## 1 Introduction
On the other hand, they present certain downsides, such as a considerable reduction in size of the recovered fibers and in their mechanical properties, both of which result in a low market value that affects their economic viability [4; 9; 10]. Thermal recycling techniques use high temperatures to break down the matrices and to recover the fibers. Pyrolysis is one of the most prominent of these techniques, whose main advantage lies in the fact that it is currently at an advanced development stage and is already suitable for application at an industrial level. In addition, pyrolysis allows the recovery of lengthy carbon fibers and does not require the use of solvents or chemical compounds. On the other hand, it presents some drawbacks, such as its high temperature requirements (400-1000 \({}^{\circ}\)C) or the carbon deposits that may appear on the fiber surfaces. The removal of these deposits may require additional processes that pose a considerable risk of altering the mechanical properties of the recovered fibers, which could represent a drastic reduction in their actual value [1; 4; 9]. [PERSON] et al. [11] managed to mitigate some of the drawbacks of pyrolysis by using a catalytic pyrolysis process where the composite material was submerged into molten ZnCl\({}_{2}\) that was capable of completely degrading the resin matrix at 360 \({}^{\circ}\)C in 80 min. They succeeded in recovering CFs that retained 95% of their tensile strength (TS), as the molten ZnCl\({}_{2}\) contributed to preventing the oxidation of the fiber surfaces. On the other hand, this process required the immersion of the CFRP pieces into a pure chemical compound, which not only makes the process more hazardous and less environmentally friendly, but also increases its economic cost and hinders its scalability for larger CFRP parts. Chemical recycling techniques use reagents and/or solvents to break down or dissolve the resin matrix and recover the carbon fibers. These techniques include acid/base digestion, electrochemical methods, and solvolysis. Acid/base digestion uses acidic or basic reagents at high concentrations. As a major advantage, they operate at low temperatures (<150 \({}^{\circ}\)C); on the other hand, these reagents can be highly corrosive or hazardous and may damage the fibers when very high concentrations are used [4]. [PERSON] et al. [12] succeeded in completely breaking down epoxy resin matrices to recover their CFs with minimal damage (1.1% TS loss). On the other hand, they required the use of an 8 M nitric acid solution at 90 \({}^{\circ}\)C for 720 min. Electrochemical methods lie in the application of electricity to break down the resin, thus recovering long, clean carbon fibers. Unfortunately, they are not cost-effective in a commercial context because of their high energy demand [1]. Solvolysis is a thermochemical recycling method that combines the use of solvents (mainly alcohols and water) with heat to degrade CFRP matrices, providing a more economical and environmentally friendly way to recover high-quality carbon fibers. It can be categorized into low-temperature (<200 \({}^{\circ}\)C) and high-temperature (200-440 \({}^{\circ}\)C) processes. Low-temperature solvolysis occurs under mild pressure and temperature conditions, reducing energy consumption and preserving the mechanical properties of the fibers, but typically requires longer reaction times and the use of hazardous solvents (e.g., benzyl alcohol, acetone), catalysts, and pretreatments for effective resin decomposition [13]. For instance, [PERSON] et al. [8] achieved over 90% resin decomposition and retained more than 90% of fiber tensile strength using a mix of H\({}_{2}\)O\({}_{2}\) and acetone, although pretreatment with nitric acid was necessary.