Methods of isolating phenols from phenol-containing media. The methods include combining a phospholipid-containing composition with the phenol-containing medium to generate a combined medium, incubating the combined medium to precipitate phenols in the combined medium and thereby form a phenol precipitate phase and a phenol-depleted phase, and separating the phenol precipitate phase and the phenol-depleted phase. The methods can further include extracting phenols from the separated phenol precipitate phase. The extracting can include mixing the separated phenol precipitate phase with an extraction solvent to solubilize in the extraction solvent at least a portion of the phenols originally present in the phenol precipitate phase.

Methods of isolating phenols from phenol-containing media. The methods include combining a phospholipid-containing composition with the phenol-containing medium to generate a combined medium, incubating the combined medium to precipitate phenols in the combined medium and thereby form a phenol precipitate phase and a phenol-depleted phase, and separating the phenol precipitate phase and the phenol-depleted phase. The methods can further include extracting phenols from the separated phenol precipitate phase. The extracting can include mixing the separated phenol precipitate phase with an extraction solvent to solubilize in the extraction solvent at least a portion of the phenols originally present in the phenol precipitate phase.

A method for improving the hue of recycled BHET is provided. The method includes: providing a recycled polyester fabric; using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric to form a de-polymerization product; distilling out the chemical de-polymerization liquid from the de-polymerization product by evaporation; dissolving the BHET in water to form a aqueous phase liquid; adding an activated carbon material to the aqueous phase liquid to adsorb impurities; and cooling the aqueous phase liquid to crystallize the BHET from the aqueous phase liquid to obtain a recycled BHET.

A method for improving the hue of recycled BHET is provided. The method includes: providing a recycled polyester fabric; using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric to form a de-polymerization product; distilling out the chemical de-polymerization liquid from the de-polymerization product by evaporation; dissolving the BHET in water to form a aqueous phase liquid; adding an activated carbon material to the aqueous phase liquid to adsorb impurities; and cooling the aqueous phase liquid to crystallize the BHET from the aqueous phase liquid to obtain a recycled BHET.

A method for improving a recovery rate of recycled bis(2-hydroxyethyl) terephthalate (BHET) is provided, which includes: providing a recycled polyester fabric; using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric, so as to form a de-polymerization product containing BHET; dissolving the BHET in water to form a aqueous phase liquid; cooling the aqueous phase liquid from a dissolution temperature to a first crystallization temperature, so as to crystallize at least a part of the BHET; and cooling the aqueous phase liquid from the first crystallization temperature to a second crystallization temperature, so as to crystallize at least another part of the BHET.

A method for improving a recovery rate of recycled bis(2-hydroxyethyl) terephthalate (BHET) is provided, which includes: providing a recycled polyester fabric; using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric, so as to form a de-polymerization product containing BHET; dissolving the BHET in water to form a aqueous phase liquid; cooling the aqueous phase liquid from a dissolution temperature to a first crystallization temperature, so as to crystallize at least a part of the BHET; and cooling the aqueous phase liquid from the first crystallization temperature to a second crystallization temperature, so as to crystallize at least another part of the BHET.

Method for depolymerising terephthalate polymer into reusable raw material, the method comprising steps of: depolymerizing terephthalate polymer by using ethylene glycol into a depolymerised mixture comprising at least one monomer and at least one dimer, wherein said at least one monomer comprises bis (2-hydroxyethyl) terephthalate (BHET), and said at least one dimer comprises dimer of bis (2-hydroxyethyl) terephthalate (BHET-dimer); removing solid compounds from said depolymerised mixture in a first separator to obtain a composition comprising the at least one dimer and the at least one monomer as solutes in a mixture of ethylene glycol and water; crystallizing BHET-dimer from said solution, thereby obtaining a mixture of BHET-dimer crystals and a first mother liquid; separating the crystallized BHET-dimer from the first mother liquid, and thereafter: forming BHET crystals from said first mother liquid, thereby obtaining a mixture of BHET crystals and a second mother liquid; and recovering the BHET crystals.

Method for depolymerising terephthalate polymer into reusable raw material, the method comprising steps of: depolymerizing terephthalate polymer by using ethylene glycol into a depolymerised mixture comprising at least one monomer and at least one dimer, wherein said at least one monomer comprises bis (2-hydroxyethyl) terephthalate (BHET), and said at least one dimer comprises dimer of bis (2-hydroxyethyl) terephthalate (BHET-dimer); removing solid compounds from said depolymerised mixture in a first separator to obtain a composition comprising the at least one dimer and the at least one monomer as solutes in a mixture of ethylene glycol and water; crystallizing BHET-dimer from said solution, thereby obtaining a mixture of BHET-dimer crystals and a first mother liquid; separating the crystallized BHET-dimer from the first mother liquid, and thereafter: forming BHET crystals from said first mother liquid, thereby obtaining a mixture of BHET crystals and a second mother liquid; and recovering the BHET crystals.

Method for depolymerising terephthalate polymer into reusable raw material, the method comprising steps of: depolymerizing terephthalate polymer by using ethylene glycol into a depolymerised mixture comprising at least one monomer and at least one dimer, wherein said at least one monomer comprises bis (2-hydroxyethyl) terephthalate (BHET), and said at least one dimer comprises dimer of bis (2-hydroxyethyl) terephthalate (BHET-dimer); removing solid compounds from said depolymerised mixture in a first separator to obtain a composition comprising the at least one dimer and the at least one monomer as solutes in a mixture of ethylene glycol and water; crystallizing BHET-dimer from said solution, thereby obtaining a mixture of BHET-dimer crystals and a first mother liquid; separating the crystallized BHET-dimer from the first mother liquid, and thereafter: forming BHET crystals from said first mother liquid, thereby obtaining a mixture of BHET crystals and a second mother liquid; and recovering the BHET crystals.

The disclosure provides a decolorization and purification method of BHET material, which includes the following steps. A first dose of activated carbon is added to preliminarily treat the BHET material. After the preliminary treatment, a first cooling crystallization process and filtration are performed to obtain BHET crystals. Afterwards, an oxidant is used to chemically react with the BHET crystals to destroy a dye or impurities, and then a second dose of activated carbon is added to adsorb a chemically reacted oxide. Next, a second cooling crystallization process, filtration, and drying are performed to obtain a finished product of BHET.