Governments worldwide have established ambitious objectives to tackle the social and environmental challenges arising from the growth of the energy industry, the reduction of pollution, the enhancement of energy security, and the mitigation of climate change (Woo et al. 2011; Gelfand et al. 2013; Stokes 2013; Jacobs et al. 2013; Patermann and Aguilar 2018; Saraswati et al. 2020; Hamed and Alshare 2022; Khalid et al. 2023). The aforementioned objectives have consistently served as significant factors driving the proliferation of wind power installations on a global scale. The majority of wind turbines now in service are situated on land, accounting for around 96% of the total. China currently holds the dominant position in the worldwide wind power market, boasting an impressive installed capacity of over 346 GW. According to the cited source, the United States ranks second globally in terms of installed capacity, with a total of about 135 GW. Germany occupies the third position with approximately 64 GW, while India follows closely with roughly 40 GW (Emec et al. 2015; Rechsteiner 2021; Tauhiduzzaman et al. 2023; Tumu et al. 2023) .
Wind turbine blades (WTBs) experience diverse adverse weather conditions, depending on their location. These conditions include exposure to sand particles, sea salt, and ultraviolet (UV) radiation, which are subject to fluctuations in temperature and humidity. Consequently, these environmental factors contribute to the degradation of the WTB surface and alterations in their properties. These changes manifest as an increase in electrostatic charge, reduced energy capture efficiency, and enhanced aerodynamic performance under unfavorable conditions (Sareen et al. 2014; Ozoemena et al. 2018; Alsaleh and Sattler 2019; Arana-Landín et al. 2020; Jani et al. 2022; Nazir et al. 2022; Varbanov 2023; Sorte et al. 2023). Based on a comprehensive examination of existing knowledge, various categories of wind turbine blades (WTBs) can be identified. These include instances of exposure to intense storm winds, precipitation in the form of raindrops or hail with velocities above 100 m/s, occurrences of icing, and instances of lightning. Furthermore, these structures are subject to recurrent wind loads, which may result in significant impact or fatigue loads, hence leading to various forms of structural deterioration. The above-mentioned loads induce various types of damage that adversely affect the performance of WTBs, which may result in their having to be shut down for repair or destined for disposal (Kolaczkowski et al. 1999; Jiang et al. 2008; Staffell and Green 2014; Sareen et al. 2014; Doagou-Rad and Mishnaevsky 2020; Fonte and Xydis 2021; Hamed and Alshare 2022; Varbanov 2023). The disposal of WTBs is a significant challenge due to their complex composition, which includes multiple materials and components. Specifically, WTBs are comprised of three primary components: an airfoil, a spar, and a shell. Composite materials, such as fibreglass or carbon fibre, in combination with epoxy resins, are frequently employed in the construction of airfoils and spars due to their advantageous properties of being lightweight and possessing high strength. The shell is commonly fabricated using durable plastics such as polyurethane or polypropylene. The sandwich layer is composed of balsa wood. Furthermore, it is worth noting that the blade of numerous WTBs is safeguarded against corrosion and wear through the application of a protective layer, such as paint or polymethyl methacrylate (Doagou-Rad and Mishnaevsky 2020; Saraswati et al. 2020; Mumtaz et al. 2023c, a, b; Muzyka et al. 2023)According to the European Parliament (Bădîrcea et al. 2021; Smol 2022), the Circular Economy can be described as a production and consumption model that encompasses activities such as sharing, leasing, reusing, repairing, refurbishing, and recycling resources and products for as long as their lifespan permits. By adopting this approach, the longevity of items' life cycles is prolonged. In reality, this entails identifying strategies to minimize waste generation. If feasible, materials derived from discontinued items are recycled or repurposed within the economy. The value of an item is enhanced as it can be repurposed for practical use. This study investigates the efficacy of oxidative liquefaction as a method for the decomposition of the WTB polymer matrix. The resulting degradation products were further analysed by chromatographic examination. The chromatographic studies were done to find out how five different factors—reaction temperature, residence time, pressure, waste-to-liquid ratio, and oxidant concentration—affect the compounds that are made when the resin breaks down. These factors include the reaction temperature, residence time, pressure, waste-to-liquid ratio, and oxidant concentration.
Additionally, a chemometric analysis was carried out to see if these methods could be used as a pre-processing step for the raw chromatographic data. The outcomes of this analysis would enable the optimisation of the investigated oxidative liquefaction process without requiring supplementary quantitative analysis.
The implementation of this approach will enhance the efficiency of optimising the oxidative liquefaction of waste plastics. Furthermore, it will enable the subsequent monitoring of process stability during extrusion.