For a long time, chemical recycling was considered an unfinished addition to established material processes. In the meantime, however, some technologies are making the leap into large-scale industrial use: an overview of the various processes and providers.

Overview of the Various Processes and Suppliers

Recycling

Umweltmanagement

Kunststoff Werkstoffe

Polypropylen

Thermoplaste

Polyurethan

Kunststoff

Bauwesen

Baustoffe

Kunststoff-Recycling

Kunststoffverarbeitung: Verfahren

Kunststoff-Aufbereitung

What Is Happening in Chemical Recycling?

The central issue in all polyurethane applications is the conversion from the past linear economy into a circular economy, and the use of sustainable raw materials in manufacturing. To do so, manufacturers are taking measures such as using bio-based raw materials, chemical recycling, and CO2 as a synthesis component. Digitalization, electromobility, autonomous driving and the construction industry are also driving PU development.

Polyurethane (PU)

Bauchemie

Automotive

Elektronik

Polyurethan-Schaumstoffe (PUR)

Halbzeuge und Zwischenprodukte

Kunststoff-Halbzeuge

Baubetrieb / Bauwirtschaft

Windkraft

Energieerzeugung

Erneuerbare Energie

Sustainable Growth

In the midterm, a worldwide increase in PU consumption of 4 to 5 % per year is to be expected. Growth drivers are the sound economic performance in the major industrialized nations so far, and in particular the increasing prosperity in China and emerging markets. In future, the PU business will be strongly influenced by digitalization and the development of closed material life cycles.

The Global PU Sales Reached a New Record in 2018 with just over 20 Million Tons

Schaumstoffe und Vorprodukte

Schaumstoffe

Standardkunststoffe

At the first glance, this year’s K was clearly focused on recycling and the circular economy. However, apart from these topics, many novelties were also exhibited in the classical plastics fields such as automotive. And many materials producers showed exciting new developments for electromobility in particular.

Automotive Trends at the K 2019

Elektromobilität

Mobilität

Streifinger, Florian

Verbände, Institutionen, Messen

Dienstleistungen

Polyamide

Electromobility and a Concept Vehicle

Utech Europe, the world-leading polyurethanes exhibition and conference taking place at the MECC in Maastricht, the Netherlands has been rescheduled to 16–18 November 2021.

Kunststoffverarbeitung allgemein

Kunststoffverarbeitung

Utech Europe Rescheduled to November 2021

How can gas mixtures from industrial production be put to good use to produce valuable materials and save crude oil at the same time? The research consortium of the project Carbon4PUR has found answers to this question.

Valued Materials from the Chimney

Thanks to new technologies and together with other chemical derivatives the greenhouse gas CO2 can be converted into plastic precursors. Covestro is developing sustainable insulating materials for the construction sector based on this raw material.

Dämmstoffe

Using CO2 in Rigid Foam Insulation Boards

Covestro, Recticel and Vita triumph in product and innovation categories, Cannon Group’s Volpato honored with Lifetime Achievement Award.

Award Winners Announced

Polymer materials, including synthetic polymers, have a bad reputation. These image problems do not just arise from the current environmental debate but also have earlier origins. In the past, too, polymer materials were subject to unjustified criticism. This often stemmed from non-scientists and frequently betrayed a lack of scientific knowledge.

On the Image of Plastics and their Responsible Use

Kunststoffe

Photonik

Optik

Polymer Materials

For almost two decades, an expert committee, meeting once a year, has supported Kunststoffe magazine in determining the state of play in the plastics industry and identifying current technical developments. This time, the traditional spring meeting gave it an opportunity to debate the consequences of the Corona virus.

Current Challenges and Options for Action in the Plastics Industry

Wirtschaftspolitik in Deutschland

Wirtschaft

Verpackungsmaterial

Logistik

Klotz, Karlhorst, Dr.

Internationale Wirtschaft

Verpackungsanlagen

Coilhandling

Kunststoff-Verpackungsmaschine

Kunststoffverarbeitung: Maschinen und Komponenten

Sondermaschinen

Medizintechnik

Starting up under the Shadow  of Corona

The increasing volume of plastic waste and the growing pollution of the oceans by such waste have brought the sustainable handling of plastic products into the focus of society and politics. Both recycling and bioplastics can be a part of a strategy for greater sustainability, but they are not free of side effects. In order to avoid irrational decisions, it is important to assess their effects comprehensively.

3D View of Sustainability

Flachfolienanlagen

Extrusionsanlagen

Blasfolienextrusion

Flachfolien- und Plattenextrusion

Extrusion

Nachhaltigkeit

Folien

Folienblasanlagen

Kreislaufwirtschaft

Why Recycled Films Are Not Necessarily Sustainable

The beneficial processing and service properties of plastics are increasingly determining the ecological fate of the world. The plastics industry has now realized that it is not enough to put the blame on consumer behavior. As K 2019 showed, numerous initiatives and technical developments are paving the way for the urgently needed establishment of a circular economy.

A Stock-Take of K 2019: The Plastics Sector Has Owned up to Its Responsibility

Messe K-Kunststoffmesse

kunststoffe-international.com

Wiederaufbereitung

Ressourcenmanagement

Produktion

The Dawning of the Circular Economy

There is little doubt where we are heading: multilayer packaging will have to become easier to recycle – but what does that mean for the technology? And what solutions will the market need and accept? Manufacturers of branded goods are not the only ones who will have to rethink their specifications.

How Film Packaging Will Have to Develop

Europe Needs to Catch up

Currently, recyclates are in high demand, including the automotive industry. Previously, component suppliers had reservations about using recyclates in safety-related areas, because mechanical properties varied too widely. Now, materials producer JSP has developed an expanded polypropylene with 25 % recyclate content precisely for these application areas. But to ensure high quality, close cooperation with the recycling company is essential.

Circular Economy for Expanded Polypropylene (EPP)

Automotive Components  Made of Packaging

Borealis, Clariant, Remondis, LyondellBasell – many of the big names in the plastics industry announced partnerships with Neste at, or in advance of, K 2019. The Finnish company is a sought-after partner in the industry.

Interview with Mercedes Alonso, Executive Board Member at Neste

Biokunststoffe

“Chemical Recycling Is Not yet Ready for Commercial Use”

Solvolysis Using Different Solvents in Practice

By means of high-performance processes, chemical recycling converts plastic waste into high-grade material for new plastic products. Moreover, freedom of design results by selecting a suitable process and the matching waste material. Hereby, the right combination permits customized polyols to be created for the desired application area.

Old mattresses, insulating material, furniture, and steering wheels – this raw material, which Rampf Eco Solutions GmbH & Co. KG, Pirmasens, Germany, processes, is not particularly appealing. The company has specialized on the recycling of polyurethane (PU) and polyethylene terephthalate (PET) waste material. For this, Rampf makes use of the solvolysis process in two of the largest multifunctional plants in Europe. Hereby, solvents are used to split the polymers – the urethane group in the case of PU, for example. The processes differ in the splitting medium applied. Water is used for the hydrolysis process, and acid for acidolysis. Depending on the process, this results in various polyols with different properties. Consequently, the most suitable polyols for the required application area can be created precisely by selecting the corresponding process.

The polyols produced in this way are then returned to the customer’s production facility either by Rampf Eco Solutions or another PU system company. Due to the renewed cross-linking, the materials reobtain their initial properties plus high quality. In this way, a recirculatory system is created, with combined economic and ecologic advantages.

For solvolysis, Rampf frequently relies on the glycolysis and acidolysis processes. With glycolysis, the urethane group is split by means of transesterification, mostly with bivalent alcohols (glycols, Fig. 1). The process can be used for practically all polyurethanes, although the hydroxyl value (OH value, which indicates the number of hydroxyl groups in a substance) is increased during the reaction. It even exceeds that of the initial polyol, which leads to a higher hardness of the end product. Therefore, polyols obtained with the glycolysis process are mainly used for the production of hard foams, hard integral foams, and durable integral foams.

In contrast, the acidolysis process splits the urethane group with acids or acid anhydride (Fig. 2). Compared with glycolysis, the acidolysis process is more complex and more expensive. Because it does not increase the OH value, the acidolysis process is used mainly to obtain polyols for the production of rigid foams, rigid integral skin foams and semi-rigid integral skin foams.

Neither process involves downcycling – instead they are self-supporting upcycling processes with a high added value. For example, by adding recycling polyols, the compressive strength of insulating foams, the chemical resistance of casting compounds, or the compatibility of polyurethane systems can be improved. Consequently, the polyols can be used for the production of numerous end products, e. g. mattresses, seating furniture, automobile and motorcycle seats, fitness and recreation products, as well as insulating materials.

Other polymers are also suitable for chemical recycling. For example, way back in 1999 Rampf Eco Solutions developed a process for chemical recycling of PET together with the Deutsche Gesellschaft für Kreislaufwirtschaft und Rohstoffe (German Society for Circular Economy and Raw Materials) in Cologne, Germany. The resulting polyols are mainly suited for the production of hard foams. High mechanical strength and improved flame retardance are the properties which are influenced decisively by these aromatic polyester polyols.

Also polyesters such as polylactide (PLA, polylactic acid), polycarbonate (PC) and polyhydroxyalkanoate (PHA) are used as raw material for producing recycled polyols. Chemical recycling of PC produces aromatic polyester polyols with rigid and very strong bisphenol A structural elements, making them highly suitable for mechanical reinforcement. The compressive strength of polyisocyanurate foams (PIR) could be improved significantly by adding PC polyols. In contrast, polyols made of bio-based PLA are purely aliphatic and very flexible. By adding these polyols, soft segments can be integrated in PU, and the embrittlement tendency of very strong hard foams and casting compounds reduced (Table 1).

Hence, functioning chemical recycling processes are available. But compared with mechanical recycling, their application is limited, although they are a good supplement for existing recycling systems – particularly for plastic waste that is difficult to recycle. For example, recycling of bulky waste still represents a great challenge. More than 60 % of the estimated 19 million t of furniture, mattresses, upholstery, textiles, and plastic garden furniture that are thrown away in European countries every year, finish up in landfills.

Therefore, to improve the logistics as well as the disposal and reuse of bulky waste, the recently completed Urbanrec project (Fig. 3) was initialized. Companies and organizations in seven countries participated, including national institutions in Belgium, Poland, Spain, and Turkey. Aim was the development and implementation of an ecologically effective and integral disposal system for bulky waste, in order to promote waste prevention as well as recycling, combined with improved logistics.

Within this project, and together with partner companies and institutions, Rampf Eco Solutions had the task of developing chemical solutions for obtaining high-grade recycled polyols from plastic waste such as mattresses and upholstery. The aim was to reduce the amount of waste delivered to landfills and incineration plants. In addition, new products based on the recycled raw materials were developed during the project, such as adhesives, foams, and insulating materials. Hereby, the polyols involved were produced with the glycolysis and the acidolysis processes.

The glycolysis polyols were used to produce insulating foams with a content of up to 50 % recycling polyol. Acidolysis polyols were used in the top layers of viscoelastic mattresses (12 % recycling content) and for PU hot-melt adhesives (up to 50 %). Hereby, it became clear that separation of the PU foam qualities – i. e. ether or ester foams based on methylene diphenylisocyanate (MDI) or toluene diisocyanate (TDI) – was necessary to ensure high-quality polyols. Separation was done by means of near infrared spectroscopy.

Basically, solvolysis is very suitable for obtaining chemical raw materials from PU and PET. Depending on the plastic waste and the required properties of the end product, the glycolysis or the acidolysis process is suitable. Gradually, chemical recycling is evolving into an alternative for mechanical recycling. Increasing prices for petrochemical products, tighter environmental regulations, and changing sustainability mindsets of consumers make it attractive. Moreover, projects such as Urbanrec illustrate the potentials of chemical recycling in practice.

Rampf Holding GmbH & Co. KG  

https://www.rampf-gruppe.de

Ausgabenartikel

Fig. 3. The Urbanrec project involved the recycling of bulky waste such as mattresses and furniture

Not only can multifunctional recycling plants split polyurethane by means of different processes; they are also able to recycle other plastics

Table 1. Performance data of Rampf’s alternative polyols, divided according to source materials

Fig. 2. Acidolysis of polyurethane: hereby, the urethane group is split by the addition of an acid

Fig. 1. Reaction equations for production and glycolysis of polyurethane

Rampf - Hauptartikel

Dr. Frank Dürsen works for the Rampf Group since 2011. As Head of Future & Sustainability, he is also involved in the development of thermosetting materials based on sustainable raw materials; frank.duersen@rampf-group.com

issue 08/2021

issue 07/2021

issue 06/2021

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