New facility to turn food waste, used water sludge into electricity

Currently, used water treatment plants in Singapore generate 20 to 25 per cent of their energy from biogas obtained from sludge alone, and the addition of food waste is expected to raise energy production to 50 per cent.
Loke Kok Fai Channel NewsAsia 17 Jun 15;

SINGAPORE: A newly-announced facility in Ulu Pandan will soon turn both food waste and used water sludge from water reclamation plants into electricity.

Announced on Wednesday (Jun 17) by Singapore’s national water agency PUB and renewable energy company Anaergia at the Singapore International Water Week, the demonstration facility will mix and process up to 40 tonnes of food waste from Clementi district and used water sludge from the Ulu Pandan Water Reclamation Plant daily into biogas for electricity generation.

It is estimated that the addition of food waste will raise energy production to 50 per cent of the plant's needs. Currently, used water treatment plants in Singapore generate 20 to 25 per cent of their energy from biogas obtained from sludge alone.

"This could potentially allow the used water treatment plant to achieve energy self-sufficiency," said PUB's Chief Technology Officer Harry Seah.

The National Environment Agency will conduct a district-level pilot for the collection of source-segregated food waste from the premises of educational institutions, hospitals and camps among others, for the 2,000 square metre demonstration plant, which will be completed in September 2015.

If found to be viable over the course of about a year, the technology would be implemented in future plants, such as the future TUAS Water Treatment Plant in 2024, with a goal of having up to 70 per cent of that plant's energy supplied by this process.

- CNA/av

Singapore to use food waste to boost energy creation
SIAU MING EN Today Online 18 Jun 15;

SINGAPORE — When it comes to transforming waste to electricity, the sum of the parts is indeed greater than their whole. By adding food waste to the process of turning used water sludge into electricity, twice as much power can be produced compared with the conventional method that digests only used water sludge.

Such technology will be tested at a new facility launched by national water agency PUB and clean-energy firm Anaergia today (June 17) at the Singapore International Water Week Technology and Innovation Summit. The co-digestion plant will be Singapore’s first, though the technology is already in use in America and Europe.

Currently, electricity generated by converting only used water sludge can meet about 20 to 25 per cent of a water-reclamation plant’s needs. With the technology offered by the co-digestion plant, the electricity produced may meet about 50 per cent of the plant’s needs.

Used water sludge is a by-product from treating used water. This is anaerobically digested in PUB water-reclamation plants — the process of breaking down organic materials without oxygen. The resulting biogas is used as fuel to produce electricity.

At the new co-digestion plant, wet organic fraction from food waste will be mixed into used water sludge. The thickened mixture will then be anaerobically digested. The mix can produce more biogas because of the higher calorific value in food waste, said a PUB spokesperson.

As the technology is in its testing phase, the plant will be able to treat only up to 40 tonnes per day of combined used water sludge from the Ulu Pandan Water Reclamation Plant and food waste collected from an upcoming food-waste recycling pilot in Clementi. It can produce about 6,000kW of electricity each day, said Anaergia’s chairman and chief executive officer Andrew Benedek at the launch.

In March, Second Minister for the Environment and Water Resources Grace Fu announced plans for a district-level pilot, where segregated food waste would be collected from premises such as shopping malls, schools, hospitals and office buildings for anaerobic co-digestion. Clementi was chosen for its close proximity to the water-reclamation plant.

Food waste accounts for about 10 per cent of total waste generated in Singapore, but less than 15 per cent of it is recycled. Last year, 788,600 tonnes of food waste were generated, of which only 13 per cent was recycled. The rest was incinerated — a process that also generates electricity — and then disposed of in landfills.

Speaking to reporters, PUB chief technology officer Harry Seah said instead of incinerating food waste, more energy could be produced when food waste is first processed in a co-digestor. “We think that if we are to segregate food waste properly, segregate it first and produce biogas, then send for incineration, (we will get) more energy,” he said, adding that the co-digesting process produces 30 per cent more energy than directly incinerating food waste.

Currently under construction at the Ulu Pandan Water Reclamation Plant, the co-digestion plant will be ready in September. Mr Seah added: “The result of this demonstration plant will validate the efficiency and cost-effectiveness of co-digestion implementation in Singapore, potentially reducing its carbon footprint and maximising energy production.”

If successful, the technology could be used at the coming Tuas Water Reclamation Plant and the National Environment Agency’s Integrated Waste Management Facility.

“The success of this project will provide opportunities for a water-reclamation plant like ours to generate enough energy for process use and bring us closer to achieving energy self-sufficiency for used-water treatment in Singapore,” Mr Seah added.

Food waste from Clementi to be collected for electricity project
Victor Loh AsiaOne 17 Jun 15;

The Public Utilities Board (PUB) announced today in a joint statement with Anaergia Pte Ltd the commencement of Singapore's first project to convert the organic compost into biogas using the Anaerobic bacteria, which can then be used to generate electricity.

Used water sludge from the Ulu Pandan Water Reclamation Plant (WRP) will be mixed with food waste collected from the Clementi district and treated in a co-digestion demonstration facility.

This new combined treatment of used water sludge and food waste has the potential to produce more biogas due to the higher calorific value in food waste, PUB said.

The co-digestion plant can treat up to 40 tons of the water sludge and food waste concoction without requiring oxygen to produce biogas using a patented process by Anorexia.

Food waste from premises in Clementi, such as educational institutions, hospitals, and camps, will be collected by the National Environment Agency (NEA) for co-digestion at the demonstration plant. The demonstration plant is currently under construction and will be completed by September 2015.

"[The demonstration plant] will provide the opportunity for the water reclamation plants to generate more electricity for process usage," Harry Seah, Chief Technology Officer, PUB, said.

"This could potentially allow the used water treatment plant to achieve energy self-sufficiency, which is using only as much energy as the treatment process itself generates."

If successful, the process could potentially be implemented at the future Tuas Water Reclamation Plant and NEA's Integrated Waste Management Facility.

The memorandum of understanding between Anaergia and PUB signed during the Singapore International Water Week (SIWW) in 2014, to explore potential research and technological collaboration, particularly in the domain of waste-to-energy.

Along with this investment, Anaergia will establish and operate its Asia Pacific Headquarters in Singapore, to serve as its base for engineering services and project management in supporting their operations in the Asia Pacific.

This project was supported with a co-funding grant from the Technology Pioneer (TechPioneer) Scheme, administered by the Singapore Economic Development Board (EDB) on behalf of the Environment and Water Industry Programme Office (EWI).

This scheme encourages water companies to tap on Singapore to testbed cutting edge technology and commercialise it in an actual operating environment. A total of 150 projects involving the testbedding of water solutions have been facilitated at PUB's installations, and more than 20 test-bedding projects are currently on-going at PUB's facilities.

New plant mixes food waste, used water to produce energy
Audrey Tan Straits Times AsiaOne 19 Jun 15;

Singapore is exploring a new way to turn unused calories into energy, and may one day be able to convert the thousands of tonnes of food dumped here each day into valuable energy sources.

When organic material in food waste and sludge from used water react with bacteria, this produces biogas for electricity generation. And a new 2,000 sq m demonstration plant at the Ulu Pandan Water Reclamation Plant will be the first in Singapore to make use of this reaction when it begins operations in September.

The co-digestion facility was launched by national water agency PUB and technology company Anaergia yesterday, the second day of the Singapore International Water Week Technology and Innovation Summit.

The PUB demonstration plant can treat up to 40 tonnes of combined food waste and used water sludge. A drop in the ocean compared with the amount of such waste produced here, but the facility will be a test-bed to see if similar processes can be rolled out elsewhere.

The country's four water reclamation plants, including the one in Ulu Pandan, are already producing biogas from sludge, which supplies up to one quarter of each plant's electricity needs. By combining used water sludge with food waste, the amount of biogas produced can be doubled due to the higher calorific value in food waste, PUB said.

Said Anaergia chairman and chief executive Andrew Benedek: "The idea is to take waste from a waste water plant and turn that into energy, and extend it further by adding food waste, and doing so efficiently, so you can turn a waste water plant into a sustainable plant, energy-wise."

The plant will run for a year and a half before the authorities decide if the technology can be used at the future Tuas Water Reclamation Plant and the National Environment Agency's (NEA) Integrated Waste Management Facility, which are located together, when the facility is ready in 2024.

PUB's chief technology officer, Mr Harry Seah, noted that if the effort was successful, Anaergia's patented technology could supply at least 50 per cent of the future plant's electricity demand.

The hope is that the plant could eventually achieve energy self-sufficiency, using only as much energy as the treatment process itself generates.

The technology harnesses anaerobic digestion, a biological process that breaks down organic materials without oxygen, to produce biogas.

Food accounts for one-tenth of all waste produced here. About 788,600 tonnes of food was thrown away last year, slightly less than the 796,000 tonnes in 2013, but still much more than the 606,100 tonnes in 2009. Only 13 per cent of last year's food waste was recycled.

Minister for the Environment and Water Resources Vivian Balakrishnan noted at the summit opening on Tuesday that as Singapore lacks a significant agricultural sector and as a lot of energy is wasted in food incineration, the best way forward was to recover the energy from food and use it to recycle used water.

"This project is significant, because it... potentially increases the yield of water from our recycling plants."