We are proud to provide a sustainable, affordable, clean and safe water supply and to manage and treat the waste water returned to us in a way that protects the environment.
Conversion of sludge into green energy
We are continuously working to develop beneficial disposal routes for the sludge remaining after sewage treatment and our latest scheme will convert green energy into power which will supply our treatment works at Bran Sands.
It will be the biggest single plant of its kind in the UK, using the emerging new technology of ‘thermal hydrolysis advanced digestion’ and will put us at the forefront of the industry.
Sludge will be squeezed to further reduce water content before being loaded into giant steam pressure cookers and then cooled before being fed into tanks for bacteria to digest. The methane given off by the bugs eating the waste will then be collected in biogas storage bags before being used to fuel engines to create enough renewable electricity to power about half of the entire treatment works site. Heat and steam generated will also be captured and used efficiently elsewhere in the process.
The digested sludge cake remaining after the process will be a safe and low odour product containing no detectable levels of pathogens, such as E-coli, and will be used as a valuable agricultural fertiliser.
The new process will improve efficiency and reduce our carbon footprint. It will reduce more than 500,000 tonnes of sludge – from the treatment of domestic sewage and industrial effluent from a population equivalent of 1,900,000 people – to about 60,000 tonnes and will generate five megawatts of green electricity.
Operations Director, Graham Neave, said: “This is another leading development at our Bran Sands works which has already won international awards for innovation. Development of this sustainable process to re-use and recover valuable resources from sludge and create renewable energy puts Bran Sands once again in the national spotlight as a centre of environmental excellence”.