Biogas to power mighty $1.5 billion integrated waste management facility in Singapore
Singapore’s National Environment Agency (NEA) has signed a US$1.5bn contract for the delivery of the Tuas Nexus Integrated Waste Management Facility (IWMF), which includes a 400 tonnes per day (tpd) anaerobic digester.
The IWMF is an integral part of NEA’s long-term plan to meet Singapore’s solid waste management needs and is the city’s first integrated facility to treat incinerable waste, source-segregated food waste and dewatered sludge from national water agency (PUB) Tuas Water Reclamation Plant (Tuas WRP) at a single facility.
Under the contract, the consortium, comprising Keppel Seghers Engineering Singapore Pte Ltd, China Harbour (Singapore) Engineering Company Pte Ltd and ST Engineering Marine Ltd, will design, construct and commission a 2,900 tonnes per day (tpd) Waste-To-Energy (WtE) Facility and a 250 tpd Materials Recovery Facility (MRF) as part of IWMF Phase 1 development. The MRF will sort household recyclables collected under the National Recycling Programme.
A separate IWMF Phase 1 engineering, procurement and construction contract for an 800 tpd Sludge Incineration Facility and a 400 tpd Food Waste Treatment Facility is in the tender phase and will be awarded later this year.
Biogas to improve overall plant performance
The IWMF will be co-located with PUB’s Tuas WRP to collectively form the Tuas Nexus. The integration of solid waste and used water treatment processes at Tuas Nexus has been designed to harness various synergies between the processes to improve overall plant performance and optimise land use.
Some of the key Tuas Nexus synergies include the co-digestion of IWMF source-segregated food waste with Tuas WRP’s dewatered sludge to improve biogas production. The biogas produced will then be combusted at IWMF to improve overall plant thermal efficiency and boost electricity generation.
The electricity generated by IWMF will be sufficient to sustain the operations of Tuas Nexus and excess electricity will be exported to the grid. The amount of excess electricity exported to the grid by IWMF when it is fully operational will be able to power up to 300,000 four-room HDB apartments.
A circular economy benchmark for the treatment of waste
“The concept of the Tuas Nexus has stirred a lot of interest in the global waste management 
industry, as well as in the used water treatment industry. It marks a new chapter for solid waste and used water treatment here in Singapore based on a circular economy approach,” said Mr Tan Meng Dui, CEO of the NEA.
“It is the first greenfield project that involves the development of two mega waste treatment facilities located side-by-side to exploit co-location synergies, and one that will spin off many similar circular economy developments in the years to come.”
Singapore aims to reduce the average daily amount of waste sent to Semakau Landfill by 30 per cent from 0.36 kg/capita in 2018 to 0.25 kg/capita by 2030. IWMF will help Singapore achieve long-term environmental sustainability goals by improving resource and energy recovery from waste.
