Producing plastic from organic waste: the invention in Treviso

Scientists are refining techniques to produce bioplastic from organic waste and waste water. But once decomposed banana peel becomes commercially available, are consumers willing to buy it?

This was the question asked by researchers of the European Res-Urbis project, dedicated precisely to the transformation of waste into new materials. They interviewed US, Spanish and Polish consumers. There emerged a willingness to pay a surcharge for eco-friendly products, more for adults than for young people.

However, it would be difficult to buy glasses, toys or bottles produced from household compost. On a large scale, the market seems ready only for waste bags derived from the waste itself.

“This closes the circle, but there is still a long way to go for a transition to a circular economy,” says Paolo Pavan, Professor of Chemical Plants and head of the Ca’ Foscari University of Venice unit in the Res-Urbis project. Significant support towards the success of the technology we offer is offered by the people themselves and by the virtuous approach of the municipal authorities in the recycling of urban waste. There is therefore the need for close cooperation and interconnection between society, made up of people, the world of research and industry.”

Ca’ Foscari University of Venice is the lead player in this challenge, thanks to the chemical engineering research team that has for years been performing its experiments in the laboratories alongside the Treviso treatment plant, which has inspired the research itself.

As part of Res-Urbis, Professor Pavan, in collaboration with colleagues from the University of Verona and "La Sapienza" University of Rome (project leader university, in particular with the research team coordinated by Professors Mauro Majone and Francesco Valentino) patented a process to synthesize biodegradable polyester polymers (polyhydroxyalkanoates or PHAs) from the organic fraction of domestic solid waste.

The result was possible thanks to the pilot system developed in the Treviso laboratories by the Ca’ Foscari and Sapienza team. The studies conducted by the project enabled the extraction over 30 kilograms of PHA with a purity of 95%, tested for the production of consumer goods.

In particular, there is the very promising application for the production of composite adhesive film, i.e. made of polyhydroxyalkanoates and other biodegradable polymers. The tests carried out on various manufactured products (see examples in the photo below) have demonstrated good resistance of the materials and contaminant levels below the limits prescribed for the products considered.

The results of the project are a step towards the “end of waste”: organic waste and waste water can guarantee valuable raw materials to produce materials that are in turn biodegradable, destined to remain in circulation in an economy that wastes nothing.

A biorefinery dedicated to this production is sustainable both for the environment and economically, the researchers conclude. Dialogue with field experts in 13 European countries laid the foundations for the future transformation of the project results into new service and business opportunities related to the valorisation of waste by the production of bioplastics.