WHAT IS LANDFILL GAS?
WHAT IS LANDFILL GAS?
Landfill gas is a complex mix of different gases, primarily made up of Methane CH4 and Carbon Dioxide CO2.
Trace amounts of other volatile organic compounds comprise the remaining gas mixture and include:
Methane CH4 (50 – 80%), Carbon Dioxide CO2 (20 – 50%), Water vapour (10 – 30%), Hydrogen H (trace), Hydrogen Sulphide H2S (50 – 50,00ppm), Nitrogen N (0 – 5%), Oxygen O (0 – 0.5%), Inorganic and non-methane organic compounds (NMOCs) <1%
- Methane CH4 is a highly flammable and potentially explosive, potent greenhouse gas
- Carbon Dioxide CO2 is a colourless gas and odorless at normally encountered concentrations, however, at high concentrations, it has a sharp and acidic odor. Carbon Dioxide is a greenhouse gas
- Hydrogen Sulphide H2S is a highly toxic poison that attacks the nervous system
Generated through three processes as outlined below, landfill gas can pose serious Safety, Health and Environmental risks.
Monitoring environmental performance through surveying landfill sites for emissions is vital for managing these risks and ensuring the sustainable performance of landfill sites.
CORROSION OF METALS
- Reactions between metals within the landfill can result in the formation of acidic gases
BACTERIAL DECOMPOSITION
- When organic waste decomposes, bacteria creates gas and chemical reactions
PHYSICAL PROCESSING AND RELEASE
- Reactions between organic compounds can form organic species. g. the formation of esters
- Heat is generated within the landfill and this can lead to the release of gas and even fires
- Gas stripping, water vapour and aerosols carrying liquid droplets
