Abstract: The present invention relates to a process for separating an isocyanate prepared by reaction of a primary amine with an excess of phosgene in the gas phase from the gaseous crude product obtained in the reaction, wherein (i) the gaseous crude product is partially liquefied by contacting with a quenching liquid, (ii) the gas phase obtained in step (i) is partially condensed, (iii) the condensate obtained in step (ii) is used as the quenching liquid in step (i), (iv) the portions of the gas phase that were not condensed in step (ii) are at least partially liquefied, (v) the liquid phase obtained in step (iv) is likewise used as the quenching liquid in step (i), and (vi) the liquid phase obtained in step (i) is worked up to the pure isocyanate without previously being used as quenching liquid.

Abstract: A process for purifying 2,5-dichlorophenol, the process comprising the steps of distillation and subsequent crystallization.

Abstract: A process for purifying at least one product from coal tar is described. The process involves separating a coal tar fraction having a boiling point in the range of about 180° C. to about 230° C. into an acidic portion and a non-acidic portion by contacting the fraction with a caustic compound. The acidic portion is separated into a cresol portion and a xylenol portion, and the non-acidic portion is separated into a naphthalene portion and a naphthalene co-boiler portion. The acidic portion and the non-acidic portions are separated by contacting with an adsorbent comprising small, discrete crystallites, the adsorbent having less than 10 wt % amorphous binder component. The various portions can be separated in a similar manner.

Abstract: Hydroxytyrosol extracted from olives and/or from the solid residues of olives after the extraction of olive oil, by acid hydrolysis and purification on resin columns eluted with water contains hydroxytyrosol and tyrosol, is free from sugars, has a residual content of Benzo[a]pyrene that is less than 2 microg/Kg (weight BaP/weight of extract as dry matter), containing a weight ratio of hydroxytyrosol to hydroxymethylfurfural of between 45:1 and 10000:1, and the content of hydroxytyrosol in the extract is at least 0.5% (w/w) with purity of at least 40% (by HPLC 280 nm).

Abstract: The present invention relates to a process for the preparation of 4-isopropyl-3-methylphenol (p-thymol) from distillation residues of thymol production.

Abstract: Disclosed herein is a process for preparing a salt of a sulfurized alkyl-substituted hydroxyaromatic composition having a reduced content of unsulfurized alkyl-substituted hydroxyaromatic compound and its unsulfurized metal salt.

Abstract: In an embodiment of the disclosure, a method for preparing a phenolic compound is provided. The method includes providing a lignin depolymerization product, and hydrogenating the lignin depolymerization product under iron oxide and hydrogen gas to prepare a phenolic compound. The prepared phenolic compound is a crude phenolic composition including phenol, methylphenol, dimethylphenol or a combination thereof.

Abstract: The subject of the present invention is a method for preparing pyrocatechol from which the impurities resulting from the method for the preparation thereof have been removed. The method for preparing purified pyrocatechol from a crude pyrocatechol containing essentially pyrocatechol, small amounts of impurities including dihydroxybenzoquinone, and traces of hydroquinone and of phenolic compounds, is characterized in that it comprises at least the following steps: dissolution of the crude pyrocatechol in water, crystallization of the pyrocatechol, separation of the purified pyrocatechol and, optionally, a step of drying the purified pyrocatechol. The method of the invention may include other steps and, depending on the embodiment chosen, that may comprise a different series of steps, it is possible to obtain pyrocatechol with various degrees of purity.

Abstract: Disclosed herein are optically active biphenol derivatives represented by the following formulas (1) and (2), a method for optically resolving a biphenol derivative represented by formula (2?), a production method of an optically active biphenol derivative (1) comprising a step for reacting a Brønsted acid with a biphenol derivative (2), and a production method of an optically active biphenol derivative (3) comprising a step for reacting a Lewis acid with an optically active biphenol derivative (1) or an optically active biphenol derivative (2).

Abstract: A process for preparing highly pure hydroquinone freed of the impurities resulting from the production thereof includes at least the following steps: a) the crude hydroquinone in a liquid form and comprising at least resorcin and pyrogallol as impurities is subjected to a controlled cooling ensuring the crystallization of pure hydroquinone, b) the pure hydroquinone crystals are separated from the mother liquors, c) heating and partial melting thereof is next is carried out, d) the purified hydroquinone is then completely melted, and e) the purified hydroquinone is recovered.

Abstract: Hydroxytyrosol is extracted from olives and/or from the solid residues of olives after the extraction of olive oil, by carrying out acid hydrolysis at a temperature within the range of 110° C. to 140° C. and at a pH within the range of 1.0 to 6.0, and by purifying the obtained solution on a column containing acid activated anion exchange resins, and a column containing an adsorbent non-ionic resin; both columns being eluted with water to recover the hydroxytyrosol.

Abstract: Hydroquinone devoid of impurities is prepared from a crude hydroquinone essentially containing hydroquinone and small amounts of impurities including at least resorcinol, pyrogallol and traces of pyrocatechol and comprises at least the following steps: dissolving the crude hydroquinone in water, crystallizing the hydroquinone, separating the purified hydroquinone, and, optionally, drying the purified hydroquinone.

Abstract: A (?)-stereoisomer of formula (I): [insert formula (I) wherein X is H or F; or a pharmaceutically acceptable salt or prodrug thereof, useful as an anesthetic.

Abstract: Purified hydroquinone is prepared and formed from raw compounds essentially containing hydroquinone associated with very small quantities of impurities including resorcinol and pyrogallol, and includes a distillation purification step in which the resorcinol and pyrogallol are eliminated, directly followed by a step in which the purified hydroquinone is formed.

Abstract: A process for preparing highly pure hydroquinone freed of the impurities resulting from the production thereof includes at least the following steps: a) the crude hydroquinone in a liquid form and comprising at least resorcin and pyrogallol as impurities is subjected to a controlled cooling ensuring the crystallization of pure hydroquinone, b) the pure hydroquinone crystals are separated from the mother liquors, c) heating and partial melting thereof is next is carried out, d) the purified hydroquinone is then completely melted, and e) the purified hydroquinone is recovered.

Abstract: A process comprising the steps of dissolving a dihydric phenol in a solvent to form a solution A, contacting the solution A with an adsorbent material selected from the group consisting of metal oxides, modified metal oxides, activated carbons, and clays, filtering the adsorbent material to form a solution B, adding an anti-solvent to the solution B to form a solution C, and distilling the solution C, wherein the dihydric phenol is represented by Formula (I): wherein R is a hydrogen atom or an aliphatic functionality having 1 to 6 carbon atoms and n is an integer having a value of 1 to 4.

Abstract: A process comprising the steps of dissolving a dihydric phenol in a solvent to form a solution A; contacting the solution A with a zeolite; filtering the zeolite to form a solution B; adding an anti-solvent to the solution B to form a solution C; and distilling the solution C; wherein the dihydric phenol is represented by Formula (I): wherein R is a hydrogen atom or an aliphatic functionality having 1 to 6 carbon atoms and n is an integer having a value 1 to 4.

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: A process is described for the recovery of phenol and biphenols from their homogeneous mixtures containing benzene, sulfolane and water, which is based on the use of an alkaline solution and benzene for the separation of biphenols from sulfolane, after removing the benzene, H2O and phenol contained in the reaction effluent.

Abstract: A method of preparing polyestercarbonates is presented in which a mixture of at least one activated diaryl carbonate is reacted under melt polymerization conditions with at least one aromatic dihydroxy compound together with at least one dicarboxylic acid. Polyestercarbonates possessing up to about percent 10 mole dicarboxylic acid residues based on the total amount of structural units derived from aromatic dihydroxy compounds are obtained. The method provides both for high levels of incorporation of the dicarboxylic acid into the polyestercarbonate backbone and a high level of polymer endcapping.

Abstract: The present invention relates to a method of neutralizing residual acid species in crude dihydric phenol comprising the step of introducing a thermally stable organic base selected from the group consisting of tetraalkyl phosphonium hydroxides, tetraorganophosphonium carboxylic acid salts, or a mixture thereof into the crude dihydric phenol.

Abstract: The present invention relates to a method of neutralizing residual acid species in crude dihydric phenol comprising the step of introducing a thermally stable organic base selected from the group consisting of tetraalkyl phosphonium hydroxides, tetraorganophosphonium carboxylic acid salts, or a mixture thereof into the crude dihydric phenol.

Abstract: There is provided a process for efficiently and economically producing a polymer which is superior in transmittances of visible light and far-ultraviolet light, has a high molecular weight and is light-colored. A process for producing a light-colored vinylphenol-based polymer by subjecting p-vinylphenol to homopolymerization or subjecting p-vinylphenol and a vinyl compound copolymerizable with p-vinylphenol to copolymerization, in the presence of a cationic polymerization catalyst or a radical polymerization initiator, which process comprises subjecting a p-vinylphenol-containing raw material to vacuum flash distillation in the presence of a phenolic compound having no unsaturated side chain and water and subjecting the resulting p-vinylphenol-containing fraction to polymerization.

Abstract: The present invention provides a process for the production of two molecules of 4-aryl-2 butanols having the general formula 1 given below: Wherein R═H or glucose from the leaves of Taxus wallichiana, which comprises: (a) defatting air dried, pulverized leaves with aliphatic hydrocarbon solvents, (b) extracting the defatted leaves with chlorinated solvents and polar solvent successively at room temperature, (b) concentrating the chlorinated solvent soluble faction to a residue and treating the residue with aqueous solution of alkali and extracting with chlorinated solvents, (d) acidifying the alkali layer with mineral acid and extracting with ethyl acetate and concentrating the ethyl acetate phase to give compound of formula 1 where R═H, (e) concentrating the polar solvent fraction from step (b) to a residue and treating the residue with aqueous solution of alkali and extracting with chlorinated solvent, and (f) acidifying the alkali phase with mineral acid and extracting wit

Abstract: At least one xylenol isomer can be separated and purified from a mixture, which contains the specific xylenol isomer and at least one organic substance other than the specific xylenol isomer, by bringing the mixture into contact with 1,1-di(4-hydroxyphenyl)cyclohexane as a host compound to form a complex of the specific xylenol isomer as a guest compound with the host compound and then having the specific xylenol isomer released from the complex. The mixture may contain at least two xylenol isomers consisting of 2,4-xylenol and 2,5-xylenol, and at least one of the xylenol isomers can be separated and purified by having it released from its complex with the host compound.

Abstract: A method is provided for industrially advantageously and effectively separating 4M2B and 3M6B from a t-butylcresol mixture containing 2-t-butyl-4-methylphenol (4M2B), 2-tbutyl-5-methylphenol (3M6B), compounds having a lower boiling point than that of 4M2B and compounds having a higher boiling point than that of 3M6B derived from a m,p-cresol mixture.

Abstract: Purification of cumene hydroperoxide cleavage products from hydroxyacetone and carbonyl compounds is accomplished via extraction of hydroxyacetone and carbonyl compounds from cleavage products with a circulating water-salt solution in an extractor during an extraction stage and subsequent conversion of hydroxyacetone and other carbonyl compounds into deep condensation products in a HAC reactor operating as a plug-flow reactor or mixing reactor or as their combination. The conversion/condensation process is conducted in the water-salt solution by treating the hydroxyacetone and carbonyl compounds with alkaline agents. Various homogenous and/or heterogeneous alkaline catalysts may be used. Optionally multiple sequential extraction stages may be connected to the HAC reactor for improved performance.

Abstract: The present invention relates generally to a method for treating phenol tar, and, more particularly to a method for separating valuable products from phenol tar by treating the tar with steam.

Abstract: A process for the purification of natural cresylic acid feedstocks which are first depitched. The depitched feedstock is extractively distilled with a polyhydric alcohol, preferably triethylene glycol, to remove virtually all neutral oil species which are indigenous to the phenol and cresol boiling ranges, most of the neutral oil species in the 2,4-2,5-xylenol boiling range, and a significant portion of the neutral oil species of the high boiling xylenol fraction (including of 2,3-xylenol, 3,5-xylenol, para-ethylphenol, meta-ethylphenol, 3,4-xylenol, and numerous C.sub.9 phenols). This process is also capable of removing tar bases such as pyridine and its alkyl homologues.

Abstract: A process for separating and recovering para-ethylphenol from methyl-ethylphenol and other alkyl phenols is described using an X zeolite adsorbent having ion exchangeable sites exchanged with barium ions, potassium ions or a mixture of barium and potassium ions. Selective adsorption of para-ethylphenol occurs possibly for recovery of the para-ethylphenol.

Abstract: Impure 2,6-diisopropylphenol (DIP) is purified by use of a distillation process in which a single distillation column is used. The process comprises: (a) subjecting the impure DIP to a first continuous distillation in the column in an inert environment to distill off lower boiling components and produce first column bottoms enriched in DIP; (b) collecting, cooling and storing the first column bottoms while continuously maintaining them in an inert environment; (c) discontinuing the first continuous distillation; (d) subjecting the first column bottoms to a second continuous distillation in an inert environment in the same column to produce a second overhead distillate composed of purified DIP. The process avoids the formation in the distilling mixtures of dose boiling impurities due to seepage of air through standard pipe flanges and fittings and consequent oxidation reactions which occur under the conditions needed for batch distillations conducted in typical industrial distillation facilities.

Abstract: Propofol is purified by reaction of the raw 2,6-diisopropylphenol with an alkaline agent, by isolation of the alkaline metal salt and by neutralization thereof. There is thus obtained a propofol having a purity of at least 99.90%.

Abstract: An extractive distillation process using a high boiling polyol such as glycerol is employed for separating high purity catechol, 3-methylcatechol and 4-methylcatechol from a high boiling, pitch-like dihydric phenol fraction. Fractional distillation first separates an impure overhead mixture of the catechol and 3-methylcatechol and an impure 4-methylcatechol bottoms. The impure overhead is extractively distilled to remove impurities and then extractively distilled again to separate the catechol and 3-methylcatechol. This produces a pure overhead of 3-methylcatechol and a bottoms of catechol and polyol which is distilled to recover the catechol and recycle the polyol. The impure 4-methylcatechol is distilled to remove residual material and then extractively distilled to remove impurities. The resulting mixture of 4-methylcatechol and polyol is distilled to recover the pure 4-methylcatechol and to recycle the polyol.

Abstract: Valuable products are recovered from phenol tar by thermocracking under controlled conditions in the presence of polyphosphoric acid. Bisphenol A tars can be optionally cracked under these conditions mixed with the phenol tar and enhanced yields obtained.

Abstract: A process for the purification of 2,6-diisopropylphenol (Propofol) by transformation of the crude Propofol into its ester with a carboxylic or sulphonic acid, crystallization and hydrolysis, is described.

Abstract: A process for purifying phenol, phenol-type compounds, and substituted phenol and phenol-type compounds of contamination by components more acidic than the phenol component comprising treating a phenol containing process stream by contacting the stream with an amphoteric porous inorganic oxide.

Abstract: A process is described for the removal of guaiacol and substituted guaiacols from naturally occurring cresylic acid feed by heating the feed with a strong base, particularly sodium hydroxide, to produce a purified cresylic acid product essentially free of guaiacol and other methoxy aromatic compounds without significant loss of cresylic acid product.

Abstract: Crude hydroxyphenylalkane, e.g., 1,1,1-tris(4'-hydroxyphenyl)ethane, is purified, to reduce color and prevent caustic solution turbidity, (a) by contacting the hydroxyphenylalkane in alcoholic solution with an alkali metal dithionite, preferably in the presence of an alkalinity agent such as an alkali metal borohydride, more preferably by introducing the dithionite into the alcoholic solution as an alkaline aqueous solution, (b) precipitating the hydroxyphenylalkane from the alcoholic solution, and optionally (c) rinsing the hydroxyphenylalkane with an alkaline aqueous solution of the dithionite.

Abstract: A process is described for the removal of guaiacol from naturally occurring cresylic acid feed by heating the feed with a strong acid, particularly hydrochloric acid or sulfuric acid, to produce a purified cresylic acid product essentially free of guaiacol and other methoxy aromatic compounds without significant loss of cresylic acid product.

Abstract: Purification of cresylic acid by guaiacol removal from lignite-based feed as well as other naturally occurring sources of cresylic acid is accomplished by catalytic demethylation in the presence of an alumina catalyst. In the process of this invention, de-pitched, dephenolated creyslic acid is vaporized and passed over a high surface area, alumina catalyst at temperature ranges of between 350.degree. C. to 400.degree. C. and at vapor flow rates measured as liquid hourly space velocity (LHSV), of about 1 hr..sup.-1 to demethylate the guaiacol.

Abstract: A process for the coextraction of para-cresol and meta-cresol from a feed mixture comprising p-cresol, o-cresol and m-cresol and one other alkyl phenol with an adsorbent comprising an X zeolite exchanged with barium ions or a mixture of barium and potassium ions at exchangeable sites to preferentially adsorb both para- and meta-cresol. The adsorbent must contain at least about 5 wt. % water (LOI method). The coextracted cresol isomers are thereafter removed from the adsorbent by contacting it with a desorbent material and recovering said coextracted cresols as a product stream. Para-cresol and meta-cresol can thereafter be recovered as purified individual isomers by a second state adsorptive separation using a second adsorbent selective for para-cresol, e.g., said first adsorbent dried to an LOI of less than about 4 wt. %, preferably about 2 wt. % water. In a preferred embodiment, the process uses a simulated moving-bed countercurrent flow system in both adsorption separation steps.

Abstract: The process for preparing 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) by reacting acetone with phenol and decomposing the resultant adduct of bisphenol A and phenol is well known. However, the quality of bisphenol A thus obtained is not always satisfactory.In the process of this invention, the adduct is washed with phenol recovered by decomposing an adduct of bisphenol A and phenol, and then bisphenol A is prepared by decomposing the washed adduct.The bisphenol A prepared by the process of this invention has an extremely high quality and is suitable for the preparation of polycarbonate used for optical parts.

Abstract: 2,4-Xylenol can be obtained in high yield and high purity from a crude 2,4-xylenol isomer mixture containing 2,5-xylenol by selectively reacting the 2,5-xylenol with an aldehyde in the presence of an aromatic sulfonic acid, thereby converting the 2,5-xylenol into a xylenol-aldehyde condensate and, subsequently, separating the 2,4-xylenol, e.g., by distillation.

Abstract: A meritorious, commercially successful process for the recovery of a high-purity m-ethylphenol from ethylphenol mixtures containing m- and p-ethylphenols as the major components is disclosed. As it is well known in the art, the ethylphenol mixtures containing m- and p-ethylphenols as the major components can easily be prepared by ethylation of phenol with ethylene or ethanol by a simple operation. Accordingly, a process for the recovery of high-purity m-ethylphenol from ethylphenol mixtures containing m- and p-ethylphenols as the major components can give great influences in the commercial production of high-purity m-ethylphenol. m-Ethylphenol is a useful intermediate for the production of pharmaceuticals and agricultural chemicals. The process comprises simply contacting an ethylphenol mixture containing m- and p-ethylphenols as the major components with a specific crystalline aluminosilicate catalyst under heating.

Abstract: This invention comprises a process for separating isomers of dihydroxybenzene (DHB) from a feed mixture comprising at least two of said isomers, which process comprises contacting the mixture at adsorption conditions with an adsorbent comprising a Y type zeolite cation exchanged with a cation in the group Ca, Ba or Li, thereby selectively adsorbing o-DHB (catechol), or K, thereby selectively adsorbing p-DHB (hydroquinone). In the case where all three isomers are present in the feed, a cation from the first group is used, the remainder of the feed mixture is removed from the adsorbent and o-DHB is recovered by desorption at desorption conditions with methanol. P-DHB is recovered from the remainder by adsorption with the same or other adsorbent listed above and desorption at desorption conditions with ethanol.

Abstract: A process for separating higher molecular weight constituents from phenol polymers, wherein the phenol polymer is dissolved in an organic solvent medium, the solution obtained is mixed at room temperature with ammonia or an amine such that there is a stoichiometric deficiency of ammonia or amine, the precipitate is separate, dried, if appropriate, and treated with aqueous acid, and the resulting sediment is filtered off, washed and dried as described. The starting phenol polymer preferably is a condensation product of optionally substituted phenol and formaldehyde. The process yields fractions possessing an increased osmometric molecular weight, a narrower molecular weight distribution range and an increased glass transition temperature.

Abstract: A substituted benzene isomer mixture containing a meta-substituted benzene or 1,3,5-substituted benzene is contacted with an adsorbent of a faujasite type zeolite containing a Ag cation and/or a Cu cation, whereby the meta-substituted benzene or 1,3,5-substituted benzene is separated and recovered as a raffinate component.

Abstract: Phenol is prepared from mixed phenols derived from coal or biomass by separation of the mixed phenols, isomerization of m- and/or p-cresols to o-cresol, demethylation of o-cresol, dealkylation of xylenols and other alkyl phenols, recycling of products other than phenol, and, optionally, reducing phenol to cyclohexanone/cyclohexanol, followed by oxidation thereof to adipic acid.

Abstract: In a process for purification of wastewater streams containing phenolic impurities wherein the wastewater stream is contacted with an ether extraction solvent for the extractive removal of the phenolic impurities, to form an ether extract phase containing at least a portion of the phenolic impurities and an aqueous raffinate phase depleted in the phenolic impurities, the improvement which comprises effecting the separation of the phases in the presence of a phase separation promoting amount of at least one polyhydric alcohol.

Abstract: A substituted benzene isomer mixture containing a meta-substituted benzene or 1,3,5-substituted benzene is contacted with an adsorbent of a faujasite type zeolite containing a Ag cation and/or a Cu cation, whereby the meta-substituted benzene or 1,3,5-substituted benzene is separated and recovered as a raffinate component.