The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 12, 1982
Filed:
Sep. 21, 1981
Kunio Koga, Ohimachi, JP;
Ryoichi Kishimoto, Sakai, JP;
Daicel Chemical Industries, Ltd., Sakai, JP;
Abstract
Disclosed is a method of recovering acetic acid by extracting from an acetic acid-containing aqueous solution with an organic extracting agent and subjecting the extract to distillation, said method comprising the first step of performing extraction by using a tertiary amine having a boiling point higher than that of acetic acid and being capable of forming a non-aqueus phase as the organic extracting agent in combination with an oxygen-containing, high-boiling-point organic solvent selected from the group consisting of di-isobutylcarbinol, isophorene, methyl benzoate, tributyl phosphate, 3,3,5-trimethylcyclohexanone and 2-ethoxyethyl acetate, the second step of performing dehydration by subjecting the extract to distillation, and the third step of subjecting the dehydrated mixture to distillation in a reduced pressure distillation column at a column bottom temperature of 120.degree. to 170.degree. C. to distill acetic acid and separate it from the organic extracting agent. According to this method, water-free acetic acid can be recovered from an acetic acid-containing aqueous solution at a high separation efficiency with reduced energy consumption, and this recovery method is suitably applied to recovery of acetic acid from acetic acid-containing aqueous solutions discharged from various chemical industrial processes.