Process for the preparation of high-purity bisphenol A
First Claim
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1. A process for the preparation of bisphenol A comprising:
- a) reacting phenol with acetone in the presence of an acidic ion exchanger and a sulfur-containing co-catalyst to produce a product mixture comprising bisphenol A, phenol, BPA isomers, un-reacted acetone, and water, wherein the resulting product mixture is not subjected to distillation upstream of steps (b) or (c) to remove readily volatile constituents including water;
b) continuously obtaining from the product mixture crystals of bisphenol A-phenol adduct by suspension crystallization in at least one crystallizer provided with at least one heat exchanger, said product mixture containing 0.1 to 6% by weight of water;
c) separating the adduct obtained in (b) by a first solid-liquid separation to obtain a first solid phase and a first liquid phase;
d) washing the first solid phase with a solution comprising phenol to obtain a washed solid phase and a second liquid phase;
e) distilling the first liquid phase and said second liquid phase to obtain a dewatered solution comprising 5 to 15 wt.-% p,p-BPA, 3 to 12 wt.-% isomers of BPA and less than 0.3 wt.-% water, the percentages based on the weight of the dewatered solution;
f) optionally introducing at least 90 wt.-% by weight of the dewatered solution into (a);
g) adding phenol and water to the washed solid phase obtained in (d) to obtain a homogeneous material system comprising 15 to 35 wt.-% p,p′
-BPA, 0.05 to 2 wt.-% isomers of BPA and 0.1 to 10 wt.-% water;
h) continuously obtaining from the homogeneous material system crystals of bisphenol A-phenol adduct by suspension crystallization in at least one crystallizer provided with at least one heat exchanger;
i) separating the crystals obtained in (h) by a second solid-liquid separation to obtain a second solid phase;
j) washing the second solid phase with a solution comprising phenol to obtain a washed adduct; and
k) optionally heating the washed adduct to at least 120°
C. to at least potentially remove phenol.
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Abstract
A process for the preparation of high purity bisphenol A is disclosed. The multi-step process entails a process whereby bisphenol A of a purity of preferably at least 99.8% can be obtained.
16 Citations
14 Claims
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1. A process for the preparation of bisphenol A comprising:
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a) reacting phenol with acetone in the presence of an acidic ion exchanger and a sulfur-containing co-catalyst to produce a product mixture comprising bisphenol A, phenol, BPA isomers, un-reacted acetone, and water, wherein the resulting product mixture is not subjected to distillation upstream of steps (b) or (c) to remove readily volatile constituents including water; b) continuously obtaining from the product mixture crystals of bisphenol A-phenol adduct by suspension crystallization in at least one crystallizer provided with at least one heat exchanger, said product mixture containing 0.1 to 6% by weight of water; c) separating the adduct obtained in (b) by a first solid-liquid separation to obtain a first solid phase and a first liquid phase; d) washing the first solid phase with a solution comprising phenol to obtain a washed solid phase and a second liquid phase; e) distilling the first liquid phase and said second liquid phase to obtain a dewatered solution comprising 5 to 15 wt.-% p,p-BPA, 3 to 12 wt.-% isomers of BPA and less than 0.3 wt.-% water, the percentages based on the weight of the dewatered solution; f) optionally introducing at least 90 wt.-% by weight of the dewatered solution into (a); g) adding phenol and water to the washed solid phase obtained in (d) to obtain a homogeneous material system comprising 15 to 35 wt.-% p,p′
-BPA, 0.05 to 2 wt.-% isomers of BPA and 0.1 to 10 wt.-% water;h) continuously obtaining from the homogeneous material system crystals of bisphenol A-phenol adduct by suspension crystallization in at least one crystallizer provided with at least one heat exchanger; i) separating the crystals obtained in (h) by a second solid-liquid separation to obtain a second solid phase; j) washing the second solid phase with a solution comprising phenol to obtain a washed adduct; and k) optionally heating the washed adduct to at least 120°
C. to at least potentially remove phenol. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A process for the preparation of bisphenol A comprising:
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a) reacting phenol with acetone in the presence of an acidic ion exchanger and a sulfur-containing co-catalyst to produce a product mixture comprising bisphenol A, phenol, BPA isomers, un-reacted acetone, and water, wherein the resulting product mixture is not subjected to distillation upstream of steps (b) or (c) to remove readily volatile constituents including water; b) continuously obtaining from the product mixture crystals of bisphenol A-phenol adduct by suspension crystallization in at least one crystallizer provided with at least one heat exchanger, said product mixture containing 0.1 to 6% by weight of water; c) separating the adduct obtained in (b) by a first solid-liquid separation to obtain a first solid phase and a first liquid phase; d) washing the first solid phase with a solution comprising phenol to obtain a washed solid phase and a second liquid phase; e) distilling the first liquid phase and said second liquid phase to obtain a dewatered solution comprising less than 0.3 wt.-% water, the percentages based on the weight of the dewatered solution; f) optionally introducing at least a portion of the dewatered solution into (a); g) adding phenol and water to the washed solid phase obtained in (d) to obtain a homogeneous material system comprising 15 to 35 wt.-% p,p′
-BPA, 0.05 to 2 wt.-% isomers of BPA and 0.1 to 10 wt.-% water;h) continuously obtaining from the homogeneous material system crystals of bisphenol A-phenol adduct by suspension crystallization in at least one crystallizer provided with at least one heat exchanger; i) separating the crystals obtained in (h) by a second solid-liquid separation to obtain a second solid phase; j) washing the second solid phase with a solution comprising phenol to obtain a washed adduct; and k) optionally heating the washed adduct to at least 120°
C. to at least partially remove phenol.
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Specification
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Current AssigneeCovestro Deutschland AG
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Original AssigneeBayer Materialscience AG (Covestro AG)
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InventorsBlaschke, Ulrich, Audenaert, Raymond, Braun, Arne, Westernacher, Stefan, Zank, Jesko
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Primary Examiner(s)Eyler; Yvonne
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Assistant Examiner(s)Gale; Kellette
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Application NumberUS11/971,314Publication NumberTime in Patent Office258 DaysField of Search568/724US Class Current568/724CPC Class CodesC07C 37/20 using aldehydes or ketonesC07C 37/84 by crystallisationC07C 39/16 Bis-(hydroxyphenyl) alkanes...
