SINGAPORE - Food waste at East Coast Lagoon Food Village is being converted to biogas to generate electricity from November, in a first for Singapore's hawker centres.
Some 60 stalls at the hawker centre generate about 150kg of food waste daily and this translates to enough electricity to power two mobile phone charging stations for public use and up to 31 wall fans at the hawker centre.
The electricity generated is also used to power the anaerobic digestion system that converts the food waste to biogas and fertiliser, said the National Environment Agency (NEA), National University of Singapore (NUS) and the National Parks Board (NParks) in a joint statement on Wednesday (Nov 17).
Anaerobic digestion is a biological process that breaks down organic materials, like those found in food waste, in the absence of oxygen to yield biogas for energy generation.
Anaerobic digesters are already being used in some hotels in Singapore, such as Marina Bay Sands, but the anaerobic digester at the hawker centre in East Coast Park is the first to be installed in a hawker centre.
The agencies said: "This pilot project... examines the feasibility of using anaerobic digestion as an on-site treatment solution to close the food waste loop at the source of food waste generation."
They also said it is an established technology that has been adopted in some countries, albeit mainly implemented off-site or at centralised facilities where food waste is aggregated from neighbouring premises.
The East Coast Lagoon project integrates sub-systems such as a waste bin loader, sorter, shredder and feeder to enhance the system's performance.
"This will automate the loading of food waste and minimise contamination of food waste fed into the anaerobic digestion system," the agencies said.
An NUS team led by Associate Professor Tong Yen Wah from the NUS Department of Chemical and Biomolecular Engineering oversees the operation and maintenance of the anaerobic digestion system.
NUS is also working with NParks to study the potential for using nutrient-rich liquid residues from the digested food waste, also known as digestate, as pathogen-free fertilisers around East Coast Park.
Aerobic digesters, which produce only non-potable water and compost but not biogas, are in use in other hawker centres, such as the one in Our Tampines Hub.
East Coast Lagoon Food Village was chosen as the pilot site as adjacent space was available to house the anaerobic digestion system, while fertilisers could conveniently be applied at the nearby East Coast Park.
"We are identifying pilot sites at East Coast Park to test the efficacy of the digestate as fertiliser, " said Mr Chia Seng Jiang, NParks' group director for parks east.
Digestate refers to the residue of the digestion process.
The agencies noted that food waste is one of the priority waste streams identified under Singapore's Zero Waste Masterplan.
Only 19 per cent of food waste was recycled, even though it accounted for about 11 per cent of the total waste generated in Singapore last year.
"Therefore, reducing food wastage, redistributing unsold or excess food, and recycling or treating food waste are important food waste management strategies," said the agencies.