Researchers have discovered a way to break down plastic into useful chemicals, using artificial lighting.
In the past ten years we have produced more plastic than in the previous 100 years. Of the 300 million tonnes of plastic produced on average each year, around 12 million tonnes end up in the oceans. A small handful of this waste is recycled. The rest is either buried or burned.
Besides our efforts to break away from this incredible addiction to plastic, we also need to find ways to break it down. Methods exist. We are thinking in particular of common catalysts made from expensive and toxic metals such as platinum, palladium or ruthenium. To melt the plastic, fossil fuels are also used.
A new, more respectful method
The ideal would be to be able to decompose plastic waste with a less expensive and more environmentally friendly method. The solution could come from Singapore. Researchers at Nanyang Technological University say they have been able to break down plastic into useful chemicals using light. They detail their work in the journal Advanced Science.
For this study, the researchers used polyethylene samples. They started to dissolve them in a solvent heated to 85 ° C, then a powder catalyst composed of vanadium was added. All this “soup” was finally exposed to artificial sunlight. In just six days, the researchers explain that they were able to break the carbon-carbon bonds of all the samples.
The advantage is that the “finished product” is also a useful product. Thanks to this method, polyethylene has indeed transformed into formic acid, which can be used for the production of energy by power plants. It can also be used for the storage of dihydrogen to supply fuel cells.
“We aimed to develop sustainable and profitable methods by harnessing sunlight to make fuels and other chemicals,” said Soo Han, lead author of the study. This new chemical treatment is the first reported process that can completely break down a non-biodegradable plastic such as polyethylene using visible light and a catalyst that does not contain heavy metals. ”
And to add: “today we are able to transform plastics, which naturally pollute the oceans, into useful chemicals”.
Towards wider use
This is just a proof of concept, with just a few samples. This means that the project is not yet commercially viable.
The researchers therefore now aim to further refine their method and make it entirely carbon neutral (using real sunlight, for example). It will also be necessary to ensure that the process can be implemented on a larger scale. Researchers estimate that with sufficient funding, they could get there within five years.