APPARATUS AND METHOD FOR PREPARING BISPHENOL A

• US 20180312456A1
• Filed: 11/21/2016
• Published: 11/01/2018
• 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
• Granted Patent: US 10,442,746 B2
• Time in Patent Office: Days
• 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 invention relates to an apparatus and a method for preparing bisphenol A, and provides an apparatus and a method for preparing bisphenol A that can increase the energy efficiency of the entire process by utilizing an internal heat source.

Claims

1. An apparatus for preparing bisphenol A comprising:

a first crystallizer to which a bisphenol A concentration stream containing a reaction product that phenol and acetone are reacted is introduced to crystallize bisphenol A and to discharge an adduct of crystallized bisphenol A and phenol;

a first solid-liquid separator in which the adduct of crystallized bisphenol A and phenol in said first crystallizer is introduced thereto, and separated from a mother liquid and discharged;

a phenol introduction port in which a phenol stream is introduced into the adduct of crystallized bisphenol A and phenol discharged from said first solid-liquid separator to discharge the mixed stream of phenol with said adduct of crystallized bisphenol A and phenol;

a first heat exchanger in which said phenol stream is heated before said phenol stream is introduced;

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

a second crystallizer to which the molten stream discharged from said second heat exchanger is introduced to recrystallize bisphenol A and to discharge the adduct of crystallized bisphenol A and phenol.

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

4. The apparatus 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.

5. The apparatus for preparing bisphenol A according to claim 2, wherein the first heat exchanger comprises a vent for discharging pentane and said vent is connected to the separation line to separate pentane.

6. The apparatus 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.

7. The apparatus for preparing bisphenol A according to claim 1, comprising a return line for returning the adduct of crystallized bisphenol A and phenol discharged from the first solid-liquid separator, wherein said return line comprises a second heat exchanger and a 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.

8. The apparatus for preparing bisphenol A according to claim 1, further comprising a main reactor in which a reaction product that phenol and acetone are reacted is discharged through a reaction product stream, and a flasher in which said reaction product stream is introduced and separated 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.

9. The apparatus for preparing bisphenol A according to claim 1, further comprising a second solid-liquid separator in which the adduct of crystallized bisphenol A and phenol, and the mother liquid, flowing out from the second crystallizer are separated and discharged.

10. The apparatus for preparing bisphenol A according to claim 9, further comprising a bisphenol A refining line for discharging the molten stream of the adduct of crystallized bisphenol A and phenol discharged from the second solid-liquid separator.

11. The apparatus for preparing bisphenol A according to claim 10, further comprising a bisphenol A refining drum into which the molten stream flowing out through a bisphenol A refining line is introduced.

12. 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.

13. The method for preparing bisphenol A according to claim 12, further comprising a step of separating pentane in the phenol stream through a separation line of the first heat exchanger.

14. The method for preparing bisphenol A according to claim 12, wherein the introduction of the phenol stream comprises introducing phenol in a range of 40°

C. to 100°

C. through the phenol introduction port.

15. The method for preparing bisphenol A according to claim 12, 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.

16. The method for preparing bisphenol A according to claim 12, wherein the mixed stream is discharged from the phenol introduction port at a flow rate of 30 to 200 ton/hr.

17. The method for preparing bisphenol A according to claim 12, wherein the molten stream is in a range of from 70°

C. to 200°

C.

18. The method for preparing bisphenol A according to claim 12, wherein the molten stream comprises 20 wt % to 60 wt % of bisphenol A.