Infrastructure, Networks & Equipment

    Sludge-to-Energy Companies

    Anaerobic digestion, incineration, and pyrolysis systems recovering energy from municipal and industrial sludge.

    37 providers

    This page is a good fit if you need:

    • Anaerobic Systems or Conventional Activated Sludge (CAS) capabilities
    • Suppliers with contractors sector experience
    • Providers operating in United Kingdom or Netherlands
    Providers
    37
    Verified
    3
    Countries
    6

    Can't find the right fit? Post a brief and let qualified suppliers come to you.

    Post a project

    Find a Sludge-to-Energy Provider

    Showing 1-20 of 37

    37 results from 37 matched providers

    Brine Consulting logo

    Brine Consulting

    Verified
    Netherlands1-50 employees
    Mechanical Vapor Recompression (MVR) · Atmospheric Evaporator · Spray Evaporator +130 more
    apac · china · europe +3 more

    BRINE CONSULTING delivers senior-level strategy, technical design, and actionable insight across the full lifecycle of water-related challenges. We support clients with advisory and due diligence, advanced brine management and resource recovery, industrial and municipal water reuse, and MLD/ZLD systems. Our team also leads ESG and climate-resilience strategy, innovation scouting, and international development and PPP advisory. With deep specialization in desalination, brine valorization, circular economy models, and high-impact infrastructure, we help organizations turn water and waste streams into opportunities, providing clear thinking, rapid delivery, and solutions built for real-world results.

    Activated Carbon Filtration
    Reverse Osmosis (RO) Systems
    Ultrafiltration (UF) Systems
    +85 more
    manufacturing
    energy-production
    Hangzhou Realize Technology Co., LTD. logo

    Hangzhou Realize Technology Co., LTD.

    Verified
    China1-50 employees
    Ultrasonic Cavitation Systems · Conventional Activated Sludge · SBR, MBR, IFAS +3 more
    china

    HANGZHOU REALIZE TECHNOLOGY CO., LTD. is a technology enterprise. The company collaborates with domestic and international universities such as Beijing University of Technology, Tsinghua University, and Berlin University of Technology to address the challenges of enhancing anaerobic efficiency and nitrogen removal in high-ammonia nitrogen wastewater. The core technologies foucs on energy-saving denitrification and enhanced green methane production. These two technologies can increase production efficiency of green methane by 20% and reduce costs of wastewater denitrification by 60%.

    Process Water Treatment
    Wastewater Treatment
    Advanced Treatment Technologies
    +8 more
    manufacturing
    energy-production
    Ecosystems International logo

    Ecosystems International

    Verified
    Indonesia51-200 employees
    Flat Sheet Microfiltration Units · Hollow Fiber MF Systems · Ceramic Microfiltration Modules +80 more
    apac · china · europe +3 more

    PT Ecosystems International (PT ESI) was established at Jakarta on 21st November 2006. We are an industrial effluent treatment systems integrator specializing in electrocoagulation (EC), a unique waste water treatment profile. PT ESI has capabilities in designing complete waste water treatment solutions by combining various effluent treatment systems such as the electro-coagulation, biological, chemical processes and membrane filtration, offering its customers a wide and comprehensive range of solutions, tailored to suit their various needs – ranging from basic effluent treatment for discharge to effluent recycling for water reuse. The Company is experienced in handling the design, engineering, procurement, construction and operation of new Effluent Treatment Plants (“ETP”) and possesses expertise in retrofitting existing ETP to increase the flow rate and treatment capability without any major infrastructure increase PT ESI is also a premier waste water treatment service company specializing in handling waste water generated from Exploration (Drilling) and Produced Water. Customers in Indonesia include major Oil & Gas companies such as Pertamina, Exxon, Chevron, Petro-China and Medco. Operations in Indonesia are provided by both mobile and fixed units. At drill sites where waste-water recycling is required, PT ESI supplement these treatment units with skid mounted mobile Reverse Osmosis systems. The technologies and solutions employed by PT ESI are developed in-house and examples of these are its proprietary Trident™ Electro Contaminant Removal (“ECR”) system, the Stage Contaminant Removal (“SCR”) process and Mobile On-Site Waste-Water Treatment (“OWT”) units

    Reverse Osmosis (RO) Systems
    Ultrafiltration (UF) Systems
    Multi-media Filtration (MMF) Systems
    +63 more
    agriculture
    manufacturing
    Hainan Litree Water Purification Technology Industry Co., Ltd. logo

    Hainan Litree Water Purification Technology Industry Co., Ltd.

    Verified
    China200+ employees
    Tubular Ultrafiltration Units · Hollow Fiber UF Modules · Flat Sheet UF Membranes +17 more
    apac · china · europe +3 more

    Litree: Pioneering Ultrafiltration for a Water-Secure World Founded in 1992, Litree has dedicated 30+ years to redefining water purification through ultrafiltration (UF) membrane technology—our core expertise and passion立升(Litree). As a global high-tech enterprise rooted in independent innovation, we’ve evolved from a membrane R&D startup to one of the world’s leading water problem solvers, with over 146 core patents and state-of-the-art manufacturing hubs in Haikou and Suzhou, China立升(Litree). Our signature hollow fiber UF membranes are engineered to deliver unmatched performance: 0.01μm precision removes 99.99% of bacteria, viruses, and contaminants while preserving essential minerals—striking the perfect balance between purity and health立升(Litree). This technology powers our diverse solutions, from residential whole-house systems to large-scale municipal projects and industrial wastewater treatment, all designed for sustainability and cost-efficiency. What truly sets us apart is our commitment to making safe water accessible. We’ve completed projects serving 50,000+ residents with centralized purification systems that cut construction costs and footprint by 50% compared to traditional setups—proof that advanced technology can also be affordable. Today, our solutions reach 60+ countries, supporting 3,000+ industrial clients and millions of households worldwide. At Litree, water isn’t just our business—it’s our mission. We believe every drop matters, and we’ll keep pushing boundaries to create a future where clean, safe water is a universal right, not a privilege

    Ultrafiltration (UF) Systems
    Membrane Filtration Technologies
    pH Adjustment and Neutralization
    +64 more
    agriculture
    manufacturing
    SEEPEX UK Ltd logo

    SEEPEX UK Ltd

    United Kingdom

    SEEPEX is a leading worldwide specialist in the design, manufacture and application of progressive cavity pumps, macerators and digital solutions which optimise uptime and reduce downtime to give an optimal TOTEX solution. Our products and expertise are applied in most applications in the wastewater industry wherever thin to highly viscous and high % DS media is conveyed. Each solution is custom-configured to suit our customers’ requirements. Pump Technology 4.0 SEEPEX Digital Solutions incorporating the Pump Monitor turn the progressive cavity pump into an intelligent field device, operating in a networked system of smart products, services and processes. SEEPEX cloud-based service provides online remote monitoring and management of the pumps and process. Data collection and advanced analytics enable process and pump optimisation and reduce inspection, downtime and operating costs, facilitating predictive maintenance and timely delivery of spare parts to improve overall equipment and plant efficiency. Unlocking the Power of Digital Our latest innovation, the most intelligent progressive cavity pump in the world, allows remote adjustment to maintain pump performance without onsite manual intervention. With SEEPEX unique SCT AutoAdjust technology, combined with our digital solutions, site visits for maintenance are eliminated and access to otherwise hard to reach pump installations can be carried out remotely. Energy Efficient Long Distance Pumping of Dewatered Sludge Our dewatered sludge handling solutions include Smart Air Injection (SAI) technology, an energy efficient system delivering energy savings of approximately 40% by combining a progressive cavity pump with pneumatic dense phase conveying to transport 14-40% DS sludge over long distances up to 1,000 meters. This alternative to conventional technologies has proven to significantly reduce operational (energy, spare parts and downtime) and total investment costs. Patented Solutions for Smart Maintenance. Fast and Simple. SEEPEX continues to extend its world class portfolio of maintain-in-place technologies for pumps with capacities up to 300m3/hr and 48 bar, able to handle flowable to highly viscous products with a high % DS content. The new patented BNM range has been designed to simplify customers’ maintenance and can reduce maintenance time by up to 80% with a significant reduction in related costs. SEEPEX latest ease of maintenance solution for big pumps complements our Smart Conveying Technology (SCT), launched in 2008 and still setting standards in the maintenance of smaller standard progressive cavity pumps, and Drive Joint Access (DJA) technology for open hopper pumps. All of these patented solutions increase uptime and plant availability.

    Renewables & Energy Management
    Chemical Dosing
    PNR ITALIA Srl logo

    PNR ITALIA Srl

    Verified
    Italy51-200 employees
    Spray Evaporator · Self-cleaning Screen Filters
    apac · europe · latam +2 more
    19 case studies

    We produce a comprehensive range of spraying solutions, encompassing everything from small-scale nozzles to large industrial spraying systems. Our diverse product line includes various types of nozzles tailored to meet the specific requirements of every application and customer need. The company was established in Milan in November 1968, focusing on distributing parts and components for fire protection systems. Over time, we expanded our offerings to include a diverse range of industrial sprayers tailored to various applications. In addition to our distribution and manufacturing of fire protection system components and industrial sprayers, we specialize in designing and producing pneumatic spray nozzles for industrial use and tank washing nozzles. Our product line also encompasses a variety of complementary accessories essential for industrial washing, including filters, spray guns, and hoses. Furthermore, we offer ejectors, blower nozzles, swivel joints, and hose clamps to provide comprehensive solutions for our customers' needs. PNR Italia is part of the Tecomec Group and oversees four other affiliated companies to form PNR Company, a consolidated reality with a significant presence on the market.

    Microfiltration (MF) Systems
    Disinfection Technologies
    Disinfection Chemicals
    +7 more
    agriculture
    manufacturing
    AE Yates Group logo

    AE Yates Group

    United Kingdom

    Established in 1870, AE Yates is a progressive civil engineering contractor with an enviable track record of successfully delivering technically demanding high quality works to the complete satisfaction of a wide variety of public and private customers. An Integrated Construction Company A E Yates has grown to be an integrated construction company with a turnover of £50m, employing over 170 managerial, professional, technical and operational staff. Our company headquarters, based in Bolton, are strategically located to serve and communicate with clients throughout the United Kingdom with immediate access to road, rail and air transport facilities. We also have an operating base in Sheffield. AE Yates Group The group companies add value for customers not just in their specialism. When working together they can offer an integrated service through resource sharing and joint management of activities. Operational interfaces are removed eliminating potential co-ordination, management and programming issues for customers. AE Yates Civil Engineering Ltd AE Yates Directional Drilling Combined Soil Stabilisation Side Grip Piling SPI Piling Tritech Ground Engineering AE Yates Haulage Equipment and Skills Investment in the development of highly skilled operational teams up to date equipment has reinforced and enhanced our capability in all areas of operations. We own and operate an extensive fleet of general civil engineering and specialist plant and equipment. Experienced and Dedicated We are a highly experienced and respected civil engineering contractor operating to an Integrated Management System which is fully accredited to IS 9001:2015, ISO14001:2015 and ISO45001:2018 by BSI. We are fully committed to meeting the required standards of quality, customer care, environmental awareness, safety, health, time and cost demanded by our clients. We are fully supportive of the UK industry’s drive towards Continuous Improvement, Best Value and Constructing Excellence.

    Renewables & Energy Management
    Contractors
    Dunphy Combustion Ltd logo

    Dunphy Combustion Ltd

    United Kingdom

    Dunphy have extensive experience in manufacturing, installing and maintaining ultra low NOx burners for sludge and wastewater treatment processes. Our burner designs mitigate the formation of thermal NOx through staged combustion supported by CFD optimised combustion heads and advanced touchscreen digital boiler/burner controls. When used with a correctly dimensioned boiler, NOx emissions are inherently low at 35mg. per kWh on gas and biogas. Burner components are designed and manufactured in materials which resist corrosion thus reducing expensive maintenance downtime. Design options also include sluice burners, retractable heads and web based software for the remote management of burners and boilers. Our factory laboratories have facilities to test the critical fuel characteristics of recovered sewerage biogases – including key calorific variations. This data then informs the engineering design of burners and boiler shells to optimise specific site combustion efficiency. Dunphy also specialise in the off-site manufacture of modular boiler houses for wastewater treatment sites. Our assembly hall adjacent to our main factory complex allows the construction of double tier containerised plant rooms which are delivered to site fully equipped and tested. The plant is ATEX compliant and we prepare all FDS reports, DSEAR analyses, SIL and risk assessments. Examples of our prefabricated energy centres can be seen on Thames Water, Severn Trent and Scottish Water sites – as well as municipal waste to energy locations. Dunphy customers benefit from direct contact with our engineers through the processes of project design, equipment manufacture and testing, installation and commissioning thus by-passing the alternative, lengthy third party contractual chain. Our customers include: Dŵr Cymru Welsh Water Uisce Éireann Northumbrian Water Severn Trent Scottish Water Southern Water Thames Water United Utilities Wessex Water Yorkshire Water

    Renewables & Energy Management
    Eliquo Hydrok Ltd logo

    Eliquo Hydrok Ltd

    United Kingdom

    ELIQUO HYDROK works with all major UK and Ireland water companies, providing practical water engineering solutions. As a specialist engineering firm with head office in Indian Queens, ELIQUO HYDROK operates at the forefront of innovative and sustainable water treatment technologies. We support the entire UK water sector, supplying every water company. Part of ELIQUO WATER GROUP, the extensive portfolio includes solutions for wastewater management, wastewater treatment, clean water treatment and surface water management; Mecana PCMF, aeration technologies, CSO screens, flow controls, storm tank flushing and Raw Water Intake Screens. Plus, a sludge treatment portfolio that helps reduce costs, improve efficiency, and meet environmental compliance requirements – through systems like ELOVAC® for vacuum degassing, and other integrated technologies in biogas, digestion, dewatering and drying. With established teams in Cornwall, Wolverhampton and Wombwell, ELIQUO HYDROK are well-equipped to support operations – from start to finish; with design, manufacture, management and install capabilities – across the UK and Ireland. This wealth of in-house expertise is backed by a forward-thinking mindset to help customers achieve their long-term goals sustainably; to deliver results in AMP 8 and beyond.

    Treatment Works Products/Services
    Asset Maintenance & Rehabilitation
    Evergreen Water Solutions logo

    Evergreen Water Solutions

    United Kingdom

    A leading supplier of progressive wastewater treatment systems Evergreen Water Solutions works closely with a number of international engineering companies whose expertise are in scalable wastewater treatment systems and containerised wastewater treatment systems for municipal and industrial application. Evergreen Water Solutions offers a comprehensive engineering service. Our company incorporates initial design and planning, to implementation of projects that are delivered on time and on budget. Our expertise in wastewater treatment covers infrastructure development, package sewage treatment systems and advanced treatment technology for wastewater recycling with the strictest treatment requirements. The goal of Evergreen Water Solutions is to exceed the expectations of our clients, foster long-term relationships, and make a positive impact on the environment and industry standards. Evergreen Water Solutions use innovative products and suppliers to source, design and implement leading environmental water and wastewater treatment products and solutions. All new equipment and suppliers are required to undergo pre-qualification program and a series of acceptances and trials are applied prior to the approval of the vendor. Evergreen Water Solutions’ pre-qualification program guarantees you our clients that the products we source are of the highest standard within the industry, these products along with the expertise within Evergreen Water Solutions ensures that the solution we provide will meet and exceed any expectation you might have.

    Treatment Works Products/Services
    Contractors
    JN Bentley Ltd logo

    JN Bentley Ltd

    United Kingdom

    JN Bentley Ltd (JNB) is a leading, privately owned construction services provider in the UK. We now have an annual turnover in the region of £100 million, generated from projects in both the building and civil engineering markets. JN Bentley JN Bentley delivers civil engineering contracting services, together with mechanical and electrical expertise. Founded in 1972, the company has grown largely from repeat work, maintaining a focus on providing construction services with an open and honest approach. The JN Bentley team numbers over 2,000 colleagues. We pride ourselves on our large, directly employed construction workforce, a team that gives us and our clients added assurances for safety and quality. We look to find innovative solutions to traditional construction challenges, applying the latest technologies to drive efficiency and reach sustainable outcomes. Across JN Bentley and our design and build companies MMB and JBA Bentley, annual revenue now exceeds £500 million. Mott MacDonald Bentley (MMB) MMB provides fully integrated civil engineering feasibility, design, construction and commissioning services to the UK water sector. Established in 1999, it harnesses the contracting strength of JN Bentley and the design specialisms of Mott MacDonald to form a 3,000-strong team – with further expertise brought in from across the Mott MacDonald Group when required. MMB was formed specifically to deliver long-term, high-volume capital programmes collaboratively with water companies. With a focus on innovation, affordability, and flexibility, since securing its first contracts with Yorkshire Water in AMP3, MMB has grown to deliver work for eight of the largest water companies in the UK.

    Renewables & Energy Management
    Contractors
    Mott MacDonald logo

    Mott MacDonald

    United Kingdom

    We are proud of being a world-class independent management, engineering and development consultancy. Being independent, wholly owned by our people, puts us in charge of our own journey and allows us to focus on what we believe is important for our clients, our colleagues and the communities we work and live in. We have more than 100 years’ experience in the water sector and are experts in every aspect of water development, with all the skills and commitment to deliver solutions that benefit every stakeholder.  We also established Mott MacDonald Bentley more than twenty years ago to deliver long-term programmes of work through a strategic focus, effective communication and flexibility in different models of working.  We are experts at building a trusted relationship with our clients. From investment planning to operational support, design to capacity building we work with private investors and listed companies, as well as national and local governments across the world in both developing and developed regions. As advisors, we think laterally and find the connections that others fail to make. We are pioneers with a thirst for innovation, who understand the challenges facing the water industry today, including biodiversity net gain, natural capital and ecosystem services, the practicalities of the journey to net zero, nature-based solutions and natural flood management and the need to consider everything from a fresh angle and turn obstacles into sustainable paths for both businesses and the lives they touch every day.

    Renewables & Energy Management
    Designers
    PBJ Engineering Services Ltd logo

    PBJ Engineering Services Ltd

    United Kingdom

    Do you need Thermal Hydrolysis Plant operational support, training and maintenance? Does your critical water process equipment require contract support and safety assurance? Visualise your assets and maintain operational efficiency through our 360 degree image capture. Invest in your operations through our professional training and technical support services. PBJ Engineering delivers a range of services to support your wastewater treatment and process facilities – we specialise in THP systems and Steam Boiler services, including CEA and BOAS accreditation.  Our team is available nationally to support you, on a contract, project or emergency basis. Supporting your facility and team with a programme custom designed to your needs, typically includes elements of: Whole System Contracts Consultation and Best Practice Commissioning and Maintenance Optimisation and Monitoring Refurbishment and Rebuild Component Fabrication and Supply Training for BOAS and CEA accreditation Some of our typical on-site activities include full capabilities in; Thermal Hydrolysis Plants Steam Boilers Sludge Dewatering Processes Water Treatment Coil and Heat Exchangers Pumps Our ancillary support services includes; 360O Image Capture – Virtual Plant Training and Maintenance Boiler Log Books – Custom design & print Boiler House design – Advice and guidance Equipment – Hire services and component spares Our priority is the safety of all personnel and the operational efficiency of your facilities.  We work with you and your team, to maintain and support your infrastructure – protecting your people, investment and optimising your asset performance. Our team is qualified with CITB / SMSTS, Achilles, and CEA / BOAS. Project involvement includes: Thames Water: Basingstoke THP (commissioning, operation, training, optimisation, maintenance) Beckton THP (energy surveys) Chertsey THP (operation, training, optimisation) Crawley THP (commissioning, operation, training, maintenance, part supply) Crossness THP (operation, optimisation, energy reduction, training, energy surveys) Longreach THP (operation, training, optimisation) Oxford THP (operation, optimisation, fault finding) Riverside THP (water treatment installation, design, energy surveys) Severn Trent: Finham THP (operational support) Strongford THP (operation, training) Southern Water: Goddards Green THP (operational support & performance monitoring) Others: Nestles – Trowbridge – steam boiler operational contract (24 hour call out) Heathrow airport – hot water boiler – scale cleaning

    Renewables & Energy Management
    Asset Maintenance & Rehabilitation
    Spaans Babcock Ltd logo

    Spaans Babcock Ltd

    United Kingdom

    Spaans Babcock was established in 1897 and has been supplying equipment into the water industry since this date. The company are the world’s largest supplier of Archimedes screws having thousands of screws installed throughout the UK & tens of thousands worldwide. Additionally the company supply, install and maintain aeration equipment (surface and brush aerators), screens and screenings handling equipment, a complete range of flow isolation equipment including penstocks, flap valves and stop-boards. Over recent years the company has expanded significantly with the addition of Archimedes screw generators to its product range. This is a natural progression for the product which is perfectly suited to low head applications, they offer several advantages over alternative technologies including no requirement for fine screens, fish friendliness, non-blocking and low maintenance due to the simple & robust design. The screw generator is offered in various alternative designs to suit given site circumstances. Spaans have agreements in place with many of the UK Water companies & agencies for the design, manufacture, supply, installation and maintenance of their equipment. Centrally based in Heywood, the company offers a full range of services from supply only contracts through to development of complete bespoke packages. Project management is handled by the companies own project teams and the company has its own SHE officer to ensure compliance with the stringent UK requirements. All installation and maintenance work is handled by in house teams of engineers.

    Renewables & Energy Management
    Veolia Water Technologies UK logo

    Veolia Water Technologies UK

    United Kingdom

    Veolia Water Technologies (VWT) provides an unrivalled combination of capabilities in the UK for the treatment of water, wastewater, sludge and odour. VWT provide turnkey solutions from feasibility studies, design and build and supply and installation of packaged treatment solutions, through to the extension or refurbishment of existing water and wastewater facilities. The company’s investment in Research & Development focuses on developing the most innovative solutions for its municipal and industrial clients, while at the same time considering the environmental challenges being faced. VWT’s goal is to develop sustainable and technologically superior solutions that balance the demand for efficient and cost effective technology whilst protecting the environment by looking at energy consumption, carbon emissions, odour pollution and safe guarding water quality. With over 125 years of experience in the UK, VWT is able to draw upon an unsurpassed knowledge of traditional and innovative solutions in order to meet the demands of both industrial and municipal clients. Performance is measured by the global satisfaction of VWT’s customers. Their technical creativity is reflected by a prestigious track record of extensive references in the UK and across the world supported by operational experience. A partnership with VWT provides the unique benefits of technical excellence, innovation, reliability and a trusted partnership. VWT offers a range of proprietary technology for applications to treat Drinking Water, Wastewater, Sludge Treatment, Odour Treatment and Industrial Effluents.

    Treatment Works Products/Services
    Asset Maintenance & Rehabilitation

    Sludge-to-Energy Technologies: Anaerobic Digestion, Thermal Hydrolysis, and Combustion

    Sludge-to-energy converts the chemical energy contained in sewage sludge organic matter into useful forms: biogas (methane, CH4) via anaerobic digestion; heat and electricity from biogas combustion in CHP (combined heat and power); or thermal energy from sludge incineration. Sewage sludge energy content: raw primary sludge 23 to 28 MJ/kg DS (similar to biomass); digested sludge 12 to 15 MJ/kg DS (after organic destruction); digestion typically destroys 35 to 55 percent of VS (volatile solids) and generates biogas at 350 to 450 L CH4/kg VS destroyed. Specific biogas yield: primary sludge 400 to 500 L/kg VS added; WAS 200 to 300 L/kg VS added; mixed primary + WAS 300 to 380 L/kg VS added. Biogas composition: 60 to 70 percent CH4, 30 to 40 percent CO2, trace H2S (100 to 3,000 ppm), siloxanes (from personal care products - must be removed before engine use). UK water companies generate approximately 1.2 TWh/year of electricity from biogas CHP, meeting approximately 30 percent of their treatment energy demand.

    Thermal hydrolysis pre-treatment (THP) significantly improves anaerobic digestion performance. THP process (Cambi, EXELYS, Veolia Biothelys): dewatered sludge (16 to 18 percent DS) is pasteurised at 165 to 180 degrees C and 6 to 8 bar for 20 to 30 minutes, then flash-cooled to atmospheric pressure ('flash'); cell walls are ruptured, releasing intracellular organics and improving biodegradability. Post-THP digestion: volatile solids destruction increases from 35 to 45 percent (conventional) to 55 to 65 percent (THP + digestion); biogas yield increases 30 to 50 percent; digester feed can be increased from 4 to 6 percent DS to 10 to 12 percent DS (reducing digester volume by 50 percent). UK THP installations: Cambi systems at Beckton (Thames Water, 6 trains, 80,000 tonnes DS/year), Davyhulme (United Utilities), Edinburgh (Scottish Water). THP also achieves Enhanced Treated Sludge (ETS) classification under ADAS Safe Sludge Matrix, enabling agricultural land application without the restrictions of conventional digested sludge.

    Sludge combustion (incineration and co-incineration): dedicated mono-incineration destroys all organics, pathogens, and pharmaceuticals/microplastics; produces non-leaching ash (rich in phosphorus, 10 to 15 percent P2O5) suitable for phosphorus recovery via thermal/acid extraction (Ash2Phos, Stuttgarter Verfahren) or direct cement clinker incorporation. Incineration process: fluidised bed combustion (FBC, Andritz, Veolia, Babcock and Wilcox) at 850 to 900 degrees C is preferred for sludge (self-sustaining combustion at DS greater than 35 percent NCV greater than 5 MJ/kg; supplementary fuel if below); waste heat recovered as steam for turbine electricity generation or heat export. Air emission controls (WID/IED Annex VI): selective non-catalytic reduction (SNCR) or selective catalytic reduction (SCR) for NOx; bag filters for particulates; activated carbon injection for dioxins and mercury; wet scrubber for SO2 and HCl; dioxin TEQ less than 0.1 ng/Nm3. Gate fee for dedicated sludge incineration: GBP 60 to 120 per tonne wet cake (25 percent DS). Co-incineration in cement kilns and power stations: lower gate fee (GBP 30 to 80/tonne) but requires dried sludge (greater than 90 percent DS) and pre-approval under co-incineration permit conditions.

    Frequently Asked Questions

    How much energy can be generated from sewage sludge?

    Sewage sludge energy generation from anaerobic digestion + CHP: a 100,000 PE WwTW producing approximately 5 tonnes DS/day of mixed sludge: biogas yield approximately 300 L/kg VS added at 65 percent VS content: total biogas approximately 975 m3/day; CHP engine at 38 percent electrical efficiency and 45 percent thermal efficiency: electrical output approximately 87 kW (2,100 kWh/day); thermal output approximately 103 kW (2,500 kWh/day heat). Treatment energy demand for 100,000 PE WwTW: approximately 3,000 to 5,000 kWh/day electrical. Thus, biogas CHP typically offsets 30 to 50 percent of site electrical demand. UK industry averages: 0.15 to 0.25 kWh electricity generated per m3 wastewater treated. With THP pre-treatment, biogas yield increases 30 to 50 percent, potentially covering 50 to 70 percent of site energy demand. UK water industry target (Ofwat, Water 2020): energy self-sufficiency; some advanced sites (Anglian Water Cambridge WWTP, Severn Trent Coleshill) claim greater than 100 percent energy self-sufficiency via maximised sludge co-digestion with food waste or FOGS (fats, oils, grease, and sugars).

    What is thermal hydrolysis and how does it improve biogas yield?

    Thermal hydrolysis pre-treatment (THP) applies high temperature (165 to 180 degrees C) and pressure (6 to 8 bar) to dewatered sludge for 20 to 30 minutes before anaerobic digestion. The process ruptures microbial cell walls and hydrolyses complex polymers (proteins, lipids, carbohydrates) that are resistant to enzymatic attack in the digester. Effect on digestion: (1) VS destruction increases from 35 to 45 percent (conventional) to 55 to 65 percent (THP+AD); (2) Biogas yield per tonne VS added increases by 30 to 50 percent; (3) Higher digester feed concentration possible (10 to 12 percent DS vs 4 to 6 percent without THP) - reduces digester volume by 40 to 50 percent; (4) Improved dewatering of digested sludge (30 to 35 percent DS on centrifuge vs 18 to 25 percent without THP). Commercial systems: Cambi (Norway, market leader), EXELYS (Veolia, continuous vs batch), BioThelys (Veolia), Haarslev, Sustec. Capital cost: GBP 3 to 8 million for a 5 to 20 tonne DS/day system. THP also achieves Enhanced Treated Sludge status enabling broader agricultural land application options.

    Can sludge be used as a fuel?

    Yes. Dried sewage sludge (DS greater than 90 percent) has a net calorific value (NCV) of 10 to 15 MJ/kg DS (compared to biomass 14 to 19 MJ/kg and coal 25 to 35 MJ/kg) - sufficient for co-incineration as a substitute fuel. Applications: (1) Cement kiln co-incineration: dried sludge pellets replace coal in cement clinker production; ash incorporated into clinker (recovering inorganic minerals including phosphorus); requires pre-approval under co-incineration permit; typical acceptance criteria DS greater than 90 percent, NCV greater than 10 MJ/kg, heavy metal limits per IED Annex VI; gate fee GBP 30 to 80/tonne dried pellets; (2) Power station biomass co-firing: dried sludge co-fired with biomass at less than 5 percent of fuel blend; permitted at some Drax-type biomass stations; requires similar quality specification; (3) Dedicated sludge incineration with energy recovery: fluidised bed combustion at 850 to 900 degrees C; gate fee GBP 60 to 120/tonne wet cake at 25 percent DS; electricity generated approximately 0.2 to 0.5 MWh/tonne DS (depending on moisture content); (4) Pyrolysis/gasification (emerging): thermal conversion at 500 to 800 degrees C in oxygen-limited environment produces syngas and biochar - limited commercial scale as of 2024.

    What regulations govern sludge-to-energy incineration?

    UK and EU sludge incineration regulations: (1) EU Industrial Emissions Directive (IED, 2010/75/EU), Annex VI: applies to dedicated waste incineration plants (capacity greater than 3 tonnes/hour) and co-incineration plants; sets emission limit values (ELVs): total dust less than 10 mg/Nm3; NOx less than 200 mg/Nm3; SO2 less than 50 mg/Nm3; HCl less than 10 mg/Nm3; CO less than 50 mg/Nm3; dioxins/furans less than 0.1 ng TEQ/Nm3; mercury less than 0.05 mg/Nm3; (2) UK: IED transposed in Environmental Permitting Regulations 2016 (EPR), Schedule 13, Part 2; regulated by EA (England), NRW (Wales), SEPA (Scotland); Environmental Permit required; (3) Best Available Techniques (BAT) conclusions: BREF documents for waste incineration (updated 2019) specify BAT-AELs for UK/EU facilities; (4) EU Sewage Sludge Directive (86/278/EEC): regulates agricultural disposal; under revision 2024 to include microplastics, pharmaceuticals, and PFAS limits; ash from sludge incineration is regulated as waste under EWC code 19 01 07/19 01 11 (hazardous if heavy metal thresholds exceeded); (5) UK EPR Schedule 3B: phosphorus recovery from sludge incineration ash is encouraged under resource recovery provisions.

    Case Study·Wastewater sludge energy recovery
    Challenge

    A regional water company in Yorkshire managing six WwTW with a combined output of 28,000 tonnes DS per year had an ageing CHP fleet averaging 32% electrical efficiency. Rising natural gas prices for digester heating and increasing sludge disposal costs (GBP 68 per tonne wet cake) were eroding the business case for the existing mesophilic digestion and centrifuge dewatering chain.

    Approach

    The company invested in thermal hydrolysis pre-treatment (Cambi THP) at its largest 280,000 PE works, enabling high-solids digestion at 10% DS feed and achieving 60% VS destruction. A new high-efficiency CHP engine (Jenbacher J620, 43% electrical efficiency) replaced two ageing units. Dried biosolids at 92% DS were secured under a 10-year co-incineration contract with a local cement manufacturer at GBP 45 per tonne, saving GBP 23 per tonne versus the previous land-bank contractor route.

    Outcome

    Biogas production increased by 44% per tonne DS input. CHP electricity output rose from 1.8 MW to 2.9 MW, meeting 87% of the works' electricity demand. Sludge disposal cost fell by GBP 336,000 per year. The project achieved positive NPV in year 8 on a GBP 6.2 million capital investment. Carbon reporting showed 1,820 tonnes CO2e reduction per year from grid electricity displacement.

    Questions to Ask Shortlisted Providers

    1. 1

      What is the current biogas yield per tonne VS destroyed and how does this compare to theoretical maximum for the sludge feedstock?

      A significant gap between actual and theoretical yield indicates inhibition (ammonia, VFA, sulphide) or incomplete hydrolysis; identifying the limiting step determines whether THP, co-digestion, or operational changes will unlock the most value.

    2. 2

      Is the digester operating at mesophilic or thermophilic temperature and what is the HRT?

      Thermophilic digestion (55 degrees C) achieves higher VS destruction and meets Enhanced Treated Sludge pathogen requirements but is more sensitive to process upsets; HRT below 15 days in mesophilic systems risks incomplete digestion and reduced biogas yield.

    3. 3

      What is the H2S concentration in the biogas and has siloxane removal been installed before the CHP engine?

      H2S above 100 ppm corrodes CHP engine components and requires iron sponge or biological desulphurisation; siloxanes above 1 mg/Nm3 Si form abrasive silicon dioxide in engine cylinders, reducing engine life to 30 to 50% of design.

    4. 4

      What is the secured biosolids end-use route and what are the gate fees or revenues for different routes?

      Whole-life economics of sludge-to-energy investment depend critically on whether biosolids can access agricultural land application (lowest cost) or must go to incineration/cement kiln (GBP 30 to 120 per tonne gate fee).

    5. 5

      What is the GGSS (Green Gas Support Scheme) eligibility for biomethane injection as an alternative to CHP?

      Ofgem GGSS pays a production tariff for biomethane injected to the gas grid; for sites close to a gas distribution network, biomethane injection may deliver greater revenue than CHP for the same biogas volume, depending on contract terms.

    What Drives Cost in This Category

    Thermal hydrolysis pre-treatment capital and operating cost

    Cambi THP systems for 5 to 20 tonnes DS/day cost GBP 3 to 8 million installed; operating costs include steam generation (from waste heat or gas boiler) at 700 to 900 kWh per tonne DS processed.

    CHP engine capital cost, efficiency, and maintenance

    Gas CHP engines (500 kW to 3 MW) cost GBP 800 to 1,500 per kWe installed; electrical efficiency ranges from 36% (older units) to 44% (Jenbacher J620); major overhaul at 40,000 hours costs GBP 150,000 to 400,000.

    Biogas cleaning (H2S removal and siloxane removal)

    Iron sponge H2S removal costs GBP 0.5 to 2 per 100 Nm3 biogas treated; activated carbon siloxane removal costs GBP 1 to 3 per 100 Nm3; together these protect CHP engine life and are essential capex for long-term CHP economics.

    Biosolids end-use route gate fees and transport

    Agricultural biosolids application costs GBP 20 to 60 per tonne DS including transport and spreading; cement kiln co-incineration costs GBP 30 to 80 per tonne dried; dedicated incineration costs GBP 60 to 120 per tonne wet cake at 25% DS.

    Key Regulations & Standards

    Environmental Permitting Regulations 2016 Schedule 13 (Waste Incineration)

    Sludge incineration plants must hold an EA Environmental Permit; continuous emission monitoring (CEM) required for NOx, CO, SO2, HCl, dust, and total organic carbon; IED ELVs must be met at all times; permit surrender requires site remediation.

    Green Gas Support Scheme (GGSS, Ofgem, 2021)

    Biomethane produced from anaerobic digestion of sewage sludge (eligible feedstock) qualifies for GGSS tariff payment on injection to the gas grid; tariff rates differentiated by technology type and volume; 15-year support period from registration date.

    Climate Change Levy (CCL) and Enhanced Capital Allowance (ECA)

    CHP plants certified under the CHPQA scheme attract CCL exemption on gas used in qualifying CHP; heat and electricity outputs must pass quality thresholds (QA, QE) for full CCL exemption benefit.

    Sludge (Use in Agriculture) Regulations 1989 and Safe Sludge Matrix

    Biosolids produced from thermal hydrolysis + digestion qualify as Enhanced Treated Sludge under the Safe Sludge Matrix; enables application on all agricultural crops except those eaten raw and uncooked; sludge analysis records must be retained for 10 years.