Sustainable futures
Recyclable aircraft materials could prove key to jet zero success
We’ve all seen the pictures of ‘aircraft graveyards’ deep in the Arizona desert, where out-of-service planes are left to decay. It is a stark reminder of how the pace of innovation and demand for new technologies can outstrip capacity to recycle and reuse materials from end of life products.
It is also illustrates that the aviation industry’s carbon footprint extends much further than simply emissions from flight. One of the major hurdles in its quest to become net zero by 2050 is how to sustainably meet demand for advanced new materials, manufacture aircraft with less waste, and how to dispose of planes at the end of life, so these materials can be recycled and repurposed.
The desire for durable, lightweight aircraft means the use of composite materials – those containing a number of different elements– is commonplace. But because of their make-up these materials are notoriously hard to recycle and can end up being discarded and sent to landfill.
Dr Thomas Turner, Associate Professor within the University’s Polymer Composites Group, said: “Typically, composites are composed of layers of materials and resins that are heated and compressed, making it very difficult to unpick these elements during the recycling process.
“This poses a big problem for the aviation industry when you consider that in the next 10 years 12,000 airliners are predicted to reach the end of their life.”
"In the next 10 years 12,000 airliners are predicted to reach the end of their life."
But at the University of Nottingham, which is home to the Institute for Aerospace Technology, researchers are leading the way when it comes to future-proofing the industry.
Work with industry included a partnership with Boeing, which became the first aircraft manufacturer to recycle 100% of its excess carbon fibre.
Yet it is estimated that by 2035, unless recycling increases across the aviation industry, an astonishing 23,360 tonnes per year of end of life carbon fibre will accumulate if left unrecycled.
Dr Turner said: “If we can get these materials back into use we are improving the market penetration of a material which enables CO2 reduction by making vehicles lightweight, while potentially also addressing cost issues and the consistency of supply.”
In the University’s Future Manufacturing Hub – a £10.3m initiative funded by the Engineering and Physical Sciences Research Council, scientists are researching new, more cost-effective, manufacturing processes for composite materials which will allow them to be used more widely.
They are also looking at recycling technologies for carbon fibre composites and have developed a new process for fibre recovery from these materials.
Dr Turner said: “Normally, when carbon fibre is recycled it is broken down into individual filaments which are short and entangled with each other, making them difficult to reuse in the same way they would have been originally as they are no longer aligned”.
“The Polymer Composites Group is working on novel fibre realignment processes which can take the fluffy recycled fibres and process them into a form that still contains the high fibre content needed for high performance components.”
Dr Thomas Turner
Dr Thomas Turner is an Associate Professor within the Polymer Composites Group and Deputy Director of the Engineering and Physical Sciences Research Council Future Manufacturing Hub in Composites, and Institute for Aerospace Technology theme lead for future materials.