公开(公告)号：US3658894A

公开(公告)日：1972-04-25

申请号：US3658894D

申请日：1968-10-02

Applicant: STANDARD OIL CO

Inventor： JUVELAND OMAR O ,  PRAMUK EDWARD M

IPC: C07C51/487 ,  C07C51/42

CPC classification number: C07C51/487 ,  C07C63/26

Abstract: A PROCESS FOR PURIFYING TEREPHTHALIC ACID BY REDUCING ITS 4-CARBOXYBENZALDEHYDE CONTENT TO BELOW A PREDETERMINED LEVEL, E.G., 100 P.P.M. OR LESS, TO PROVIDE A PRODUCT SUITABLE FOR USE IN APPLICATIONS SUCH AS FORMING SYNTHETIC FIBERS COMPRISING RAISING SOLID, IMPURE TEREPHTHALIC ACID TO A TEMPERATURE SUFFICIENT TO CAUSE SUBLIMATION, E.G., 235* C. TO 285*C. IN A REACTION ZONE, PASSING A GAS CONTAINING MOLECULAR OXYGEN THROUGH THE REACTION ZONE TO OXIDIZE THE 4-CARBOXYBENZALDEHYUDE TO TEREPHTHALIC ACID AND THEREAFTER RECOVERING THE SUBLIMATED TEREPHTHALIC ACID. TO REDUCE FORMATION OF UNDESIRABLE SIDE-PRODUCTS FORM THE TEREPHTHALIC ACID, THE OXYGEN-CONTAINING AS MAY CONTAIN WATER VAPOR.