Spain: Waste Recycling Biowaste as a Source of Polymers
The European project RES Urbis (Resources from Urban Bio-waste), showed that different biowaste produced in an urban environment can be treated within the same chain of valorisation. It can be used to obtain products with biological origins, such as bioplastics, with a higher economic value than that of compost and biogas.
Barcelona/Spain — More than 70 % of the people in Europe live in urban areas and produce a great amount of biowaste that mainly originates from the treatment of waste waters. In a circular economy, the city waste being turned into resources, is therefore of great importance. The RES Urbis project confirmed the technical and economic viability of using biowaste as a source for products such as bioplastics.
The experimental part of the project was carried out in two pilot plants, located in Lisbon (Portugal) and Treviso (Italy), and in five laboratories — one of them in the Faculty of Chemistry of the UB. It produced a total of 30 kg of polyhydroxyalkanoates (PHA), the basic polymer to create bioplastic with volatile fatty acids from waste decomposition. This PHA was obtained through three new extraction methods carried out within the project, and later, processed by the industrial entities of the consortium to obtain commercial-use bioplastic.
The scientists obtained film samples of bioplastic to use them as an interlayer with adjacent film, with a great commercial potential. These bioplastics can be used as long-lasting goods and biocomposites with fibres produced with waste from parks and gardens.
Regarding commercialization of these bioplastics, the team considered the European regulatory frame on the potential risks for health and environment of chemical products (Reach-CLP), and although there is still a lot to do on the definition of the final condition of the product known as waste final, “the scenario for the commercialization of the product is highly favourable”, notes Joan Mata, professor from the Department of Chemical Engineering and Analytical Chemistry, who leads the participation of the University of Barcelona in the project.
More Efficient Refineries
The analysis of the life cycle of these bioplastics showed that the materials and energy used by PHA production through the presented biorefinery in the project have a lower environmental impact than the one generated by the plastic production with fossil origin.
The RES Urbis technological chain improved the plants on anaerobic digestion of biowaste. Its economic analysis in the analysed scenario — among which is the Metropolitan Area of Barcelona — shows the production of PHA is viable after a price of 3 Euro/kg (approx. $ 3.3) and even one less if considering the most favourable conditions of the process. This price, compared to the price of the current commercialized PHA obtained from specific cultures of cereals with a 4-5 Euro/kg (approx. $ 4.4 to 5.6) cost, shows the economic viability of the process. “The next step will be to get funding through the EU and the private sector to build a demonstration plant”, says Mata.