Title of Invention	PROCESS FOR PURIFYING ACETIC ACID
Abstract	A process for purifying acetic acid which comprises: introducing a feedstock aqueous solution of acetic acid having an acetic acid concentration of from 10 to 50% by weight into an extractor; supplying an extracting medium containing isopropyl acetate in an amount from 0.6 to 3.0 times by weight the amount of the feedstock solution thereinto in such a manner that the extracting medium is made in contact with the feedstock solution; extracting acetic acid into the extracting medium; separating the extracting medium containing acetic acid from an extraction residue; supplying the extraction medium containing acetic acid into an azeotropic distillation column; distilling off the isopropyl acetate contained in the extraction medium from a top of the azeotropic distillation column via azeotropic distillation with water; condensing a distillate from the top of the azeotropic distillation column, to divide the distillate into a water-poor phase being rich in isopropyl acetate and a water-rich phase being rich in water; returning at least a portion of the water-poor phase into the extractor as the extracting medium; and recovering the acetic acid, which has been thus dehydrated and purified, from a bottom of the azeotropic distillation column.

Title of Invention

PROCESS FOR PURIFYING ACETIC ACID

Abstract

A process for purifying acetic acid which comprises: introducing a feedstock aqueous solution of acetic acid having an acetic acid concentration of from 10 to 50% by weight into an extractor; supplying an extracting medium containing isopropyl acetate in an amount from 0.6 to 3.0 times by weight the amount of the feedstock solution thereinto in such a manner that the extracting medium is made in contact with the feedstock solution; extracting acetic acid into the extracting medium; separating the extracting medium containing acetic acid from an extraction residue; supplying the extraction medium containing acetic acid into an azeotropic distillation column; distilling off the isopropyl acetate contained in the extraction medium from a top of the azeotropic distillation column via azeotropic distillation with water; condensing a distillate from the top of the azeotropic distillation column, to divide the distillate into a water-poor phase being rich in isopropyl acetate and a water-rich phase being rich in water; returning at least a portion of the water-poor phase into the extractor as the extracting medium; and recovering the acetic acid, which has been thus dehydrated and purified, from a bottom of the azeotropic distillation column.

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Patent Number

193269

Indian Patent Application Number

369/MAS/1996

PG Journal Number

35/2005

Publication Date

16-Sep-2005

Grant Date

19-Jul-2005

Date of Filing

08-Mar-1996

Name of Patentee

M/S. SHOWA DENKO K. K

Applicant Address

13-9 SHIBADAIMON 1-CHOME, MINATO-KU TOKYO

Inventors:

#	Inventor's Name	Inventor's Address
1	TAKAHARU SASAKI	SHOWA DENKO K.K., 2, OAZA NAKANOSU, OITA-SHI, OITA,
2	MASAYUKI FUJIMOTO	SHOWA DENKO K.K., 2, OAZA NAKANOSU, OITA-SHI, OITA,
3	TAKASHIGE MIYANARI	SHOWA DENKO K.K., 2, OAZA NAKANOSU, OITA-SHI, OITA
4	HIROSHI NISHINO	SHOWA DENKO K.K., 2, OAZA NAKANOSU, OITA-SHI, OITA,

PCT International Classification Number

B01D3/36

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	7-254004	1995-09-29	Japan