considered quite viable with enough resources it can drastically cut back on our petroleum consumption and provide a greener planet in the process.