An evaluation will start this week on the use of processed sewage pellets (PSP) as a new waste-derived fuel at the Lafarge cement works in Dunbar, following the go-ahead from the Scottish Environment Protection Agency (SEPA).
A successful community consultation run in August last year through local media, exhibitions and a newsletter, explained the proposal to use the new fuel. Since then, SEPA has approved the works’ application to evaluate the fuel, and a new silo and handling facilities have been installed.
The evaluation will involve careful monitoring of how the fuel is managed on-site, how it fits into the production process, and to what extent emission levels are impacted. This evaluation will take place over approximately four months, after which the results will be written up and reported back to SEPA by April 2013. If the evaluation period is concluded to the satisfaction of SEPA, PSP will become part of Lafarge’s operating permit at Dunbar.
The works has already managed to replace over 35 per cent of its annual coal usage each year with established waste-derived fuels comprising tyres and recycled liquid fuel. Adding PSP to the fuel ‘portfolio’ will take coal replacement rates near to 50 per cent, helping reduce the site’s carbon footprint and supporting Scotland’s zero waste strategy.
Nigel Blair, works manager, said: “Waste-derived fuels continue to offer many benefits to our business – they help us maintain our environmental performance, reduce our carbon footprint and manage our very high energy costs.”
The fuel is made from heat treating the sludge remaining after sewage treatment; almost a million tonnes of this dry material is generated in the UK each year. While some ends up as agricultural fertiliser – in fact it is currently being considered for use on organic land – much is sent to landfill. Using it instead as a fuel will help the Scottish Government achieve its target to cut waste sent to landfill to five per cent by 2025.
Nigel Blair added: “PSP is already used as an effective fuel in the cement-making process in many countries including Austria, Spain, France and South Korea.
“We anticipate that by using 12,000 tonnes of PSP each year, over 7,000 tonnes of coal will be replaced and our carbon footprint will be reduced by the equivalent of taking 11,500 cars off the road.”