Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Bayer Aktiengesellschaft

Otto Weiberg

Helmut Waldmann

Hermann Seifert

Gerd Schreyer

Gunter Prescher

Wolfgang Swodenk

Wulf Schwerdtel

Rolf Wirthwein

Willi Hofen

Herbert Klenk

Rudolf Fahnenstich

Herbert Tanner

Wolfgang Weigert

Karl-Hermann Reissinger

Wilhelm Alfons Schuler

Manfred Kruger

Jurgen Troger

A process for the preparation of .epsilon.-caprolactone comprising:

Preparation of .epsilon.-caprolactone

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 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.

There is provided a continuous process for the production of water free or substantially water free peralkanoic acids with 2 to 4 carbon atoms by reaction of aqueous hydrogen peroxide with an alkanoic acid having 2 to 4 carbon atoms in the presence of acidic catalyst at a mole ratio of hydrogen peroxide to alkanoic acid of 0.5 to 30:1, preferably from 0.8 to 20:1, in a reactor by countercurrent extraction of the reaction solution with an organic solvent, recovery of a substantially water free solution of peralkanoic acid as extract and in a given case, eventually after addition of an additional solvent, dehydration of the extract by azeotropic distillation, the entire aqueous raffinate or a portion thereof is led to an evaporator unit, in which the water brought in with the starting materials and formed during the reaction is distilled off under reduced pressure, whereupon the concentrated raffinate as well as in a given case the non-concentrated portion of the raffinate is returned to the reactor and the reactor is replenished with sufficient aqueous hydrogen peroxide and alkanoic acid that the starting conditions are again produced.

Process for the production of percarboxylic acid solutions in organic

In the production of perpropionic acid by reaction of hydrogen peroxide and propionic acid in an aqueous medium and in the presence of an acid catalyst, e.g. sulfuric acid, to produce the peracid and water, the danger of explosion is reduced by employing a molar ratio of hydrogen peroxide to propionic acid of more than 3.5:1, a temperature of up to 60.degree. C., and an initial hydrogen peroxide:water ratio of up to 0.8, and a catalyst concentration of 10-40% by weight.

Process for the preparation of perpropionic acid solutions

In the production of perpropionic acid by reaction of hydrogen peroxide and propionic acid in an aqueous medium and in the presence of an acid catalyst, e.g. sulfuric acid, to produce the peracid and water, the danger of explosion is reduced by employing a molar ratio of hydrogen peroxide to propionic acid of less than 1.4:1, a temperature of up to 60.degree. C, and an initial hydrogen peroxide:water ratio of up to 1.2, and a catalyst concentration of 10-40% of weight.

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).

Process for the preparation of percarboxylic acid solutions

1,1'-PEROXYDICYCLOHEXYLAMINE IS PREPARED FROM CYCLOHEXANONE, HYDROGEN PEROXIDE AND AMMONIA IN THE ABSENCE OF CATALYST AND UNDER ANHYDROUS FORM. The ammonia is in gaseous or liquid form.

Process for the production of 1,1'-peroxydicyclohexylamine

Propylene glycol esters of propionic acid are added to silage to improve the quality thereof.

Growing community of inventors

Neu Isenburg, Germany

Otto Weiberg