Abstract: Aldehydes are prepared in a hydroformylation apparatus by the multiphase hydroformylation reaction of one or more olefins with hydrogen and carbon monoxide, where the continuous phase contains a solvent mixture and the hydroformylation catalyst is present in the continuous phase, at least one olefin is present in the dispersed phase, and the loading factor of the tube reactor is greater than or equal to 0.8.

Abstract: Aldehydes are prepared by a process, which comprises: hydroformylating olefins having 3 to 21 carbon atoms under an atmosphere of CO/H2 in the presence of a rhodium catalyst in a hydroformylation reactor; and upon discharging the reaction product from the reactor, a) separating the discharged material into a gaseous phase and a liquid phase, b) separating the liquid phase into a top fraction containing unconverted olefins and aldehydes and a bottoms fraction containing the rhodium catalyst, and c) cooling the bottoms fraction below the temperature of the material discharged from the hydroformylation reactor and feeding a gas containing carbon monoxide into the bottoms fraction.

Abstract: A process for conducting multiphase reactions, especially the preparation of &agr;,&bgr;-unsaturated ketones by condensation of aldehydes with ketones.

Abstract: Aldehydes are prepared by a process, which comprises:

Abstract: A nickel-containing hydrogenation catalyst is prepared by reducing nickel-containing catalyst material in the liquid phase in a single-stage process by means of hydrogen.

Abstract: Aldehydes are prepared in a hydroformylation apparatus by the multiphase hydroformylation reaction of one or more olefins with hydrogen and carbon monoxide, where the continuous phase contains a solvent mixture and the hydroformylation catalyst is present in the continuous phase, at least one olefin is present in the dispersed phase, and the loading factor of the tube reactor is greater than or equal to 0.8.

Abstract: A process is described for preparing 2,2,6,6-tetramethylpiperidine-N-oxyl and its 4-position substituted derivatives by oxidation of 2,2,6,6-tetramethylpiperidine and its 4-position substituted derivatives in the presence of hydrogen peroxide and low concentrations of divalent metal salts.

Abstract: 4,4,8,8,10-pentamethylbicyclo[4,4,0]-decene-(1,6)-one(2), is produced from the bottom product of the acetone condensation reaction collecting in the production of isophorone by fractionation. A ketone blend consisting essentially of C.sub.15 compounds where the main components are isomers [B] and [C] as shown in the general formulas: ##STR1## is isolated. This ketone blend is selectively hydrated in the presence of a noble metal catalyst at hydrogen pressures of 20 to 250 mbars and at temperatures between 25.degree. and 150.degree. C. The 4,4,8,8,10-pentamethylbicyclo[4,4,0]-decene-(1,6)-one(2) is obtained by rectifying the hydration output.

Abstract: A process for the production of the bicyclic compound 4,4,8,8,10-pentamethyl-10-cyano-bicyclo[4.4.0]-dec-1,6-en-2-one which comprises the steps of (a) reacting a ketone fraction comprising ##STR1## or mixtures thereof, (b) by adding HCN to the ketone fraction the presence of a base, at a temperature of 50.degree.-200.degree. C. to obtain an addition product comprising the bicyclic compound, and(c) isolating the addition product.