New Carbon and Glass Fibre Composite Recycling Method Promises to Curtail Rising Industry Waste

Dr Ali Hadigheh holding waste material from an aircraft. Image: Stefanie Zingsheim, University of Sydney.
  • Researchers at the University of Sydney have developed a More efficient composites recycling method to address an impending waste crisis in the automotive, aerospace, and renewable sectors.
  • The new approach increases material recovery, reduces energy use, and preserves mechanical properties of the fibres, retaining up to 90% of their original strength.
  • The annual global CFRP waste from industries like aviation and wind energy alone could reach a staggering 840,300 tonnes by 2050 if effective recycling strategies are not implemented.

As the demand for carbon and glass fibre composites (CFRP) increases, so too does the potential for environmental harm. However, pioneering research from the University of Sydney brings new hope in the fight against CFRP waste, presenting an innovative recycling method that promises significant energy efficiency and reduced waste.

Carbon fibre composites, described as a ‘wonder’ material for their versatility and resilience, are used extensively across industries including wind turbines, construction, yachts, hydrogen tanks, and aircraft and automobile manufacturing. The global reliance on these materials is expected to grow by 60% in the next decade, according to Dr Hadigheh from the School of Civil Engineering at the University of Sydney.

While CFRPs are undeniably beneficial, their potential waste implications are alarming. Dr Hadigheh warns that CFRP waste from the renewable energy sector alone is projected to hit 500,000 tonnes by 2030. Moreover, if suitable recycling strategies are not employed, the annual CFRP waste from the aviation and wind turbine industries could escalate to 840,300 tonnes by 2050 – enough to fill 34 full stadiums.

“Carbon fibre composites are considered a ‘wonder’ material – they are durable, resistant to weathering and highly versatile – so much so that their use is projected to increase by at least 60 percent in the next decade alone,” said Dr Hadigheh from the School of Civil Engineering. “But this huge growth also brings a huge increase in waste. For instance, it’s been estimated that around 500,000 tonnes of carbon and glass fibre composite waste from the renewable energy sector will exist by 2030.”

Dr Ali Hadigheh, School of Civil Engineering at the University of Sydney

Conventional recycling methods are insufficient, with the bulk of CFRP waste either ending up in landfills or incinerated. The production of “virgin” composites carries its own environmental baggage, including resource depletion and high energy input during production.

However, the new recycling method proposed by Dr Hadigheh and his recent PhD graduate Dr Yaning Wei, published in Composites Part B: Engineering, promises a paradigm shift in CFRP waste management. This method leverages solvolysis pre-treatment, which allows enhanced breakdown at lower temperatures, preserving the mechanical properties of fibres and reducing energy consumption.

The method was tested on real-world CFRP products, including bicycle frames and airplane scraps, and yielded successful results. The recycled fibres retained up to 90% of their original strength, surpassing the strength of fibres recovered through thermal degradation alone by 10%.

A detailed evaluation of 10 different waste treatment systems by Dr Hadigheh’s team, factoring in economic efficiency and environmental effects, revealed solvolysis to be a viable method that delivers a high net profit. Additionally, it leads to significantly lower CO2 emissions compared to landfilling and incineration.

The researchers also emphasise the necessity of manufacturers shifting their focus from creating virgin material to developing recycled products. Dr Wei acknowledges the opportunity to create an advanced manufacturing industry by developing local recycled products amid growing supply chain disruptions.

Dr Hadigheh’s team is not stopping at these promising developments. They are in the process of developing more methods for the recycling of composites and recently patented a machine to align recycled carbon fibres accurately for repurposing.

This breakthrough research underscores the imperative need for widespread recycling of next-generation construction materials, shining a light on a more sustainable and efficient solution for the industry’s burgeoning waste problem. As the demand for CFRPs continues to rise, such innovations will prove crucial in curbing the growing waste stream and fostering sustainable practices across key industries.

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