Abstract: In a process for producing C1-C10 aldehydes by oxidative dehydrogenation of C1-C10 alcohols over a shaped catalyst body obtainable by three-dimensional shaping and/or arranging in space of silver-containing fibers and/or threads, the average diameter or the average diagonal length of an essentially rectangular or square cross section of these silver-containing fibers and/or threads is in the range from 30 ?m to 200 ?m.

Abstract: A reactor includes an essentially horizontal cylinder for carrying out an autothermal gas-phase dehydrogenation of a hydrocarbon-comprising gas stream using an oxygen-comprising gas stream to give a reaction gas mixture over a heterogeneous catalyst configured as monolith. The interior of the reactor is divided by a detachable, cylindrical or prismatic housing, which is arranged in the longitudinal direction of the reactor and is gastight in the circumferential direction, into an inner region having one or more catalytically active zones, each having a packing composed of monoliths stacked on top of one another, next to one another and behind one another and before each catalytically active zone in each case a mixing zone having solid internals are provided and into an outer region, which is supplied with an inert gas, arranged coaxially to the inner region. A heat exchanger is connected to the housing at one end of the reactor.

Abstract: The invention relates to a tube bundle reactor with a flat feed hood. Alternatively, the release hood may also have a flat design. The flat design reduces the heat of reaction which arises in the hood in the case of reaction types which take place not only in the tube bundle (uncatalyzed reactions and reactions with homogeneously distributed catalyst). This greatly suppresses undesired reactions which already take place in the hood owing to accumulated heat, which achieves a higher selectivity in the case of thermally sensitive reactions. In addition, the thermal distribution within the hoods can be controlled precisely. The tube bundle reactor comprises a tube bundle which has a feed end which is connected to a feed hood of the tube bundle reactor, wherein the feed hood is configured in a flat design with a cross-sectional area at the feed end and an internal volume, and the ratio of internal volume to cross-sectional area is less than 0.35 m.

Abstract: The present invention relates to a process for preparing at least one monocyclic ketone having from 4 to 20 carbon atoms by reacting a mixture G1 comprising at least one monocyclic olefin having from 4 to 20 carbon atoms with a mixture G2 comprising at least dinitrogen monoxide, wherein said reaction is performed adiabatically.

Abstract: A reactor (1) in the form of an essentially horizontal cylinder for carrying out an autothermal gas-phase dehydrogenation of a hydrocarbon-comprising gas stream (2) by means of an oxygen-comprising gas stream (3) to give a reaction gas mixture over a heterogeneous catalyst configured as monolith (4), wherein the interior of the reactor (1) is divided by a detachable, cylindrical or prismatic housing G which is arranged in the longitudinal direction of the reactor (1) and is gastight in the circumferential direction and open at two end faces of the housing into an inner region A having one or more catalytically active zones (5), in which in each case a packing composed of monoliths (4) stacked on top of one another, next to one another and above one another and before each catalytically active zone (5) in each case a mixing zone (6) having solid internals are provided, and an outer region B arranged coaxially to the inner region A, is proposed.

Abstract: The present patent application describes a method of regenerating a ruthenium catalyst for the hydrogenation of benzene, which comprises flushing the catalyst with inert gas in a regeneration step until the original activity or part of the original activity has been attained.

Abstract: A process for heterogeneously catalyzed gas phase partial oxidation of an organic starting compound over a fixed catalyst bed freshly installed into a reaction chamber, in which the reduction in the quality of the fixed catalyst bed is restored with increasing operating time by replacing a portion of the fixed catalyst bed by a replacement fixed catalyst bed part whose volume-specific activity is lower than the volume-specific activity of the replaced fixed catalyst bed part in its freshly installed state.

Abstract: A process for heterogeneously catalyzed gas phase partial oxidation of an organic starting compound over a fixed catalyst bed freshly installed into a reaction chamber, in which the reduction in the quality of the fixed catalyst bed is restored with increasing operating time by replacing a portion of the fixed catalyst bed by a replacement fixed catalyst bed part whose volume-specific activity is lower than the volume-specific activity of the replaced fixed catalyst bed part in its freshly installed state.

Abstract: A gas-phase mixture of propene and oxygen is catalytically oxidized by passing a reactant gas mixture comprising propene and oxygen through a plurality of catalyst containing contact tubes in a fixed bed reactor and simultaneously passing only one heat-exchange medium at elevated temperature over the exterior surfaces of the contact tubes in a longitudinal flow pattern which is cocurrent with the direction of flow of the reactants through said tube; simultaneously superposing a transverse flow on said longitudinal flow of heat exchange medium by means of an arrangement of successive baffles along the contact tubes which leave passage cross-sections free, thereby resulting in a meandrous flow of the heat-exchange medium through the reactor and setting the flow rate of said heat-exchange medium so that its temperature between the point of entry of the medium into the reactor and its point of exit increases by 2.degree. to 10.degree. C.; and obtaining product acrolein at a selectivity .gtoreq.

Abstract: A process for the catalytic gas-phase oxidation of acrolein to acrylic acid in a multiple contact tube fixed-bed reactor through whose space surrounding the contact tubes only one heat-exchange medium circuit is passed, at elevated temperature on catalytically active multimetal oxides with an acrolein conversion for a single pass of .gtoreq.95 mol % and an acrylic acid formation selectivity of .gtoreq.

Abstract: A process for the catalytic gas-phase oxidation of propene or isobutene to acrolein or methacrolein in a tubular fixed bed reactor or catalytically active oxides with a .gtoreq.90% conversion of the initial olefin on a single passage, wherein the temperature of the gases containing the reactants in the direction of flow along the tubes from their entrance until the conversion of the initial olefin is from 30 to 70% is from 360.degree. to 420.degree. C. and is then adjusted to from 360.degree. to 300.degree. C. until the conversion of the initial olefin is from 80 to 90% and is thereafter maintained at from 330.degree. to 390.degree. C. until the gases emerge from the tubes, is described.