Circular Economy: An Interview with Prof. Manfred Renner "Complex problems don't have simple answers."

Prof. Dr.-Ing. Manfred Renner, director of the Fraunhofer UMSICHT Institute, discusses the key role of the circular economy in a sustainable plastics industry. He makes it clear that quick, one-off solutions are not the answer.

When we talk about the circular economy, the conversation quickly turns to the recycling of plastic waste. But there’s much more to the term than that. After all, the circular economy is, above all, one thing: an economic model.  It’s based on the idea of reusing resources over and over again. Instead of extracting raw materials, manufacturing products, and disposing of them after use. 

The circular economy is therefore much more than just a solution to the problem of waste. It provides answers to issues such as resource scarcity, increasing environmental pressures, and global supply chain crises.

A minor flaw: In many cases, this is just a nice theory. How can this be changed? We spoke with Prof. Dr.-Ing. Manfred Renner about this.

PlastXnow: The circular economy is considered key to a sustainable plastics industry. What needs to happen for this concept to become a reality on a large scale?

Prof. Dr.-Ing. Manfred Renner: There are several major levers. One lever relates to the consumption of products. If we shift the logic on a large scale from “buy, use, and throw away” to “buy, use for a long time, and reuse” or “use instead of own”—through new business models in which the product remains the property of the manufacturer—the impact will be immense. 

What else could be used as a lever?

When products—especially their plastic components—reach the end of their life cycle, they must be recycled into high-quality recycled materials. Given current crude oil prices, this requires significant economic incentives—whether in the form of penalties or bonuses—for companies to cover the enormously high costs of building the necessary infrastructure. 

That sounds feasible at first glance.

Those are just two levers. Because one thing is especially true for the circular economy: Extremely complex challenges don’t have simple answers!  

You are working on new materials and recycling processes. Which development currently makes you particularly optimistic that plastics will be recycled much more frequently in the future?

I find the wide range of developments in science and industry encouraging; often, these even extend to the pilot and demonstration plant scale. I am fully convinced that we do not have a technological problem. However, we must reach a binding agreement on a system or target metrics and on how to implement such a system across Europe. 

Product design—especially for short-lived, single-use packaging produced in extremely large volumes—is the first building block. The methods of collection, sorting, material processing, and recycling, as well as the use of digitalization and AI throughout the entire process, are also fundamental building blocks.

Are there any other "rising stars"?

It also gives me hope that there are customers for high-quality and circular solutions. This is especially true for B2B business models—particularly product-service systems—but also for B2C products, for which customers are willing to pay more because they see value in them. 

Communicating these values—linked, for example, to design, durability, high quality, branding, and lifestyle—and fostering a sense of pride in purchasing or using these products is the role of communication and marketing on many levels. So far, the EU, member states, and companies have been doing this on a scale that is far too small to bring about truly significant change. This is yet another building block—not a monolithic solution.

Many people want more sustainable products, but at the same time, these products must remain affordable and high-performing. How can research help bridge this gap?

Innovations and their scaling to a global level are a fundamental key to reducing costs compared to small-scale production. One of the Fraunhofer Society’s key tasks is to scale innovations from the laboratory level to larger-scale production. To achieve this, intensive and multifaceted communication between businesses, policymakers, society, and the Fraunhofer Society is essential. 

What does that mean?

To shape the technological future, it is essential to make technologies understandable while also understanding the direction in which development should proceed and what is truly desired. A never-ending cycle—not of materials, but of continuous communication aimed at defining goals and then achieving them together.

Thank you very much for the interview!