Waste management from multiple perspectives

The Westphalian University of Applied Sciences, more precisely the Department of Mechanical, Environmental and Building Engineering, hosted the third Zirkel.Training station. In order not to compete directly with the German team’s European Championship match, the event started an hour earlier than originally planned, with a good turnout of 40 participants from five universities in NRW.

The world of plastics

After a short introduction of the department and the course of studies by Prof. Holzhauer, Prof. Dr. Thomas Brümmer introduced the topic of plastics, which nowadays characterize our everyday life in many different ways.

A look at history shows that plastics are a very young material. The first polymers – the chemically more precise name – were created around the middle of the 19th century. However, a steep increase in production volumes was not recorded until the 1950s, when plastics were primarily produced from crude oil.

Thanks to their typical properties, plastics quickly became established in industry: For example, they can be processed at relatively low temperatures, are easy to color, and can be processed in a wide variety of ways – from injection molding to extrusion.

Despite the increasing problematization of plastic packaging in the public debate, annual plastic production continues to grow. According to nova-institute, the global production volume for 2019 is just under 377 million tons; in Germany, according to the Federal Environment Agency, it was 14.2 million tons, of which the largest shares were processed into packaging and in the construction industry.

But what about recycling and recirculation? Basically, three different forms of recycling are possible: mechanical recycling, feedstock recycling and energy recovery (incineration). In the case of closed-loop recycling, the collected plastics flow back into production. However, the share of recycled plastics in Germany in 2019 was significantly lower than the amount of plastics from primary raw materials.

Practical projects for waste collection

In his presentation, Prof. Dr. Ralf Holzhauer first took a look at the prerequisites of waste management and then presented two of his own research projects on waste collection.

One of the important milestones on the (still long) way to a circular economy is that supply and disposal have been thought of together since the 1990s, which is reflected, among other things, in the extended product responsibility of companies. The subject area is complex and ramified not only by the numerous, sometimes competing terms and approaches, but also by the intertwined areas of responsibility of the most important actors: politics, companies and consumers.

So how can circularity in the area of collection and recycling be improved in practical terms? The first project example on this topic presents an experiment with the pump manufacturer Wilo on the return of used pumps. The goal: Functioning components and high-quality raw materials such as rare earths should not end up in the scrap press, but should be recovered. This was achieved by returning used pumps to the manufacturer via various return routes such as collection by Wilo or collection by scrap dealers. There, functioning components and raw materials could be extracted via various processes and reused after a quality check.

The second project presented explored how to improve municipal waste collection in a pilot test. A bag-in-bin system was proposed and tested for this purpose. This meant that instead of different waste garbage cans, the participating households were given different colored sacks to collect and separate the waste and only one garbage can to hold the sacks.

An accompanying app enabled participants to report filled garbage cans to the municipal waste company. With the exception of the paper fraction, which experienced a deterioration in sort purity, the project was able to improve sort purity in collection and achieve CO2 savings through dynamic collection.

Sustainability in the plastics industry - a stakeholder discussion

The third part of the event was contested by students from the master’s program “Systems Engineering in the Environment and Building Technology” and they chose a very exciting format for it. They discussed the key question “How important is a sustainable plastics industry?” in a staged round of talks with a wide range of stakeholders.

Guided by a confident moderator, the participants exchanged their arguments on three sub-questions from their respective roles and positions:

Should a mandatory 25% recycled content be introduced for all plastic products?
Are biodegradable plastics a sustainable alternative to conventional plastics?
Should the digital product passport be introduced?

While the basic materials industry, for example, saw biodegradable plastics as a possible alternative and potential for CO2 savings, NGOS advised against it, citing “greenwashing.” Consumers declared themselves willing in principle to pay more for it, but only up to a certain level. Finally, the circular economy stated that recycling of biodegradable plastics is currently still difficult and that the other stakeholders must cooperate to ensure good separability.

This was flanked by a survey of the audience on the responsibility of the stakeholders in each case before and after the discussion – and so at least here the circle could be closed.

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