Wastewater Methane Recovery Using Vacuum Degassing
Client – Scottish Water
Supporting Scottish Water’s Net Zero Ambitions Through ELOVAC Innovation.
The Challenge
Scottish Water identified an opportunity to introduce innovative ELOVAC vacuum degassing technology at Nigg WWTW & STC to recover methane from digested sludge that would otherwise be released into the atmosphere.
The project required the successful integration of a new technology within an operational wastewater treatment facility while progressing through Scottish Water’s governance, design and approval processes. During the design phase, newly issued SEPA compliance directives created a significant challenge, requiring substantial revisions to the proposed design to ensure full compliance with the updated environmental requirements.
Working collaboratively with Scottish Water and technology partner Eliquo Hydrok, RSE developed a compliant solution that incorporated existing site infrastructure wherever possible, maximising value while minimising construction requirements and site disruption.
The Solution
Implementing innovative vacuum degassing technology to recover methane, reduce greenhouse gas emissions and increase renewable energy generation.
RSE is working in collaboration with Scottish Water and Eliquo Hydrok to deliver the implementation of ELOVAC vacuum degassing technology.
The project has progressed through the required governance, outline design and detailed design stages, with the ELOVAC unit early procured to support programme delivery. During the design development process, newly issued SEPA directives significantly impacted the original proposal. To meet the updated requirements, RSE worked closely with Scottish Water to develop a compliant design solution incorporating reinforced concrete trough systems for below-ground pipework, allowing infrastructure to be visually inspected and providing additional environmental protection.
A key aspect of the project has been the innovative reuse of existing site infrastructure within the new design. By incorporating existing below-ground assets wherever feasible, construction requirements have been optimised while maximising value for Scottish Water.
Once operational, the ELOVAC system will recover methane from digested sludge that would otherwise be lost to the atmosphere. The recovered biogas will be redirected to the site’s existing Combined Heat and Power (CHP) plant, increasing renewable energy generation and reducing operational energy costs.
The project is predicted to deliver carbon savings of approximately 446 tonnes CO₂e per year, equating to around 40% of the site’s methane emissions. Through collaborative design, innovative thinking and the introduction of new technology, the scheme will support Scottish Water’s long-term decarbonisation objectives while demonstrating the potential of ELOVAC technology within the wastewater treatment sector.
Key Benefits:
- Predicted carbon savings of approximately 446 tonnes CO₂e per year
- Reduction of approximately 40% of site methane emissions
- Recovery of biogas currently lost to atmosphere for reuse within the existing CHP plant
- Supports Scottish Water’s wider Net Zero ambitions and decarbonisation strategy
- Maximises use of existing site infrastructure, reducing construction requirements and project impact
Want to Know More?
To find out more about how our modular approach speeds up delivery, reduces embodied carbon and supports the secure and sustainable growth of water infrastructure, click on the button below and please fill in the form. We’ll get back to you shortly.
