Techniques of recycling end-of-life wind turbine blades in the pavement industry: A literature review

<p>Rapid global industrialization has increased the amounts of greenhouse gas emissions leading to global warming and severe weather conditions. To lower such emissions, several countries are swiftly seeking sustainable and low-carbon energy alternatives. As a green energy source, wind power has gained recent popularity due to its low cost and lower carbon footprint; but with a short blade life span, the industry faces a blade waste issue. Wind turbine blade recyclability is challenging due to factors such as blade sheer size, material complexity, low economic feasibility, and a lack of suitable recycling policies; yet, many blades are still being constructed and others are being decommissioned. This paper aims to discuss different wind turbine blade recyclability routes under the pavement sector. Wind turbine blades are made of composite materials, and based on literature data, it was found that recycled fibers can be extracted from the composites using methods such as pyrolysis, solvolysis, and mechanical processing; of these methods, solvolysis provides cleaner and better fibers. The recycled fibers, when incorporated in both asphalt and concrete, improved their mechanical properties; nevertheless, recycling of fibers from carbon fiber-reinforced polymers (CFRPs) was more economical than glass fiber-reinforced polymers (GFRPs). Waste wind turbine blades can take other routes, such as processing them into waste wind turbine aggregates, roadside bicycle shades, bridge girders, and road acoustic barriers.</p>