Abstract: A process for ethanolysis of PET is disclosed wherein a feed comprising PET is reacted with ethanol and recovering ethylene glycol and an aromatic diethyl ester such as diethyl isophthalate and/or diethyl terephthalate. PET, or a terpolymer comprising terephthalate monomer and ethylene glycol monomers, is reacted with ethanol and ethanol, diethyl terephthalate, ethylene glycol and optionally diethyl isophthalate are recovered. Recovered diethyl components can be subjected to liquid-phase oxidation to produce aromatic carboxylic acid. Acetic acid may also produced via liquid-phase oxidation of recovered diethyl components. The aromatic carboxylic acid can be used to form polymer.

Abstract: A process for oxidation with oxygen of at least one aromatic hydrocarbon having oxidizable, substituents that maximizes the utilization of oxygen without reduction in the quality of the carboxylic acid products produced by means of a stagewise countercurrent oxidation system is disclosed.

Abstract: A process is disclosed for producing at least one high purity aromatic carboxylic acid by oxidizing an aromatic feedstock with oxygen in a reaction medium comprising the aromatic feedstock, a promoter, a heavy metal catalyst, and a solvent which comprises benzoic acid and water to produce a reactor effluent wherein substantially all of the aromatic carboxylic acid produced remains in solution; and then hydrogenating the reactor effluent in the presence of a catalyst and hydrogen. This process efficiently and effectively produces high purity aromatic carboxylic acids by utilizing a common solvent for both oxidation and purification and eliminating the need for intermediate process steps and equipment.

Abstract: A process is disclosed for producing at least one high purity aromatic carboxylic acid by oxidizing an aromatic feedstock with oxygen in a reaction medium comprising the aromatic feedstock, a promoter, a heavy metal catalyst, and a solvent which comprises benzoic acid and water to produce a reactor effluent wherein substantially all of the aromatic carboxylic acid produced remains in solution; and then hydrogenating the reactor effluent in the presence of a catalyst and hydrogen. This process efficiently and effectively produces high purity aromatic carboxylic acids by utilizing a common solvent for both oxidation and purification and eliminating the need for intermediate process steps and equipment.

Abstract: Disclosed is a method and solvent composition capable of removing iron oxide deposits from the surface of titanium components without substantially damaging the underlying titanium component. Iron oxide deposits may be removed from the surface of a titanium component by contacting the titanium component with the solvent composition of the invention. The solvent composition may then be removed from contact with the titanium component to obtain a recyclable solvent composition which is recycled into repeated contact with the titanium component. The solvent composition comprises an aqueous mixture of an organic acid and a hydrohalide acid.

Abstract: Disclosed is a method and solvent composition capable of removing iron oxide deposits from the surface of titanium components without substantially damaging the underlying titanium component. Iron oxide deposits may be removed from the surface of a titanium component by contacting the titanium component with the solvent composition of the invention. The solvent composition may then be removed from contact with the titanium component to obtain a recyclable solvent composition which is recycled into repeated contact with the titanium component. The solvent composition comprises an aqueous mixture of an organic acid and a hydrohalide acid.

Abstract: Disclosed is a method and solvent composition capable of removing iron oxide deposits from the surface of titanium components without substantially damaging the underlying titanium component. Iron oxide deposits may be removed from the surface of a titanium component by contacting the titanium component with the solvent composition of the invention. The solvent composition may then be removed from contact with the titanium component to obtain a recyclable solvent composition which is recycled into repeated contact with the titanium component. The solvent composition comprises an aqueous mixture of an organic acid and a hydrohalide acid.

Abstract: Processes for the production of aromatic carboxylic acids is disclosed. The aromatic acids are produced by the liquid phase oxidation of a suitable acid precursor in a reaction medium comprising benzoic acid. According to one embodiment, the oxidation is carried out under plug-flow reaction conditions in a plug-flow reactor. The plug-flow conditions can be achieved by the use of a series of continuous stirred tank reactors. In another embodiment, the oxidation is carried out in two continuous stirred tank reactors fluidly connected in series. The preferred oxidation products are terephthalic acid, isophthalic acid, trimellitic acid, 2,6-naphthalene dicarboxylic acid, 1,5-napthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid and phthalic acid.

Abstract: Processes for the production of aromatic carboxylic acids is disclosed. The aromatic acids are produced by the liquid phase oxidation of a suitable acid precursor in a reaction medium comprising benzoic acid. According to one embodiment, the oxidation is carried out under plug-flow reaction conditions in a plug-flow reactor. The plug-flow conditions can be achieved by the use of a series of continuous stirred tank reactors. In another embodiment, the oxidation is carried out in two continuous stirred tank reactors fluidly connected in series. The preferred oxidation products are terephthalic acid, isophthalic acid, trimellitic acid, 2,6-naphthalene dicarboxylic acid, 1,5-napthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid and phthalic acid.

Abstract: Economical processes are disclosed for preparing relatively pure polycarboxylic acid from typical crude products of liquid phase oxidation, which do not involve intermediate steps of ester formation or require any alkanol containing solvent, for purification of "crude" polycarboxylic acid containing impurities which include one or more monofunctional aromatic compounds, trifunctional aromatic compounds, and/or color causing organic compounds formed by oxidation of a corresponding substituted aromatic compound in a liquid phase, e.g. 2,6-naphthalene dicarboxylic acid by liquid phase oxidation of 2,6-dimethyl naphthalene. The invention provides integrate processes which comprise reacting crude oxidation product with a polyalkyl amine amine, e.g. trialkylamine, forming an aqueous solution of the salts thus obtained, separating deleterious compounds from the solution, and recovering the polyalkyl amine and a relatively pure polycarboxylic acid product.

Abstract: A process for preparing purified 2,6-naphthalenedicarboxylic acid which comprises hydrolyzing a dialkyl-2,6-naphthalenedicarboxylate with water at a reaction temperature of at least about 450.degree. F. under liquid phase condition, the amount of water present being sufficient to solubilize, at the reaction temperature, at least about 10 percent of the 2,6-naphthalenedicarboxylic acid formed; and a process for purifying 2,6-naphthalenedicarboxylic acid comprising combining impure 2,6-naphthalenedicarboxylic acid with a purification solvent, heating the resulting mixture under liquid phase conditions at a temperature of at least about 500.degree. F. to form a product mixture and thereafter recovering from the product mixture purified 2,6-naphthalenedicarboxylic acid.

Abstract: A process for preparing purified 2,6-naphthalenedicarboxylic acid which comprises hydrolyzing a dialkyl-2,6-naphthalenedicarboxylate with water at a reaction temperature of at least about 450.degree. F. under liquid phase condition, the amount of water present being sufficient to solubilize, at the reaction temperature, at least about 10 percent of the 2,6-naphthalenedicarboxylic acid formed; and a process for purifying 2,6-naphthalenedicarboxylic acid comprising combining impure 2,6-naphthalenedicarboxylic acid with a purification solvent, heating the resulting mixture under liquid phase conditions at a temperature of at least about 500.degree. F. to form a product mixture and thereafter recovering from the product mixture purified 2,6-naphthalenedicarboxylic acid.

Abstract: A process for preparing purified 2,6-naphthalenedicarboxylic acid which comprises hydrolyzing a dialkyl-2,6-naphthalenedicarboxylate with water at a reaction temperature of at least about 450.degree. F. under liquid phase condition, the amount of water present being sufficient to solubilize, at the reaction temperature, at least about 10 percent of the 2,6-naphthalenedicarboxylic acid formed; and a process for purifying 2,6-naphthalenedicarboxylic acid comprising combining impure 2,6-naphthalenedicarboxylic acid with a purification solvent, heating the resulting mixture under liquid phase conditions at a temperature of at least about 500.degree. F. to form a product mixture and thereafter recovering from the product mixture purified 2,6-naphthalenedicarboxylic acid.

Abstract: Processes are disclosed for recovery and purification of dibasic aromatic acids from waste polyester film, fiber, bottles, manufacturing residues, and other manufactured articles. The processes comprises: depolymerization of polyester resin in a molten polyester resin containing solvent with superheated stem, and vaporization of the aromatic carboxylic acid and other volatile products of hydrolysis to obtain a vaporized mixture containing aromatic acid, dihydric alcohol, other volatile products of hydrolysis, and water. This vapor mixture is, advantageously, substantially free of less volatile and non-volatile impurities including metals, and many colored and color causing compounds, which are, typically, found in post-consumer polyester resins.

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 wherein the orthotolylpentene or phenylhexane is cyclized to the dimethyltetralin using an ultra-stable crystalline aluminosilicate molecular sieve Y-zeolite.

Abstract: A continuous process for preparing a dialkylester of a naphthalenedicarboxylic acid comprising passing a liquid phase reaction mixture comprising a low molecular weight alcohol, a naphthalenedicarboxylic acid and a dialkylester of a naphthalenedicarboxylic acid at an elevated temperature through series arranged reaction zones while introducing a naphthalenedicarboxylic acid and a low molecular weight alcohol to an upstream reaction zone, agitating at least one reaction zone, and removing a liquid product mixture comprising the dialkylester of the naphthalenedicarboxylic acid produced by the reaction of the naphthalenedicarboxylic acid with the low molecular weight alcohol from a downstream reaction zone.

Abstract: Disclosed is a method for preparing an aromatic carboxylic acid comprising oxidizing in the liquid phase an aromatic feed compound containing at least one alkyl or acyl group with a molecular oxygen-containing gas, in a solvent comprising a low molecular weight aliphatic carboxylic acid, and in the presence of a heavy metal oxidation catalyst, thereby forming an oxidation reaction product mixture comprising an aromatic carboxylic acid; subsequently heating the oxidation reaction product mixture at a temperature of at least about 500.degree. F. to form a second product mixture; and recovering from the second product mixture the aromatic carboxylic acid. The method of this invention provides for purer, larger particle size aromatic carboxylic acid product.

Abstract: A method for the acid catalyzed cyclization of an alkenylbenzene feedstock to a dimethyltetralin in a liquid phase reaction wherein the desired dimethyltetralin is removed from the reaction mixture by distillation simultaneously with the addition of the feedstock to the reaction mixture.

Abstract: A method for purifying a naphthalenedicarboxylic acid comprising contacting an impure naphthalenedicarboxylic acid with hydrogen in the presence of a hydrogenation catalyst and a solvent comprising a low molecular weight carboxylic acid, at a temperature of at least about 500.degree. F., and a pressure sufficient to maintain the solvent at least partially in the liquid phase and thereafter recovering purified naphthalenedicarboxylic acid.

Abstract: A method for preparing one or more diemthylnaphthalenes from one or more dimethyltetralins, and optionally for preparing one or more other specific dimethylnaphthalenes by isomerization of the aforesaid dimethylnaphthalene(s) is disclosed.