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.

Insulation boards and metal composite elements are the primary applications for PU in the construction industry. Since buildings are  responsible for 40 % of global energy consumption, more efficient materials in this area can generate big savings, such as through improved insulations

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.

In China, for the first time, PU resin is becoming commercial for the production of glass fiber-reinforced wind rotor blades

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.

In total, 22 BASF materials were used in Hymer’s VisionVenture concept vehicle. Exciting new developments have been used, particularly for the paintwork and for the bathroom wall paneling seemingly made of solid slate

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.

16:9

20:7

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.

Insulating panels made of rigid polyurethane foam based on Carbon4PUR technology.

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.

Using innovative CO2 technology, Covestro already produces the CO2-based precursor cardyon, which is utilized in the manufacture of mattresses, sports flooring, textile fibers and components for vehicle interiors

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.

The winners of the Utech Europe Polyurethane Award 2021

Award Winners Announced

Covestro is collaborating with Fairphone, a Dutch social enterprise building a market for ethical smartphones, on the use of circular material solutions for its smartphones.

With partially recycled polycarbonates and thermoplastic polyurethanes (TPUs), Covestro is helping smartphone manufacturer Fairphone achieve its sustainability goals.

Polycarbonat

Kreislaufwirtschaft

Covestro Supports Circular Material Solutions for Smartphones

From April 13 – 16, 2021 Hanser launches international virtual trade fair D-Expo Circular Economy for professionals with a focus on sustainability, recycling, eco-design, life-cycle, and more.

D-EXPO Circular Economy will take place as a digital event from April 13 to 16, 2021

Kunststoffverarbeitung: Maschinen und Komponenten

Nachhaltigkeit

Regenerieren

Kunststoff-Regenerate

Digital Trade Fair for Plastics Sustainability

Henkel significantly expands partnership with social enterprise Plastic Bank. The partners opened their first three plastic waste collection centers in Cairo

Henkel and Plastic Bank opened the first three collection centers in Cairo

Polyethylen

Polyethylenterephthalat

Kunststoffhandel

Handel

Kunststoff-Rezyklat

Henkel and Plastic Bank Open First Collection Centers in Egypt

A new chemical recycling unit at Borealis production site in Stenungsund, Sweden, is expected to commence operations in 2024.

Aerial view of Borealis production location in Stenungsund, Sweden

More Circular Base Chemicals and Plastic Products

Biodegradable plastics are special polymers designed to biodegrade after use. But conventional granulation equipment cannot handle biodegradable production rejects adequately. The new Bio-Gran technology by CMG Granulators was designed to accomplish this objective.

The range of capacities of the Bio-Gran line spans form 200 kg/h all the way to 2000 kg/h.

Recycling Made Possible with Bio-Gran

LyondellBasell starts commercial production of polymers using raw material derived from plastic waste at its Wesseling site.

The chemical company starts commercial production of polymers using raw material derived from plastic waste at Wesseling

Polymers Made from Plastic Waste

PlasticsEurope plans to significantly increase investment in chemical recycling: from EUR 2.6 billion in 2025 to EUR 7.2 billion in 2030. To further accelerate investments in this key technology and the transition towards a circular economy, the Association calls for a strong policy and regulatory framework.

1.2 million t of recycled plastics is the industry’s target for chemical recycling in 2025. By 2030, this figure is expected to rise to 3.4 million t per year

Verbände

kunststoffe.de

European Plastics Manufacturers Invest in Chemical Recycling

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 03/2022

issue 02/2022

issue 01/2022

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