E.i. Dupont De Nemours and Company

Imperial Chemical Industries Limited

Invista North America S.a.r.l.

Other

John Arthur Turner

Eric Hindmarsh

David G Parker

Alan Macpherson Ure

Ian Peter Milne

Keith Whiston

Duncan C Woodcock

Samuel Duncan Housley

Thomas E Vos

Vinay Medhekar

Joan Fraga-Dubreuil

Stewart Forsyth

David John Royall

Ian Charles Jeffery

Graham Howard Jones

Duncan Stuart Hugall

Disclosed are nickel-containing complexation precursors having high complexation activity for bidentate phosphite ligands. Also disclosed are methods of making the complexation precursors. The disclosed method of generating the nickel-containing complexation precursor includes including contacting a nickel starting material with a reductant under conditions sufficient to generate a nickel-containing complexation precursor having at least about 1,500 ppmw sulfur in the form of sulfide.

Nickel having high ligand-complexation activity and methods for making the same

Claimed is a process for producing a phosphorus-containing ligand, preferably a diphosphite ligand structure (DLS) such as structure I. The method includes contacting a phosphorochloridite (structure II) with a compound having the structure X&#x2014;OH (which can be a bisaryl compound), and a tertiary organic amine to provide structure I' and as preferred embodiment structure I. 

Method for making organodiphosphites from phosphorochloridites characterized by measuring side-product levels to determine further additions

The present invention relates to a method for increasing the production capacity of a conventional oxidation reactor for catalytic liquid phase oxidation of paraxylene by staging the oxidation reaction into a first high pressure and high solvent ratio reaction zone followed by the conventional reactor.

Method for increasing oxidation reactor production capacity

Improved process for producing aromatic carboxylic acids by catalytic liquid phase oxidation of a corresponding precursor in a suitable solvent comprising feeding the reactants to a first oxidation reaction zone at high pressure and high solvent ratio, wherein uptake of oxygen is less than that required for full conversion of the precursor to its corresponding carboxylic acid, and then feeding the resulting reaction medium to a second oxidation reaction zone.

Process for producing carboxylic acids

An aromatic carboxylic acid such as terephthalic acid is produced by the liquid phase oxidation of a precursor thereof, the oxidation being carried out in such a way that substantially all of the aromatic carboxylic acid produced in the course of the reaction is maintained in solution during the reaction.

Production of terephthalic acid

A process for producing pure carboxylic acids by catalytic liquid phase oxidation of a suitable precursor in a solvent in which the oxidation reaction is carried out in a plug flow reaction zone at a high solvent:precursor ratio and reaction conditions sufficient to maintain the pure acid in solution as it is formed, and product produced from such process.

Process for producing pure carboxylic acids

Process for removing organic constituents from a high pressure exhaust gas stream in a bromine assisted air oxidation process in which the exhaust gas contains methyl bromide.

Effluent gas treatment

A terephthalic acid slurry in acetic acid is produced by oxidising p-xylene in acetic acid, removing water by evaporation of a stream of water and acetic acid, and returning acetic acid to the oxidation step. The terephthalic acid is separated from the reaction medium in a first zone to leave a deposit on a band, the deposit is washed with a first aqueous medium in a second zone, removed from the band in a third zone, and admixed with a second aqueous medium. Reaction medium is passed from the first zone to the oxidation step and terephthalic acid is recovered, preferably after further purification.

Process for the production of terephthalic acid

Purified terephthalic acid is prepared by a process of subjecting an aqueous solution of crude terephthalic acid to hydrogenation to reduce impurities, crystallizing this solution to produce a slurry of purified terephthalic acid in an aqueous liquor, and carrying out an integrated separation washing process.

Process for the production of purified telephthalic acid

Separation process

Purified terephthalic acid is prepared by a process of subjecting an aqueous solution of crude terephthalic acid to hydrogenation to reduce impurities, crystallizing this solution to produce a slurry of purified terephthalic acid in an aqueous liquor, and carrying out an integrated separation washing process using a centrifuge having washing facilities.

Process for the production of purified terephthalic acid

A terephthalic acid slurry in acetic acid is produced by oxidizing p-xylene in acetic acid, removing water by evaporation of a stream of water and acetic acid, and returning acetic acid to the oxidation step. The terephthalic acid is separated from the reaction medium in a first zone to leave a deposit on a band, the deposit is washed with a first aqueous medium in a second zone, removed from the band in a third zone, and admixed with a second aqueous medium. Reaction medium is passed from the first zone to the oxidation step and terephthalic acid is recovered, preferably after further purification.

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Cleveland, United Kingdom

John Arthur Turner