Process for the production of crystalline adduct of bisphenol A and phenol and apparatus therefor

• US 5,345,000 A
• Filed: 03/03/1993
• Issued: 09/06/1994
• Est. Priority Date: 07/10/1991
• Status: Expired due to Term

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Chiyoda Corporation (Mitsubishi Corporation)
• Inventors: Onda, Nobuhiro, Kameda, Takao, Shimoda, Keiji, Kouzaki, Takeshi, Yasui, Makoto, Asaoka, Sachio, Nishijima, Hiroaki, Moriya, Nobuo, Sakashita, Kouji, Maejima, Tetsuo
• Primary Examiner(s): LONE, WERREN
• Application Number:
  US08/026,126
• Time in Patent Office: 552 Days
• Field of Search: 568/724, 568/727, 568/722
• US Class Current: 568/722
• CPC Class Codes: B01D 3/141 where at least one distillation column contains at least one dividing wall
• 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

Abstract

High purity, crystalline adduct of bisphenol A and phenol is produced multi-stage crystallization of a phenolic slurry of bisphenol A with a crystal separation and washing step being interposed between each of the two stages. Each of the crystallization stage includes a series of crystallization towers operated at decreasing temperatures. The crystallization of the slurry is performed by continuously discharging a portion of the slurry from each of the crystallization towers, introducing the discharged slurry into one or more coolers and then recycling the cooled slurry to the tower. Another portion of the slurry in each crystallization slurry is continuously discharged, heated for dissolving fine crystals of the adduct and then recycled to the crystallization tower so that large crystals are grown in each of the crystallization steps. An apparatus having a plurality of coolers and suitable for effecting the above crystallization is also disclosed.

Claims

1. A process for the production of a crystalline adduct of bisphenol A and phenol, comprising the steps of:

providing two or more, first to n-th crystallization zones connected in series and each having an outer tubular housing and an inner tubular member defining therein an inner passage and coaxially disposed within said outer tubular housing to define an outer passage therebetween, said inner passage being in fluid communication with said outer passage only at an upper portion of said inner passage;

crystallizing an adduct of bisphenol A and phenol in each of said first to n-th crystallization zones at a temperature of 45°

-70°

to form a slurry;

discharging the slurry from the bottom of the inner passage of each of said first to n-th crystallization zones;

cooling a portion of the slurry discharged from each of said two or more crystallization zones and recycling the cooled slurry to the corresponding crystallization zone so that the slurry in each of said first to n-th crystallization zones is cooled such that the temperature of the slurry in one crystallization zone is lower than that in the adjacent crystallization zone located upstream of said one crystallization zone;

heating another portion of the slurry discharged from said n-th crystallization zone to dissolve fine crystals contained therein and recycling said heated slurry to said n-th crystallization zone;

admixing a solution of bisphenol A dissolved in phenol with said cooled slurry to be recycled to said first crystallization zone, feeding the resulting admixture to a lower portion of the outer passage of the first crystallization zone and passing same to the inner passage to effect the crystallization of the adduct of bisphenol A and phenol;

mixing part of the slurry discharged from each of said first to (n-1)th crystallization zones with the cooled slurry to be recycled to that crystallization zone located immediately downstream thereof, feeding the resulting mixture to a lower portion of the outer passage of that crystallization zone and passing same to the inner passage of that crystallization zone to effect the crystallization of the adduct of bisphenol A and phenol; and

recovering a further portion of the slurry discharged from said n-th crystallization zone,

each of said heated slurry, said admixture and said mixture being fed to the outer passage of the corresponding crystallization zone such that the slurry in said outer passage forms a vortex flow.

9. A process as claimed in claim 1, wherein the first solution has a temperature which is 1°

-20°

C. higher than a saturation temperature of the adduct.

10. A process as claimed in claim 1, wherein the first solution contains bisphenol A in an amount of 7-50% by weight.

11. A process as claimed in claim 1, wherein the second temperature is from 3°

-10°

C. less than the first temperature.

12. A process as claimed in claim 1, wherein the fourth temperature is equal to or up to 10°

C. lower than the third temperature.

13. A process as claimed in claim 1, wherein the fourth slurry has a concentration of the adduct of 35% by weight or less.

14. A process as claimed in claim 1, wherein the adduct has a temperature which is 1°

-20°

C. higher than a saturation temperature of the adduct.

15. A process as claimed in claim 1, wherein the portion of slurry discharged from each of the two or more crystallization zones which is to be cooled is cooled from a temperature on discharge to a temperature no more than 10°

C. less than the temperature upon discharge.

16. A process as claimed in claim 1, wherein the portion of the slurry discharged from the n-th crystallization zone which is to be heated is heated from a temperature on discharge to a temperature 0.5°

to 5°

C. higher than the temperature on discharge.

17. A process as claimed in claim 1, wherein the portion of the slurry discharged from the n-th crystallization zone which is to be heated is heated for a time sufficient so as to dissolve fine particles of the adduct having a size of 100 μ

m or less.

18. A process as claimed in claim 1, wherein the temperature of the slurry in the (n) crystallization zone is from 3°

-10°

C. lower than the temperature in the (n-1) crystallization zone.

20. A process as claimed in claim 1, further comprising heating another portion of the slurry discharged from each of said first to (n-1)th crystallization zones to dissolve fine crystals contained therein and recycling said heated slurry to the corresponding crystallization zone to facilitate the formation of said vortex flow.

2. A process for the production of a crystalline adduct of bisphenol A and phenol, comprising the steps of:

providing a crystallization zone having an outer cylindrical housing and an inner cylindrical member defining therein an inner passage and coaxially disposed within said outer cylindrical housing to define an annular, outer passage therebetween, said inner passage being in fluid communication with said outer passage only at an upper portion of said inner passage;

admixing a solution of bisphenol A dissolved in phenol with a cooled slurry to form an admixture;

feeding said admixture to a lower portion of the outer portion passage of said crystallization zone and passing same to said inner passage so that an adduct of bisphenol A and phenol is crystallized at a first temperature of 45°

-70°

C. to obtain a slurry containing crystals of the adduct;

discharging the slurry from the bottom of the inner passage of said crystallization zone;

cooling a first portion of the slurry discharged from said crystallization zone to a temperature not more than 10°

C. less than the first temperature to obtain said cooled slurry;

heating a second portion of the slurry discharged from said crystallization zone to a temperature 0.5°

-5°

C. more than the first temperature to dissolve fine crystals contained therein and recycling said heated slurry to said crystallization zone; and

recovering the crystals from the slurry discharged from said crystallization zone,

each of said admixture and said heated slurry being fed to said outer passage of said crystallization zone such that the slurry in said outer passage forms a vortex flow.

19. A process as claimed in claim 2, wherein the second portion of the slurry discharged from the crystallization zone is heated for a time sufficient so as to dissolve fine particles of the adduct having a size of 100 μ

m or less.

3. A process for the production of a crystalline adduct of bisphenol A and phenol, comprising the steps of:

providing a crystallization zone and a plurality of cooling zones connected in parallel with each other and each having a cooling surface adapted to cool a liquid upon contact therewith;

feeding a solution of bisphenol A dissolved in phenol to said crystallization zone and cooling same to a temperature of 45°

-70°

C. to crystallize an adduct of bisphenol A and phenol and to obtain a slurry containing crystals of the adduct;

discharging the slurry from said crystallization zone;

introducing a portion of the slurry discharged from said crystallization zone to all of said cooling zones except one cooling zone whose cooling surface bears deposits of crystals of the adduct to cool the slurry introduced thereinto with the simultaneous formation of crystals of the adduct on the cooling surfaces thereof;

recycling the cooled slurry to said crystallization zone so that the slurry in said crystallization zone is cooled;

recovering the crystals from the slurry discharged from said crystallization zone; and

removing the deposits from the cooling surface of said one cooling zone.

4. A process as claimed in claim 3, wherein said removal of the deposits is performed by heating the cooling surface by contact with a heating medium.

5. A process as claimed in claim 3, wherein each of said cooling zones is provided with a pump operable for feeding the slurry to the corresponding cooling zone and to recycle the cooled slurry to said crystallization zone and wherein the pump of said one cooling zone is also warmed by contact with said heating medium for the removal of deposits of the crystals formed during previous use.

6. A process for the production of a crystalline adduct of bisphenol A and phenol, comprising:

(A) a first stage including the steps of;

(A-a) feeding a solution of bisphenol A dissolved in phenol to a crystallization zone and cooling same to crystallize an adduct of bisphenol A and phenol and to obtain a slurry containing crystals of the adduct, and

(A-b) discharging said slurry from said crystallization zone and introducing same into a solid-liquid separating zone to separate said slurry into a solid phase containing crystals of the adduct and a liquid phase containing phenol; and

(B) one or more, second to n-th stages following said first stage and each including the steps of;

(B-a) dissolving the solid phase obtained in the immediately preceding stage into solvent phenol to obtain a solution,

(B-b) feeding said solution obtained in step (B-a) to a crystallization zone and cooling same to crystallize an adduct of bisphenol A and phenol and to obtain a slurry containing crystals of the adduct, and

(B-c) discharging said slurry obtained in step (B-b) from said crystallization zone and introducing same into a solid-liquid separating zone to separate said slurry into a solid phase containing crystals of the adduct and a liquid phase containing phenol, said process further comprising the steps of;

washing the solid phase obtained in the n-th stage with purified phenol to obtain a washed solid product and used phenol,

recovering the washed solid product,

recycling at least one of a first part of said used phenol and a first part of said liquid phase obtained in said n-th stage to step (B-a) of the (n-1)th stage as at least part of said solvent phenol,

washing the solid phase obtained in the (n-1)th stage with at least one of a second part of said used phenol and a second part of said liquid phase obtained in said n-th stage, and

controlling the purity of the solvent phenol used in each of said second to n-th stages so that the content of impurities in the solvent phenol used in one stage of said second to n-th stages is greater than that of the stage immediately following said one stage.

7. A process for the production of a crystalline adduct of bisphenol A and phenol, comprising:

cooling a solution of bisphenol A dissolved in phenol to crystallize an adduct of bisphenol A and phenol and to obtain a slurry containing crystals of the adduct, and

filtering said slurry to separate the crystals such that the separated crystals contain less than 20% by weight of crystals with a particle diameter of 100 μ

m or less.

8. A process as claimed in claim 7, further comprising washing the separated crystals with purified phenol.