Tsinghua Researchers Turn Wind Turbine Blades Into Silicon Carbide and Graphene

Researchers from Tsinghua University in China have transformed used wind turbine blades into silicon carbide and graphene. Their method, presented on November 6 in the journal Chem Circularity, uses very rapid heating to recover materials that can strengthen the resins of new blades.

The process uses flash heating by Joule effect and raises the waste to about 2,000 °C in a few seconds. It exploits the components of the blades, which generally combine glass fibers containing silica and a carbon-rich resin. At this temperature, carbon can react with silica to form silicon carbide, while part of it reorganizes into graphene.

In the reported tests, the addition of 0.3 percent by mass of recovered materials improved the resin’s resistance to deformation by 27 percent in tension and 9 percent in bending. These results pertain to the properties of the tested materials and do not constitute a measure of the lifespan of a complete wind turbine.

The challenge lies in the difficulty of recycling the blades, which are designed to withstand years of harsh weather and significant mechanical stress. Their robustness complicates their processing, as the first generations of wind farms reach the end of their service life.

The team is now working on scaling up the process and is seeking industrial partners. The reuse of waste in new blades remains a development prospect, rather than an already established sector.

Scaling and economics

The researchers first created a mixture of pulverized blade waste and nearly pure elemental carbon, then subjected the mixture to flash Joule heating across several experiments. A typical experiment converted about 56% of the mixture into a silicon carbide and graphene composite made up of 34% silicon carbide and 66% graphene.

The largest batch tested was just 10 grams. His team has already designed and built a larger-scale reactor to process a 200-gram batch, but it still requires some optimization. In particular, Bi highlighted a need to make sure that this new reactor can heat the material uniformly and produce consistent product quality.

At a commercial scale, the researchers estimate that their blade recycling approach could turn a profit of about $80 per ton of blade material, due to the high value of the recovered silicon carbide and graphene. Conventional recycling methods require wind farm operators to pay for waste processing. Pyrolysis costs roughly $460 per ton, while chemical dissolution costs about $1,800 per ton, according to Bi.

Why it matters

Wind turbine blades are difficult to recycle because they are built to withstand harsh weather and mechanical stress for decades. As early wind farms reach the end of their service life, finding ways to reuse blade waste could reduce landfill use and support a more sustainable manufacturing cycle for wind energy.

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Sources

• beninwebtv.com: Wind Turbines: Used Blades Transformed into Materials to Strengthen New Resins - BENIN WEB TV
• gizmodo.com: Scientists Found a Better Way to Recycle Wind Turbine Blades

This article was drafted with AI assistance and checked against the sources above. Company claims are reported as claims. Cover image is AI-generated.