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

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: 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: 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: 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: 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: A method and installation for separating and purifying a crude mixture containing hydroquinone, resorcinol and possibly tars and/or catechol, comprising the following steps: —a possible distillation stage (I) in order to obtain a catechol head, —the foot (I) or crude mixture undergoes distillation (II) in order to obtain a fraction that is rich in resorcinol, —the foot of (II) undergoes distillation (III) in order to obtain a fraction that is rich in hydroquinone, whereupon said rich fractions are refined (IV or V). Preferably, one or several stages in which tar is removed (I,I?) precede stage (I) or (II).

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: Natural cresylic acid is processed to remove neutral oil impurities by countercurrent liquid/liquid extraction using a heavy phase solvent of a mixture of glycerol and another polyhydric alcohol, preferably triethylene glycol. The light phase solvent is a light paraffinic or cycloparaffinic hydrocarbon.

Abstract: A discrete impure cresylic acid distillate fraction derived by fractional distillation of a natural cresylic acid feedstock from which tar bases and/or neutral oils have not been removed is subjected to extractive distillation with a polyhydric alcohol extractant and subsequent separation of the discrete cresylic acid fraction. The extractive distillation removes tar bases, neutral oils, undesirable phenolic substances, sulfur compounds, color-forming impurities and odor-imparting impurities.

Abstract: A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating th

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: A process for removing guaiacols from naturally-occurring cresylic acid mixtures by pyrolysis is described.

Abstract: A process of using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for se

Abstract: A process for the separation of 2,4 DCP from a hydrocarbon feed mixture comprising 2,4 and 2,6 DCP which process employs an adsorbent comprising a type X or type L zeolite which has been cation exchanged at appropriate conditions with one or more cations selected from the group consisting of alkaline metals, alkaline earths and Group VIII elements of the Periodic Table. The adsorbed DCP isomer(s) thereafter is removed from the adsorbent by contacting it with a desorbent material and is recovered to an extract product stream, likewise the remainder of the feed material is recovered to a raffinate product stream. In a preferred embodiment the process uses a simulated moving-bed countercurrent flow system.

Abstract: A purified desired isomer which is either 3,4- or 3,5-dimethylphenol is separated with a high yield from a dimethylphenol-containing fraction which contains both 3,4- and 3,5-dimethylphenols. The fraction is distilled so as to give a distillate which is enriched with the desired dimethylphenol isomer to be separated and which contains at least 35% by weight of the desired isomer. The desired DMP isomer is crystallized from a melt of the enriched distillate in two stages with at least part of the filtrate separated from the precipitated crystals in the second crystallization stage being circulated to the first crystallization stage. The enriched distillate is introduced into the first crystallization stage when it contains the desired isomer in a concentration of from 35% to less than 70% by weight, or it is introduced into the second crystallization stage when it contains the desired isomer in a concentration of 70% by weight or higher.

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: A method is provided for separating alkylated phenols based on differences in their dissociation constants without the consumption of neutralizing acid or base. This is accomplished by selectively reacting the mixed alkylated phenol having the having dissociation constant to the salt form and isolating the salts from the mixture in an aqueous solution. The alkylated phenols are then recovered from the aqueous solution in unreacted form with an organic solvent. Essentially all solvents and solutions can be recycled.

Abstract: 4-Hydroxydiphenyl (mono-OD) and 4,4'-dihydroxydiphenyl (DOD) are obtained simultaneously from a mixture which contains these two substances, if such a mixture is treated with an aqueous alkali, and the resulting solution and the solid phase formed are separated at a temperature from -28.degree. C. to +40.degree. C. and the solution and the solid phase are acidified separately in order to form the free mono-OD and DOD. Mono-OD and DOD can be present in the starting mixture in the free form or in the form of the alkali metal phenolates. After formation of the alkali metal phenolates, where this is required, the aqueous alkali still contains 1-15 mol of alkali metal hydroxide per mol of the diphenyl compounds. The concentration of alkali metal hydroxide should be 4-25% by weight, relative to the amount of water present. In this process, it is also possible to employ industrial mixtures of the alkali melts of the associated diphenyl-sulphonic acids.

Abstract: Separate isomers via supercritical gas extraction.

Abstract: A process for the separation of isomeric cresols includes the step of crystallizing from a medium containing phenolic and solvent components.

Abstract: A process is disclosed for separating 3,5-xylenol or 3,4-xylenol from other closely boiling polymethylated phenolics by treating a mixture of the phenolics with a metal halide salt. The metal halide salt preferentially forms a complex with the xylenol over other related phenolics in the mixture. The preferentially-formed complex of the xylenol may then be isolated from the mixture and the complex decomposed to provide a product substantially enriched in, or substantially entirely composed of the xylenol.

Abstract: A process is provided for recovering the crystallization medium used for separating a 2,6-disubstituted phenol (DSP) from a feedstock containing it and a phenol in which only one of the 2 or 6 carbon positions are substituted (MSP).

Abstract: A process is disclosed for reducing the concentration of o-ethylphenol in m,p-cresol by partially t-butylating a mixture of the above and equilibrating the resultant mixture to convert o-ethylphenol and its 6-t-butyl derivative to the thermodynamically most stable 4-t-butyl-o-ethylphenol. The resultant mixture may then be separated by fractional distillation to isolate m,p-cresol low in o-ethylphenol, optionally, the mono-t-butylated derivatives of m,p-cresol and leave behind the 4-t-butyl-o-ethylphenol, along with di-t-butylated derivatives of all the phenols.

Abstract: A process is disclosed for separating 5-isopropyl-m-cresol from other isopropylated m-cresols by treating a mixture of the isopropylated m-cresols with a metal halide salt. The metal halide salt preferentially forms a complex with 5-isopropyl-m-cresol over other related closely-boiling isopropylated m-cresols in the mixture. The preferentially-formed complex of 5-isopropyl-m-cresol may then be isolated from the mixture and the complex decomposed to provide a product substantially enriched in, or substantially entirely composed of, 5-isopropyl-m-cresol. The process is particularly suitable for isolating 5-isopropyl-m-cresol from closely-boiling isomers, and diisopropylated m-cresols.

Abstract: A process is disclosed for separating t-butylated phenolic compounds from other t-butylated and unbutylated phenolics by treating a mixture of the phenolics with a metal halide salt. The metal halide salt preferentially forms a complex with one of the phenolics over other related phenolics in the mixture. The preferentially-formed complex of one of the phenolics may then be isolated from the mixture and the complex decomposed to provide a product substantially enriched in, or substantially entirely composed of, one phenolic. The process is particularly suitable for resolving a mixture comprising phenol or cresol from their ortho-t-butylated derivatives, or a mixture of two isomeric t-butylated phenols or cresols or a mixture of mono- and di-t-butylated phenols or cresols.

Abstract: Para-cresol is separated from a mixture comprising meta-cresol and various other methylated and ethylated phenols by preferentially complexing the para-cresol with one or more anhydrous or dehydrated inorganic salts selected from the group consisting of calcium bromide, lithium bromide, manganese bromide and magnesium chloride. The anhydrous inorganic salt is added to the phenolic mixture in an amount to give a mole ratio of salt to para-cresol in the mixture in the range of about 0.5 mole to one to about 1.5 mole to one. The para-cresol and salt form a complex and the complex is removed from the mixture of methylated and ethylated phenols. Then the complex is decomposed to recover the para-cresol and salt; the recovered salt may be recycled to complex with more para-cresol.

Abstract: A process for the separation of at least one cresol isomer from a feed mixture containing the cresol and xylenol which process employs a crystalline aluminosilicate adsorbent to selectively adsorb the cresol from the feed mixture. The process employs a desorbent material to recover the cresol. The process may employ a simulated moving bed flow scheme.

Abstract: A method for a purifying aqueous effluent streams containing BPA and phenol using liquid-liquid extraction with methyl isobutyl ketone.

Abstract: A process for selective cracking of 1,4-disubstituted benzene compounds having at least one polar substituent. Mixtures containing isomers of such a compound are brought into contact with a specified type of shape selective crystalline zeolite catalyst under conditions of temperature and pressure conducive to reaction of said benzene compound, thereby selectively reacting the 1,4-disubstituted isomer in preference to the 1,2- and 1,3-disubstituted isomers of said polar benzene compound. The shape selective zeolite catalysts employed herein are crystalline zeolites characterized by a silica to alumina ratio of at least about 12 and a constraint index within the approximate range of 1 to 12.

Abstract: Disclosed is a novel process for the separation of meta and para isomers of the sodium salt of bromophenol. Derivatives of the sodium salt of metabromophenol are useful chemical intermediates.

Abstract: Effluent containing cresols such as are contained in Lurgi tar acids are separated by preferentially treating the cresols with an aqueous alkali metal carbonate or bicarbonate at elevated temperature for a time sufficient to form the alkali metal salt of at least part of the cresols, but not so long as to form any appreciable alkali metal salt of 2,6-xylenol or o-ethylphenol. The water soluble alkali metal salts of cresols are then separated from the water insoluble phenols and said salts acidified to "spring" the cresols and the water insoluble cresols separated from the aqueous solution.

Abstract: A process is disclosed for the stepwise separation of para-cresol and meta-cresol from a mixture of methylated and ethylated phenols. The para-cresol preferentially forms a complex with a dehydrated or anhydrous inorganic salt selected from the group consisting of calcium bromide, lithium bromide, manganese bromide and magnesium chloride. The meta-cresol isomer is separated from the mixture by formation of a complex with urea. Where the anhydrous or dehydrated inorganic salt is added firstly to the mixture of methylated and ethylated phenols including para-cresol and meta-cresol, the salt is provided in an amount to give a mole ratio of the salt to para-cresol in the mixture in the range of about 0.5 to one to about 1.5 to one. The para-cresol complexes with the salt and the complex is then removed from the mixture. The para-cresol-salt complex is thereafter decomposed to recover the para-cresol.

Abstract: A process is disclosed for the stepwise separation of para-cresol and meta-cresol from a mixture of methylated and ethylated phenols. The para-cresol forms a complex with a dehydrated or anhydrous inorganic halide salt selected from the group consisting of calcium bromide, lithium bromide, manganese bromide and magnesium chloride. The meta-cresol isomer is separated from the mixture by formation of a complex with sodium acetate. Where the anhydrous or dehydrated inorganic halide salt is added firstly to the mixture of methylated and ethylated phenols including para-cresol and meta-cresol, the halide salt is provided in an amount to give a mole ratio of the halide salt to para-cresol in the mixture in the range of about 0.5 to one to about 1.5 to one. The para-cresol complexes with the halide salt and the complex is then removed from the mixture. The para-cresol-salt complex is thereafter decomposed to recover the para-cresol.

Abstract: Para-cresol and meta-cresol are separated from a mixture of methylated and ethylated phenols by a two-stage process wherein the para-cresol is preferentially complexed with one or more anhydrous or dehydrated inorganic salts selected from calcium bromide, lithium bromide, manganese bromide and magnesium chloride. Then the meta-cresol is successively preferentially complexed with calcium bromide from the mixture of methylated and ethylated phenols from which the para-cresol complex has been removed. The anhydrous or dehydrated inorganic salt is added to the mixture of methylated and ethylated phenols including para-cresol and meta-cresol in an amount to give a mole ratio of the salt to para-cresol in the mixture in the range of about 0.5 to one to about 1.5 to one. The para-cresol-salt complex is removed from the mixture of methylated and ethylated phenols and then decomposed to recover the para-cresol.

Abstract: A method is described for the selective dealkylation of 4-tertiary-alkyl-2,5-xylenol while it is admixed with 6-tertiary-alkyl-2,4-xylenol by contacting the mixture of alkylated xylenols with a polymer-bound sulfonic acid catalyst at temperatures of 60.degree. C. or less and pressures of from about 0.5 to 5 atmospheres. The method is useful in separating 2,4-/2,5-xylenol mixtures.

Abstract: Mono and polyvalent phenols are recovered from gasified coal by scrubbing the phenol-containing gas with water, separating the extracted phenols into a monovalent phenol-rich fraction and a polyvalent phenol-rich fraction and recovering the monovalent phenols separately from the polyvalent phenols by solvent extraction.

Abstract: An inclusion compound comprising meta-cyclophane of the formula ##STR1## and at least one benzene derivative included therein. And a process for separating an isomer containing a substituent at least at the 1- and 4-positions from a mixture containing isomers of a benzene derivative, which comprises contacting the meta-cyclophane with the mixture containing isomers of a benzene derivative thereby to form an inclusion compound in which an isomer containing a substituent at least at the 1- and 4-positions is included in the meta-cyclophane, then separating the inclusion compound from the mixture, and thereafter separating the isomer from the inclusion compound.

Abstract: The waste water being formed upon the preparation of hydroxy aromatics, preferably of resorcinol and .beta.-naphthol, by caustic alkaline melt of the corresponding aryl-sulfonic acids or aryl sulfonates is purified by wet oxidation with oxygen or oxygen-containing gases at temperatures of from about 100.degree. to 370.degree. C. and under a pressure of from about 1 to 300 bars. The COD-decomposition rates amount to about 90% and more.When a hydroxy aromatic is prepared by means of a caustic soda melt, this process provides a sulfate, especially sodium sulfate, which is of sufficient purity for further use without complementary purification stages. The obtention of the pure salt is important for the economy of the process.

Abstract: A process for improving the quality of diphenols by recrystallization from aqueous solvent systems.

Abstract: Mono and polyvalent phenols are recovered from gasified coal by scrubbing the phenol-containing gas with water, separating the extracted phenols into a monovalent phenol rich fraction and a polyvalent phenol rich fraction and recovering the monovalent phenols separately from the polyvalent phenols by solvent extraction.