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Landfill Aeration as a contribution to landfill stabilisation and climate protection
Published on 12 December 2019
Germany
About this good practice
After closure of landfills (LF) collection and utilisation of LF gas is required over several decades. However, traditional methods are not sufficient to utilise all the LF gas. It is estimated that German LF emit 8 -10 Mio. MgCO2-eq./year. By converting an anaerobic into an aerobic LF, biodegradation will be accelerated by the factor 3-5 and result in a biologically stabilised LF with a low emission potential in about 8-10 years. In many countries this method to improve the emission behaviour and to reach an earlier release from aftercare is discussed or already applied. In Germany this method is in operation or finished at more than 50 LF. Actual, most of the in situ aeration projects are based on low-pressure aeration or aeration by over-suction, both with off-gas treatment. The essential technical equipment comprises: -Gas wells and pipes for aeration and for off-gas collection or over-suction. -Gas distribution system to adjust the aeration rates, the overpressure, and off-gas collection rates. -Aeration aggregates in the gas booster station (in case of active aeration). -Off-gas treatment: autothermic methods (RTO), gas flares or FLOX-burner. In case of an additional installation of gas wells for the aeration and off-gas collection, this retrofitting can already be made in early stages of the standard gas collection and utilization. Thereby the gas collection rate is increased, so that the gas utilisation can be operated more economical and for a longer time.
Resources needed
Costs with regard to low pressure aeration or aeration due to over-suction:
- Investment and operation costs
- Devices for the collection of gas
- Plant technology may be hired
- Stabilisation may be offered as service
Basic costs of ca. 0.5 - 2 €/m³ landfill volume under favourable conditions
- Investment and operation costs
- Devices for the collection of gas
- Plant technology may be hired
- Stabilisation may be offered as service
Basic costs of ca. 0.5 - 2 €/m³ landfill volume under favourable conditions
Evidence of success
The evidence of the in situ aeration is measurable via monitoring:
- off-gas composition (CH4, CO2, volume, pressure) at the off-gas treatment stage (online measurement and visualisation) or at gas wells or in distribution/collection stations
- temperature measurements inside landfill body
- periodical settlement measurements
- monitoring of the leachate composition
Because of the positive results the aerobic in situ stabilisation became part of the German Landfill Ordinance
- off-gas composition (CH4, CO2, volume, pressure) at the off-gas treatment stage (online measurement and visualisation) or at gas wells or in distribution/collection stations
- temperature measurements inside landfill body
- periodical settlement measurements
- monitoring of the leachate composition
Because of the positive results the aerobic in situ stabilisation became part of the German Landfill Ordinance
Potential for learning or transfer
Climate change is a main global problem. The reduction of uncontrolled long-term emissions of methane from landfills can be achieved by landfill gas collection and utilisation within the first 10-15 years after landfill closure. After that period this can be achieved
• due to gas collection and thermal off-gas treatment over decades or
• as an ecologically worthwhile alternative due to in situ aeration to accelerate the biodegradation processes and to avoid the methane production inside landfill body to a great extent.
The described problems are of global relevance and can be solved especially by means of the described methods.
Moreover, in many countries this method to improve the emission behaviour of landfills and to reach an earlier release from aftercare is now in discussion or already planned for application
• due to gas collection and thermal off-gas treatment over decades or
• as an ecologically worthwhile alternative due to in situ aeration to accelerate the biodegradation processes and to avoid the methane production inside landfill body to a great extent.
The described problems are of global relevance and can be solved especially by means of the described methods.
Moreover, in many countries this method to improve the emission behaviour of landfills and to reach an earlier release from aftercare is now in discussion or already planned for application
Further information
Website
Good practice owner
Organisation
IFAS - Ingenieurbüro für Abfallwirtschaft Prof. R. Stegmann und Partner
Germany
Hamburg
Contact