Hundreds of millions of tons of municipal waste are generated in the EU every year. According to the European Environment Agency, around 34 % of the total amount is biowaste, which is collected either separately or together with mixed residual waste.
“This biowaste presents a great burden to the environment if landfilled,” explains Thomas Dietrich, project manager of Food & Health at TECNALIA, Spain, and coordinator of the EU-funded VOLATILE project. “It creates methane, a very potent greenhouse gas.”
To address this, EU Member States are obliged to establish national strategies to reduce biodegradable waste going to landfills. The EU has also set the ambitious goal of recycling 65 % of its municipal waste by 2035.
Good intentions are not enough, however. New and innovative processes are needed if these targets are to be met, and if biowaste is to be recycled into viable, reusable products.
This was the objective of VOLATILE, which set out to develop new ways of extracting more value from biowaste. “The question we sought to answer was: what can we do with all this waste to protect our environment?” adds Dietrich. “How can we bring organic waste back into our economy, and reduce the use of non-renewable feedstocks?”
The solution developed by the VOLATILE project team was to optimise volatile fatty acid (VFA) production under anaerobic conditions.
During anaerobic digestion, a mixture of different bacteria and microorganisms use biowaste as food, converting it into these so-called VFAs. The VOLATILE team found a way to separate the VFAs and microorganisms using a membrane with minuscule openings, which allows only the VFAs to pass.
The separated VFAs can then be used as a platform for the chemical industry, or as feedstock in other biotechnological processes. Downstream processing was developed with economic feasibility and environmental sustainability in mind.
“We believe that this VFA platform has the potential to help biogas plants to increase their revenue considerably,” says Dietrich. “It will also transform biowaste treatment facilities into feedstock suppliers for other industries, establishing a circular bioeconomy.”
Potential consumer applications
The big picture is that the VOLATILE project stands to make a valuable contribution towards the establishment of a circular bioeconomy, in which waste and residues are revalorised and put back into the economy. This will help to decouple growth from the consumption of finite resources.
In addition, the potential consumer-based applications of this process are impressive. Specialised bacteria can be used to transform the VFAs into polyhydroxyalkanoates (PHA), a biodegradable polymer used as an alternative to fossil-based plastics in bioplastic and packaging materials.
“Some yeasts are able to convert volatile fatty acids into single cell oils, which can be used in oleochemical applications such as soaps,” notes Dietrich. “VFAs can also be transformed into Omega-3 rich microalgae oil for food or feed applications. Omega-3 fatty acids are well known for their health promoting effects.”
In addition, the project team has developed a web-based decision support tool, to help analyse the potential for implementing VFA platforms to upcycle municipal biowaste. A European Committee for Standardization (CEN) workshop was also organised on the sustainable use of municipal biowaste, to help drive standardisation in the sector.
“Discussions are ongoing on how to bring the technology to a higher technological readiness level,” explains Dietrich. “The fermentation approaches we pioneered will be further developed, ready to be moved onto the market. We believe there is huge market potential here.”
Fuente: European Commission