Perhaps the answer to a more sustainable planet is thinking outside the (used) box. See how NTU scientists are using junk in ingenious ways to fuel our world
by Junn Loh / Video by Hanafi Ramdan
OLD SOLAR PANELS → SILICON FOR BATTERIES
Ever wondered what happens to expired solar panels? They get thrown out, just like most obsolete hardware.
Now there’s an efficient way to save them from the incinerator. The solar panels are simply soaked in phosphoric acid – a substance commonly used in the F&B industry – twice to achieve a high recovery rate of silicon and at a higher purity.
The process is more sustainable and cheaper than existing methods of recycling. Even better, the high-quality silicon recovered is good enough to be used in lithium-ion batteries that power electric vehicles.
PLASTIC → CLEAN FUEL
We all know that plastic can cause huge pollution problems. But life with plastics may become less problematic – with some fantastic ideas to turn them into fuel.
One team took marine litter collected from local waters and converted it into hydrogen and carbon products for clean electricity generation.
Another team developed a chemical process that uses light and a catalyst to break down the stubborn polymer bonds of plastics. Acids formed during this eco-friendly process can be applied in the production of green fuels such as hydrogen.
TAMARIND SHELLS → ELECTRICAL CONDUCTORS
A quintessential tropical fruit, tamarind is a key ingredient in dishes like assam prawns and pad thai. The shell of the pod-like legume need not be thrown away during food production, since it can be used to conduct and store electricity.
This is done by exploiting the rich carbon makeup and porous nature of the tamarind shells, turning them into extremely thin sheets that can conduct electricity in energy storage devices for cars, trains and lifts.
SEE WHAT OTHER TRASH NTU SCIENTISTS HAVE TRANSFORMED INTO TREASURE
ORANGE PEELS → PRECIOUS METALS
On the NTU Smart Campus, food isn’t just fuel for us, it’s also juice that powers up the environment. Citrus peels that are normally discarded can be used to turn old batteries into new ones.
The dried citrus peels are ground up into a powder and combined with citric acid to extract and reuse precious metals from spent lithium-ion batteries to create brand new ones. This method is an environmentally friendly alternative to the harmful chemicals and high temperatures used in common battery recycling processes.
Plus, 90% of precious metals were extracted from the old batteries, comparable to current approaches. Now that’s a-peeling.
WASTEPAPER → CARBON FOR BATTERIES
Don’t discard your used paper bag just yet, since cheap wastepaper can be turned into crucial battery parts – all while releasing hardly any greenhouse gases.
Wastepaper is cut into smaller pieces and exposed to high temperatures, reducing it to pure carbon anodes, which are essential electricity-storing components in batteries.
This story was published in the Sep-Oct 2023 issue of HEY!. To read it and other stories from this issue in print, click here.
