Carbon fibers: ecological material seeks recycling channel

Aviation, wind turbines, automotive, nautical, bicycles, sports equipment… All these sectors have in common the great interest in carbon fiber composites. As solid as steel, but much lighter, they have all the qualities… except that they are recyclable. At least for a while. Because the challenge whets the appetite of many start-ups that have embarked on the adventure: finding a solution to recycle carbon fiber composites, if possible, keeping all their qualities and limiting the ecological cost of the operation.

In 2019, carbon fibers accounted for just 1% of total composite production, with around 100,000 tonnes produced, for a market estimated at US$24 billion. However, this emerging sector is growing, with an estimated annual growth rate of 11-12% per year. Three sectors monopolize half of the market: wind energy, aeronautics and automobiles, but carbon fiber composites can invade all sectors: sports equipment, mobility, telecommunications or even plumbing. “Tomorrow, water heaters could be made of carbon fiber composite, they would be lighter and stronger, therefore with a longer lifespan than metal,” said Abdelaziz Bentaj, founder of Xcrusher, which is developing carbon fiber recycling technology.

Because while the material is of increasing interest to manufacturers for its strength and lightness properties – which allows, for example, substantial fuel savings – it remains very expensive (between 33 and 55 euros per kg according to Xcrusher), and above all very little recyclable. But solutions are emerging that make it possible to ecologically recycle this increasingly popular material.

mechanical recycling

That’s what Fairmat offers, a deeptech start-up born in October 2020 specializing in the mechanical recycling of carbon fiber composites that raised 8.6 million euros in September 2021. Its robots learn to cut the composite, thanks to an artificial intelligence, which makes it possible to obtain carbon bricks, explains its founder Benjamin Saada: “We found a very high performance basic material, which we sell, available to all industrialists”.

Advantage of this technology, unlike its competitors who often seek to separate resin and carbon fibers using heat (pyrolysis) or solvents, Fairmat requires little energy and therefore CO2 emissions. Approximately 9 kg of CO2 for one kg of recycled composite, compared to about 50 kg to produce one kg of “virgin” composite, for materials that are in turn recyclable, which have a useful life of 10 to 20 years. With commercialization starting in November 2021, the start-up has already opened a first production site in Nantes and secured 1,000 tonnes of material to be recycled per year, for a total capacity of 5,000 tonnes per year at the moment. It already estimates its market share at 35% of industrial carbon fiber waste available in France.

aircraft disassembly

A solution that caught the attention of Dassault Système, Siemens Gamesa (second European leader in wind energy) or Tarmac, a company owned by Suez, Airbus and Safran, European leader in aircraft dismantling, for R&D partnerships. “Carbon has been in all aircraft since the 1980s. But until the A380, it represented less than 5% of the aircraft’s weight,” says Sébastien Medan, director of infrastructure, health and safety and environment at Tarmac. Participation has only increased. In the A350, 90% of the aircraft’s weight is made up of carbon fiber.” Currently, the company generates between 150 and 200 tons of composite waste per year. A volume that can turn around ten thousand tons in 10 to 15 years.

“In airplanes, there is only one new waste that really poses a problem for its end of life: carbon fiber composites, and it is one that will become increasingly important”, worries Sébastien Medan, while the carbon parts of Lifeless aircraft are now incinerated or buried.

Tarmac therefore signed a non-exclusive agreement with Fairmat to supply the required amount of composites, to “bring in an industry that can handle high volumes”. As long as the costs aren’t skyrocketing. “We don’t have a commercial agreement with Fairmat, we still don’t know how much it will cost us to manage our waste. We are willing to invest a little to reduce our impact, but it is not possible that this will cost us twice as much.”

several possibilities

Be that as it may, the needs will be such within a few years – Fairmat estimates its total addressable market at $9 trillion over 50 years – that the solution to a circular carbon economy is unlikely to be unique.

And for good reason, if Fairmat, -which also announced a commercial contract to recycle production scrap from Duqueine, which produces parts in particular for the A350-, is the only one to offer a solution by mechanical grinding, without separating the resin, more and more labs and start-ups are positioning themselves in this carbon fiber recycling niche, such as Xcrusher, labeled as a Solar Impulse solution.

This company founded in 2006 by Abdelaziz Bentaj works with pulsed energy: “we store electrical energy in a capacitor to restore it as quickly as possible, which allows us to release enormous power, equivalent to that of an EPR over 20 nanoseconds, which generates a series of phenomena such as sonic or subsonic shock waves”, explains Abdelaziz Bentaj. A technology that can be used to recycle bitumen, polyester, as pool liners or carbon fibers. Xcrusher is thus able to recycle resin-impregnated carbon fibers to remake spools of “virgin” fibers. On this subject, Xcrusher works with Suez Environnement, Airbus’ waste delegate, to recycle their production waste. grinding them into micron powder, capable of modifying the conductivity of a surface. Mixed with paint, this powder can, for example, allow a wall to become tactile.

die to build

Whatever the solution, if manufacturers seem convinced of the need to recycle their carbon fiber composites, the point-of-sale problem remains. “There are many technologies, but if you don’t find a buyer, it’s no use. What will count for the emergence of a true carbon recycling sector is having a reliable point of sale, someone who can consume this material”, warns Sébastien Medan.

If these opportunities still seem incipient, Fairmat remains confident. Already a supplier to a vaccine-producing machine manufacturer, a bicycle manufacturer and a French start-up in connected objects, the start-up sees its recycled composite in particular replacing aluminum in all objects that need resistance, such as rackets. in sneakers or car bodies.

“It’s not about producing airplanes or wind turbines in recycled composite, assures Benjamin Saada. The priority is that the planes are light, safe and consume less, and that the wind turbines produce. ), the question must be asked: is the environmental sacrifice really worth it?

And Abdelaziz Bentaj adds: “the carbon fiber market has an exponential future that could allow us to break out of the deadly mining industry for many materials.”

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