Standard Oil Company (indiana)

Amoco Corporation

The Standard Oil Company

George E Kuhlmann

David A Palmer

Hobe Schroeder

Juergen K Holzhauer

Nicholas C Huie

Houssam M Naim

Alan G Bemis

Sydney G Horsfield

James Spanswick

Stephen V Hoover

Paul A Sanchez

Joseph D Fox

David L Sikkenga

Wayne P Schammel

Walter Partenheimer

Gregory P Hussmann

Jon J Harper

David A Young

Martin A Zeitlin

Ricky L Wittman

Paul K Behrens

Rosemary F McMahon

John G Hundley

Keith D Larson

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.

Method for preparing aromatic carboxylic acids

Provided is a continuous process for producing 2,6-naphthalenedicarboxylic acid by the liquid phase oxidation of 2,6-dimethylnaphthalene comprising continuously adding to a reaction zone the oxidation reaction components comprising 2,6-dimethylnaphthalene, a source of molecular oxygen, a solvent comprising an aliphatic monocarboxylic acid, and a catalyst comprising cobalt, manganese and bromine components, wherein the atom ratio of manganese to cobalt is about 5:1 to about 0.3:1, the total of cobalt and manganese is at least about 0.40 weight percent based on the weight of solvent, and maintaining the contents of the reaction zone at a temperature of about 370.degree. F. to about 420.degree. F. and at a pressure sufficient to maintain at least a portion of the monocarboxylic acid in the liquid phase thereby oxidizing the 2,6-dimethylnaphthalene to 2,6-naphthalenedicarboxylic acid. By operating according to the process of this invention, 2,6-naphthalenedicarboxylic acid can be continuously produced in high yield and with low levels of impurities.

Process for preparing 2,6-naphthalene-dicarboxylic acid

Aromatic dicarboxylic acids, specifically 4,4'-dicarboxydiphenyl ether, terephthalic acid, 4,4'-carboxybis(benzoic acid) and the like, are purified by dissolving the crude acid in a monocarboxylic acid anhydride, purifying the resulting solution, and recovering a purified acid product therefrom.

Process for purification of aromatic dicarboxylic acids

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.

Method for making 2,6-naphthalene dicarboxylic acid

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.

Method for producing a di-(mono- or poly-)carboxyaryl ether

Aryl arylate esters substituted with an acyl moiety on both the aryl and arylate groups of said esters which can be produced by the oxidation of alkyl substituted aryl arylate esters using a heavy metal/bromine catalyst.

Polyacyl aryl arylates

A thermal process for the decarboxylation and dehydration of aromatic acid residue to convert such residue to grindable form and recover the solvent of reaction therefrom.

Thermal process for the liquefaction of aromatic hydrocarbon oxidation

A catalyst for the oxidation of hydrocarbons comprising a phosphorus and vanadium mixed oxide wherein the catalyst prepared by using an organic medium can be recycled according to our process thus conserving up to ninety percent of the vanadium used in the preparation of the catalyst. The mixed oxide can also be promoted by a transitional element of the IV and V period of the periodic table. These catalysts are particularly useful for the oxidation of C.sub.4 hydrocarbons to maleic anhydride.

Maleic anhydride catalyst recycle

An improved two-step catalytic neat oxidation of liquid xylene is provided wherein there is no separation of oxidation products from the first oxidation step nor minimum limitation imposed on the liquid o-xylene concentration entering the second step according to the prior two-step oxidations of o-xylene. Rather the first step is conducted under conditions such that the liquid effluent from the first step contains from 6 up to 30 weight percent liquid o-xylene and from 8 up to 40 weight percent o-phthalic acid and such effluent is directly oxidized with air in the second step. By such improved two-step oxidation there is obtained a liquid product containing o-phthalic acid in yields of up to 85-87% of the theoretical yield and also containing impurities separable from o-phthalic acid after it has been converted to its anhydride in vapor form and the anhydride vapors are separated from water vapor. Such two step neat oxidation of liquid o-xylene provides a route to phthalic anhydride commercially competitive with routes starting with the vapor phase oxidation of o-xylene.

Continuous production of ortho-phthalic acid product by two-step

A novel process for obtaining maleic anhydride having age molten and Hazen color below 125 after 20 hours at 140.degree. C., said process comprising polymerizing at a temperature of about 53.degree. to 90.degree. C. in the presence of metal chloride catalyst, color bodies present in crude maleic anhydride prior to fractionating the crude maleic anhydride and distilling off the purified maleic anhydride.

Process for the manufacture of maleic anhydride having improved age

Catalytic liquid phase molecular oxygen oxidation of methyl-substituted aromatic hydrocarbons having two or more methyl-substituents on adjacent ring carbon atoms in acetic acid reaction medium have, in general, resulted in a substantial production of the desired ortho-oriented di-, tri-, and higher polycarboxylic substituted aromatic acids but also in the co-production of substantial amounts of oxygenated intermediates including methyl-substituted mono- and non-ortho polycarboxylic acids. Several theories have been proposed, including inherent auto-inhibiton, for such incomplete oxidations.

Oxidation of di- and trimethyl aromatic hydrocarbons having

This invention relates to the preparation of o-phthalic acid by the oxidation of liquid o-xylene with a source of molecular oxygen at a temperature in the range of from 150.degree. C. up to 235.degree. C. in the presence of catalysis provided by the combination of components which include a source of bromine and at least cobalt as metal oxidation catalyst, in the presence of liquid water in an amount to activate said catalysis and solubilize a catalytically effective amount of metal oxidation catalyst in liquid phthalic acid and under conditions which retain substantially all the o-phthalic acid in the free acid form but in the absence of any material extraneous to the oxidation reaction or its products as solvent. Such preparative process results in yields of 85 to 92 mole percent and higher to o-phthalic acid in but a single oxidation step with recycle thereto of only o-xylene vaporized from the reaction zone and recovered.

Preparation of phthalic acid by solventless oxidation of liquid

Phthalic anhydride of commercially acceptable quality can be recovered from the neat catalytic oxidation of liquid o-xylene with air in the presence of the catalysis system provided by cobalt, manganese and bromine conducted in a single step and in the presence of a small amount of benzoic acid to make miscible liquid o-phthalic acid and liquid oxylene conducted in a single step to an 80 to 90 mole percent yield of o-phthalic acid provided the resulting liquid oxidation effluent is subjected to rapid dehydration of o-phthalic acid to its anhydride and rapid evaporation of the anhydride, water and compounds boiling between water and said anhydride which evaporation entrains phthalide in the vapor mixture followed by contact of the vapor mixture with Pd/C and introducing the vapor mixture into a fractionating system whose reflux liquid is inert, boils at a temperature below the boiling temperature of phthalic anhydride and is a solvent therefor at a temperature below the freezing temperature of said anhydride whereby impure liquid anhydride is withdrawn as water-free liquid and charged to a step of heating with alkali metal hydroxide to remove phthalide and then fractionated to remove benzoic acid as a first fraction, high purity phthalic anhydride as a second fraction and materials boiling higher than the anhydride as a liquid third fraction.

Production of liquid ortho-phthalic acid and its conversion to high

Phthalic anhydride of commercially acceptable quality can be produced continuously in yields of from about 80 up to about 83 mole percent (% of theoretical) through a combination of steps starting with the neat oxidation of liquid o-xylene with air in the presence of the catalysis provided by cobalt, manganese and bromine. Said oxidation is conducted in two steps wherein the first step is conducted under mild conditions and short residence time to provide a liquid effluent containing 8 to 40 weight percent o-phthalic acid and 6 to 30 weight percent o-xylene and the second step oxidizes such liquid effluent composition under more vigorous conditions including higher reaction temperature and longer residence time until substantially all of the o-xylene and precursors of o-phthalic acid have been converted to o-phthalic acid. Thereafter the second liquid oxidation effluent is subjected to simultaneous rapid dehydration and phthalic anhydride evaporation followed by contact of the resulting mixture of vapors first with a noble metal catalyst to remove bromine contamination and then with a reflux liquid in a fractionation system to remove water as part of a top fraction and provide a liquid partially purified anhydride as the bottom fraction which is heated with a catalytic amount of KOH to remove phthalide and finally the phthalide-free liquid partially purified anhydride is fractionated to obtain, in known manner, high purity phthalic anhydride product.

Growing community of inventors

Naperville, IL, United States of America

George E Kuhlmann