Abstract: The goal of this invention is to produce phenol of high purity by conversion of impurities that are present in the starting phenol, which is produced by the decomposition of cumyl hydroperoxide. The indicated goal is achieved by purifying the phenol containing admixtures of aliphatic and aromatic carbonyl compounds with an aluminum zirconium catalyst.

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 method is provided for the efficient, low cost removal of acetol from a phenol stream. The method results in removal of substantially all of the acetol from the phenol stream without the formation of substantial amounts of additional methylbenzofuran. The method also avoids the use of expensive reagents and capital intensive distillation equipment.

Abstract: A bioengineered synthesis scheme for the production of quinic acid from a carbon source is provided. Methods of producing quinic acid from a carbon source based on the synthesis scheme as well as conversion of quinic acid to hydroquinone are also provided.

Abstract: A process is disclosed for producing ?-methylstyrene, acetone, and phenol wherein the amount of ?-methylstyrene produced may be controlled by selectively converting a portion of the cumene hydroperoxide to dimethyl phenyl carbinol, the hydrated form of ?-methylstyrene. The dimethyl phenyl carbinol thus produced will lead to increased production of ?-methylstyrene upon dehydration in the acid cleavage unit of the phenol plant. By controlling the fraction of the cumene hydroperoxide reduced to dimethyl phenyl carbinol, the amount of ?-methylstyrene produced in the plant can be continuously set to meet the demand of the market for ?-methylstyrene. Also disclosed is a non-acidic catalyst for reduction of cumene hydroperoxide.

Abstract: A process for extracting phenol from a phenol-containing aqueous solution is disclosed. The process entails contacting the aqueous solution with an extracting agent that comprise a mixture of 60 to 99% of methyl isobutyl ketone, 1 to 40% of anisole and 0 to 20% of mesitylene.

Abstract: Bisphenol-A-bis(neopentylglycolphosphate) products of enhanced properties and processes for preparing them are described. One of the processes includes (a) mixing and reacting neopentyl glycol and bisphenol-A-bis(dichlorophosphate) in an inert polar organic solvent which (1) if mixed by itself with an equal volume of water at 25° C., will form a separate phase, (2) the solvent by itself will dissolve at least about 10 wt % of bisphenol-A-bis(neopentylglycolphosphate) at a temperature in the range of 25 to 50° C., and optionally but preferably (3) the solvent by itself can be completely vaporized at a temperature below about 180° C.; (b) washing bisphenol-A-bis(neopentylglycolphosphate) product formed in a) while dissolved in inert organic solvent having such characteristics at least once with an aqueous alkaline washing solution; and (c) optionally but preferably, recovering bisphenol-A-bis(neopentylglycolphosphate) product from organic solvent having such characteristics.

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 method of producing reduced coenzyme Q10 crystals suitable for commercial scale production thereof.

Abstract: The components of cigarette smoke, known until now, do not explain the overwhelming hazardous effects of smoking; this invention describes the isolation, identification and procedures for determination of the structure, properties and assay of a relatively stable major harmful oxidant (cs-oxidant) present in the cigarette smoke, the content of which is about 190±10 &mgr;g per cigarette; the cs-oxidant alone almost quantitatively accounts for the oxidative damage of proteins produced by the aqueous extract of whole cigarette smoke, it is also responsible for the oxidative damage of DNA; since the cs-oxidant is relatively stable, it further explains the deleterious effects of the side stream smoke and passive smoking; a number of chemical compounds/agents including vitamin C have been found to prevent the cs-oxidant induced protein oxidation in vitro.

Abstract: A process for purifying a phenol derivative selected from alkylphenols having a number average molecular weight of from 200 to 4 000 and Mannich adducts thereof is described, in which the phenol derivative is brought into intimate contact with an extracting agent having a polarity ET(30) of from 57 to 38 kcal/mol, a phase containing the phenol derivative and an extracting agent phase are allowed to separate from one another and the extracting agent phase is removed.

Abstract: The present invention relates to a method for obtaining purified hydroxytyrosol from products and by-products derived from the olive tree by means of two-step chromatographic treatment. The invention uses a non-activated ion exchange resin chromatographic method, followed by a second treatment on an XAD-type absorbent non-ionic resin which concentrates and completely purifies the hydroxytyrosol by means of elution with a methanol or ethanol:water dissolution (from 30 to 33%). The method of the invention can also be applied to two-phase pomaces, three-phase pomaces and stones if they are subjected to a steam explosion process.

Abstract: A method is provided herein for the extraction of phenol from a waste water stream. The method is used in conjunction with a process for producing acetone and phenol from cumene. The method for extracting phenol from waste water includes contacting in a countercurrent mode a phenol-containing waste water stream with a hydrocarbon stream derived from a bottoms stream from the acetone finishing column to produce a dephenolated waste water stream and a phenol-containing hydrocarbon stream. The phenol-containing hydrocarbon stream is preferably washed with an aqueous caustic solution to provide a hydrocarbon stream, which is then conveyed to the alpha-methylstyrene recovery system. Preferably the hydrocarbon stream derived from the bottoms stream of the acetone finishing column is water washed prior to contacting the phenol-containing waste water stream.

Abstract: A bioengineered synthesis scheme for the production of quinic acid from a carbon source is provided. Methods of producing quinic acid from a carbon source based on the synthesis scheme as well as conversion of quinic acid to hydroquinone are also provided.

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: A process for the recovery of furfural, furfuryl alcohol, low molecular weight phenols and/or cellulose or a cellulose-rich material from a lignocellulosic material comprising: feeding a carrier gas into a reaction chamber to facilitate a fluidised bed effect and to carry reaction products and residues away from the reactor via entrainment; introducing a feedstock comprising particulate lignocellulosic material of a predetermined particle size into the reaction chamber; degrading the feedstock in the reaction chamber under an oxygen-containing atmosphere at a temperature of from 250° C. to 320° C.; and quenching the degraded feedstock and carrier gas to deposit solid residue entrained in the carrier gas and to condense a liquid product.

Abstract: This invention discloses a substance which is a betaine ester of a functional alcohol that has an amido bond in its molecule and releases the functional alcohol.

Abstract: There is provided a process for removing and recovering one or more unassociated phenolic compounds dissolved in aqueous fluid, the process comprising the steps of: (a) transferring the one or more unassociated phenolic compounds from the aqueous fluid to an alkaline stripping solution, wherein transfer of the one or more unassociated phenolic compounds from the aqueous fluid to the alkaline stripping solution occurs across a membrane; wherein the membrane is a non porous, selectively permeable membrane; (b) regulating the volume of alkaline stripping solution employed relative to the volume of aqueous fluid treated so that the total phenolic compound concentration in the alkaline stripping solution, comprising the sum of the dissociated and unassociated phenolic compound concentrations, is above the solubility of the phenolic compounds in the acidified stripping solution of step (d); (c) regulating the pH of the alkaline stripping solution in contact with the membrane to a value at least 0.

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: Low-particulate dihydric aromatic compounds such as bisphenol-A that can be used in the synthesis of low-particulate polycarbonates are prepared by introducing into a desorber column containing a non-aggregate packing material an adduct of bisphenol and phenol and optionally a stripping gas. The column is maintained at an operating temperature that is sufficiently high and an operating pressure that is sufficiently low such that the adduct is distilled. The stream of phenol and the stripping gas is recovered from the top of the column. A second stream containing bisphenol that is substantially free of added particulate matter is recovered from the bottom of the column. This purified stream of bisphenol-A can further be used in a method of producing optical-grade polycarbonate.

Abstract: A method is disclosed for recovering a substantially water-soluble solvent from a reaction mixture comprising at least about 35% by weight aromatic hydroxy compound, which comprises the steps of: (i) extracting a reaction mixture at least once with aqueous acid wherein the solvent remains substantially in the organic phase; and (ii) recovering solvent from the organic phase.

Abstract: Impurities are removed from phenol by a process, comprising: first treating phenols containing impurities with at least one acid catalyst which converts the impurities into compounds which can be separated from phenol; separating the acid treated phenol from the compounds; and treating the distilled phenol a second time with at least one acid catalyst; thereby effectively removing the impurities from phenol.

Abstract: A process for reducing the salt content of fractions comprising high boilers obtained in the preparation of phenol from cumene, by extraction, is claimed. In the preparation of phenol from cumene, not only phenol and acetone but also by-products such as dimethyl phenyl carbinol or acetophenone are formed in the cleavage of cumene hydroperoxide. In the work-up of the cleavage product phase by distillation, these by-products are obtained as a fraction which boils only at high temperatures. These fractions further comprise alkali metal in the form of salts as a result of the neutralization by means of aqueous sodium hydroxide after the acid catalyzed cleavage. The presence of salt in this phase makes the work-up of this phase considerably more difficult. The salt is usually removed from the fraction by extraction of the fraction with water. However, considerable problems can occur if the aqueous phase cannot be cleanly separated from the organic phase.

Abstract: A process for converting carbonyl-type impurities contained in a phenolic solvent to high-boiling derivatives is provided by contacting the phenolic solvent with a hydrotalcite-type material (HTM). The phenol can be separated from the high-boiling derivatives using conventional separation techniques, such as distillation, so the invention also provides a process for separating carbonyl-type impurities, such as hydroxyacetone (HA), from a phenolic solvent. The process can be applied in the conventional industrial process for converting cumene to phenol to remove carbonyl-type impurities from the phenol product. A process and a facility for producing purified phenol by converting cumene to phenol are provided. In the conversion of cumene to phenol, the phenol often contains carbonyl-type impurities. The phenol and carbonyl-type impurities are reacted in the presence of an HTM to produce phenol and high-boiling derivatives.

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: A process for treating phenol with a strong acid ion exchange resin to reduce the level of methylbenzofuran is provided. The process is capable of being carried out at elevated temperatures for extended periods, such that cooling of the phenol from distillation temperatures prior to the resin treatment is not required. The process can reduce or eliminate the substantial costs associated with conventional processes that require cooling and re-heating the phenol.

Abstract: Injection of even very small amounts of supplemental water to the spent-air stream at points upstream from the heat exchanger cooler(s) used in processing spent-air streams from a cumene-to-phenol process allows these heat exchanger coolers to act as both extractors and condensers. It is therefore possible to recover from the heat exchanger cooler a methanol/water condensate, thereby substantially reducing the amount of methanol in the spent-air stream prior to discharge. Thus, known methods for manufacture of phenol from cumene in which an oxygen-containing gas stream is passed through liquid cumene to produce an oxidate product and a spent-air stream comprising methanol and cumene and a saturating amount of water; and in which the spent-air stream is passed through one or more heat exchanger coolers and a carbon bed prior to discharge can be improved.

Abstract: The present invention relates to a process for the continuous production of dihydroxydiarylalkanes (bisphenols) by the reaction of fresh phenol, phenol and isoalkenylphenol from the decomposition of by-products, and ketone. In this process the bulk of the bisphenol is recovered from the reaction mixture by crystallization and the mother liquor obtained is freed from phenol by distillation. The phenol is returned to the reaction and the bottoms obtained during the distillation are decomposed in a reactive rectification after addition of a basic catalyst. The phenol and isoalkenylphenol leaving at the top are led back into the reaction; the bottoms from the first reactive column are acidified and in a second reactive rectification, in the presence of an acid catalyst, are further decomposed into phenol, which distils off and is reused in the reaction, and bottoms, which are disposed of.

Abstract: The present invention relates to a process for the continuous production of dihydroxydiphenylalkanes (bisphenols) by the reaction of fresh phenol, and of phenol obtained from the cracking of by-products, with isoalkenylphenol and ketone. In the course of this process, the reaction mixture is worked up by distillation and a high purity bisphenol is produced. The bottom products and distillates containing the by-products are cracked under basic conditions and optionally thereafter under acidic conditions. The cracked products, which substantially consist of isoalkenylphenol and phenol, are recycled, optionally after purification, with the phenol obtained during the purification of bisphenol, to the reaction to form bisphenol, and the residue obtained from cracking is disposed of.

Abstract: A method for removing of metal ions from cresol or from mixtures of aromatic compounds containing cresol is disclosed, wherein the water content in the cresol mixture is adjusted to at least about 0.5 per cent by weight by the addition of water and the water-and-cresol mixture is subsequently passed over an acid ion exchanger. As a result of this process a metal ion content of less than 20 ppb per metal ion is achieved.

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: A method for efficiently recovering a hydroxyaromatic compound from aqueous extract streams of diaryl carbonate reaction mixtures, comprises contacting the aqueous extracts with a suitable solvent, preferably diphenyl carbonate or anisole. The aqueous stream may then be further recycled or reclaimed, and the hydroxyaromatic compound isolated from the solvent for disposal or further use.

Abstract: The disclosure is of a process for recovering valuable phenol and acetone from by-products of the condensation of phenol and a ketone from a mother liquor obtained for example upon crystallization of a 1:1 adduct of phenol and bisphenol, the mother liquor containing phenol, bisphenol, isomers, contaminant by-products of the condensation reaction of phenol with the ketone and acidic impurities. The mother liquor is distilled/evaporated leaving a tarry residue, which is the feedstock for the process of the invention. The recovery comprises catalytically cracking the feedstock with catalytic proportions of an aromatic sulfonic acid to extract the bisphenol-A values as phenol and acetone.

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: The invention relates to a 3-step process for removing water-soluble organics from waste streams. The first step involves contacting a waste stream with base, the second step involves contacting the organics-containing water with free oil and finally the free oil phase is separated from the aqueous phase to produce substantially organic-free water.

Abstract: An improved process for producing a catechol derivative (1) useful as a intermediate of pharmaceuticals and agricultural chemicals, being shown by the following reaction scheme. The process is characterized in that formulation in the first step is carried out in the two stages, that is, the reaction is carried out in the presence of a tin catalyst at 60-85.degree. C. to a conversion of 30 to 80% and then is completed at 95-105.degree. C. to produce a salicylaldehyde derivative (3) in a high yield and a high selectivity. Thereby, the objective catechol derivative (1) can be obtained in a high yield and with a high purity. ##STR1## In the above formula, R is alkyl, cycloalkyl, aralkyl, alkoxy, halogen atom, allyl, or aryl, and R.sup.1 is a hydroxy protective group.

Abstract: Liquid-liquid extraction is used for the removal of phenolics from wastewater streams using an ether extractant which has a high partition coefficient and a low solubility in water such as methyl tertiary-butyl ether. The resulting phenolics-ether mixture may be separated by distillation or by the use of an aqueous solution of an alkali metal hydroxide to form a phenate in an aqueous phase and the ether in an organic phase followed by phase separation. Any ether dissolved in the wastewater is removed by distillation or the solubility of the ether in the wastewater is retarded by adding an aqueous alkali salt solution. In the distillation embodiment, an environmentally acceptable wastewater is readily obtained. In the salt treatment embodiment, the wastewater is suitable for treatment in the overall plant complex associated with the phenol/acetone plant.

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: Alkali metal aryloxides may be speedily dried by removing water while the aryloxide is molten. Such dried alkoxides are useful as chemical intermediates. Molten alkali metal aryloxides may be contacted with carbon dioxide to quickly produce the dialkali metal salts of aromatic hydroxycarboxylic acids, which upon acidification yield the corresponding aromatic hydroxycarboxylic acids. Aromatic hydroxycarboxylic acids are useful as chemical intermediates and as monomers for polymers. Solid metal aryloxides may be reacted with carbon dioxide in a reactor in which the contents, even when pasty, may be agitated so that the reaction is more rapid than in prior methods.

Abstract: Phenol dissolved in an aqueous sulphatic stream discharged from a reactor in which cumene hydroperoxide is oxidized to phenol and acetone is recovered by extracting phenol present in said aqueous sulphatic stream containing phenol, Na.sub.2 SO.sub.4 and organic impurities, in a multi-step extractor with an organic solvent, thereby forming an extracted product organic phase and a refined aqueous product phase, the ratio of the extracted product phase to the refined product phase ranging from 0.1 to 1 v/v at a temperature ranging from 20.degree.-70.degree. C., and obtaining phenol by distillation or re-extraction of the recovered extracted product organic phase.

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: The present invention relates to a method of separating and purifying phenol in a simple and economical manner, by employing a step of adding high pressure carbon dioxide to the aqueous phenol solution to form a solid clathrate of phenol. According to the method of separating phenol of the present invention, phenol can be separated from the highly concentrated phenol solution without employing solvent or post-treatment step, finally to give 100 mole % of a solid phenol and 0.6 mole % of an aqueous phenol solution by employing only one step. Moreover, since the method is carried out at the temperature of below room temperature without excess energy consumption, the separation of phenol can be made in a simple and economical manner.

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 purifying impure 2,6-diisopropylphenol (DIP) mixtures having lower and higher boiling phenolic impurities is described. The process involves washing the mixture with aqueous alkali metal hydroxide solution in an inert atmosphere and separating the aqueous and organic phases, washing the resulting organic phase with water, and then subjecting the water-washed organic phase to distillation in an inert environment to recover purified DIP. Since only one distillation is required rather than two, the development of impurities in the DIP caused by in situ oxidation reactions at elevated temperatures due to the inevitable presence of traces of air in commercial distillation facilities is reduced to acceptable levels.

Abstract: Organic values are salvaged from scrap polycarbonate by heating in the presence of an acid catalyst and a C.sub.1-4 alkyl phenol such as m- or p-cresol. Among the compounds which can be salvaged are polyalkylated xanthenes, phenol and diaryl carbonate.

Abstract: This invention embodies a process for releasing acidic organic compounds in high yield and good purity from aqueous solutions of their salts which comprises converting the salts by carbon dioxide to their corresponding free acidic organic compounds and metal hydrogen carbonates, removing the acidic organic compounds from the mixture by extraction with an essentially water-insoluble organic solvent, and re-extracting the organic phase with carbon dioxide containing water. Using this process, the acidic organic compounds are completely released from their corresponding salts, i.e., the organic solution is free of salt. The acidic organic compounds released by the claimed process are organic compounds which contain acidic protons which can be replaced by metals. Some examples are carboxylic acids, sulfonic acids, phosphonic acids, phenols, naphthols, and aliphatic alcohols.

Abstract: A process for the purification of a crude bisphenol comprises the following steps:(1) preparing a mixture comprising from about 35 to about 70% of a crude bisphenol and from about 65 to about 30% of water, by the total weight of bisphenol and water, without addition of a substantial amount of an organic solvent or an alkaline compound, at a pressure above atmospheric and a temperature above about 100.degree. C.,(2) crystallizing bisphenol at a pressure below atmospheric,(3) separating crystalline bisphenol from the mother liquor,(4) dividing at least a portion of the mother liquor into a bisphenol-rich oil phase and a water-rich phase,(5) preparing a mixture comprising at least a portion of the bisphenol-rich oil phase, water and optionally an additional amount of crude bisphenol at a pressure above atmospheric and a temperature above about 100.degree. C.,(6) cooling the mixture and crystallizing bisphenol; and(7) separating crystalline bisphenol from the mother liquor.

Abstract: The present invention is an improved method for the recovery of phenol from a cleavage mass resulting from the sulfuric acid cleavage of cumene hydroperoxide comprising neutralizing the cleavage mass, forming an aqueous phase and an organic phase, separating the organic phase into an acetone-rich stream and a phenol-rich stream, removing phenol tars from the phenol-rich stream and cracking the phenol tars wherein the improvement comprises maintaining the pH of the cleavage mass during neutralization between 4.0 and about 4.9 whereby the sulfuric acid is converted to the bisulfate salt and substantially no free sulfuric acid remains in the cleavage mass and corrosion of process equipment is reduced.As a result of this improved process, a phenol tar waste stream containing less than about 4 parts per million by weight of chromium is obtained.