Landfill gas, abbreviated as LFG, is a complex mix of different gases created through the action of microorganisms within the landfill. As the decomposable materials in the landfill start to break down, landfill gas is produced. The production rate is directly affected by landfill geometry and also the amount of waste. These factors influence the population of bacteria within the landfill, its chemical makeup, moisture entry, the escape of the gas, and its thermal characteristics.
Landfills are heterogeneous by nature. There is a wide range of physical and biological ecosystems within most dump sites. The heterogeneity and unclear nature of the contents make the landfill gas production challenging to calculate and control compared to the standard industrial bioreactors in sewage treatment. The continuous manufacture of LFG causes the gas’ discharge into the atmosphere. Security problems, environmental concerns and hygiene issues become great problems emanating from such emissions. Additionally, fire risks, explosions and the contamination of underground water by organics compounds exist in almost all landfills.
Gas produced in landfills requires monitoring due to risks presented by landfill gases as some of these gases are hazardous. Experts have developed some monitoring techniques with the use of flame ionisation detectors to measure total VOC levels and methane levels. Monitoring of the surface, subsurface, as well as ambient air, has to be carried out regularly.
Landfill gas is about 40 to 60 per cent methane, and the rest is carbon dioxide. It also contains a variable quantity of oxygen, water vapour, hydrogen sulphide, nitrogen and other contaminants that are non-methane organic compounds. These non-methane organic compounds make up less than 1% of the landfill gas. Mercury and inorganic contaminants may as well be present in LFG.
Most landfills in Australia are composed of municipal waste, thus already producing methane. These are the principal sources of anthropogenic methane emission in Australia contributing to an estimated 200 billion cubic feet of methane each year.
LFG can be collected and be used to generate electricity or heat. Landfill gasification projects have increased since 2006. They have been very popular because they lessen greenhouse emissions and control energy costs. Waste management uses landfill gas as its energy source. Landfills can generate enough energy to power thousands of homes every day. Today it is easy to know how much gas is being produced using modern tools such as GasFlux – http://www.biogassystems.com.au. This system efficiently monitors LFG in real time. With this system, it is easy to tell the gas behaviours which will assist in making some significant decisions. The system helps collect real-time data which is then stored in the cloud. The date can be accessed using any smartphone or computer for as long as you have the logins. Contact biogas systems for more information.