Bayer Aktiengesellschaft

Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Degussa Aktiengesellschaft

Wulf Schwerdtel

Wolfgang Swodenk

Helmut Waldmann

Hermann Seifert

Kurt Halcour

Gerd Schreyer

Gunter Prescher

Rolf Wirthwein

Norbert Schenk

Otto Weiberg

Hubert Lauer

Manfred Martin

Paul Losacker

Hermann Thelen

Herbert Klenk

Johann Grolig

Gerhard Scharfe

Axel Vogel

Jorg Krekel

Wolfgang Biedermann

Gerd Siekmann

Joachim Priemer

Josef Heinrich

Karl-Hermann Reissinger

Helmut Waldman

Gunter Wolf

Hermann Seifer

Kurt-Wilheim Eichenhofer

Bruno Engelhard

Kurt Halcourt

An improved process for working-up crude liquid vinyl acetate which contains vinyl acetate, acetic acid, water, and ethyl acetate, possibly together with small amounts of other impurities, by distillation is disclosed, wherein a mixture essentially containing vinyl acetate and water is obtained as the top product and essentially acetic acid is obtained as the bottom product, and a sidestream, in which ethyl acetate is concentrated is removed. According to the process the top product is condensed and, after phase separation, a portion of the vinyl acetate phase is recycled as reflux into the distillation. The improved process involves the introduction of water above the point of introduction of the crude vinyl acetate. Preferably, the water is introduced in an amount which is not greater than the amount required to achieve a maximum water content in the vapors leaving the distillation at the top.

Process for working up crude liquid vinyl acetate

A new catalyst which can be prepared from certain aluminosilicates and certain clay minerals, a process for its preparation and a process for the skeletal isomerization of n-alkenes to iso-alkenes which is carried out in the presence of this catalyst.

Catalyst, a process for its preparation and an isomerization process in

The invention relates to a process for the production of .epsilon.-caprolactone having a purity of 99.9% and increased color and storage stability which comprises feeding .epsilon.-caprolactone, which has been made by reacting cyclohexanone with a solution of a percarboxylic acid, into a first distillation unit, operating at 0.1 to 500 mbars and drawing off as the top product a mixture consisting of .epsilon.-caprolactone and lower-boiling impurities, feeding the bottom product of said first distillation unit into a second distillation unit, operating at 0.1 to 500 mbars and then drawing off the pure .epsilon.-caprolactone as the top product. The .epsilon.-caprolactone is useful as an intermediate for the production of known useful compounds such as polyesterols which are subsequently converted to polyurethanes.

Process for the manufacture of very pure .epsilon.-caprolactone

Aldehydes and diols are prepared by reacting an olefine with hydrogen peroxide in the presence of a Group Va or VIa metal compound, such as molybdenum-(III)-acetylacetonate.

Process for preparing aldehydes and diols

A process for the preparation of hexahydrophthalic acid anhydride which comprises hydrogenation .DELTA..sup.4 -tetrahydrophthalic acid anhydride in the liquid phase at a temperature of from 70.degree. to 150.degree. C. and at a pressure of from 30 to 200 bar in the presence of a catalyst selected from palladium, ruthenium, nickel or mixtures thereof arranged in a fixed bed, wherein the catalyst is applied to a carrier of alumina of which at least 20% by weight has been converted into lithium aluminium spinel and the liquid phase is a mixture of .DELTA..sup.4 -tetrahydrophthalic acid anhydride and hexahydrophthalic anhydride in a proportion by weight of from 1:1 to 1:100.

Process for the preparation of hexahydrophthalic acid anhydride

A process has been found for the preparation of anthraquinone by catalytic oxidation of naphthalene in the gas phase to provide a reaction product, obtained by quenching, cooling or quenching and cooling, containing naphthaquinone and phthalic anhydride, treating said reaction product directly with butadiene to provide tetrahydroanthraquinone, oxidation by means of molecular oxygen to the tetrahydroanthraquinone contained in this reaction product, to give anthraquinone, and separation of naphthalene, phthalic anhydride, anthraquinone and by-products by distillation, the gases produced in the quenching and/or cooling of the gases from the naphthalene oxidation and the gases from the oxidation of the tetrahydroanthraquinone to give anthraquinone being completely or partially recycled to the oxidation of naphthalene, in which a compound with an alkaline reaction is introduced between the reactor in which naphthalene is oxidized and the reactor in which the reaction with butadiene takes place, and/or into the gas streams which are recycled to the oxidation of naphthalene. The process of the invention reduces considerably the formation of higher-boiling products formed in the continuous preparation of anthraquinone from naphthalene and increases the selectivity of the conversion of naphthalene to anthraquinone. In addition, the process of the invention provides greater freedom in separation of the reaction products since the production of troublesome high-boilers is minimized; and the process results in a reduced formation of carbon dioxide in the oxidation of naphthalene.

Process for the preparation of anthraquinone

A process for the production of pyrocatechol and hydroquinone by the hydroxylation of phenol in the nucleus with hydrogen peroxide, wherein phenol is reacted at the start of the reaction with substantially anhydrous hydrogen peroxide and wherein the reaction is carried out in the presence of a strong acid.

Process for the hydroxylation of phenol

A process has been invented for the preparation of pyrocatechol and hydroquinone which comprises reacting a solution which is substantially anhydrous and free from hydrogen peroxide, of a percarboxylic acid in an inert, organic solvent, with phenol at temperatures from -10.degree. C. to 80.degree. C. The compounds obtained according to the invention are known, important industrial chemicals which are used in large amounts in the field of photography and of dyestuffs and plastics and in the field of scents and flavorings.

Process for the preparation of polyhydric phenols

A process has been invented for the preparation of dihydric substituted phenols which comprises reacting a solution, which is essentially anhydrous and free from hydrogen peroxide, of a percarboxylic acid in an inert organic solvent with a monohydric substituted phenol, which is derived from benzene, naphthalene or anthracene and still contains at least one free hydrogen atom in the aromatic nucleus, at temperatures from about -20.degree. C. to about 120.degree. C. The dihydric substituted phenols obtained according to the invention are known, important industrial intermediate products used in the fields of photography, dyestuffs and plastics, as well as in the scent and flavoring areas.

A process for the hydroxylation of phenols and phenol ethers in the nucleus with hydrogen peroxide wherein a phenol or a phenol ether is reacted at the start of the reaction with substantially anhydrous hydrogen peroxide and wherein the reaction is carried out in the presence of a strong acid.

Process for the hydroxylation of phenols and phenol ethers in the nucleus

Process for continuous production of propylene oxide (FIG. 1) from propylene and aqueous hydrogen peroxide. The aqueous hydrogen peroxide is first reacted with propionic acid in the presence of acid catalyst to form perpropionic acid (1). The perpropionic acid is taken up by extraction in benzene (5, 18) and following drying of the benzene solution (21), the perpropionic acid in the solution is reacted with propylene (24) for oxidation of the propylene to propylene oxide and conversion of the perpropionic acid back to propionic acid. The reaction mixture is worked up to separate propylene oxide, propionic acid and benzene (30, 32, 37, 39), and the latter two are recycled. In the benzene extraction (5, 18), an aqueous raffinate (7) is formed containing hydrogen peroxide and acid catalyst. The aqueous raffinate can be divided into a stream which is recycled to the propionic acid reactor (1), and a second stream which can be distilled to remove water with the concentrate being recycled to the propionic acid reactor. (1)

Process for the preparation of propylene oxide

Process for the preparation of cycloaliphatic hydrocarbons by gas phase hydrogenation of aromatic hydrocarbons in the presence of palladium catalyst, characterized in that palladium catalyst is used which contains the palladium applied to a support which comprises aluminium oxide of which at least 20% by weight, relative to the weight of the support, has been converted to lithium-aluminium spinel. The gas phase hydrogenation can be carried out at atmospheric pressure.

Gas phase aromatic hydrogenation using palladium lithium aluminum spinel

Process for continuous production of propylene oxide (FIG. 1) from propylene and aqueous hydrogen peroxide. The aqueous hydrogen peroxide is first reacted with propionic acid in the presence of acid catalyst to form perpropionic acid (1). The perpropionic acid is taken up by extraction in benzene (5 , 12), and following drying of the benzene solution (16), the perpropionic acid in the solution is reacted with propylene (18) for oxidation of the propylene to propylene oxide and conversion of the perpropionic acid back to propionic acid. The reaction mixture is worked up to separate propylene oxide, propionic acid and benzene (25, 27, 31, 33), and the latter two are recycled. In the benzene extraction (5, 12), an aqueous raffinate (7) is formed containing hydrogen peroxide and acid catalyst. Water is removed from the aqueous raffinate (8) and the concentrate is recycled to the propionic acid reactor. Make-up hydrogen peroxide can be added to the aqueous raffinate before the removal of water.

Process for the continuous preparation of organic solutions of percarboxylic acids by reaction of aqueous hydrogen peroxide with the corresponding carboxylic acid in the presence of an acid, water-soluble catalyst, extraction of the resulting reaction mixture with an organic solvent and recycle of the raffinate, containing hydrogen peroxide, after reconcentration by the removal of water by distillation into the reaction. The raffinate is fed, together with the whole of that amount of hydrogen peroxide which essentially to the consumption of hydrogen peroxide in the reaction or with a part thereof, into the distillation for the removal of water. The amount of water which essentially corresponds to the sum of the water of reaction formed during the reaction and the water introduced into the process with the feed products is distilled off under reduced pressure. The sump product, thus obtainable, from the distillation is recycled into the reaction.

Process for the continuous preparation of percarboxylic acids in organic

Process for continuous production of substantially anhydrous solutions of perpropionic acid in benzene. Aqueous hydrogen peroxide is first reacted with propionic acid in the presence of acid catalyst to form perpropionic acid and water (1). The perpropionic acid is extracted with benzene (5), to provide a benzene phase containing the perpropionic acid (11) and an aqueous raffinate (7). The benzene phase is subjected to an extraction with water (12) involving at least 3 stages, to remove hydrogen peroxide, and the resulting benzene extract (15) is subjected to azeotropic distillation (26) to provide the anhydrous solution (17). The aqueous raffinate, which contains hydrogen peroxide, is distilled to remove water (8) and the resulting concentrate is recycled (2) for use in the reaction (1).

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Leverkusen, Germany

Wulf Schwerdtel