Abstract: In a process for the continuous heterogeneously catalyzed gas-phase partial oxidation of an organic compound in an oxidation reactor, whose feed gas mixture comprises, apart from the organic compound to be partially oxidized and molecular oxygen as oxidant, at least one diluent gas which is essentially inert under the conditions of the heterogeneously catalyzed gas-phase partial oxidation, where the essentially inert diluent gas consists partly of combustible gases, after passage through the oxidation reactor, the combustible constituents of the inert diluent gas present in the product gas stream leaving the oxidation reactor are not recirculated to the heterogeneously catalyzed gas-phase partial oxidation, but are put to further use for the purposes of another chemical reaction.

Abstract: The present invention relates to a process for the preparation of carbonyl compounds of the formula ##STR1## in which R.sup.1 denotes a hydrogen atom or an alkyl radical containing from 1 to 3 carbon atoms, R.sup.2 denotes a hydrogen atom or a radical of the formula ##STR2## in which R.sup.3 denotes a hydrogen atom or, together with R.sup.4, an oxygen atom, R.sup.4 denotes the radical OR.sup.6 or, together with R.sup.3, an oxygen atom, R.sup.5 denotes a hydrogen atom or an alkyl radical containing from 1 to 8 carbon atoms or a cyclohexyl or cyclopentyl radical, and R.sup.6 denotes an alkyl radical containing from 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical or a radical of the formula--CH.sub.2 --CHO or --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CHO,by gas-phase oxidation of methanol or alcohols of the formula ##STR3## in which R.sup.1 and R.sup.5 have the meanings specified above and R.sup.7 denotes a hydrogen atom or a radical OR.sup.8, and R.sup.

Abstract: The invention relates to a process for removing nitrogen oxides from a gas stream containing same, which comprises passing the gas stream(A) through a stage for absorbing the nitrogen oxides other than N.sub.2 O in an absorbent or reacting the nitrogen oxides other than N.sub.2 O with an absorbent at a pressure of from 1,5 to 20 bar, and(B) through a stage for reducing the amount of N.sub.2 O, preferably employing the pressure level of step A, and to apparatus therefor and the use thereof.

Abstract: A process for continuous industrial production of unsaturated aliphatic aldehydes having a boiling range from 95 to 136.degree. C. by oxidative dehydrogenation of the corresponding alcohols with an oxygen-comprising gas over a supported catalyst consisting of copper, silver and/or gold on an inert support in a tube bundle reactor, rapid cooling of the reaction gases and removal of the aldehydes from the resulting condensate with recycling of the unconverted alcohols comprisesa) vaporizing the alcohol,b) admixing the alcohol vapor with an oxygen-comprising gas,c) initially passing the resulting oxygen-comprising alcohol vapor at above the dew point of the alcohol but below the commencement temperature of the reaction through a layer of one of the abovementioned supported catalysts which is at least 0.5 cm in thickness and only thend) reacting the oxygen-comprising alcohol vapor at from 300 to 600.degree. C.

Abstract: A process for the dehydrogenation of ethylbenzene to styrene with input of heat by a heat-transfer medium on a dehydrogenation catalyst which is essentially located in a tube bundle, wherein the heat-transfer medium flows countercurrently to the reaction mixture in the region of the tube bundle, and, if required, another reaction chamber is located downstream of the tube bundle and is provided with a catalyst for adiabatic reaction.

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: In a process for preparing acrolein, acrylic acid or a mixture thereof from propane, propane is partially dehydrogenated to propylene in a first stage, the product gas mixture resulting therefrom is, after separating off hydrogen and water vapor, used as feed to an oxidation reactor, the propylene formed in the dehydrogenation is partially oxidized in the oxidation reactor using molecular oxygen in the presence of non-dehydrogenated propane as inert diluent gas to give acrolein, acrylic acid or a mixture thereof and the propane present in the product gas mixture of the partial oxidation is subsequently recirculated to the dehydrogenation stage A.

Abstract: In a process for the continuous heterogeneously catalyzed gas-phase oxidation of propylene to acrolein, acrylic acid or a mixture thereof in an oxidation reactor whose feed gas mixture comprises, apart from propylene and molecular oxygen as oxidant, only at least one diluent gas which is essentially inert under the conditions of the heterogeneously catalyzed gas-phase oxidation and where, in continuous operation, at least a part of the essentially inert diluent gases present in the product gas mixture is separated off therefrom and is reused as a constituent of the feed gas mixture to the oxidation reactor, the essentially inert diluent gas mixture comprises more than 85% by volume of at least one saturated hydrocarbon having from 1 to 5 carbon atoms.

Abstract: Phthalic anhydride is prepared in a multiple tube reactor provided with separate salt baths, the temperature of the salt bath used for cooling the first layer of catalyst, as regarded in the direction of flow of the reaction mixture, being from 2.degree. to 20.degree. C. higher than that of the salt bath(s) associated with the following layer(s).

Abstract: In a tube bundle reactor for carrying out catalytic organic reactions in the gas phase, comprising reaction tubes (A) arranged between tubesheets (B), the reaction tubes have an inside diameter ranging from 0.5 to 3 cm, the ratio of reaction tube length to inside diameter ranges from 2 to 10, and the reaction tubes (A) are surrounded by a fluid heat transport medium flowing in the crosswise direction; said tube bundle reactor is useful in particular in exothermic organic reactions.

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.

Abstract: Aldehydes and ketones of the general formula I ##STR1## where R.sup.1 is hydrogen or an organic radical of 1 to n carbon atoms and R.sup.2 is a non-aromatic organic radical of 1 to m carbon atoms, (m+n) ranging from 2 to 24 and R.sup.1 and R.sup.2 being combinable to form a 4- to 12-membered ring, are prepared in a continuous manner by oxidizing an alcohol of the general formula II ##STR2## with oxygen or an oxygen-containing gas at elevated temperatures in the gas phase in the presence of a catalyst, by effecting the oxidation by means of a supported catalyst composed of an inert carrier having a smooth surface and from 0.1 to 20% by weight, based on the amount of carrier, of an active layer of copper, silver and/or gold in a tubular reactor or tube bundle reactor where the internal diameter D of the tube or tubes ranges from 10 to 50 mm and the largest diameter d of the coated supported catalysts is subject to the relationship d=from 0.1 to 0.2 D.