Using glass fiber-reinforced plastics (GFRP) in wind turbine blades creates significant recycling challenges because GFRP is hard to break down and reuse. Unlike thermoplastics, which can be melted and reused, glass-fiber composites made with thermosets are permanently cured and cannot return to their original state.
With wind turbines from the 1990s now nearing the end of their lifespan, disposing of blades made mostly of GFRP is difficult. These blades are heavy, with GFRP making up about two-thirds of their weight, and manufacturing them wastes around 15% of the material.
The need to recycle wind turbine waste has become critical as wind energy expands. Researchers at Washington State University have developed an eco-friendly method to recycle turbine blades without harsh chemicals. This process recovers high-strength glass fibers and resins, offering a sustainable way to repurpose turbine blades into useful products.
Researchers developed a process to recycle glass fiber-reinforced polymer (GFRP), a common material in wind turbine blades. They cut the lightweight material into two-inch blocks, soaked them in low-toxicity organic salt with superheated, pressurized water for two hours, and successfully broke it down.
The recovered components were then repurposed to create stronger plastics, offering an innovative solution for recycling turbine blades.
Researchers used a mild zinc acetate solution, commonly found in medicines and food additives, to recover glass fibers and resins from turbine blades. The recovered materials were added to thermoplastics, creating composite materials with up to 70% recycled fibers.
They reused most of the zinc acetate solution through simple filtration. When added to nylon, the recycled fibers made it over three times stronger and eight times stiffer. The recycled material can reinforce other plastics like polypropylene and those used in milk jugs and shampoo bottles.
Researchers didn’t need to thoroughly break down all the bonds in the material. Instead, they focused on breaking the cross-linked network into smaller, melt-processable pieces. These pieces were then blended directly with nylon to form a new composite. The process combines both the resin and the fiber, without separating them, to create the final composite material.
