Beijing: Researchers at Tsinghua University in China have developed a technique to convert discarded wind turbine blade material into valuable substances that could potentially be reused in the manufacture of stronger composite materials.
The method uses a powerful electrical pulse to heat processed wind turbine blade waste to approximately 2,000 degrees Celsius in just half a second. The process, known as flash Joule heating, transforms the material into silicon carbide and graphene.
Wind turbine blades are generally made from glass fibres embedded in thermoset resin. While this construction makes them strong enough to withstand years of operation, it also makes them difficult to recycle after they reach the end of their service life.
The research team, led by Bing Deng, collected retired turbine blade material from a wind farm in southern China and ground it into a fine powder. The material was mixed with carbon black and placed between graphite electrodes inside a quartz tube.
When an intense electrical current was applied, the mixture reached around 2,000 degrees Celsius. The silica present in the glass fibres reacted with carbon to form silicon carbide, while carbon from the resin was converted into graphene.
The researchers then tested the recovered material as an additive in fresh epoxy resin. At an addition level of 0.3 per cent by weight, the samples showed an approximately 11 per cent increase in tensile strength and a 27 per cent increase in tensile stiffness. Bending strength also improved.
The study further reported improved heat-transfer properties in the tested material.
The researchers noted that these results were demonstrated in laboratory resin samples and not in complete wind turbine blades. Further testing will be required to establish the technique’s performance and suitability for large-scale industrial use.
The approach could offer another route for addressing the growing challenge of wind turbine blade waste while recovering useful materials from retired renewable-energy equipment.
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