Norfolk County Council has begun installing micro-generation energy systems to recover methane gas at two of its disused landfill sites, as part of the Environment Agency’s Assessing, Capturing and Utilising Methane from Expired and Non-operational landfills (ACUMEN) project.

Part-funded by the EU LIFE+ project, the EU’s financial instrument that supports environmental and nature conservation projects, ACUMEN seeks to demonstrate new techniques for managing methane emissions (a greenhouse gas with over 20 times the global warming potential of carbon dioxide) from closed landfill sites.

Having begun in September 2012, the project will run until August 2015 and will involve combining ‘innovative technologies and techniques’ to curb the amount landfill gas emitted into the atmosphere from historic sites, thus helping to reduce greenhouse gas emissions.

Norfolk’s old landfill sites in Docking (which closed in 2000) and Strumpshaw (which closed in 1988) are two of six sites selected by the Environment Agency to take part in the ACUMEN project.

According to Geoff Baxter from the ACUMEN project, the Docking site is set to receive two Stirling engines, which operate by cyclically compressing and expanding air (or, in this case, gas), and will manage some of the gas that is currently being flared at the site.

He said: "This will be the first time that this type of engine has been installed and used operationally to manage gas at a closed landfill site in the UK and the second time in Europe, and we feel confident that the lessons learnt will be applicable to other closed landfills around the UK."

The Strumpshaw site is to see gas piped through a "specially-developed compost mixture containing bacteria" that will help to break down the methane.

Baxter said that this pilot could help "assess the efficiency of bio-oxidation as a way of reducing methane emissions".

‘Bringing about a step change in the way landfill sites are controlled’

Charles Wright, who leads Norfolk County Council's landfill management team, said: “Landfills generate methane for as long as they are breaking down waste. Speeding up the waste degradation process helps the restoration of landfills, but this can also lead to an increase in the quantity of harmful methane emitted. A major part of our job is to manage this process to minimise these emissions and their impact on the environment.

"One of the best ways of doing this is to convert the gas into energy... We have a long record of managing gas at these sites, and this project will enable us to compare and evaluate the effect of different systems on the landfill sites and the effectiveness of the different methods of using the gas.”

He added that the council was “very excited” to be taking part in a project that could deliver a “major shift” in the way small, older landfills are managed.

The new energy systems will be continuously monitored for two years and the information used to identify viable systems for extracting gas economically from old sites. It is hoped that this could improve the efficiency of gas flows on old landfill sites and ‘prove the business case for their wider take up’.

David Harrison, Norfolk County Council's Cabinet Member for Environment, said he was “pleased that the communities around Docking and Strumpshaw are to be among the first to directly benefit from an initiative that could bring major environmental improvements for many more across the country”.

He added that he hoped the trials could help “bring about a step change in the way landfill sites are controlled in the future”.

Other closed landfill sites trialling new methane-recovery equipment are:

• Otterspool, owned by Liverpool City Council, which is being fitted with a prototype low-calorific flare;
• Sugden End, owned by City of Bradford Metropolitan District Council, which is to see a power generation demonstrator installed;
• Maesbury Road, owned by Shropshire Council (technology TBC); and
• a site in Poland, run in assistance with Warsaw University of Technology (technology TBC).

As well as demonstrating different technologies to capture methane gas, the ACUMEN project seeks to:

• demonstrate an ‘effective approach’ for assessing methane production from a range of closed landfill sites;

• establish the ‘technical and economic viability of capturing, utilising and mitigating methane from closed landfills’ by monitoring and assessing the results from the project; and

• communicate the lessons learnt from ACUMEN and ‘disseminate the outputs to encourage other public bodies to capture methane from closed landfill sites’.

ACUMEN is a multi-partnership project between the Environment Agency; Norfolk County Council; Ground Gas Solutions; Biogas Technology; the Department of Energy & Climate Change; the Department for Environment, Food & Rural Affairs; and Warsaw University of Technology.

Each of the partner organisations is reportedly contributing resources towards the delivery of the project.

Find out more about the ACUMEN project.