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Sardinian thistles play key role in bioplastics

Sardinian thistles play key role in bioplastics
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According to a recent study carried out by the University of Georgia, 275 million tons of plastic waste are produced each year around the world. Around 32 million tons of that plastic waste ends up on coasts and 8 million tons in the ocean — disfiguring beaches, polluting the environment and threatening biodiversity.

We don't take land away from agriculture, instead we try to give value to land that agriculture has lost

A solution to this problem could come from the cardoon, a thistle-like plant closely related to the artichoke. In northern Sardinia, it is being grown to produce the oils needed to make bioplastics.

As part of the “European Project “FIRST2RUN”,”: the companies Novamont and Versalis have created a joint venture called “Matrìca”, aimed at using that plant to make plastic products that are all biodegradable and recyclable and will ultimately serve as fertilizers.

To make these bioplastics, oil is extracted from cardoon seeds and mixed with sunflower oil. Nothing in the plant gets wasted: the leaves and stem are burnt to produce the energy needed to run the factory, and what remains of the seeds is used in a special feed for sheep.

And unlike biofuels, which are often criticized for reducing the number of crops available for food products, growing thistles in the northern Sardinian region of Porto Torres does not compete with agriculture.

“We don’t take land away from agriculture, instead we try to give value to land that agriculture has lost,” Michele Falce, agronomist in charge of developing the agricultural activities of Novamont, told Euronews.

“In this part of Sardinia, there are about 60,000 hectares that were abandoned in the last 30 years. Here, we want to recover a small percentage — 3 to 4 percent — of these lands through the cardoon, which is perfectly suited to the Mediterranean environment. It doesn’t need irrigation water, only rain.”

The bioplastics factory is located on an old, previously abandoned industrial site, which has been brought back to life. Machines for acid distillation and silos for acid storage now work at full steam to produce the bioplastics.

The transformation of vegetable oil into acids used for bioplastics happens as the oil goes through four reactors, in an entirely automated process.

From a control room, technicians only monitor the machines, valves, and pressure inside the pipes. Researchers also carefully analyse both the quality of the original vegetable oil and of the final products.

No solvents are used throughout the process: the chemical reactions are obtained with water, air and hydrogen peroxide, none of which pollute the environment.

“It’s a completely new process, unique, that transforms the vegetable oil without using toxic and explosive gases such as ozone,” says Luigi Capuzzi, the head of research at Novamont.

“From the vegetable oil, we derive an acid that is the raw material fundamental for bioplastics, which are used for example in grocery bags. But we also obtain another acid that, as such, can be used as a bioherbicide and replace much more toxic molecules.”

It can also be transformed and used in lubricants or cosmetics that don’t contain any palm oil, or even in tyres to replace toxic and carcinogenic oils, he says.

Among the bioproducts made in Sardinia, there is a biolubricant for ships, which is non-polluting and dissolves in the sea: a major step forward, considering that around 3 million tons of lubricating oil made from petrol end up in the sea each year in Europe alone.

For now, the bioplastics made in Sardinia are more expensive to buy than chemical ones, but being biodegradable they have no disposal costs. Scientists note however that they won’t revolutionize the entire plastics industry nor save the planet on their own – they need to come hand in hand with better recycling of traditional plastics.