Landfill gas

Gases including methane are usually generated with the accumulation of waste in the landfill, which is a result of the biological decomposition of wastes placed in. Among the composition of the landfill gas, the methane and carbon dioxide are the main components. As mentioned earlier, the methane is important as it has a great calorific value which gives rise to energy generation benefits. MSW landfill gas typically has roughly 45 to 60% methane and 40 to 60% carbon dioxide. With proper separating, the methane can be extracted from the landfill gas and become an alternative energy for fossil fuel. Moreover, it should be noticed that other minor components such as H₂S, NO_x, SO₂, CO, NMVOCs, PAHs, PCDDs, PCDFs are all harmful to human health at high doses.

In fact, the awareness of utilize the energy in the landfill gas actually has a long length of history. It is important to emphasize that the interests in landfill gas collection in the past are resulted by concerns for protecting adjacent properties, and also due to the escalating prices of energy. Besides, the reasons for extracting energy from waste are the same as the landfill gas collection. However, with the new concerns on climate nowadays, the interests in landfill gas utilization have become much more intensive now.