Title:
INDUSTRIAL METHOD FOR RECOVERING TEREPHTHALIC ACID FROM PULVERIZED PRODUCT OF RECOVERED POLYETHYLENE TEREPHTHALATE
Document Type and Number:
Japanese Patent JP3917811
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To economically recover terephthalic acid having a large particle diameter from a pulverized product of a recovered PET by a practical and industrial process.
SOLUTION: This method is to thermally degrade the pulverized product of the recovered polyethylene terephthalate in the presence of an alkali into a terephthalate and ethylene glycol, remove the ethylene glycol from the resultant thermal degradation slurry, provided a solid terephthalate, dissolve the solid terephthalate in water, afford an aqueous solution of the terephthalate, add an acid to the aqueous solution of the terephthalate, neutralize the aqueous solution and deposit the terephthalic acid. The addition of the acid is carried out in plural stages so that the pH of the aqueous solution in the final stage is 2-4 and the resultant terephthalic acid crystal from the final stage is returned to the previous stage and dissolved.
Inventors:
Jinichi Yazaki
Kozaburo Sakano
Nobuyuki Funakoshi
Kazuho Tanaka
Kozaburo Sakano
Nobuyuki Funakoshi
Kazuho Tanaka
Application Number:
JP2000347848A
Publication Date:
May 23, 2007
Filing Date:
November 15, 2000
Export Citation:
Assignee:
Toyo Seikan Co., Ltd.
Tsukishima Machinery Co., Ltd.
Tsukishima Machinery Co., Ltd.
International Classes:
B01D9/02; C07C51/43; B03B5/28; B03B5/66; C07C51/09; C07C63/26; C08J11/16; C08L67/02; (IPC1-7): C07C51/43; B01D9/02; B03B5/28; B03B5/66; C07C51/09; C07C63/26; C08J11/16; //C08L67:02
Domestic Patent References:
| JP41012304B1 | ||||
| JP2184651A | ||||
| JP7017903A | ||||
| JP7291896A | ||||
| JP2000212117A | ||||
| JP2001151709A |
Attorney, Agent or Firm:
Yoshihisa Nagai
Previous Patent: STORAGE BOX FOR CARGO RECEIVING PLATFORM ELEVATING DEVICE
Next Patent: EXHAUST DEVICE
Next Patent: EXHAUST DEVICE