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Transforming treated sludge into green electricity: Ofwat awards trailblazing innovations in latest Water Breakthrough Challenge

An innovative solution to reduce the environmental impact of managing sewage sludge by turning it into a source of hydrogen and low-carbon products is one of the winners of a £40 million competition from Ofwat, the water regulator.

  • Ofwat’s Innovation Fund today announces 17 winners from the fourth Water Breakthrough Challenge, a competition that invited solutions with the potential to deliver wide-scale, transformational change benefitting customers, society and the environment.
  • An initiative converting treated sludge into green electricity is among those awarded a portion of the innovation fund.
  • All of the winning solutions contribute to Ofwat’s mission to improve life through water, including ensuring the sector delivers cleaner rivers and seas for customers.

The Sewage Sludge Gasification project is a novel approach to sludge management that has today been awarded £2.3 million by Ofwat’s Innovation Fund. The project is one of 17 solutions awarded a share of £40 million today in the water regulator’s latest innovation competition – the Water Breakthrough Challenge 4. Each solution is committed to fostering innovative approaches to water and waste management.

Sludge is a bi-product of treating sewage – a treated combination of solid matter and dead bacteria left over from the treatment process. The treated sludge is pathogen-free, rich in phosphorus and nitrogen, and has, for many years, been used in agriculture to enrich soil and improve its moisture retention.

Across the UK and Europe, there is a growing realisation that sludge also poses environmental challenges, since it may also contain microplastics, metals and PFAS (indestructible chemical compounds, also known as “forever chemicals”) which may enter the soil and eventually waterways. Innovative alternatives to managing sludge are needed.

Led by Yorkshire Water, the Sewage Sludge Gasification project seeks to alleviate significant challenges for the UK water industry and offer an alternative to recycling sludge to land.

The Advanced Thermal Conversion gasification process will convert treated sewage sludge into usable products such as biochar, vitrified ash ‘stones’ and a hydrogen-rich synthesis gas (syngas). By operating at a high temperature, the process aims to destroy other contaminants such as forever chemicals including PFAS and microplastics.

The project will demonstrate the circular economy in action by testing the biochar to treat wastewater and also as an additive in brick manufacturing. The carbon-rich biochar, which resembles small pieces of charcoal, could also be used as a soil improver to increase water and nutrient retention, and as it doesn’t readily decompose, it’s also a vehicle for sequestering carbon in soil – though it must be properly managed to ensure soil pH levels are not negatively impacted.

The vitrified ash ‘stones’ could be used as aggregate in the construction industry to reduce the embodied carbon footprint of concrete. Syngas is a blend of hydrogen, carbon monoxide, carbon dioxide and methane, and has the potential to be used to produce green electricity, along with other high-value products.

Yorkshire Water suggests that by using a power optimised plant configuration the gasification process could take the 160,000 dry tons of sludge it produces each year and generate around 50Mwe of power – enough that the gasification process would be energy self-sufficient.

On a national level, the UK produces around 1.2 million dry tons of sludge per year and this is increasing. The gasification process could potentially covert this sludge sustainable products, remove all sludge to land and generate 375 MW of renewable energy for use by the wider industry.

Other winners include £1.8 million to investigate how to remove and destroy PFAS, £6.2 million to prove the concept of sewage sludge pyrolysis, £1.9 million to recover heat from sewers and use it as an energy source, and £700,000 to stimulate the market for biochar.

Dr Danielle Hankin, Innovation Programme Manager, Yorkshire Water, said: 

“Converting treated sewage sludge into gas, biochar and ash ‘stones’ opens up new, more sustainable uses for this waste product. We’re proud to be pre-empting changes in legislation and consumer attitudes, by delivering a groundbreaking technology that benefits customers, the environment and future-proofs the water industry.

“Once proven, the gasification process will produce sustainable wastewater treatment media and construction material, generate green electricity, and could create high-value products such as biomethanol aviation fuel or hydrogen. Our work represents a pivotal step in driving the UK towards a greener, more resource-efficient future.”

Helen Campbell, Senior Director, Ofwat said:

“What we do with treated sludge is not the most glamorous of subjects but cannot be ignored. The current approach of spreading treated sludge to land has environmental consequences, which could include microplastics and forever chemicals – both of which may enter the water system and affect water quality. This is not a problem unique to the UK – alternative solutions are needed around the world. The Innovation Fund has awarded funding to four projects today that will help accelerate innovative solutions to the problem and provide wider environmental benefits in the process.”

The Water Breakthrough Challenge is part of a series of competitions from Ofwat, run by Challenge Works with Arup and Isle Utilities, designed to drive innovation and collaboration in the sector to benefit individuals, society and the environment.

It supports initiatives that help to tackle the biggest challenges facing the water sector, such as achieving net zero, protecting natural ecosystems and reducing leakage, as well as delivering value to society.

Beyond sludge-focused solutions, today’s competition also acknowledged projects looking to better monitor leaks via self-driving robots in pipes and technology to non-invasively repair underground pipes.

For more information, visit: https://waterinnovation.challenges.org/breakthrough4/

Notes to Editors

For all media enquiries, please contact waterinnovation@seven-consultancy.com or call +44 (0)20 7754 3610

Full list of winners: About the 17 winners of the Water Breakthrough Challenge 4

ALL-Streams HTO – led by Anglian Water – £1,380,591. The project will demonstrate how a treatment method called Hydrothermal Oxidation can transform biowaste management in the water industry. This could create new and exciting ways to reuse resources by recovering nutrients and energy, all while helping us reach Net Zero emissions and eliminate landfilling biosolids and harmful air pollution.

Developing a market-based approach to deliver SuDS through street works – led by Thames Water – £1,340,610. The risk of flooding in London from heavy rain is increasing. This project incentivises utility companies to refill some of the 165,000 holes they dig in London every year with ‘sustainable drainage systems’ (such as raingardens). These will reduce strain on drains from rainwater and create a greener city.

Local Regeneration of Granular Activated Carbon – led by Dwr Cymru Cyfyngedig (Welsh Water) – £1,262,367. Granular Activated Carbon (GAC) is used to remove organics, such as pesticides and taste and odour compounds. GAC needs to be regenerated thermally, typically every 3 years, which is both costly and carbon intensive. This project will investigate different ways to regenerate GAC locally reducing both financial and carbon costs.

METREAU: Microbial Electrochemical Technologies for REsource recovery And Utilisation – led by Northumbrian Water – £1,656,489. METREAU will ready microbial electrochemical technology for scaled use in wastewater utilities to support against capacity pressures, reduce energy needs and carbon footprint and recover resources of economic value. A high-performing mobile unit will be developed for companies to test the benefits in wastewater treatment efficiencies ready for roll out.

No dig leak repair – From concept to reality – led by Thames Water – £6,039,069. Leakage of drinking water from buried networks is increasingly unacceptable, but replacing water mains is costly and protracted. Repairing hidden leaks must therefore be increased sustainably and this project will develop technology to repair leaks from within live water mains, without disruptive excavations and with minimal interruptions to water supplies.

PFAS – A whole system approach to an impossible problem – led by Severn Trent Water – £1,781,200. PFAS (per- and polyfluoroalkyl substances) are synthetic chemical compounds that exist in water. Most PFAS are so durable that they won’t break down in the environment for many years, earning them the nickname “forever chemicals.” The project will investigate treatment options for removing and destroying concentrations of PFAS from water.

Pipebot Patrol – led by Northumbrian Water – £1,615,325 Pipebot Patrol will develop an autonomous sewer robot that lives in the sewer, constantly inspecting and raising alerts to the precise location of blockages, as they are beginning to form. This proactive approach allows maintenance teams enough time to react before blockages cause sewer flooding, keeping sewage where it belongs.

Pipebots for Rising Mains – Technology Development Phase 2 – led by Thames Water – £1,656,229. Pipebots for Rising Mains Phase 2 builds on work successfully completed through previous rounds of the Water Breakthrough Challenge. The project will develop technology for condition assessment inspections in live sewer rising mains to enable rehabilitation works to be planned and prioritised, reducing the risk of failure leading to pollution.

Proving the concept of sewage sludge pyrolysis – led by Thames Water – £6,205,773. We aim to deliver the first continuously operating, sludge-fed UK-based pyrolysis demonstration plant. Pyrolysis (a high temperature process with no oxygen present) can be used to recycle sludge to maximise the value of biosolids; ensuring a circular economy and reducing the requirement for sludge to be recycled to agricultural land.

Reducing Water Demand through Behavioural Incentivisation – led by Severn Trent Water – £1,874,010
We have partnered with Nectar, the UK’s largest loyalty scheme and customer behaviour experts to develop a utility-sector first: using smart meter gamification to incentivise customers to reduce their consumption by awarding points for water-efficient behaviour. This can also drive lower water and energy bills for customers.

River Deep Mountain AI – led by Northumbrian Water – £5,080,719. We will develop open-source, scalable, digital models to inform effective action to tackle waterbody pollution. Our novel use of Machine Learning will efficiently analyse existing data and new diverse data inputs. This will unlock new insights into the complex factors impacting waterbodies, bringing deeper understanding and accelerating positive change.

Self-Calibrating Sensor Networks for Sustainable Water Management (SCSN) – led by Southern Water Services Limited – £1,586,000. Using AI tools to develop and deploy smart water quality sensors across our catchments. Developing this virtual capability will aim to increase the accuracy and quality of data across the sector, improving reliability for our customers and to protect the environment.

Sewage Sludge Gasification (Sustainably addressing sludge-to-land, net-zero and emerging contaminant risks) (formerly known as SENECA) – led by Yorkshire Water – £2,329,332
Our multi-partnership consortium, led by YW, identified Advanced Thermal Conversion (ATC) Gasification as an alternative approach to ‘Sludge to land’. This will allow us to prove the technical and economic viability of gasifying 100% sewage sludge and provide the water industry with the confidence to exploit the technology globally.

SuDS iQ: A National SuDS Collaboration & Evaluation Platform – led by Southern Water Services Limited – £959,243. SuDS-iQ will deliver a national online collaborative Sustainable Drainage Systems (SuDS) platform that will support a collective understanding of what SuDS are, how SuDS work, and the benefits they provide. The platform will accelerate efficiencies in partnership working and consideration for and implementation of environmentally beneficial drainage solutions.

Support for All – led by Northumbrian Water – £1,849,851. Support-for-All will be a national, secure, cross-sector platform sharing Priority Services Register (PSR) and other vulnerability data between water, energy, telecommunication and support organisations, ensuring a better experience for vulnerable customers. Supporting a ‘tell-us-once’ approach and utilitising enhanced matching, customers will receive consistent and accurate support across their utility services.

Tapping into sewer heat – led by Severn Trent Water – £1,978,515. Wastewater holds a substantial amount of heat energy that could help the UK in its efforts to reduce carbon emissions. However, this resource remains largely untapped. The goal of this project is to encourage widespread adoption of in-sewer heat recovery by showcasing a reliable technical and commercial solution.

Transforming Bioresources – the Benefits of Biochar – led by Severn Trent Water – £694,431. By-products from wastewater treatment are carefully managed. The project will investigate biochar production as an alternative to conventional biosolids management practices. Biochar is a charcoal-like product that can be created from sewage by-products. Biochar has several potential benefits, including improving soil fertility, sequestering carbon, and reducing greenhouse gas emissions.

About the Ofwat Innovation Fund

Ofwat’s £200 million Innovation Fund aims to grow the water sector’s capacity to innovate, enabling it to better meet the evolving needs of customers, society and the environment. It is encouraging new ways of working that go beyond business-as-usual innovation practices in the water industry, in particular, increasing and improving collaboration and building partnerships from within and outside the water sector. The Innovation in Water Challenge, Water Breakthrough Challenges 1-4, and Water Discovery Challenge were delivered by challenge prize experts Challenge Works in partnership with Arup and Isle Utilities. Following the first three of these, Ofwat received 40 submissions in response to its consultation about the future direction of the Fund.

In July 2022 Ofwat set out its headline decisions on the approach we will take for the Innovation Fund for 2022-25. Ofwat consulted on its proposal to extend the Innovation Fund beyond 2025 in ‘Creating tomorrow, together: consulting on our methodology for PR24’ and will now consider extending the Fund. Ofwat consulted on its proposals for the innovation fund beyond 2025 in ‘Ofwat innovation fund consultation – approach for 2025-30’, including doubling the size of the fund to £400million for 2025-30. The consultation closed on 30 April 2024. Ofwat will announce its final decisions later in 2024.

The Innovation Fund forms part of Ofwat’s approach to innovation in the water sector. Ofwat with the Environment Agency and Drinking Water Inspectorate also runs StreamLine, a joint service for innovators and businesses to get informal regulatory advice.

To contact Ofwat’s press office, please call 07458 126271.

About Challenge Works

Challenge Works is a global leader in the design and delivery of high-impact challenge prizes that incentivise cutting-edge innovation for social good. In the last 10 years, we have run more than 80 prizes, distributed £84 million in funding and engaged with 12,000 innovators.

Challenge prizes champion open innovation through competition. We specify a problem that needs solving, but not what the solution should be. We offer large cash incentives to encourage diverse innovators to apply their ingenuity to solving the problem. The most promising solutions are rewarded with seed funding and expert capacity building support, so that they can prove their impact and effectiveness. The first or best innovation to solve the problem wins. This approach levels the playing field for unknown and previously untested innovators so that the best ideas, no matter their origin, are brought to bear on the most difficult of global challenges.

About Arup

Dedicated to sustainable development, Arup is a collective of designers, consultants and experts working globally. Founded to be humane and excellent, we collaborate with our clients and partners using imagination, technology, and rigour to shape a better world. https://www.arup.com/Together we help our clients solve their most complex challenges – turning exciting ideas into tangible reality as we strive to find a better way and shape a better world. With a community of over 1700 water professionals, Arup is leading global thinking across key areas like innovation, resilience, net zero carbon and sustainable water management.  Find out more: www.arup.com

About Isle Utilities

Isle is a global team of independent scientists, engineers, business and regulatory experts with a common drive to make a positive environmental, social and economic impact through the advancement of innovative technologies, solutions and practices.  Our passion and expertise in technology and innovation enables us to connect expertise, investment and inspired ideas across the globe. At the core of all our activities is our ambition to make the world a better place. Find out more: www.isleutilities.com http://www.isleutilities.com/

Channel website: http://www.ofwat.gov.uk/

Original article link: https://www.ofwat.gov.uk/transforming-treated-sludge-into-green-electricity-ofwat-awards-trailblazing-innovations-in-latest-water-breakthrough-challenge/

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