Rutgerswerke Aktiengesellschaft

Georg Grigoleit

Gerd Collin

Kurt Matern

Helmut Kohler

Rudolf Oberkobusch

Jurgen Stadelhofer

The catalytic dehydrogenation of piperidine to pyridine in the gas phase using hydrogen as the carrier gas is carried out with a silicon dioxide carrier activated with copper, nickel and chromium as the catalyst, the metals copper, nickel and chromium being present in an amount of 5-12:1-5:0.1-&lt;0.7 parts by weight per 100 parts by weight of catalyst. The optimum hydrogen/piperidine molar ratio is 5:1, and purified and dried conversion gas from the dehydrogenation reaction is preferably recycled and used as the hydrogen.

Process for the catalytic dehydrogenation of piperidine

A process for the production of thionaphthene by dissociation of thionaphthene sulfonic acid such as obtained, for example, in the partial sulfonation of naphthalene fractions of coal tar, characterized in that the density of the reaction mixture is maintained essentially constant during the entire duration of the dissociation reaction and the thionaphthene formed is not removed by azeotropic distillation; a product of high purity is obtained in high yield in a substantially reduced reaction time.

Process for the production of thionaphthene from thionaphthene sulfonic

In a process for obtaining substantially sulfur free pure naphthalene from bituminous coal tar and thionaphthene as a by-product, a de-phenolized thionaphthene-containing naphthalene fraction from oxidative purification is extracted with concentrated sulfuric acid and acetic acid anhydride in benzene. The thionaphthene is converted into its sulfonic acid derivative and water washed from the benzene-naphthalene mixture. The benzene is distilled leaving pure naphthalene. The sulfonic acid group is cleaved from the thionaphthene with superheated steam to yield thionaphthene.

Process for obtaining sulfur free pure naphthalene from bituminous coal

A process for the catalytic conversion of o-ethylaniline to indole in a gaseous phase and in the presence of hydrogen or steam and an SiO.sub.2 -containing catalyst modified by chromium dioxide and copper, wherein said conversion is conducted at about 400.degree. - 700.degree. C.; said catalyst comprising at least about 15% by weight copper and at least about 8% by weight of a chromate of a metal of Group IIA of the Periodic Table. A catalyst for use in the invention is provided.

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Dorsten, Germany

Georg Grigoleit