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: 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: A continuous process for the separation of phenol is disclosed. The process includes (a) feeding a stream of material, produced while preparing bisphenol A by reacting phenol with acetone, into a distillation column containing at least 5 theoretical separation stages, b) distilling-off the phenol as a top product and discharging from the column a bottom product containing secondary components, c) continuously introducing a portion of the bottom product into a dwell-time container operating at process parameters sufficient to cause, in the presence of an acidic catalyst, at least partial isomerization of the secondary components to form an isomerized product and d) introducing the isomerized product to the distillation column. The introducing of the bottom product is at a rate that is more than 30% of the rate of feeding of the stream at temperatures greater than 190° C. and hydrodynamic dwell time of at least 120 minutes.

Abstract: A continuous process for the separation of phenol is disclosed. The process includes (a) feeding a stream of material containing 40 to 90% phenol, 5 to 40% bisphenol A and 5 to 40% of side products into a distillation column containing at least 5 theoretical separation stages, b) distilling-off the phenol as a top product and discharging from the column a first portion of the bottom product c) continuously introducing a second portion of the bottom product into a dwell-time container operating at process parameters sufficient to cause, in the presence of an acidic catalyst, an at least partial isomerization of the side products to form an isomerized product and d) introducing the isomerized product to the distillation column. The introducing of said portion of the bottom product is at a rate, in Kg/hour, that is more than 30% of the rate of feeding of the stream, and said process parameters include temperatures greater than 190° C. and hydrodynamic dwell time of at least 120 minutes.

Abstract: A process for the work up of a reaction mixture obtained from the preparation of diaryl carbonate by direct carbonylation of aromatic hydroxy compounds is disclosed. The process entails obtaining a reaction mixture that contains diaryl carbonate, aromatic hydroxy compound, water, base and quaternary salt, separating the mixture in a distillation apparatus having only one theoretical separation stage into a liquid phase and a gas phase and recycling the liquid phase without further work up to the reaction step of the direct carbonylation.

Abstract: A process for the production of an aromatic carbonate is disclosed. Accordingly, an aromatic hydroxy compound is reacted with carbon monoxide and oxygen in the presence of a platinum group metal catalyst, a co-catalyst, a base, and optionally a quaternary salt as well as an inert organic solvent. The reaction is carried out under conditions whereby the inert organic solvent forms an azeotrope with the water arising during the reaction. The azeotrope is then removed from the reaction mixture.

Abstract: A process for the work up of reaction mixtures containing diaryl carbonate, aromatic hydroxy compound, water, base and quaternary salt, which are obtained in the preparation of diaryl carbonates by direct carbonylation of aromatic hydroxy compounds, is described. In the process of the present invention an adduct of diaryl carbonate and aromatic hydroxy compound is crystallized from the reaction mixture. A distillate comprising aromatic hydroxy compound is removed from the liquid phase either prior to or after crystallization of the adduct of diaryl carbonate and aromatic hydroxy compound. The liquid phase remaining after the crystallization and distillation steps may be recycled, without further work up, back to the direct carbonylation process step by which the diaryl carbonate is initially prepared.

Abstract: The present invention relates to a process for the production of bis(4-hydroxyaryl)alkanes by an acid-catalyzed reaction between aromatic hydroxy compounds and ketones, in which the temperature, ketone content and water content of a liquid reaction mixture are adjusted by means of a suitably composed gas phase.

Abstract: The present invention relates to a process for the production of bis-(4-hydroxyaryl)-alkanes by a heterogeneously catalyzed reaction of aromatic hydroxy compounds with ketones in at least two reactors connected in series, which, as the reaction progresses, are operated at higher temperatures, wherein the total quantity of ketone is divided between the individual reactors in such a manner that the higher is the temperature of the particular reactor, the smaller is the proportion per reactor, the highest possible reactor loading is maintained and the temperatures and temperature gradients are kept as low as possible.