Biocover—a new technology developed at DTU—is designed to reduce greenhouse gas emissions from refuse tips. It has now been included in the Danish national budget, which has allocated DKK 184 million to it until 2017.
“It makes us proud,” relates Peter Kjeldsen, Professor atDTU Environment and the person behind the development of Biocover.
“We started off in the mid-1990s with some simple experiments in lab flasks, and have been running full-scale trials for several years. The solution is now being rolled out in a nationwide initiative financed by the Danish government. I don’t think I’ve ever seen anything like this before.”
Peter Kjeldsen’s idea was simple: The greenhouse effect of methane is approximately 25 times that of CO2. And the gas seeps continuously from refuse tips all over the world. Reducing these emissions would therefore make a real difference for the climate.
The Biocover technology concept is to seal the surfaces of old refuse tips to prevent methane penetrating them. Instead, the gas will have to make its way up through the mountains of rubbish, eventually becoming what can best be described as a compost heap— where microorganisms convert the methane into CO2.
Refuse tips continue to emit methane for many years after deposits of organic waste cease, so even though Denmark relies less on landfill than many other countries, the technology still contains potential from a Danish perspective.
100 biocovers
Through a range of trials at the Klintholm Deponi tip, which is located between Nyborg and Svendborg on the island of Fyn, and at a number of other landfill sites, Peter Kjeldsen—in collaboration with Associate Professor Charlotte Scheutz—has succeeded in developing a method for proving the emission of methane. In this case, the emission rate was calculated at around 10 kg per hour. The team then applied their Biocover solution, which reduced the emission rate to a little over 1 kg per hour.
This was one of the trials that resulted in the decision to establish around 100 Biocover installations at closed Danish refuse tips. The Danish Environmental Protection Agency, which is responsible for the installation work, expects a reduction equivalent to 0.3 million tonnes of CO2 in 2020.
However, Peter Kjeldsen emphasizes that the real potential of the technology will most likely be reaped abroad:
“Denmark doesn’t have anywhere near the number of refuse tips other countries have, and it is clear that the solution has started to attract international attention. For example, I’ve been invited to China and Turkey to talk about it. If we can get our foot in the door there, we can really start to tackle the issue of methane emissions from rubbish tips. At the same time, it’s an excellent opportunity to export technology—which is a key area of focus for both us and the Danish Environmental Protection Agency.”
Article in DTUavisen no. 2, February 2015.