By how much can methane emissions at landfill sites be reduced in order to reduce global warming?A new, ambitious research project at Fakse Landfill Site in Denmark is currently analysing a variety of options to determine how best to use bacteria to convert methane to the less damaging greenhouse gas CO2 by covering the landfill with humus and compost.This would achieve a reduction in landfill site methane emissions, which account for between 7 and 20 per cent of total global emissions. The results of the project at Fakse Landfill Site can be applied globally.
"The method is well known," explains COWI project manager Niels Erik Houe, "but the project can help document that there is a relatively cheap way of preventing methane emissions into the atmosphere.The issue is attracting international attention, as there is global interest in running landfill sites in such a way as to reduce emissions of greenhouse gases. But because of lack of knowledge and money, waste is often left lying uncovered at landfill sites."
Lecturer Peter Kjeldsen of the Institute of Environment and Resources at the Technical University of Denmark is heading the research project, with background material being contributed by COWI and others.
Methane is emitted when organic materials such as household waste, timber from building waste etc. are left decomposing in big, exposed piles at landfill sites. In Denmark the gas emissions at some 20-30 landfill sites are being utilised to produce heat and electricity. But at the remaining landfill sites the quantities are so small that it does not pay to use the gases for energy production.
One goal of the project is to determine where methane emissions are occurring at Fakse Landfill Site and how the gas can best be converted to CO2. The idea is to install so-called bio windows where different levels of earth, drainage and compost are built up.The project, due for completion in 2008, is being financed by the EU's Financial Instrument for the Environment (LIFE), the Danish Ministry of the Environment, I/S FASAN (waste management company) and Renosam (waste management association). The COWI Foundation is supporting the project by providing DKK 120,000 for analysis equipment. By Christina Tækker, cht@cowi.com Published: 27.10.2006