Nanyang Technological University, Singapore and the National Environment Agency (NEA) have started a new Waste-to-Energy Research Facility that converts municipal solid waste from the NTU campus into resources and electricity.
(Video credit: Nanyang Technological University)
Its launch has helped to move closer toward Singapore’s goal of becoming a zero-waste nation.
The facility is situated in Tuas South and is a $40 million project supported by the National Research Foundation Singapore, NEA, the Economic Development Board (EDB), and NTU, for its development and operation over its estimated lifetime.
The innovative facility in Singapore is supervised by NTU and accommodates an exclusive slagging gasification plant, which can heat up to 1600 ○C, in contrast to traditional mass burn incinerators which work at almost 850 ○C.
The high temperature of the plant converts rubbish into syngas (predominantly hydrogen and carbon monoxide) that can be used to generate electricity, slag (a glass-like material that can possibly be used as a building material), and metal alloy granulates that can be recycled.
The plant designed and constructed by a multidisciplinary group from NTU, working closely with national agencies and industry, was opened by Guest-of-Honor, Mr Masagos Zulkifli, Minister for the Environment and Water Resources on 27th May, 2019.
The research facility, headed by NTU’s Nanyang Environment and Water Research Institute (NEWRI), will assist test-bedding of ground-breaking technologies for turning waste into energy and useful materials through unique plug-and-play features. These technologies, if verified successful and implemented, can allow recovery of more energy and materials from waste, thus extending the lifetime of Semakau Landfill.
In Singapore’s perspective, slagging gasification technology holds promise in complementing the current mass burn technology since it can treat different mixed waste streams that cannot be managed by these current mass burn incinerators.
This slagging gasification plant also represents another first with the use of “clean” biomass charcoal as auxiliary fuel—an exceptional combination that has not yet been established in the market.
The new research facility makes NTU the sole educational institution in Singapore to treat all of its solid waste using its own amenities.
As a global leader in green technologies, NTU has deep expertise in waste management and environmental technologies. Being able to treat our own campus waste and to use it for research is well aligned with the NTU Smart Campus vision, to be a living testbed for advanced tech-enabled solutions aimed at tackling some of the most pressing challenges which Singapore and the world are facing. The NTU and NEA Waste-to-Energy Research Facility will enable our scientists to scale up promising ideas from lab prototypes into practical engineering solutions for sustainable waste management, contributing to NTU’s aspiration to become a zero-waste campus and Singapore’s vision of a zero-waste economy where waste is upcycled into valuable resources.
Professor Subra Suresh, President, NTU
This partnership with NTU Singapore reflects NEA’s expanding focus on waste management technologies, building on NEA’s traditional strengths in waste-to-energy facilities. The Waste-to-Energy Research Facility is the first of its kind in Singapore. It achieves both waste-to-energy and waste-to-resource at one waste treatment facility, producing syngas to power the plant and slag which can be used for construction. The launch of this research facility in this Year Towards Zero Waste is thus timely, and holds special significance.
Mr Tan Meng Dui, Chief Executive Officer, NEA
Possible Research Projects at the New WtE Research Facility
For the next few years, NTU researchers and engineers from NEWRI will work together with industry and academic partners to begin different research projects intended to create and test technologies in the waste-to-energy domain.
One of the special features of the research facility is the potential to test-bed new technologies in “plug-and-play” style, which has the ability to process various feeds such as incineration bottom ash, municipal solid waste, and sludge; provisions for the assessment of gas separation technologies to supply enriched-oxygen air; syngas upgrading; and innovative flue gas treatment methods.
How the Gasification Plant Works
Municipal waste from the NTU campus is carried to the facility, which can treat 11.5 tons of waste every day.
The waste is separated, shredded, and carried through a conveyor and a bucket lifted to the top of the furnace tower to be fed along with biomass charcoal that aids in maintaining the high temperature of the molten slagging layer at the base of the furnace.
As the waste moves down the furnace, it is dried and gasified. Around 85% of the waste weight will be converted into syngas, 12% into slag and metal alloy, and 3% into fly ash.
The syngas travels from the top of the furnace to the secondary combustion chamber, where it is incinerated to heat a boiler to produce steam.
The steam then induces a turbine-generator to produce electricity to compensate the energy consumption to run this research facility. In such a commercial larger scale plant, the amount of electricity output could be adequately substantial to self-sustain the plant operations with the surplus channeled into the electricity grid.
The exhaust flue gas from the boiler is subsequently treated with activated carbon and slaked lime and passed through bag filter, prior to being released as purified gas via a stack into the atmosphere.
In the future, NTU hopes to collaborate with more companies to create and test new solutions at this open test-bed facility that intends to contribute to Singapore’s mission to be a more sustainable nation.