Apparatus and method for preparing bisphenol A

• US 10,683,251 B2
• Filed: 09/09/2019
• Issued: 06/16/2020
• Est. Priority Date: 11/19/2015
• Status: Active Grant

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Kim, Tae Woo, Lee, Sung Kyu, Shin, Joon Ho
• Primary Examiner(s): Nguyen, Huy Tram
• Application Number:
  US16/565,047
• Publication Number:
  US 20200017431A1
• Time in Patent Office: 281 Days
• Field of Search: 422187
• CPC Class Codes: B01D 9/00 Crystallisation crystallisation directly from the vapour phase B01D7/02; making single crystals C30B ; crystallisation as part of the Bayer process also classified in C01F7/14
• CPC Class Codes: B01D 9/0059 General arrangements of crystallisation plant, e.g. flow sheets
• CPC Class Codes: B01L 9/00 Supporting devices; Holding devices
• CPC Class Codes: C07C 37/685 Processes comprising at least two steps in series
• CPC Class Codes: C07C 37/84 by crystallisation
• CPC Class Codes: C07C 39/16 Bis-(hydroxyphenyl) alkanes; Tris-(hydroxyphenyl)alkanes
• CPC Class Codes: Y02P 20/10 Process efficiency

Abstract

The present application relates to a bisphenol A preparation apparatus and preparation method, and provides a bisphenol A preparation apparatus and preparation method, which can increase the overall energy efficiency of a process by using an internal heating source.

Claims

1. A method for preparing bisphenol A comprising steps of:

crystallizing bisphenol A through a first crystallizer in a bisphenol A concentration stream comprising a reaction product that phenol and acetone are reacted and discharging the adduct of crystallized bisphenol A and phenol;

separating the adduct of crystallized bisphenol A and phenol in said first crystallizer from the mother liquor through a first solid-liquid separator and discharging it;

introducing a phenol stream into the adduct of crystallized bisphenol A and phenol discharged from said first solid-liquid separator through a phenol introduction port and discharging a mixed stream of the phenol with said adduct of crystallized bisphenol A and phenol;

heating said phenol stream through a first heat exchanger before introducing the phenol stream through said phenol introduction port;

melting the adduct of crystallized bisphenol A and phenol in the mixed stream flowing out from said phenol introduction port through a second heat exchanger to discharge a molten stream; and

introducing said discharged molten stream to recrystallize bisphenol A through a second crystallizer.

2. The method for preparing bisphenol A according to claim 1, wherein the first heat exchanger comprises a separation line for separating pentane present in said phenol stream.

3. The method for preparing bisphenol A according to claim 2, further comprising a step of separating pentane in the phenol stream through a separation line of the first heat exchanger.

4. The method for preparing bisphenol A according to claim 1, wherein the introduction of the phenol stream comprises introducing phenol in a range of 40°

C. to 100°

C. through the phenol introduction port.

5. The method for preparing bisphenol A according to claim 1, wherein the introduction of the phenol stream comprises introducing phenol having a flow rate of 10 ton/hr to 50 ton/hr through the phenol introduction port.

6. The method for preparing bisphenol A according to claim 1, wherein the mixed stream is discharged from the phenol introduction port at a flow rate of 30 to 200 ton/hr.

7. The method for preparing bisphenol A according to claim 1, wherein the molten stream is in a range of from 70°

C. to 200°

C.

8. The method for preparing bisphenol A according to claim 1, wherein the molten stream comprises 20 wt % to 60 wt % of bisphenol A.

9. The method for preparing bisphenol A according to claim 2, wherein the separation line introduces separated pentane into the second crystallizer.

10. The method for preparing bisphenol A according to claim 1, wherein the first heat exchanger heats the phenol stream by introducing a heat source of 120°

C. or lower.

11. The method for preparing bisphenol A according to claim 9, wherein the first heat exchanger comprises a vent for discharging pentane and said vent is connected to the separation line to separate pentane.

12. The method for preparing bisphenol A according to claim 1, wherein the second heat exchanger melts the adduct of crystallized bisphenol A and phenol by introducing steam having a pressure of 200 kPa to 500 kPa.

13. The method for preparing bisphenol A according to claim 1, comprising returning the adduct of crystallized bisphenol A and phenol discharged from the first solid-liquid separator via a return line, wherein said return line comprises the second heat exchanger and the phenol introduction port, and a stream flowing out through said return line is again mixed with the adduct of crystallized bisphenol A and phenol discharged from the first solid-liquid separator.

14. The method for preparing bisphenol A according to claim 1, further comprising reacting phenol and acetone in a main reactor, discharging a reaction product from the main reactor via a reaction product stream, and introducing said reaction product stream into a flasher, and separating the reaction product stream into a bisphenol A concentration stream and a phenol concentration stream,

wherein the bisphenol A concentration stream separated from said flasher is introduced into the first crystallizer and the mother liquid stream separated in the first solid-liquid separator flows out to said main reactor.

15. The method for preparing bisphenol A according to claim 1, further comprising separating the adduct of crystallized bisphenol A and phenol, and the mother liquid, flowing out from the second crystallizer in a second solid-liquid separator.

16. The method for preparing bisphenol A according to claim 15, further comprising discharging the molten stream of the adduct of crystallized bisphenol A and phenol discharged from the second solid-liquid separator via a bisphenol A refining line.

17. The method for preparing bisphenol A according to claim 16, further comprising introducing a molten stream flowing out through the bisphenol A refining line into a bisphenol A refining drum.