Abstract: A reactivation process for a deactivated supported palladium catalyst involves contacting the catalyst with an organic polar solvent for naphthalenic compounds at a temperature below about 200.degree. C. The organic polar solvent has a dielectric constant at 25.degree. C. in the range of about 4 to about 80 and has a boiling point at atmospheric pressure in the range of about 30.degree. C. to about 230.degree. C. Preferred organic polar solvents are acetone and methanol, as well as mixtures thereof.

Abstract: A method for the production of a monoalkenylated benzene is disclosed. In this method an alkylbenzene is reacted with a C.sub.4 to C.sub.5 conjugated diene in a fixed catalyst bed containing a supported alkali metal catalyst. A monoalkenylated reaction product is produced and is separated from the reactants.

Abstract: A method is disclosed for preparing one of more specific dimethylnaphthalene isomers by the isomerization of one or more other specific dimethylnaphthalene isomers in the liquid phase and in the presence of a solid zeolitic isomerization catalyst.

Abstract: A method for preparing one or more specific dimethyltetralins from either 5-(o-, m-, or p-tolyl)-pent-1- or -2-ene or 5-phenyl-hex-1- or -2-ene, and optionally for preparing one or more specific dimethylnaphthalenes from the aforesaid dimethyltetralins is disclosed.

Abstract: A method for making 2,6-naphthalene dicarboxylic acid by the oxidation of 2,6-diisopropylnaphthalene or its oxidation derivatives in the presence of a catalyst comprising cobalt, manganese, cerium and bromine components is disclosed.

Abstract: A method of separating 3,3',4,4'-tetramethyldiphenyl ether from its solid mixture with 2,3,3',4'-tetramethyldiphenyl ether.

Abstract: Solutions of crude isophthalic acid are purified by hydrogenation to provide purified isophthalic acid having a predetermined color scale b*-value or optical density.

Abstract: A method for purifying a naphthalene dicarboxylic acid produced by the liquid phase oxidation of a kialkylnaphthalene or partially oxidized derivative thereof in the presence of a catalyst comprising a bromine-containing component and at least one of a cobalt- or manganese-containing component.

Abstract: Solutions of crude isophthalic acid are purified by hydrogenation in the presence of a catalyst comprising two Group VIII noble metal-containing components.

Abstract: A catalyst-recovery method for catalyst used in a continuous liquid phase oxidation process of an aromatic alkyl to an aromatic carboxylic acid product is disclosed. The aromatic carboxylic acid product is withdrawn from an oxidation reactor as an aqueous product and is thereafter subjected to crystallization to produce the aromatic carboxylic acid product and a product mother liquor stream. The product mother liquor stream is separated into a solvent-rich stream and a solids-containing catalyst-rich stream. The solids-containing catalyst-rich stream is separated into a by-product cake and a catalyst-bearing stream that is substantially free of solids. A portion of the catalyst-bearing stream is contacted with the vapor stream passing through the absorber system, and a catalyst-rich bottoms stream is thereafter withdrawn from the absorber system. A portion of the catalyst-rich bottoms stream is returned to the reactor.

Abstract: A method is disclosed for the liquid-phase oxidation of a di- (mono- or poly-)alkylaryl ether in the presence of a catalyst comprising cobalt, manganese and bromine components to a di- (mono- or poly-)carboxyaryl ether.

Abstract: A method is disclosed for the preparation of diaryl ethers and diaryl sulfides by heating a phenol, a thiophenol, a .beta.-hydroxy-substituted fused armomatic ring-system compound or a .beta.-thio-substituted fused aromatic ring-system compound in the presence of thoria deposited on a neutral support.

Abstract: Excess burning of pseudocumene, lowering concentration of use of cobalt and replace it with manganese by the use of less than the previously used 3.0 to 0.1 milligram atom of zirconium, preferable from 0.005 up to 0.075 milligram atom of zirconium, per 1.0 milligram atom of total of transition metals cobalt and manganese or cobalt, manganese and cerium.

Abstract: Improved acid yield and product quality are realized in the oxidation of aromatic hydrocarbons in a two-stage process, employing an aqueous solvent system and an increased proportion of bromine, and, optionally, of catalytic metals, in the second stage.

Abstract: Aqueous solutions of crude terephthalic acid are purified by hydrogenation in the presence of plural noble metal catalysts in separate layers. Initially, the solution to be purified is passed through a layer of ruthenium-on-carbon catalyst, rhodium-on-carbon catalyst, or platinum-on-carbon catalyst, and thereafter through a layer of palladium-on-carbon catalyst. Optionally, the purified aqueous terephthalic acid solution can be treated further to decrease the 4-carboxybenzaldehyde content thereof by passing it through a layer of rhodium-on-carbon catalyst downstream from the palladium-on-carbon catalyst layer.

Abstract: A method for purifying a dimethyl naphthalene dicarboxylate produced from a naphthalene dicarboxylic acid which is in turn produced by the liquid phase oxidation of a dialkylnaphthalene or partially oxidized derivative thereof in the presence of a catalyst comprising a bromine-containing component and at least one of a cobalt- or manganese-containing component.

Abstract: A method for the highly selective production of 2,6-diethylnaphthalene involving the use of a specific Lewis acid catalyst and a highly regiospecific ethylating agent.

Abstract: The method and apparatus for manufacturing terephthalic acid (TA) are capable of producing TA having a closely controlled, desired amount of contaminant, 4-carboxy-benazldehyde (4-CBA), therein and/or a closely controlled optical density. In the method, a feed of para-xylene or similar feedstock mixed with catalyst components and solvent system is fed to a reactor stage comprising one or more reactors with oxygen for carrying out an exothermic oxidation reaction in the reactor stage, and an output slurry from the reactor stage is fed with oxygen to a first crystallizer of a crystallizing stage. The method comprises the steps of: determining empirical relationships between (1) the desired level of contaminant in the TA output product from the crystallizing stage and the oxygen uptake in the first crystallizer and (2) the oxygen uptake in the first crystallizer and the CO.sub.2 in the vent gas from the reactor stage; monitoring the CO.sub.

Abstract: A method is disclosed for producing purified 5-t-butylisophthalic acid by the liquid-phase oxidation of 5-t-butyl-m-xylene in a solvent and in the presence of a catalyst comprising cobalt, manganese and bromine components.

Abstract: A method is disclosed for reactivating a Group VIII noble metal catalyst employed in the purification of crude terephthalic acid formed by the liquid-phase oxidation of p-xylene in the presence of a catalyst comprising cobalt, manganese and bromine components.