Abstract: A method is disclosed for treating a residual stream from bisphenol manufacture, wherein the residual stream comprises unreacted phenols, bisphenol isomers, trisphenols, organic sulfides and water. The method comprises contacting at least a portion of the residual stream or a reaction product thereof with an acidic catalyst under conditions sufficient to allow acid-catalyzed hydrolysis of organic sulfides in the residual stream to the corresponding thiols and produce an effluent stream, and then distilling at least a portion of the effluent stream to recover distillate products comprising phenols and thiols and produce a bottoms product comprising bisphenol isomers and trisphenols, and having a lower content of organic sulfides than the residual stream.

Abstract: Disclosed is a method for recovering phenol and acetone from the cracking reaction product of bisphenol-A residue, by which economic feasibility and efficiency may be improved by utilizing a phenol/acetone purification process used for preparing bisphenol-A.

Abstract: Provided are an apparatus and a method for preparing bisphenol A. In the present invention, all or some of a mother liquid stream is circulated to a flash rector through a bypass line after crystallization in a process of preparing bisphenol A so as to increase a conversion rate of bisphenol A in a reactor, reduce energy, and use a heating source of phenol to be discharged to an upper side of the flash reactor, and thus the reaction efficiency of the whole process can be increased.

Abstract: A method for improving the yield during the production of crystalline alpha lactose is suggested, wherein (a) An aqueous lactose solution is adjusted to a temperature of between about 62 and 67° C., (b) The solution is cooled down to between about 20 and 30° C., (c) The solution is held at this temperature for a period of from 0.5 to 5 h, (d) Subsequently, the solution is re-heated to between about 35 and 40° C., (e) The solution is held at this temperature for a period of from 0.5 to 5 h, (f) Subsequently, the solution is cooled down to about 10° C., and (g) Eventually, the precipitated alpha-lactose crystals are separated from the mother liquor.

Abstract: A method for separating a salified phenolic compound from a reaction medium including same is described. Also described, is a method for separating salified phenolic compounds from an aqueous reaction medium resulting from the reaction of a phenolic compound and glyoxylic acid in the presence of a base, which leads to a reaction medium including at least the excess of the starting salified phenolic compound and the various salified mandelic compounds resulting from the reaction, wherein the reaction medium including the starting salified phenolic compound is contacted with an adsorbent substrate. This leads to the selective adsorption of the phenolic compound onto said substrate and to the recovery of an aqueous flow containing the salified mandelic compounds from the reaction, and in that the phenolic compound attached onto the adsorbent is desorbed by means of a regenerating treatment of the adsorbent.

Abstract: Disclosed are: a cyclic compound which has high solubility in a safe solvent, is highly sensitive, enables the formation of a resist pattern having a good shape, and rarely causes resist pattern collapse; a process for producing the cyclic compound; a radiation-sensitive composition containing the cyclic compound; and a resist pattern formation method using the composition. Specifically disclosed are: a cyclic compound having a specific structure; a process for producing the cyclic compound; a radiation-sensitive composition containing the compound; and a resist pattern formation method using the composition.

Abstract: In one embodiment, a process for producing a bisphenol A product comprises: reacting phenol with acetone in the presence of a sulfur containing promoter to obtain a reaction mixture comprising bisphenol A, phenol, and the promoter; after reacting the phenol with the acetone, cooling to form a crystal stream comprising crystals of bisphenol A and phenol; separating the crystals from the crystal steam; melting the crystals to form a molten stream of bisphenol A, phenol, and sulfur; contacting the molten stream with a base to reduce a sulfur concentration in the molten stream and form a reduced sulfur stream; and removing phenol from the reduced sulfur stream to form a bisphenol A product. Also disclosed herein is a container comprising: a polycarbonate formed from a bisphenol A having a sulfur concentration of 0.5 to 15 ppm based upon the weight of the bisphenol A.

Abstract: A process for recovery of materials from a mother liquor residue comprising cracking a mother liquor residue with an aromatic sulfonic acid catalyst to form a cracked product mixture and separating phenol from the cracked product mixture wherein the mother liquor residue results from distillation of a mother liquor resulting from bisphenol A synthesis and isolation.

Abstract: Methods for extracting bisphenols from polymer substrates are described. The methods include contacting the polymer substrate with an aqueous composition which includes a phase transfer agent, a base and optionally an oxidant, whereby the bisphenol is extracted into the aqueous composition. Suitable phase transfer agents are delineated. Also described are compositions which can be used in the present methods.

Abstract: In one embodiment, a process for producing a bisphenol A product comprises: reacting phenol with acetone in the presence of a sulfur containing promoter to obtain a reaction mixture comprising bisphenol A, phenol, and the promoter; after reacting the phenol with the acetone, cooling to form a crystal stream comprising crystals of bisphenol A and phenol; separating the crystals from the crystal steam; melting the crystals to form a molten stream of bisphenol A, phenol, and sulfur; contacting the molten stream with a base to reduce a sulfur concentration in the molten stream and form a reduced sulfur stream; and removing phenol from the reduced sulfur stream to form a bisphenol A product.

Abstract: A method for the evaporative production of phenol-BPA adduct crystals in a crystallizer is provided. First, a supersaturated BPA solution is introduced into a crystallizer that includes a cylindrical vessel and a concentrically-disposed draft tube that defines an annular space between the vessel and tube. Next, the BPA solution is circulated through the draft tube and annular space while a coolant is uniformly distributed in the circulating flow by radially injecting a volatile hydrocarbon compound at between about 30% and 60% of a radial extent of the annular space of to form a BPA mixture. Phenol-BPA adduct crystals are produced in the vessel by evaporating the volatile hydrocarbon compound out of the BPA mixture. The method provides a consistent and uniform concentration of coolant across the surface of the boiling zone that prevents or at least reduces unwanted crystal nucleation.

Abstract: In one embodiment, a process for producing a bisphenol A product comprises: reacting phenol with acetone in the presence of a sulfur containing promoter to obtain a reaction mixture comprising bisphenol A, phenol, and the promoter; after reacting the phenol with the acetone, cooling to form a crystal stream comprising crystals of bisphenol A and phenol; separating the crystals from the crystal steam; melting the crystals to form a molten stream of bisphenol A, phenol, and sulfur; contacting the molten stream with a base to reduce a sulfur concentration in the molten stream and form a reduced sulfur stream; and removing phenol from the reduced sulfur stream to form a bisphenol A product. Also disclosed herein is a container comprising: a polycarbonate formed from a bisphenol A having a sulfur concentration of 0.5 to 15 ppm based upon the weight of the bisphenol A.

Abstract: In a method of recovering phenol and acetone from a feed stream containing bisphenol-A and isomers thereof, the feed stream is contacted with water and a source of hydroxyl ions under conditions effective to decompose at least part of said bisphenol-A and isomers thereof to phenol and acetone. The conditions include a temperature of about 150° C. to about 300° C., a pressure sufficient to keep the water substantially in the liquid phase at said temperature, and a molar ratio of hydroxyl ions to hydroxyphenyl groups in the residue stream from about 0.3:1 to about 0.9:1.

Abstract: A detection method of bisphenol A by the surface-enhanced Raman spectroscopy includes: soaking and extracting bisphenol A present in a sample with an organic solvent to form an extraction solution, adding methanol to the extraction solution to cause a polymer to precipitate from the extraction solution and leaving a filtrate behind, filtering and concentrating the filtrate, diluting the concentrated filtrate to volume with methanol, filtering the diluted filtrate through a filter with a pore size of 0.45 ?m to obtain a pretreated sample; detecting bisphenol A present in the sample by Raman spectroscopy under an incident laser power of 100 to 300 mW, and a scan time of 2 to 20 seconds; mixing the pretreated sample with the colloidal gold in an appropriate ratio, followed by adjusting pH value, and then carrying out the detection of bisphenol A present in the sample by Raman spectroscopy.

Abstract: In a method of recovering phenol and acetone from a feed stream containing bisphenol-A and isomers thereof, the feed stream is contacted with water and a source of hydroxyl ions under conditions effective to decompose at least part of said bisphenol-A and isomers thereof to phenol and acetone. The conditions include a temperature of about 150° C. to about 300° C., a pressure sufficient to keep the water substantially in the liquid phase at said temperature, and a molar ratio of hydroxyl ions to hydroxyphenyl groups in the residue stream from about 0.3:1 to about 0.9:1.

Abstract: In a method of treating a residue stream from the production of bisphenol-A, the residue stream is contacted with an aqueous solution of a base under conditions effective to hydrolyze at least part of said residue stream into acetone and phenol and produce an effluent stream. Acetone is recovered from the effluent stream to produce a phenol-containing mixed phase stream which is substantially free of acetone and which contains water and unhydrolyzed heavy organic compounds. The phenol-containing mixed phase stream is then treated with a water-immiscible organic solvent to extract phenol and unhydrolyzed heavy organic compounds into said solvent and produce an organic phase containing the solvent, phenol and unhydrolyzed heavy aromatic compounds and an aqueous phase with reduced concentrations of phenol and unhydrolyzed heavy organic compounds. At least part of the phenol and the organic solvent are subsequently recovered from the organic phase.

Abstract: Methods for extracting bisphenols from polymer substrates are described. The methods include contacting the polymer substrate with an aqueous composition which includes a phase transfer agent, a base and optionally an oxidant, whereby the bisphenol is extracted into the aqueous composition. Suitable phase transfer agents are delineated. Also described are compositions which can be used in the present methods.

Abstract: A nucleic acid aptamer capable of binding specifically to bisphenol A and a method of detecting and removing bisphenol A using the nucleic acid aptamer. The nucleic acid aptamer capable of binding specifically to bisphenol A has affinity for bisphenol A at nM concentration, and thus can detect even a very small amount of bisphenol A. Also, the nucleic acid aptamer can specifically detect only bisphenol A without showing affinity for other bisphenols, including bisphenol B having no difference from bisphenol A except for a single methyl group. Accordingly, the nucleic acid aptamer is effective in detecting and removing the environmental hormone bisphenol A which is difficult to detect by conventional methods.

Abstract: In a method of reducing the viscosity of a residue stream from the production of bisphenol-A, the residue stream is combined with at least one of (a) a bottoms stream comprising polyalkylaromatic compounds and remaining after the fractionation of an effluent from an aromatics alkylation process to remove monoalkylaromatic compounds, (b) a stream containing at least 90 wt % phenol and (c) a mixture of phenol and said bottoms stream (a) to produce a combined stream.

Abstract: An improved process is provided for producing bisphenol-A (BPA) comprising steps of (1) contacting benzene and a C3 alkylating agent to produce an alkylation effluent comprising cumene; (2) oxidizing the cumene to produce the corresponding hydroperoxide; (3) cleaving the hydroperoxide to produce product comprising phenol and acetone; (4) reacting acetone with phenol to form a reaction product stream comprising crude bisphenol-A product; (5) distilling the reaction product stream, while sending downstream to a BPA-phenol adduct crystallization and purification step, the resulting concentrated BPA phenolic feed stream; (6) producing BPA-phenol adduct crystals by crystallization of the concentrated BPA phenolic feed stream; (7) separating the BPA-phenol adduct crystals by solid-liquid separationr; (8) cracking a stream comprising at least a portion of said final mother liquor to recover a product; and (9) recovering and feeding the phenol product of step (8) to step (4) and/or step (7).

Abstract: The present disclosure enables phenol recovery, purification and recycle in a simple, economic manner from waste streams from, for example, a phenol/acetone production process, e.g., a phenol/acetone plant or an upstream cumene hydroperoxide cleavage process step, and BPA production step, for use in the reaction with acetone to produce BPA. The disclosure therefore reduces the overall consumption of phenol in the production of BPA.

Abstract: The present disclosure enables phenol recovery, purification and recycle in a simple, economic manner from waste streams from, for example, a phenol/acetone production process, e.g., a phenol/acetone plant or an upstream cumene hydroperoxide cleavage process step, and BPA production step, for use in the reaction with acetone to produce BPA. The disclosure therefore reduces the overall consumption of phenol in the production of BPA.

Abstract: Processes for producing bisphenols (e.g., bisphenol A (BPA)) having a purity greater than 99.7% are described, such processes including reacting a phenol and acetone in the presence of an acidic catalyst to form a product mixture comprising a bisphenol; removing at least a portion of the bisphenol from the product mixture in the form of a bisphenol/phenol adduct by crystallization, filtration and washing to provide bisphenol/phenol adduct crystals; and removing at least a portion of the phenol from the bisphenol/phenol adduct crystals to provide the bisphenol having a purity of more than 99.7%; wherein the crystallization comprises continuous suspension crystallization and is carried out in at least three crystallization devices arranged such that the product mixture is first cooled in a first stage of the crystallization to a temperature of 50 to 70° C.

Abstract: There is provided a method for obtaining an aqueous solution of an alkali metal salt of an aromatic dihydroxy compound by decomposing a waste aromatic polycarbonate by an alkali metal hydroxide aqueous solution. The method comprises (1) a dissolution step of dissolving a waste aromatic polycarbonate in a chlorinated hydrocarbon solvent, (2) a decomposition step of adding an alkali metal hydroxide aqueous solution to this solution to decompose the aromatic polycarbonate, (3) a re-dissolution step of adding water to this decomposed solution to dissolve a solid, (4) a two phase formation step of leaving the treated solution obtained in the step (3) to stand to form an organic solvent phase (organic phase) and an aqueous solution phase (aqueous phase), and (5) a separation/collection step of separating the aqueous phase from the organic solvent phase and collecting the aqueous phase.

Abstract: Disclosed herein is a process to prepare a poly(carbonate-co-urea) copolymer comprising reacting in the melt: (a) a dihydroxy reaction component comprising a dihydroxy compound, (b) a diaryl carbonate reaction component comprising a diaryl carbonate, (c) a urea reaction component comprising a urea compound in the presence of (d) a transesterification catalyst during at least part of the reaction and removing a phenolic byproduct to produce a poly(carbonate-co-urea) copolymer, wherein the urea and dihydroxy compounds are reacted in a molar ratio: (total moles of urea compound)/((total moles of urea compound)+(total moles of dihydroxy compound)) of less than or equal to 0.5.

Abstract: In a method of reducing the viscosity of a residue stream from the production of bisphenol-A, the residue stream is combined with at least one of (a) a bottoms stream comprising polyalkylaromatic compounds and remaining after the fractionation of an effluent from an aromatics alkylation process to remove monoalkylaromatic compounds, (b) a stream containing at least 90 wt % phenol and (c) a mixture of phenol and said bottoms stream (a) to produce a combined stream.

Abstract: A process for recovering a solid adduct of a bis(4-hydroxyaryl)alkane and a phenolic compound from a suspension comprising the addict is disclosed. The process comprises the steps of a) supplying the suspension to a rotary filter, b) filtering the supplied suspension in the rotary filter to retain adduct as an adduct cake, c) pre-drying the adduct cake with an inert gas, d) washing the pre-dried adduct cake, e) optionally drying the washed adduct cake, and f) discharging the washed adduct cake from the rotary filter.

Abstract: An improved process is provided for producing bisphenol-A (BPA) comprising steps of (1) contacting benzene and a C3 alkylating agent to produce an alkylation effluent comprising cumene; (2) oxidizing the cumene to produce the corresponding hydroperoxide; (3) cleaving the hydroperoxide to produce product comprising phenol and acetone; (4) reacting acetone with phenol to form a reaction product stream comprising crude bisphenol-A product; (5) distilling the reaction product stream, while sending downstream to a BPA-phenol adduct crystallization and purification step, the resulting concentrated BPA phenolic feed stream; (6) producing BPA-phenol adduct crystals by crystallization of the concentrated BPA phenolic feed stream; (7) separating the BPA-phenol adduct crystals by solid-liquid separation; (8) cracking a stream comprising at least a portion of said final mother liquor to recover a product; and (9) recovering and feeding the phenol product of step (8) to step (4) and/or step (7).

Abstract: The present invention relates to a process for the avoidance of solids deposits in droplet separators (demisters) by metering in suitable liquids, in particular in the production of bis(4-hydroxyaryl)alkanes.

Abstract: The present disclosure enables phenol recovery, purification and recycle in a simple, economic manner from waste streams from, for example, a phenol/acetone production process, e.g., a phenol/acetone plant or an upstream cumene hydroperoxide cleavage process step, and BPA production step, for use in the reaction with acetone to produce BPA. The disclosure therefore reduces the overall consumption of phenol in the production of BPA.

Abstract: The invention describes a process for producing bisphenol with a content of less than 15 wt. % of phenol, wherein a suspension crystallisation of a product mixture containing bisphenol A, minor components and phenol is performed in a crystalliser, the product mixture being pumped through a heat exchanger. Due to deposition (fouling, i.e. crystallisation and deposition on the surface of the heat exchangers) in the heat exchanger, the pressure difference increases from 0.5 to 3 bar across the heat exchanger. The resulting reduced flow rate, which would lead to increased fouling in the crystalliser, is offset by continuously increasing the speed of the pump, the pump speed being regulated in such a way that the current consumption of the pump is maintained such that it fluctuates by a maximum of 5%.

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.

Abstract: Methods for purifying a p,p-bisphenol A generally include distilling a feed stream comprising p,p-BPA in a distillation column at a pressure less than or equal to 20 millibars. The distillation column separates the bisphenol feed stream to produce a light fraction, an intermediate fraction and a heavy fraction. The intermediate fraction comprising the purified bisphenol contains lesser impurities that the p,p-BPA in the feed stream. In one embodiment, the intermediate stream is recovered using a side-draw. The side-draw is located between a first zone and a third zone in the distillation column.

Abstract: Disclosed is a method for preparing an alkali metal salt of a hydroxy-substituted hydrocarbon which comprises the steps of (i) contacting in solvent media at least one hydroxy-substituted hydrocarbon with a base comprising an alkali metal cation; and (ii) devolatilizing the solvent media comprising alkali metal salt by adding or spraying the solvent media into a substantially water-immiscible organic solvent, said solvent being at a temperature greater than the boiling point of solvent media at the prevailing pressure. In one embodiment the solvent media comprises water, and optionally at least one water-soluble protic organic solvent.

Abstract: Bisphenol-A is purified in a process which comprises the following steps: a) cooling a liquid mixture comprising bisphenol-A and water in a bisphenol-A crystallizer to form bisphenol-A crystals in a liquid phase; b) separating the bisphenol-A crystals from the liquid phase; c) dividing at least a portion of the liquid phase into a bisphenol-rich organic phase and a water-rich phase; d) feeding phenol and at least a portion of the bisphenol-rich organic phase into a adduct crystallizer to form a crystalline adduct of phenol and bisphenol-A in a mother liquor, and e) separating the crystalline adduct from the mother liquor. Bisphenol-A of high purity at a high yield is obtained.

Abstract: In a process for producing bisphenol A, an adduct of bisphenol A with phenol is promptly recovered in highly purity and high efficiency from a reaction mother liquor in the case of singling out bisphenol A from a reaction product. An adduct layer of bisphenol A with phenol is formed by crystallizing an adduct of bisphenol A with phenol from a solution of bisphenol A in phenol to form a slurry, the bisphenol A being produced by reacting phenol and acetone in the presence of an acid catalyst, subjecting the resultant slurry to a solid-liquid separation treatment, and thereafter removing the phenol from solid components, characterized by pouring onto a filter, a slurry solution of bisphenol A in phenol, the slurry solution containing in a crystalline state, an adduct of bisphenol A having an average particle size in the range of 0.05 to 1 mm with phenol, and filtering the slurry solution under reduced pressure in an atmosphere of an inert gas stream at 30 to 80° C.

Abstract: A continuous crystallization process comprising the steps of supplying a crystallization material containing bisphenol A to a crystallizer to form crystals of an adduct of bisphenol A and phenol or crystals of bisphenol A, subjecting the slurry discharged from the crystallizer to solid/liquid separation, and recovering the crystals, wherein part of the mother liquor is circulated to the crystallizer. According to this process, the heat duty to be removed is reduced, deposition of solids on the inner surfaces of the crystallizer, particularly on the heat transferring surface of the cooler is restrained, and consequently the continuous operating time of the apparatus is prolonged.

Abstract: The process of the present invention comprises a first step in which crude molten bisphenol A containing phenol is supplied to a flash evaporator and separated into a gaseous phase comprising phenol and a liquid phase comprising bisphenol A and residual phenol, and a second step in which the liquid phase obtained in the first step is heated by a thin film evaporator and separated into a gaseous phase comprising phenol and a liquid phase comprising concentrated bisphenol A and residual phenol, part of the liquid phase obtained in the second step being circulated to the first step and supplied to the flash evaporator along with crude molten bisphenol A. It is possible with this process to obtain high-quality bisphenol A stably from phenol-containing bisphenol A.

Abstract: The purpose of the invention is to improve thermal stability of bisphenol compounds. The resolving means of the invention is to include a pyridine compound in bisphenol compounds.

Abstract: The present application relates to a process for producing high-purity bis(4-hydroxyaryl)alkanes from adducts of bis(4-hydroxyaryl)alkanes and aromatic hydroxy compounds, which are obtained by acid-catalysed reaction of the aromatic hydroxy compounds with ketones.

Abstract: The application relates to a process for producing high-purity bis(4-hydroxyaryl)alkanes from adducts of bis(4-hydroxyaryl)alkanes and aromatic hydroxy compounds, which are obtained by acid-catalysed reaction of the aromatic hydroxy compounds with ketones.

Abstract: The present invention provides crystals of an adduct of a bisphenol and a phenol and methods of producing those crystals. The crystals may find use in preparing bisphenols.

Abstract: A system and method are provided for producing Bisphenol-A (BPA) using direct crystallization of BPA in a single crystallization stage. In one embodiment the method comprises reacting Phenol and Acetone in the presence of a catalyst to form a product solution including Bisphenol-A and Phenol; removing a part of the Phenol from the product solution if required, and providing a selective amount of solvent, so as to obtain a product solution with the desired phase equilibrium behavior; and feeding the product solution with a selective composition to a crystallization stage operated at a selected temperature, so as to recover substantially pure Bisphenol-A in crystal form.

Abstract: A method for the manufacture of bisphenols comprises introducing a combined feed stream comprising a feed stream and a recycle stream into a reactor system comprising at least one reactor containing a catalytic proportion of an acid catalyst and wherein the combined feed stream comprises a carbonyl compound and a stoichiometric excess of phenol; removing from the reactor system a reactor effluent; splitting the reactor effluent into a crystallization feed stream and an effluent recycle stream; extracting from said crystallization feed stream a bisphenol adduct, remainder comprising a mother liquor stream; dehydrating said mother liquor stream and said effluent recycle stream in a dehydrator wherein excess water and carbonyl compound are removed; and recycling the dehydrated mother liquor and the dehydrated effluent recycle stream back to the combined feed stream to effect improved production of p,p-bisphenol, along with increased reactor selectivity and reduced promoter quantities.

Abstract: There is provided a stable single-phase composition of bisphenolic stillbottoms and methods for making such compositions. There is also provided a resole and a novolac composition that includes in the manufacture of the resins the use of a stable solution of bisphenolic stillbottoms. Methods for making the resins are also provided. There is further provided a low molecular weight phenolic resin useful in the manufacture of paper laminates, such that the resin exhibits improved paper saturation and reduced phenol emissions during treating when compared to the prior art. There is also provided a laminate composition that results in a paper laminate that exhibits improved flexibility when compared to the prior art.

Abstract: 2,2-bis(4-hydroxyphenyl)propane (BPA) is produced by reacting acetone and phenol in the presence of cross-linked sulfonated polystyrene resins and then separating the BPA off from the reaction solution.

Abstract: Process and related apparatus are disclosed for economically producing a very high quality bisphenol A product by a multistage crystallization process utilizing a new cross-flow wash design whereby a high purity wash phenol stream is fed to every washing stage, optionally also in combination with a modified stream flow/recycle design which avoids increased by product production and yield losses otherwise expected from processing increased volumes of wash phenol.

Abstract: The present invention provides crystals of an adduct of a bisphenol and a phenol and methods of producing those crystals. The crystals may find use in preparing bisphenols.

Abstract: A method for producing bisphenol A in prill form is disclosed. Molten bisphenol is top-fed into a prilling tower via a plate containing a plurality of nozzles. A gas coolant guided through a circuit is led into said tower in a counter flow direction. The prills are cooled to about room temperature, collected at the bottom of the tower and removed. Also disclosed is the device for carrying out the inventive method and the prills thus produced.

Abstract: The process of the present invention comprises a first step in which crude molten bisphenol A containing phenol is supplied to a flash evaporator and separated into a gaseous phase comprising phenol and a liquid phase comprising bisphenol A and residual phenol, and a second step in which the liquid phase obtained in the first step is heated by a thin film evaporator and separated into a gaseous phase comprising phenol and a liquid phase comprising concentrated bisphenol A and residual phenol, part of the liquid phase obtained in the second step being circulated to the first step and supplied to the flash evaporator along with crude molten bisphenol A. It is possible with this process to obtain high-quality bisphenol A stably from phenol-containing bisphenol A.