Case Study: Turning UK Wastewater into Clean Hydrogen and Graphene

Sector: Water
Customer: United Utilities
Funded by Department for Energy Security & Net Zero | Net Zero Innovation Portfolio - GOV.UK*

The water industry faces two critical challenges: how to process wastewater in a way that reduces emissions and how to manage the financial burden of wastewater treatment. With support from the Department for Energy Security and Net Zero’s Hydrogen BECCS Innovation Programme, Levidian and United Utilities partnered to explore an innovative solution - converting wastewater-derived biogas into clean hydrogen and graphene.

In this two-phase project, the team demonstrated how raw biogas from United Utilities’ treatment processes could be transformed using Levidian’s LOOP decarbonisation technology. The result: two high-value outputs - hydrogen, a clean fuel, and graphene, a super-material with numerous industrial applications.

The potential impact is significant. Findings suggest the opportunity for UK sewage waste to produce up to 75,000 tonnes of hydrogen annually - enough to fuel more than 40% of the country’s bus and coach journeys – while also producing high-quality graphene.

The Challenge

Water and wastewater utilities account for 5% of global greenhouse gas (GHG) emissions[1]. At United Utilities’ Davyhulme Wastewater Treatment Works, which serves 1.2 million people daily, biogas is produced through anaerobic digestion of sewage sludge. Traditionally used to generate power on-site, this biogas presents an opportunity to deliver greater environmental and economic value, capturing the carbon from the gas to drive down emissions and produce two high value products that could help unlock future decarbonisation initiatives.

Adapting LOOP for Biogas

This pioneering project repurposed LOOP - originally designed for methane from natural gas sources - to process the different composition of biogas. Compared to natural gas, biogas typically contains lower methane concentrations and has potentially higher moisture levels, posing technical challenges for conversion.

Following a successful feasibility and design phase, the team proceeded to a large-scale demonstration at the Manchester Bioresources Centre, which forms part of the Davyhulme site. Here, bioresources from across the North West are digested to produce biogas, comprising mainly of methane and carbon dioxide.

A LOOP100 unit was installed, capable of processing roughly 15 cubic metres of biogas per hour. This demonstration, backed by £3 million from the Hydrogen BECCS Innovation Programme, tested the technology’s potential to use biogas as a fully sustainable feedstock to produce hydrogen.

Outcomes and Impact

The trial successfully adapted LOOP to handle biogas with approximately 60% methane content. This is the UK’s first example of hydrogen and graphene production from sewage waste, pushing the boundaries of wastewater resource recovery.

Key outcomes include:

Scaling: The LOOP system has been successfully scaled up to the LOOP100H model, now capable of processing biogas flows of up to 15 m3/hr.
Feedstock Flexibility: LOOP has demonstrated the ability to process wastewater-derived biogas from an anaerobic digestion plant.
Graphene Production: LOOP effectively converts methane from biogas into functional, high-value graphene - enabling onward decarbonisation of products and processes and offsetting the cost of producing clean hydrogen.
Hydrogen Extraction: A yield of 50% hydrogen has been successfully extracted from biogas, providing a clean fuel source and adding value to the process output.
Carbon Impact: Preliminary carbon assessment data indicates that the current LOOP configuration results in total emissions of 140.39 gCO₂eq/MJLHV, exceeding the threshold for the UK Low Carbon Hydrogen Standard (LCHS)[2]. However, there are three key improvements that can be made to the carbon intensity: use of renewable energy in the electricity supply; switching the inert gas used for purging to nitrogen; and allocating feedstock emissions by energy. Implementing these measures would result in an emissions factor of 12.97 gCO₂eq/MJLHV, comfortably below the threshold set out by LCHS of 20 gCO₂eq/MJLHV.
Local and Regional Opportunity: Opportunities for LOOP adoption exist across United Utilities’ sites, while broader regional applications have been identified across manufacturing industries seeking alternative fuels and raw materials, as well as local authorities aiming to decarbonise public transport fleets.
National Interest: The project has demonstrated significant potential for LOOP’s application across the UK water industry. By converting anaerobic digester biogas into valuable products while capturing carbon, LOOP supports more sustainable wastewater treatment – contributing to national decarbonisation goals.

Looking Ahead

The next step is to build the business case for broader deployment, including scaling up to larger LOOP systems like the Gen2 model, which is capable of meeting the higher capacity needs of the UK water sector with a target throughput of 150 m3/hr.

Levidian and United Utilities together have shown that it is possible to turn sewage into a sustainable hydrogen source. Long-term projections suggest up to 75,000 tonnes of hydrogen could be generated from the UK’s sewage waste annually – enough to fuel a significant share of UK public transport - and producing graphene for use in key industries like construction and transport.

Conclusion

This collaboration illustrates how cutting-edge technology can transform waste into valuable, sustainable resources. By converting biogas into hydrogen and graphene, Levidian and United Utilities are helping drive a circular economy and advancing the UK’s net zero ambitions - setting a new standard for innovation in the water industry.

Project Accolades

Notes and references:

*This project has received funding from the government’s £1 billion Net Zero Innovation Portfolio, which provides funding for low-carbon technologies and systems. Decreasing the costs of decarbonisation, the Portfolio will help enable the UK to end its contribution to climate change.

[1] How tackling wastewater can help corporations achieve climate goals | World Economic Forum, 2022 | Decentralizing wastewater treatment can help corporations achieve climate goals | World Economic Forum

[2] UK Low Carbon Hydrogen Standard | Department for Energy Security and Net Zero, 2022 | UK Low Carbon Hydrogen Standard - GOV.UK