Homes heated by sewage given UK trial

Millions of tonnes of sewage sludge can be transformed into energy and clean water.

A project that could transform sewage sludge into clean water and energy has been awarded a share of £4.5 million by the regulator for water in England and Wales.

The Aston University project developed in partnership with engineering consultancy ICMEA-UK, involves extracting energy from the waste produced during sewage and water treatment and transforming it into hydrogen and/or methane. The gases can then be used to power engines or heat people’s homes.

The aim is to create a sustainable and cost-efficiently run wastewater processes, plus extra energy.

“We will be taking a waste product and recovering two important products from it: clean water and renewable energy.

Dr Jude Onwudili, Aston University

The initiative was one of ten winners of Ofwat’s Water Discovery Challenge, of which the Aston University scientists and two industrial partners have been awarded £427,000. Dr Jude Onwudili based at Aston University’s Energy & Bioproducts Research Institute (EBRI) is leading the team of scientists who will work with the partners to develop a trial rig to transform solid residues from wastewater treatment plants into hydrogen and methane.

The two-stage process will involve the initial transformation of organic components in the sludge into liquid intermediates, which will then be converted to the fuel gases in a second stage. The project is called REvAR - Renewable Energy via Aqueous-phase Reforming, and Dr Onwudili will be working with lead partner and engineering consultancy company ICMEA-UK and infrastructure company Costain.

REVAR combines the use of hot-pressurised water or hydrothermal conditions with catalysts to achieve high conversion efficiency. The technique can treat sewage sludge in just minutes, and it is hoped that it will replace existing processes.

Gases extracted from sewage can be used to heat homes. Image: Jay Mullings / Unsplash

In 2013, a Chartered Institution of Water & Environmental Management report stated that the sector is the fourth most energy intensive industry in the UK.

Dr Onwudili said, “This project is important because millions of tonnes of sewage sludge are generated in the UK each year and the water industry is struggling with how to effectively manage them as waste. Instead, they can be converted into valuable feedstocks which are used for producing renewable fuel gases, thereby increasing the availability of feedstocks to meet UK decarbonisation targets through bioenergy.

“We will be taking a waste product and recovering two important products from it: clean water and renewable energy. Overall, the novel technology will contribute towards meeting UK Net Zero obligations by 2050 and ties in with the University’s purpose to make our world a better place through education, research and innovation.”

The Water Discovery Challenge aims to accelerate the development and adoption of promising new innovations for the water sector. Over the next six months, winners will also receive non-financial support and will be able to pitch their projects to potential water company partners and/or investors.

The 10 winning teams are from outside the water industry and were chosen because of their projects’ potential to help solve the biggest challenges facing the sector.  The competition is part of the Ofwat Innovation Fund, run by the water regulator Ofwat, with Challenge Works, Arup and Isle Utilities, and is the first in the water sector to invite ideas from innovators across industries.

Helen Campbell, senior director for sector performance at Ofwat, said, “This competition was about reaching new innovators from outside the sector with different approaches and new ideas, and that’s exactly what the winners are doing.

“The products and ideas recognised in this cross-sector challenge will equip water companies to better face challenges of the future – including achieving sustainability goals and meeting net zero targets – all while providing the highest-quality product for consumers.”