New S$20m lab to develop less toxic e-waste recycling methods

SINGAPORE: A S$20-million research centre which aims to develop greener ways of recycling electrical and electronic waste (e-waste) was launched on Wednesday (Mar 13) by the Nanyang Technological University (NTU) and French Alternative Energies and Atomic Energy Commission (CEA).

The centre focusing solely on e-waste recycling is believed to be a world-first.

Among its goals: To extract substantially more valuable metals from lithium-ion batteries and to recycle silicon from solar panels.

The centre, called the NTU Singapore-CEA Alliance for Research in Circular Economy, also wants to make the process of recycling printed circuit boards cheaper and more environmentally friendly, and to detoxify more plastic parts in e-waste, given that plastics form a major part of devices like printers and flat screens.

READ: 60% of large electrical appliances must be collected for e-waste recycling

To recycle lithium-ion batteries more efficiently, the centre has developed a shredder which can crush the batteries in an oxygen-less environment, necessary to prevent them from burning up.

Current industrial methods involve incineration, which is costly and energy-intensive, producing toxic fumes that might pollute the environment.

With the new method, researchers can extract valuable metals from the crushed material by dissolving it in a chemical solution and then letting it precipitate in a process called hydrometallurgy.

The centre aims to extract up to 75 per cent by weight of valuable materials like lithium, cobalt and manganese – 15 times more than the current 5 per cent. These can be used to produce new lithium-ion batteries, commonly found in laptops, smartphones and electric vehicles.

Hydrometallurgy can also be used to detoxify plastic parts in e-waste. Currently, only a small amount of this plastic is recycled as it is difficult to separate and remove. It also contains flame retardants that are toxic to human health and the environment.

After detoxifying the plastic, the plastic is put through an advanced process which involves heating it using microwaves and breaking it down into fuel.

In addition, the centre is exploring how this high-grade plastic can be used for “novel applications”, like filaments for 3D printing and as a base to grow stem cells.

It is also looking into new ways of recycling printed circuit boards to replace current industrial methods, which emit harmful pollutants that have to go through costly treatment processes before they can be safely released into the environment.

Instead, researchers first use X-ray sorting to separate components into different groups based on their metal content. This allows them to choose the best chemical method of recycling, reducing costs by about 20 to 30 per cent.

One new method involves the use of a carbon dioxide-based fluid to “trap” the metals; the carbon dioxide is then re-converted into recyclable gas, leaving behind only the metals.

For silicon-based solar panels, the centre aims to extract the silicon from the panel. This silicon, which requires a lot of energy to make, can be used to produce new panels and reduce the costs involved.

Currently, industries only recycle the metal frame, glass surface and silver components in a solar panel as it is difficult to separate the thin silicon, which is glued tightly to the rest of the layers.

To overcome this, researchers use a technique called delamination, which involves dislodging the glue using benign means – as opposed to heating – that will not destroy the silicon. These include the use of environmentally friendly solvents, and bacteria or microorganisms to “eat” the glue.

ARE THESE TECHNOLOGIES SCALABLE?

The two organisations and the National Environment Agency (NEA) will pour S$20 million into the collaboration, which comes after the Government identified e-waste as a major stream of trash under its zero waste masterplan.

The Government will also implement a mandatory e-waste management system by 2021.

READ: Compulsory e-waste management system to be enforced by 2021

Singapore generates about 60,000 tonnes of e-waste a year, equivalent to the weight of 220 Airbus A380 airplanes.

“This is a significant and timely development,” Senior Minister of State for the Environment and Water Resources Amy Khor said at the launch of the centre. “We are investing in research and development (R&D) in close partnership with industry and research institutions to overcome technological barriers.”

Co-director of the centre, Professor Madhavi Srinivasan, said the aim is for a majority of these technologies to be scalable within the next three years. This means ensuring it can work with 10kg to 100kg of e-waste, before partnering with the industry for larger-scale testing.

On Wednesday, the centre also signed a letter of intent with four companies – battery producer Durapower, chemicals company Arkema, electric car sharing firm BlueSG and e-waste recycler Virogreen – to kickstart research with industry.

NEA’s director of environment technology Patrick Pang said he was impressed by the progress made by the centre, which was first announced last August.

“(The Government’s) interest in this is to make sure the R&D results in options (that are) proven to be cost-effective and of course environmentally safe,” he said.

Mr Pang added that the Government can adjust its infrastructure plans, which can include setting up purpose-built plants to treat e-waste.

“The actual data of e-waste collected and recycled will allow us to size the appropriate facilities,” he said.

However, Mr Pang added that it was too early to commit to a timeline, or tell how many of such facilities there will be.

“As R&D powers our enterprises and creates new opportunities for (the centre and the companies), it will also create highly skilled jobs for our citizens,” Dr Khor said.