Bioplastics from waste

* Updated version of the 2023 article.

Definition

Waste streams are to be made usable as sustainable sources of carbon for the production of plastics, i.e. polymers.  Direct polymer sources such as agricultural and forestry waste, not to mention side streams from paper or wood processing, are used. Meanwhile, sewage sludge and organic waste from households and gardens, the food industry and livestock farming, plus carbon dioxide (CO₂) from industrial emissions and the atmosphere can serve as sustainable carbon sources too. What all these sources have in common is that their quality and exact composition vary over time. 

The organic components are converted into biopolymers through biotechnological and/or chemical processes. They can be similar in structure to conventional petroleum-based plastics – hence the end product also being called “drop-in bioplastics” – or consist of entirely new building blocks with similar or novel functions.  

Current applications and opportunities

Although bioplastics only make up a small fraction of the total volume of plastics, their applications are diverse. They are used in automotive engineering for interior panels and acoustic insulation, in chemicals, electronics and agriculture, for packaging, in medtech for resorbable materials such as sutures, in toys – such as Lego – and textiles. Bioplastic is also added to concrete to enable self-healing. But the focus lies on short-lived plastics for everyday applications.  

Bioplastics from waste offer significant environmental opportunities. The main advantage is the fact that it is possible to reduce or completely avoid the use of fossil raw materials. Bioplastics from waste also harbour tremendous economic potential. Centralised, fossil-based plastics production could be replaced in the long term by decentralised, bio-based systems. However, when this transformation will take place remains largely unclear. 

Although Switzerland will not be a location for large-scale bioplastics production due to the low margins involved, it is can become a technological leader thanks to its excellence in fundamental research. Opportunities are arising particularly in researching and developing polymers based on the natural structures of plant-based raw materials. 

Challenges

Manufacturing bioplastics from waste streams involves a series of technical challenges that currently still impede widespread application. A key problem is the quality of some bioplastics, which does not yet match the mechanical and functional properties of conventional petrochemical plastics. Another challenge is the heterogeneity of the starting materials, which differ significantly in composition and quality. This variability makes standardised processes and products more difficult to achieve. 

Logistics for decentralised resources also present challenges. While fossil raw materials are typically extracted and processed centrally, biogenic waste materials are usually generated locally, requiring new infrastructure. Although Switzerland has experience with such regional material flows in the paper and pulp processing sector, the relevant expertise has been largely lost and needs to be rebuilt.  

Last but not least, there is competition for plant-based raw materials. Materials used for bioplastics are sometimes also used as animal feed or for energy generation. So use of the same must therefore be considered within the overall context of a bioeconomy. 

Legal regulations mean that the approval requirements for bioplastics are higher than they are for petroleum-based products, both in Switzerland and internationally. Political decision-makers have the power to promote value creation from waste through appropriate regulation. This includes building pilot and demonstration facilities and providing credit guarantees for pioneering companies. 

Focus on industry

Companies that invest early in manufacturing and/or using bioplastics from waste can expect an image boost, since interesting opportunities are opening up in relation to sustainability. The use of bioplastics is also likely to become financially relevant for the carbon footprint of manufacturing and user companies in the future. Moreover, waste is a local resource whose use permits a certain degree of independence from global supply chains. 

The waste materials used for bioplastics production is highly heterogeneous. Developers need a good understanding of chemistry and sound knowledge in polymer and materials science, not to mention capabilities in microbiology. The skills profile is rounded off by process-related and engineering competencies. Using biological waste requires interdisciplinary teams and an appropriate mindset for productive and efficient communication and collaboration in such teams. Similar skills are needed on the user side, although a basic understanding is sufficient. Education at universities and in training companies provides a good foundation. Universities are responding to developments by adapting their degree programmes. The availability of skilled workers is good, but does not extend to management levels. 

Breaking down plant-based polymer sources is a fundamental process in paper manufacturing. However, the industry in question has migrated from Switzerland and skilled workers may have to be recruited from abroad. 

There is a lack of interdisciplinary exchange between industry and universities. Funding instruments such as the National Centres of Competence in Research (NCCRs) of the Swiss National Science Foundation or Innosuisse’s Flagship Initiative could help with this. 

International perspective

With regard to development, Switzerland is performing well in an international comparison despite its weakness in extracting the polymer cellulose from wood. Its strength lies primarily in the chemical processes involved in plastics production. Compared to other European countries, Switzerland generally has little expertise in biorefinery. 

Switzerland has only a small plastics and paper industry and depends on international cooperation for marketing. The EU also offers good basic services with respect to the likes of credit guarantees and access to European research projects. Swiss companies are increasingly relocating to other parts of Europe. Internationally, including outside the EU, the market is developing faster and more broadly than in Switzerland. Industry pressure there is greater than it is domestically. 

Future applications

Global development focuses on applications with large volumes and small margins, including the likes of packaging and additives. Plastics and composite materials for the automotive industry and for building infrastructure such as wind turbines are also possible applications. 

With regard to future applications, Switzerland is focusing on high-tech products in the aerospace industry and medtech, for example, which are manufactured in small batches but promise high margins. Additionally, agricultural applications are becoming increasingly important due to new EU regulations on sustainable fertilisers. Although efforts to use bioplastics for medical products such as stents and heart valves have been around for a long time, high regulatory requirements make scaling up more difficult. 

Bioplastics from waste streams can make a key contribution to a more sustainable plastics economy. The use of organic, renewable raw materials can replace fossil resources and reduce emissions. The technology strengthens regional cycles and opens up long-term opportunities for decentralised, resource-efficient production. At the same time, technical and economic hurdles impede widespread implementation, as material quality remains limited, raw materials are heterogeneous and building appropriate infrastructure is expensive. Companies currently lack economic incentives – for the time being, benefits are mostly restricted to image gains, while costs remain high. Targeted political support is essential if the full potential of this technology is to be realised.