	US 12,441,675 B2
	Method for preparing terephthalic acid, and terephthalic acid prepared therefrom
Yu-Mi Chang, Gyeonggi-do (KR); Ju-Sik Kang, Gyeonggi-do (KR); Jeong Ho Park, Gyeonggi-do (KR); and Hee-Il Chae, Gyeonggi-do (KR)
Assigned to SK CHEMICALS CO., LTD., Gyeonggi-do (KR)
Appl. No. 18/726,819
Filed by SK CHEMICALS CO., LTD., Gyeonggi-do (KR)
PCT Filed Aug. 30, 2023, PCT No. PCT/KR2023/012907 § 371(c)(1), (2) Date Jul. 5, 2024, PCT Pub. No. WO2024/053928, PCT Pub. Date Mar. 14, 2024.
Claims priority of application No. 10-2022-0112229 (KR), filed on Sep. 5, 2022; and application No. 10-2023-0083806 (KR), filed on Jun. 28, 2023.
Prior Publication US 2025/0091978 A1, Mar. 20, 2025
Int. Cl. C07C 51/09 (2006.01); C07C 63/26 (2006.01); C08G 63/183 (2006.01)

CPC C07C 51/09 (2013.01) [C07C 63/26 (2013.01); C08G 63/183 (2013.01)]

15 Claims

1. 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, Na₂CO_3,NaOMe, KOH, K₂CO_3,KOtBu, CsOH, Ca(OH)_2,LiOH, NH₄OH, Na₂TPA, and sodium monobutyl terephthalate.