Biogas content analysis

As the waste decomposes in a landfill over a 20 - 25 year period, 150m3 to 200m3 of gas can be recovered per tonne of waste. Production of gases is not continuous and may fluctuate depending on the design of the landfill, season and nature of waste. Initial high output of biogas will follow with a low yield after a certain period. The longevity of the production of gas depends highly on the landfill design eg. Proper capping, optimized oxygen levels, and biogas extraction control. The extraction biogas will have a temperature of 30 to 45°C, 40 - 55% CH4, 30 - 40% CO2, 5 - 20% N2 and trace elements. Calorific value typically 14,400kJ/m3 or Lower Heating value (LHV) of 5.0 kWh/m3. Production of gases is not continuous and may fluctuate depending on the design of landfill, season and nature of waste.

The trace elements eg. H2S, Ammonia by products from the micro biological process, fluorocarbons, chlorinated Hydrocarbons from spray cans, coolants, plastics must be removed before being used as a fuel source.

These trace elements increases engine wear and tear and has to be removed prior to gas feed. Coalescent filter with refrigerant system is used to remove the humidity. Scrubbers using Activated Carbon or Catalytic medium is used to remove the H2S.