The CompositeLoop project is a feasibility study that proposes short term solutions in Flanders, Belgium for the valorisation of large thermoset

end-of-life GFRP (glass fiber reinforced plastics) structures such as wind turbine blades, boats and yachts, profiles, silos. The study is based on literature review and input captured during three interactive workshops with stakeholders over the entire decommissioning to waste valorisation value chain. It identifies promising local short-term scenario’s, with the purpose of initiating synergies within the value chain, allowing further technical and commercial development of recycling solutions as a next phase.

Decommissioning, waste and recycling

PES WIND1

PES ESSENTIAL

WWW.PESWIND.COM 2

1 Large GFRP structures with fast-growing waste volumes

Wind energy is the strongest renewable energy source currently in Europe and it will only increase because to reach the EU goals of 32% renewable energy by 2030, significant increase in wind power capacity is required. Wind turbines are being built since 1980s and boomed around 90s and 00s. They have 20-25 years of lifetime. Thinking about the development in wind energy in the last 40 years, it is understandable that every year more wind turbines are reaching their end of life. In 2018 alone, total of 421MW of wind power was decommissioned where 14MW was from offshore wind plants1.

The expected blade waste till 2050 is shown in Figure 1. In Belgium, these volumes are quite limited compared to the whole Europe. In the CompositeLoop project, it is predicted that in 2035 about 4000 tonnes of blade waste will be available in Belgium by considering the existing wind farms and their commissioning years. The wind turbine blades are mostly composed of GFRP, the internal lay-up usually consists of different layers and fiber directions of glass fiber and other materials such as balsa, some metals at the root and coatings as well. This variation and the internal layup have no standard distribution; it changes from one blade to another. This makes recycling of the blades quite challenging.

It is estimated that 6 million recreational boats exist in Europe alone. With boat lifespans of 30-45 years, some 140,000 of these vessels per year can be expected to become due for scrapping. Most will be composite and the majority of those will be GFRP. Since 140,000 vessels are expected to be end of life per year, many initiatives have described a way forward for the recycling of boats. For example, researchers of the BOATCYCLE project in Spain and Italy, calculated that the average cost of conventionally dismantling a 7 m long boat, including logistics, is €800, rising to some

€1500 for a 10-12 m craft and €15,000 for a 15 m vessel.

Compared to metals, composites have a very low scrap value, making it uninteresting for vessel owners to recycle them. In practice, many boats are abandoned, leaving marina and the authorities in charge. In Belgium, it was estimated that there are 85 vessels/year going to waste, representing composite waste of around 100 ton/year. At European level, 50.000 tons/year is estimated for 2020 in the entire Europe.

The table below summarises the numbers in previous paragraphs, for the year 2035:

Waste streams in Belgium are fairly small, and expected to be most easily organized for wind industry, where boats and vessels can be an important added stream. It should be noted that waste from building and construction and storage application are also significant, but not taken into account for short term solutions, due to the non-uniform and unstable nature of the waste stream.

2 Dismantling, transportation and processing

Reducing the dismantling costs requires on-site handling and shredding of composite blades into granulate, and subsequently postprocessors of granulate should be located as close as possible to land farms. New technologies to efficiently combine transport and shredding needs are fully explored in industry today by companies that typically provide both solutions. For example, the company Reciclalia has chosen for the approach of

transporting the waste treatment equipment to the on shore wind turbine, where the blades are handled, processed and immediately ready for transport. In the case of on shore wind turbines, it is often a waste treatment company that executes the whole action chain: decommissioning, transport, recycling. In off shore blades, the process typically includes the installer of wind turbines, for efficient management of the transportation actions to the harbour. For the cutting technology, specific precautions are taken to prevent uncontrolled emission of saw dust and other waste to air and soil. Most often grinding and

sawing is used, but waterjet cutting is a promising alternative, limiting dust and severe laminate damage during cutting.

3 End of life strategies

3.1 Reuse-Repurpose

The reuse approach has a large potential for high value reuse, resulting in several case studies, shown in the pictures. The implementation of reuse and repurpose is still rare.

3.2 Thermal Recycling (incineration and co-processing)

For an efficient waste treatment, incineration of GFRP is of little interest, since 50-70% of the material (the glass fiber fraction) is of mineral origin and is left behind as ash after the process. Still, most of the GFRP that is collected through mixed industrial waste, is processed via this route. However, co-processing is gaining more attention as it is pushed forward by the European Cement Association (CEMBUREAU) as the best option for recycling glass fiber reinforced thermosets.

In the case of co-processing in a cement oven, all components within the composite material utilized: the matrix is energetically valorised as a replacement for fossil fuels (approx. 12 MJ / kg waste), while the glass fibers, and any fillers - mostly calcium carbonate, are incorporated into the cement as a filler material. There is ‘material reuse’ up to 70% and ‘energy recovery up to 30% (the organic fraction). However, the route is not always economically interesting as long as landfilling remains an option.

3.3 Recycling

In this section we distinguish end of life scenario’s where the glass fiber is retained at least as a filler material. The longer the Figure 1. Predicted blade waste volumes in Europe until 2050 (reproduced from (Pu Liu, 2017)2)

Europe Belgium

Wind 180 kton 4 kton

Boats/vessels >50 kton 100 ton

0

100000

200000

300000

400000

500000

600000

2015 2020 2025 2030 2035 2040 2045 2050 2055

Blad

e m

ass [

tonn

es]

Year

WWW.PESWIND.COM 2

PES ESSENTIAL

retained fibers are, the higher the mechanical performance is of the resulting products. In general the outcome of the recycling process is a ‘new’ raw material with specific characteristics.

3.3.1 Mechanical Process

In mechanical processing, GFRP waste is processed as follows:

• Cutting to transportable size

• Dry mechanical shredding processes in function of the fiber length required (except for thermal valorization)

• Separation of ferrous and non-ferrous metals and other contaminants

• Crushing (and sieving) to required particle size

• Conditioning of the feedstock

The resulting fractions are then valorized as filler materials. If the fillers don’t significantly contribute to the material properties, they need to compete with material like calcium carbonate which are low value materials (0.5 €/kg or less). The low value of those filler materials often prevents this application to become commercially successful. If the fillers contribute to the material properties of the application, the value might be significantly higher. The process control and quality assurance to provide consistent feedstock based on a variety of incoming GFRP waste is a significant challenge. The combination of those challenges and lack of maturity of the process will probably prevent this recycling route from breaking

through on short term. In other cases, the granulate is used as a raw material, subsequently mixed with a matrix material. In most cases this mixture is then processed through compression molding. This process is mature and applied by several companies. In the Figures below examples of commercial actors are shown. Even though the technology is readily available, and subsequent research is done for further optimization of the technology, building a viable business remains a challenge.

3.4 Thermochemical recovery of glass fibers

Some commercial installations in the UK (for example ELG) , Spain (Reciclalia) and Germany are processing fiber reinforced composite materials through pyrolysis and focus almost exclusively on carbon fiber waste streams. Due to the high process temperature (400-750°C) the glass fiber sizing and glass fiber structure degrade, embrittling the fiber and making it unfit for structural applications. Applications like insulation panels based on recycle glass fibers are a good alternative (see: Insulation Wool Mat – ReFiber ApS) and are demonstrated, but the challenge of recycling a low cost material with an expensive process remains.

4 Conclusions

Entrance of processed GFRP waste streams from large structures can be expected, but it will take time. Nevertheless, today’s application market is large enough if sufficient end of life waste is provided. It is key that the applications that have the largest potential have the following characteristics:

• High value applications using the specific characteristics of the newly formed composite materials in useful functionalities like: low weight, high strengths, corrosion free, UV-resistant, slip

PES ESSENTIAL

Examples of wind turbine blade reuse (Wikado playground, the Netherlands)

PES WIND3

PES ESSENTIAL

PES WIND4

resistant surface, electrical insulator,…

• Large potential demand with little variety in form and characteristics

• In a start-up phase applications with a market allowing to provide in discontinuous manner allowing to provide products based on waste influx

• Scalable production technology

• Applications with short material loops keeping the distance between decommissioning, recycling and revalorization (production) limited

The mass balance as shown below illustrates that there is a large potential of value adding products (up to 8 kton/yr) only in Belgium. The potential market figures are primarily based on the known demand from rail and light rail infrastructural products like cable ducts, crossovers, etc. Even with a significant uncertainty in the figures the high level mass balance indicates that the potential market is probably larger than the waste for large composite structures.

It is concluded that the value and waste stream allow only one large waste processor for Belgium (Flanders). The most feasible and desired process today is mechanical recycling. To assure the influx of material it seems inevitable that to focus on collaboration with neighboring regions/countries.

The influx of GFRP waste streams from large structures will need to be balanced, the availability of end of life waste should be organized and centered around this waste processor, with production waste to balance the supply a demand.

Furthermore, legislation should come to support such initiatives overcoming high production costs and low material value, complemented with joined initiatives from industry.

www.sirris.be

blog.sirris.be

techniline.sirris.be

1 Wind Europe. (February 2019). Wind Energy in Europe in 2018. Wind Europe.

2 Pu Liu, C. Y. (2017). Wind turbine blade waste in 2050. Waste Management, 229-240.

3 Fiberline, fiberline.com, accessed in November 2016

Glass fiber reinforced composite waste being shredded to be used in the cement industry3

Identified influx waste streams of large composite structures

1.11.2019 1© sirris | www.sirris.be | info@sirris.be |

Offshore wind

Onshore wind

Yachts Marine

Yachts other

Silo’s & piping

Other large sizewaste

Recycling potential

Rail

Infrastructure(water,…)

Maritimeapplications

Industrial applications

Identified potential market demandof products made from FRP waste

1400 ton/yr

Starting with +/-15 ton in 2030

3000 ton/yrStarting with +/-40 ton in 2025

50 ton/yrCurrent waste stream

Current waste stream? ton/yr

10 ton/yrCurrent waste stream

Current waste stream10 ton/yr

Total: 70 t/yr tot 4500 t/yr

5000 ton/yr

? ton/yr

? ton/yr

150 ton/yr ?

Total: 5000 t/yr tot 8000 t/yr