FAQs About Landfill Gas
How is landfill gas generated?
Landfill gas management (LFG) is produced by the bacterial decomposition of organic waste in MSW landfills, a natural process. The amount of gas and its constituent parts that an MSW landfill produces are influenced by a variety of factors. Among them are the sorts and age of the garbage buried in the landfill, the number and kinds of organic compounds present, as well as the waste's moisture content and temperature. The climate in the area affects temperature and moisture levels.
What components make up landfill gas?
LFG is composed of around 50% methane, 50% carbon dioxide, and 50% water vapour by volume. It also has trace amounts of inorganic compounds, less than 1% non-methane organic compounds (NMOCs), and minor amounts of nitrogen, oxygen, and hydrogen. Some of these substances have overpowering, unpleasant smells (for example, hydrogen sulphide). NMOCs is made up of a few hazardous air pollutants (HAPs) and volatile organic compounds (VOCs), which, if left unchecked, can combine with sunlight to produce ground-level ozone (smog). Uncontrolled LFG has been found to include almost 30 organic hazardous air pollutants, including vinyl chloride, benzene, toluene, and ethyl benzene. It's possible for these contaminants to have a negative impact on your health.
How are non-methane organic compounds generated in landfill gas?
NMOCs can be found in discarded items including household cleaning supplies, materials covered in paint or adhesive, and other things. Methane, carbon dioxide, and other gases can strip NMOCs from the waste during the decomposition process and transport them to LFG. The synthesis of NMOCs and their transfer to LFG are caused by three distinct mechanisms:
- biological decomposition of heavier organic compounds into lighter, more volatile components.
- Vaporisation (the change of state from liquid or solid to vapour) of organic compounds up until the equilibrium vapour concentration is reached.
- The chemical reaction of materials already present in the landfill.
Can landfill gas be used for energy?
When employed as a source of energy to produce electricity or heat, LFG can be useful. With a heating value of 350 to 600 British thermal units (Btu) per cubic foot, roughly half that of natural gas, it is categorised as a medium-Btu gas. In many situations, LFG can be utilised in place of traditional fossil fuels. It is a dependable source of energy because it is produced every day, every week, without fail. Landfills can drastically reduce their methane emissions and minimise the need to burn fossil fuels to produce electricity, which lowers emissions of carbon dioxide, sulphur dioxide, nitrogen oxides, and other pollutants from the burning of fossil fuels.
What are the economic benefits of using landfill gas as a resource?
LFG energy projects are a win-win situation for all parties concerned, including the landfill operator/owners, the neighbourhood utility, the local authority, and the local community. LFG energy projects create jobs for local communities before they generate revenue from the sale or consumption of electricity. Engineers, construction companies, equipment suppliers, utilities, and end users of the generated electricity are all involved in LFG energy projects. A large portion of this expenditure is spent locally on drilling, building, and operations employees, resulting in greater employment and local sales, which further supports the local economy. Once the landfill gas management system is in place, the captured gas can either be transformed and sold on the energy market as renewable "green" power or sold for use as fuel or heat.
What are the environmental benefits of using landfill gas as an energy resource?
LFG conversion minimises emissions of air pollutants that cause local smog and acid rain while reducing the requirement for non-renewable resources like coal and oil. LFG energy projects also mitigate climate change since they lower methane emissions, a more potent greenhouse gas than CO2. Burning the LFG also destroys organic substances, including methane and organic substances other than methane (NMOCs). These organic substances undergo chemical reactions with oxygen in the presence of heat during burning, dissolving to produce water vapour, carbon dioxide, and other less volatile substances. LFG energy initiatives support local efforts to improve air quality and cut back on greenhouse gases that contribute to climate change.