Title:
METHOD FOR MANUFACTURING REFINED TEREPHTHALIC ACID
Document Type and Number:
Japanese Patent JP2015140342
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide an economical dryer-less process for directly refining wet crystals of manufactured crude terephthalic acid in aqueous solution without drying to powder, through efficient water-washing of the crude terephthalic acid crystals and efficient collection of acetic acid contained in washing drain water with energy saving.SOLUTION: In washing of crystals separated from slurry of crude terephthalic acid crystals, crystals which contain substantially no acetic acid are collected in parallel with collection of separated water-washing drain water. The washing drain water is subjected to extraction of acetic acid with an extractant without dehydration distillation. After separation of water, the acetic acid extract is supplied to a dehydration distillation column for collection of acetic acid. Based on the finding on efficient relations between the acetic acid content in the washing drain water and the amount of the extractant (solvent ratio), an easy water-washing process with reduced losses of acetic acid and energy can be found.
Inventors:
HARA NORIAKI
ITO ETSUSHI
YAMAZAKI HATSUTARO
ITO ETSUSHI
YAMAZAKI HATSUTARO
Application Number:
JP2014015996A
Publication Date:
August 03, 2015
Filing Date:
January 30, 2014
Export Citation:
Assignee:
HITACHI LTD
International Classes:
C07C51/42; C07C51/16; C07C51/487; C07C63/26
Attorney, Agent or Firm:
Isono Dozo
Etsuo Tada
Etsuo Tada