Abstract: Provided is a method for producing a recycled polyester including a step of washing a polyester (PEs) composite material using a washing solvent obtained by mixing a solvent composed of a phenolic solvent and/or a chlorine-based organic solvent and one or more solvents selected from the group consisting of an aromatic hydrocarbon-based solvent, an aliphatic hydrocarbon-based solvent, a ketone-based solvent, an aldehyde-based solvent, an alcohol-based solvent, an ether-based solvent, and water, a step of dissolving PEs in the washed PEs composite material in a dissolving solvent containing a solvent composed of a phenolic solvent and/or a chlorine-based organic solvent, subjecting the solution to solid-liquid separation to obtain a liquid component, a step of obtaining PEs from the liquid component using a poor solvent having a boiling point of 130° C. or lower, and a step of drying PEs.

Abstract: Provided is a method for producing a recycled PBT including a step of dissolving a PBT composite material in a solvent containing a phenolic solvent to obtain a solution containing PBT dissolved therein, a step of removing an insoluble matter from the solution containing PBT dissolved therein to obtain a liquid component containing PBT dissolved therein, a step of mixing the liquid component and a solvent capable of precipitating PBT by being mixed with the liquid component to precipitate PBT, thereby obtaining a slurry, and then separating the slurry into solid and liquid to obtain a solid PBT, and a step of drying the solid PBT to obtain a recycled PBT.