Allied Chemical Corporation

Allied Corporation

Alliedsignal Inc.

Jan F Van Peppen

William B Fisher

Stylianos Sifniades

William J Boyle, Jr

In a process for production of cyclohexanol comprising the selective catalytic hydrogenation of phenol to a product mixture comprising a major portion of cyclohexanol and a substantially smaller portion of cyclohexanone, then distillation of said product mixture to obtain cyclohexanol containing a minor amount of cyclohexanone meeting desired specification levels; the improvement comprising adding to said product mixture an effective amount of a polyamine such as hexamethylene diamine and distilling the product mixture to obtain an improved yield of said cyclohexanol containing a minor amount of cyclohexanone.

Process for production cyclohexanol

This invention is a method to restore the metal content of a supported noble metal hydrogenation catalyst comprising adding the appropriate amount of a noble metal salt of a weak acid to a fluid feed passing across the catalyst.

Method to restore the metal content of a noble metal hydrogenation

Alpha-methyl styrene, obtained as a byproduct in the manufacture of phenol is hydrogenated to cumene using hydrogen and standard hydrogenation catalysts which are selective for the ethylenic side chain. Prior to hydrogenation the alpha-methyl styrene is treated to effect removal of hydroxy acetone present. By reducing or eliminating hydroxy acetone, poisoning of the catalyst is prevented. Hydroxy acetone is removed from the alpha-methyl styrene by catalytic pretreatment.

Method to purify alpha-methyl styrene prior to catalytic hydrogenation

In the process of phenol hydrogenation to cyclohexanol, improved yields of cyclohexanol are obtained by maintaining a hydrogen atmosphere throughout the entire operation. Of particular importance is that the hydrogen atmosphere is maintained during the time period when the nickel catalyst is allowed to settle and prior to decantation of the clear liquids.

Process for manufacture of cyclohexanol from phenol

A method is disclosed to purify crude phenol containing acetol and alpha-methyl styrene prior to hydrogenation to cyclohexanone comprising

Catalytic purification of phenol

In a process for producing cyclohexanone comprising hydrogenating phenol in the liquid phase in the presence of a catalyst composed of a carrier having deposited thereon a layer of palladium and an alkali metal compound as a promoter, the improvement wherein the carrier consists of carbon particles having diameters of 5 to 300 microns and the catalyst is admixed with 0.1 to 10 parts by weight, per part of catalyst, of carbon particles having diameters less than 5 microns. This improvement effectively reduces long-term accumulation of catalyst poisons on the catalyst, including catalyst poisons that are by-products of the hydrogenation reaction.

Process for producing cyclohexanone

A computer controlled process for preparation of cyclohexanone by liquid phase, catalytic hydrogenation of phenol in three or more hydrogenation stages by using a computer control system interrelated with a phenol hydrogenation system in such a manner that it is capable of correlating a predetermined mole ratio of phenol to cyclohexanone with a predetermined maximum temperature in each of the hydrogenation stages, whereby intrinsic safety of operation is achieved by operating at temperatures at or below the atmospheric boiling point in each reactor.

Production of cyclohexanone

A controlled process for preparation of cyclohexanone by liquid phase, catalytic hydrogenation of phenol in two or more hydrogenation stages by correlating a predetermined mole ratio of phenol to cyclohexanone with a predetermined maximum temperature in each of the hydrogenation stages, whereby intrinsic safety of operation is achieved by operating at temperatures at or below the atmospheric boiling point in each reactor. The process provided improved control by use of a hydrogenation gas comprising hydrogen and nitrogen and recycling unreacted gas to the reaction zone to promote flashing overhead of product cyclohexanone. At least part of the recycling gas is treated by a cryogenic hydrogen recovery process to remove inerts from the system.

In production of cyclohexanone by hydrogenating phenol in the presence of a hydrogenation catalyst, improved catalyst life and improved hydrogenation rate are obtained if ketone impurities, particularly hydroxyacetone, are removed from the phenol prior to the hydrogenation. The present invention provides an improved method for reducing the ketone impurities in the phenol by contacting the phenol with a polyethylenimine and distilling the mixture formed to separate the phenol. The invention is particularly useful in production of cyclohexanone from phenol obtained by decomposition of cumene hydroperoxide.

Resolution of .alpha.-amino-.epsilon.-caprolactam with simultaneous racemization of the undesired D-.alpha.-amino-.epsilon.-caprolactam enantiomer is effected by forming a coordinately saturated .alpha.-amino-.epsilon.-caprolactam complex with NiCl.sub.2, preferably crystallizing the L-.alpha.-amino-.epsilon.-caprolactam complex in the presence of fine seed crystals of L-.alpha.-amino-.epsilon.-caprolactam complex of NiCl.sub.2 and catalytic amounts of a strong base selected from the alkoxides or hydroxides of Ni(II) and recovering L-.alpha.-amino-.epsilon.-caprolactam hydrochloride from the crystalline product.

Single stage resolution/racemization of

Resolution of .alpha.-amino-.epsilon.-caprolactam with simultaneous racemization of the undesired .alpha.-aminocaprolactam enantiomer is effected by preferentially crystallizing the L- (or D-) .alpha.-amino-caprolactam compound in the presence of a racemization catalyst. In a narrower embodiment racemization of .alpha.-amino-.epsilon.-caprolactam is effected by alternate routes of forming a coordinately saturated aminolactam-metal complex and reacting with a strong base or reacting a mixture of an aminolactam salt and aminolactam free base with a chelating carbonyl compound and a metal ion or reacting a mixture of an aminolactam salt and aminolactam free base in the presence of a salen derivative complex.

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Chester, VA, United States of America

Jan F Van Peppen