Abstract: A mixture (M1) comprising an alkene and oxygen is worked up by a process in which (i) oxygen is removed from the mixture (M1) by a nondistillative method to give a mixture (M2) and (ii) the alkene is separated off from the mixture (M2) by distillation.

Abstract: A mixture (M1) comprising an alkene and oxygen is worked up by a process in which (i) oxygen is removed from the mixture (M1) by a nondistillative method to give a mixture (M2) and (ii) the alkene is separated off from the mixture (M2) by distillation.

Abstract: A catalyst which contains, in its active composition, from 0.05 to 1.0% by weight of at least one metal or compound of a metal of the 10th group of the Periodic Table of the Elements and from 0.05 to 1.0% by weight of at least one metal or compound of a metal of the 11th group of the Periodic Table of the Elements, with the weight ratio of the metal of the 11th group to the metal of the 10th group being from 0.95 to 1.05, and, as support, an SiO2 -containing catalyst support having a BET surface area of from 2 to 400 m2/g, wherein at least 20% of the total pore volume of the catalyst is made up by pores having a diameter greater than 100 nanometers, can be used in processes for removing alkynes, dienes and/or monounsaturated hydrocarbons from streams of materials.

Abstract: A catalyst comprising, in its active composition, from 0.05 to 1.0% by weight of at least one metal or compound of a metal of the 10th group of the Periodic Table of the Elements and from 0.05 to 1.0% by weight of at least one metal or compound of a metal of the 11th group of the Periodic Table of the Elements, with the weight ratio of the metal of the 11th group to the metal of the 10th group being from 0.95 to 1.05, and, as support, an SiO2-containing catalyst support having a BET surface area of from 2 to 400 m2/g, wherein at least 20% of the total pore volume of the catalyst is made up by pores having a diameter greater than 100 nanometers, can be used in processes for removing alkynes, dienes and/or monounsaturated hydrocarbons from streams of materials.

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: 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: In a process for removing water by pervaporation or vapor permeation from mixtures with alcohols and/or carboxylic acids and/or carboxylic esters by bringing the mixture into contact with one side of a membrane and removing the water-containing permeate in vapor form from the other side of the membrane, the membrane used has been obtained by plasma polymerization.

Abstract: Water is removed from a mixture containing water, CO.sub.2 and one or more amines by pervaporation by bringing the mixture into contact with one side of a membrane and removing the water-containing permeate as a vapor from the other side of the membrane.

Abstract: CO.sub.2 and, if necessary, H.sub.2 S are removed from a gas which contains CO.sub.2 and may contain H.sub.2 S with an absorption liquid by a process in which the gas which contains CO.sub.2 and may contain H.sub.2 S is treated in an absorption zone with the absorption liquid, the treated gas is removed from the absorption zone, the absorption liquid which is obtained from the absorption zone and is laden with CO.sub.2 and may be laden with H.sub.2 S is then regenerated in that the said absorption liquid is let down in one or more let-down stages and a let-down gas is taken off at the top of the first let-down stage or, in the case of a plurality of let-down stages, at the top of one or more of the first to penultimate let-down stages, and the partially regenerated absorption liquid obtained from the last let-down stage is, if required, fed to a stripping zone for further regeneration, one or more acid gas streams which contain the CO.sub.2 and may contain H.sub.

Abstract: Gases containing CO.sub.2 and/or H.sub.2 S in a first absorption stage, at from 40.degree. to 100.degree. C., with an aqueous absorption liquid containing from 20 to 79% by weight of methyldiethanolamine, the gas obtained at the top of the first absorption stage is fed to a second absorption stage in which, it is treated at from 30.degree. to 90.degree. C. with an aqueous absorption liquid which contains from 20 to 79% by weight of methyldiethanolamine and has a lower content of CO.sub.2 and/or H.sub.2 S than the absorption liquid fed into the first absorption stage, the treated gas is taken off at the top of the second absorption stage, the aqueous absorption liquid obtained at the bottom of the second absorption stage and preladen with CO.sub.2 and/or H.sub.2 S is fed to the top of the first absorption stage, the aqueous absorption liquid obtained in the lower part of the first absorption stage and laden with CO.sub.2 and/or H.sub.

Abstract: 1,3-Butadiene is isolated from a C.sub.4 -hydrocarbon mixture containing 1,3-butadiene and small amount of propyne and C.sub.5 -hydrocarbons by extractive distillation with a selective solvent and subsequent distillative purification of the crude 1,3-butadiene obtained in the extractive distillation.

Abstract: A C.sub.4 -hydrocarbon mixture which essentially contains n-butenes and butanes is separated by a process in whichthe mixture is reacted with a carboxylic acid in the presence of an acidic catalyst to form a butyl carboxylate,the reaction mixture obtained from the esterification zone is distilled to give, as the top product, a fraction containing the butanes, and, as the bottom product, a fraction containing the resulting butyl carboxylate,the butyl carboxylate is decomposed at elevated temperatures to give the carboxylic acid and n-butenes, andthe mixture of n-butenes and carboxylic acid is then distilled, the n-butenes being obtained as the top product, and the carboxylic acid as the bottom product.

Abstract: CO.sub.2 and/or H.sub.2 S are removed from gases which contain CO.sub.2 and/or H.sub.2 S by means of an aqueous absorption liquid containing an alkanolamine, by a process wherein the said gas is treated, in an absorption stage, at from 40.degree. to 100.degree. C., with an aqueous absorption liquid containing from 20 to 70% by weight of methyldiethanolamine, the treated gas is taken off at the top of the absorption stage, the aqueous absorption liquid laden with CO.sub.2 and/or H.sub.2 S is taken off at the bottom of this stage and is regenerated by being let down in two or more flash stages, and the final flash stage is operated under reduced pressure and the regenerated absorption liquid is recycled to the absorption stage.