The present invention provides an effective and selective process for the depolymerization of polyethylene terephthalate (PET), polyethylene furanoate (PEF), polylactic acid, polycarbonates, polyethers and polyamides into pure and high yielding valorized products by combining the glycolysis-hydrolysis reactions using a homogeneous acidic ionic liquid (AIL) catalyst, resulting in excellent polymer conversion.

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 producing recycled polyester chips from a recycled polyester fabric is provided. The method includes: providing the recycled polyester fabric attached with dyes and/or coating glue; performing a color removal process to at least partially remove the dyes and/or the coating glue attached to the polyester fabric; performing a de-polymerization process which includes: using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric, so as to form a de-polymerization product containing bis(2-hydroxyethyl) terephthalate (BHET) and oligomers; performing a purification process, so as to enhance a purity of the BHET in the de-polymerization product; and performing a granulation process, so as to re-polymerize the purified BHET and form the recycled polyester chips (r-PET).

A method for producing recycled polyester chips from a recycled polyester fabric is provided. The method includes: providing the recycled polyester fabric attached with dyes and/or coating glue; performing a color removal process to at least partially remove the dyes and/or the coating glue attached to the polyester fabric; performing a de-polymerization process which includes: using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric, so as to form a de-polymerization product containing bis(2-hydroxyethyl) terephthalate (BHET) and oligomers; performing a purification process, so as to enhance a purity of the BHET in the de-polymerization product; and performing a granulation process, so as to re-polymerize the purified BHET and form the recycled polyester chips (r-PET).

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 of obtaining a purified regenerated diacid from a depolymerization of a polyester in a waste material wherein the depolymerization provides a depolymerized mixture comprising a regenerated diol, a regenerated diacid, and a catalyst is disclosed. The method comprises: separating a regenerated composition including the regenerated acid and the catalyst from the regenerated diol; providing the regenerated composition in a liquid medium to form a pre-aged mixture; subjecting the pre-aged mixture to thermal cycling wherein the cycling occurs within 25° C. and within a temperature range of from 150° C. or more to 300° C. or less to form an aged mixture; and separating the regenerated composition from the liquid medium in the aged mixture.

The present invention relates to a method of producing a chitin oligomer, including subjecting chitin-containing biomass to partial hydrolysis while pulverizing the chitin-containing biomass with a pulverization apparatus in the co-presence of water and an acid catalyst selected from phosphoric acid, nitrous acid, and an organic acid (Method 1); a method of producing N-acetylglucosamine, including hydrolyzing a chitin oligomer obtained by the Method 1 by adding water thereto, followed by heating (Method 2); and a method of producing a 1-O-alkyl-N-acetylglucosamine, including alcoholyzing a chitin oligomer by adding an alcohol thereto (Method 3).

The present invention relates to a method of producing a chitin oligomer, including subjecting chitin-containing biomass to partial hydrolysis while pulverizing the chitin-containing biomass with a pulverization apparatus in the co-presence of water and an acid catalyst selected from phosphoric acid, nitrous acid, and an organic acid (Method 1); a method of producing N-acetylglucosamine, including hydrolyzing a chitin oligomer obtained by the Method 1 by adding water thereto, followed by heating (Method 2); and a method of producing a 1-O-alkyl-N-acetylglucosamine, including alcoholyzing a chitin oligomer by adding an alcohol thereto (Method 3).

The present disclosure relates to the formation of dimethyl terephthalate (DMT). The present invention also relates to the depolymerization of polyethylene terephthalate (PET) and the recovery of dimethyl terephthalate (DMT).