Method for preparing terephthalic acid, and terephthalic acid prepared therefrom
AssigneeSK Chemicals Co., Ltd.
InventorsYu-Mi Chang, Ju-Sik Kang, Jeong Ho Park, Hee-Il Chae
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Abstract
The present invention relates to a method for preparing terephthalic acid, and terephthalic acid prepared therefrom. Specifically, according to one embodiment of the present invention, by including the step of hydrolyzing a compound prepared by depolymerizing a waste polyester using a specific hydrolysis catalyst, terephthalic acid can be prepared in an environmentally friendly manner, and high purity terephthalic acid can be provided.
Claims15
A process for preparing terephthalic acid, which comprises:
- hydrolyzing bis (2-hydroxyethyl) terephthalate (BHET) or a compound which is liquid at room temperature and is prepared by depolymerizing waste polyester,
- wherein the depolymerizing comprises alcoholysis, and the alcoholysis is carried out using an alcohol having 4 or more carbon atoms, and
- wherein a hydrolysis catalyst is used in the hydrolyzing and comprises at least one selected from the group consisting of NaOH, NaHCO3, Na2CO3, NaOMe, KOH, K2CO3, KOtBu, CsOH, Ca(OH)2, LiOH, NH4OH, Na2TPA, and sodium monobutyl terephthalate.
Recycled terephthalic acid, which is prepared according to a process for preparing terephthalic acid, which comprises:
- hydrolyzing a compound which is liquid at room temperature and is prepared by depolymerizing waste polyester,
- wherein the depolymerizing comprises alcoholysis, and the alcoholysis is carried out using an alcohol having 4 or more carbon atoms, and
- wherein a hydrolysis catalyst is used in the hydrolyzing and comprises at least one selected from the group consisting of NaOH, NaHCO3, Na2CO3, NaOMe, KOH, K2CO3, KOtBu, CsOH, Ca (OH)2, LiOH, NH4OH, Na2TPA and sodium monobutyl terephthalate, and
- wherein the recycled terephthalic acid has a total metal content of less than 100 ppm when measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES).
Dependencies are inferred from the claim text.