The practice describes a method created by IPCC to calculate the amount of landfill gas production.
Methane emissions from landfills are the main source for greenhouse gases in the sector waste and waste water. In order to manage the degassing system of landfills, the future utilization of the gas and necessary aftercare measures, the IPCC model (IPCC 1996 Revised Guidelines), adjusted by the First Order Decay (FOD) method, can be applied to simulate the methane (CH4) production from solid waste over time. The model is empirically based. The results can be used for further meta-analysis.
The assumption of the model is that the biodegradable organic-C-pool is mainly converted to CH4. So the organic C-pool of the waste disposed is the crucial input factor to run the simulation. The data can be obtained by documentations of waste disposal. The time of disposal is of importance, as decomposition steadily occurs. Howev-er, unfortunately, in most cases the quality of the waste is unknown. The quality and C-content can be estimated by the year of disposal (usually waste composition from each decade differs from each other) and by analysis of waste, extracted from the landfill by core drilling.
Other main factors of the model are the half-life value and the methane correction factor.
The output of the simulation shows the different phases of landfillgas production, which are characterized by a specific composition of the gas. Gas treatment system can be planed according to the results and adapted.
The only resource is needed is the knowledge about the landfill.
Evidence of success
As soon as the measure has been implemented and evaluated, the data can be used for the future degassing system installation and further planning.
In order to predict gas production, time of deposition and quan-tities must be known. For older landfills it is difficult to gather information and therefore a simplified model (IPCC Tier 1) has to be applied, which only considers current emissions. In some cases an accurate gas prediction fails.
Potential for learning or transfer
In the EU are 500.000 landfills. These landfills develop methane and carbon dioxide. The gases reinforce the greenhouse effect.
In order to avoid these effects a gas prediction can be used to plan a degassing system and utilisation more efficiently.
The treatment of gas is crucial to reduce emissions and green-house effect since CH4 is 21-time more harmful than CO2.
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