Coverings for a Secondary Digester to Capture and Extract Methane

Reducing process emissions to meet overall net-zero targets within the water industry

Severn Trent are looking for innovative solutions to cover secondary digesters that structurally are unable to support the weight of a fixed solid roof to capture and extract methane.

Application Deadline
January 27th, 2022
Share this Challenge



At Severn Trent and throughout the water industry, several complex biological processes are used to treat wastewater and safely return it to the environment. However, these biological processes can emit greenhouse gasses (GHG)s specifically methane (CH4) and nitrous oxide (N2O) as by-products.  


As part of Severn Trent’s Bioresources process, we use secondary digesters to treat sludge as part of the wider process. These tanks are not enclosed, and we believe that a quantity of methane is stripped to the atmosphere as part of this process, therefore we are investigating the possibility of covering these tanks and embedding an extraction mechanism to extract said methane then recycling this methane as an energy source, if possible.

Severn Trent has engaged with the market and found that there are some solutions that can tackle the above challenge however they have encountered a further challenge in that some of their tanks are structurally not able to hold the weight of a fixed solid roof and they are looking for solutions to assist with this.  

Severn Trent has 26 digestors sites across the Midlands in the UK. 141 secondary digesters, with the smallest 180 & largest 8000 m3.

What's in it for you?

The UK water industry has committed to be Carbon Net-Zero by 2030, demonstrating a clear commitment to tackling climate change and Severn Trent is looking to lead on new technologies/ processes and assets that will help us meet this goal. 

Collaborating with Severn Trent in this area, delivering measurable reductions in process emissions could result in a commercial contract with Seven Trent, but it will also give the successful innovators a platform to showcase the assets/ technologies/ new processes to the rest of the industry.