Chevron Research Company

John B Wilkes

Robert G Wall

Shigeto Suzuki

Robert G Anderson

Alan E Straus

The life of the hydrogenation catalyst in reducing a mixture of glycolate ester to ethylene glycol can be extended by lowering the polyglycolide ester content of the mixture by transesterification, that is, heating in the presence of alcohol, after which the resulting mixture is hydrogenated.

Process of prolonging the life of ester hydrogenation catalyst

A catalyst composition having an intrinsic surface area above about 60 square meters per gram as measured by the BET nitrogen adsorption method, said catalyst comprising from about 1 to 30 weight percent of a finely divided silica component, and from about 1 to 99 weight percent of a hydrogenating component comprising copper in either elemental or compound form and zinc oxide.

Hydrogenation process

In the reaction of 3-methyl-3-buten-1-ol with aqueous formaldehyde forming isomeric alkene-1,5-diols, particularly 3-methylene-1,5-pentanediol and 3-methyl-2-pentene-1,5-diol, it has been found that yields of the diols surprisingly are substantially increased if the reaction is effected in the presence of added isobutene and the mol ratio of 3-methyl-3-buten-1-ol to formaldehyde is at least 1:1.

Process for the production of alkene-1,5-diols

Hydrogenation catalyst

An alkenediol is produced from an alkenol by contacting the alkenol with formaldehyde at a pH maintained between about 4 and 7. Preferably this pH range is maintained by adding a buffering agent composed of a weak acid and the salt of a weak acid. Particularly advantageous buffering agents are the lower organic polycarboxylic acids with disodium or dipotassium hydrogen phosphate and sodium or potassium dihydrogen phosphate with disodium or dipotassium hydrogen phosphate.

Alcohol production

At a temperature in the range 100.degree. C to 225.degree. C the destructive dissociation of cobalt carbonyl compounds to cobalt metal and residue is inhibited by the action of one or more azoxy-dentated chelation ligands.

Hydroformylation of olefins using azoxy-dentated ligands

At a temperature in the range 100.degree. C. to 225.degree. C. the destructive dissociation of cobalt carbonyl compounds to cobalt metal and residue is inhibited by the action of one or more azoxy-dentated chelation ligands.

Straight chain aldehydes are prepared from straight chain olefins of about 3 to 20 carbon atoms by catalytic hydroformylation with carbon monoxide and hydrogen in the presence of cobalt catalyst and in the presence of soluble primary, secondary or tertiary aliphatic, or cycloaliphatic amine modifier of 1 to 12 carbon atoms.

Preparation of straight chain aldehydes

In a process for the conversion of normal butane to maleic anhydride at a pressure between about 15 and 100 psig and a temperature above 675.degree. F, by contacting the normal butane with an oxygen-containing gas and an oxidation catalyst disposed in a fixed catalyst bed or set of tubes in a reactor vessel, and withdrawing an effluent comprising unreacted normal butane, oxygen, Co, Co.sub.2, N.sub.2 and maleic anhydride from the catalyst bed or tubes, improvements in yield, product quality and plant operability are obtained by rapidly cooling the effluent gas to a temperature below 675.degree. F. One method of accomplishing this is by contacting the effluent gas with cooling coils contained within the reactor but below the catalyst bed.

Maleic anhydride process

A process for the preparation of citric acid which comprises contacting an unsaturated compound selected from 3-methylene-1,5-pentanediol and its esters with a nitric acid solution in an amount of 2 to 50 mols of nitric acid feed per mol of unsaturated compound feed, and at least 0.005 mol percent nitrogen dioxide based on nitric acid, at a temperature between -10.degree. and 120.degree. C., to thereby oxidize said unsaturated compound to citric acid. Preferably the contacting of the unsaturated compound so as to synthesize citric acid is carried out in the absence of any substantial amount of vanadium as the presence of vanadium catalysts has been found to effectively prevent the recovery of good yields of citric acid from the process. The citric acid synthesis preferably is carried out by an overall process wherein isobutene is reacted with two mols of formaldehyde to produce 3-methylene-1,5-pentanediol, which is then converted to citric acid by reaction with nitrogen dioxide/nitric acid. Citramalic production from 3-methyl-3-buten-1-ol is also disclosed.

Citric acid and citramalic acid preparation

Carboxylic acids are prepared from high-molecular-weight paraffins by vapor phase cracking at a temperature of at least about 500.degree.C and a residence time of from about 0.1 seconds to about 10 seconds in the presence of carbon dioxide.

Production of carboxylic acids from paraffins and carbon dioxide

The destructive dissociation of a cobalt carbonyl complex compound in the liquid phase is inhibited by the presence of an aryl sulfonate stabilizer.

Hydroformylation using aryl sulfonate stabilizer for cobalt catalyst

In hydroformylation reactions at temperatures in the range 100.degree.-225.degree.C. the destructive dissociation of cobalt carbonyl complex compounds to cobalt metal and residue is inhibited by the presence of minor amounts of 2,2'-bipyridine, alkyl-substituted 2,2'-bipyridines, N-alkyl-substituted alkylene diamines and mixtures of these compounds.

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Richmond, CA, United States of America

John B Wilkes