Abstract: A process for long-term operation of a continuous heterogeneously catalyzed partial dehydrogenation of a hydrocarbon to be dehydrogenated, in which a reaction gas mixture stream comprising the hydrocarbon to be dehydrogenated in a molar starting amount KW is conducted through an overall catalyst bed comprising the total amount M of dehydrogenation catalyst and the deactivation of the overall catalyst bed is counteracted in such a way that, with increasing operating time, the contribution to the conversion in the first third of the total amount M of dehydrogenation catalyst in flow direction decreases, the contribution to the conversion in the last third of the total amount M of dehydrogenation catalyst in flow direction increases, and the contribution to the conversion in the second third of the total amount M of dehydrogenation catalyst in flow direction passes through a maximum.

Abstract: The present invention relates to a coating material comprising (A) at least one binder as component (A) and (B) at least one photocatalytically active particle comprising a core composed of at least one first substance having a diameter of 0.1 to 1 ?m and at least one envelope at least partly surrounding the core and composed of at least one second substance having an average layer thickness of 0.1 to 10 nm as component (B).

Abstract: A process for regenerating a catalyst bed deactivated in the course of a heterogeneously catalyzed partial dehydrogenation of a hydrocarbon, in which a gas comprising molecular oxygen is conducted at elevated temperature through the deactivated catalyst bed and, in the course of the regeneration, the content of molecular oxygen in the regeneration gas is increased repeatedly and the increase in the carbon oxide content of the regeneration gas as it flows through the deactivated catalyst bed is restricted to values of ?5% by volume.

Abstract: The present invention relates to a process for the purification of a contaminant-containing stream by bringing the stream to be purified into contact with a heterogeneous photocatalyst with irradiation with light, where the bringing into contact takes place in the presence of at least one compound dissolved in the stream and comprising at least one metal selected from the group consisting of iron, chromium, nickel, cobalt, manganese and mixtures thereof, and to the use of a heterogeneous photocatalyst for the purification of a contaminant-containing stream, where, in the stream to be purified, at least one compound comprising at least one metal selected from the group consisting of iron, chromium, nickel, cobalt, manganese and mixtures thereof is present in dissolved form.

Abstract: A process for preparing butadiene, comprising A) providing a stream (a) comprising n-butane; B) feeding stream (a) comprising into at least one first dehydrogenation zone and nonoxidatively catalytically dehydrogenating n-butane to obtain a stream (b) comprising n-butane, 1-butene, 2-butene, butadiene, hydrogen and low-boiling secondary constituents; C) feeding stream (b) and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating n-butane, 1-butene and 2-butene to obtain a stream (c) comprising n-butane, 2-butene, butadiene, low-boiling secondary constituents, carbon oxides and steam, wherein stream (c) has a higher content of butadiene than stream (b); D) removing the low-boiling secondary constituents and steam to obtain a stream (d) substantially consisting of n-butane, 2-butene and butadiene; E) separating stream (d) into a stream (e1) consisting substantially of n-butane and 2-butene and a stream (e2) consisting substantially of butadiene by extractive distillation

Abstract: The present invention relates to a method of purifying wastewater by contacting the wastewater which is to be purified with a rod-shaped TiO2 photocatalyst which has a BET surface area of 25 to 200 m2/g, a pore volume of 0.10 to 1.00 ml/g, and a median pore diameter of 0.005 to 0.050 ?m, with irradiation by light, and to the use of such a rod-shaped TiO2 photocatalyst which has a BET surface area of 25 to 200 m2/g, a pore volume of 0.10 to 1.00 ml/g, and a median pore diameter of 0.005 to 0.050 ?m, for purifying wastewater with irradiation by light.

Abstract: A process for continuous heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated in a reactor which is manufactured from a composite material which consists, on its side in contact with the reaction chamber, of a steel B with specific elemental composition which, on its side facing away from the reaction chamber, either directly or via an intermediate layer of copper, or of nickel, or of copper and nickel, is plated onto a steel A with specific elemental composition, and also partial oxidations of the dehydrogenated hydrocarbon and the reactor itself.

Abstract: The invention relates to a process for preparing a catalyst support, in which zirconium dioxide powder is mixed with a binder, if desired a pore former, if desired an acid, water and, if desired, further additives to give a kneadable composition and the composition is homogenized, shaped to produce shaped bodies, dried and calcined, wherein the binder is a monomeric, oligomeric or polymeric organosilicon compound. Suitable binders are monomeric, oligomeric or polymeric silanes, alkoxysilanes, aryloxysilanes, acryloxysilanes, oximinosilanes, halosilanes, aminoxysilanes, aminosilanes, amidosilanes, silazanes or silicones. The invention also provides the catalyst support which has been prepared in this way, a catalyst comprising the support and its use as dehydrogenation catalyst.

Abstract: The present invention relates to a coating material comprising (A) at least one binder as component (A) and (B) at least one photocatalytically active particle comprising a core composed of at least one first substance having a diameter of 0.1 to 1 ?m and at least one envelope at least partly surrounding the core and composed of at least one second substance having an average layer thickness of 0.1 to 10 nm as component (B).

Abstract: The present invention relates to a process for producing coated nanoparticles comprising a core comprising at least one first substance and at least one envelope at least partly surrounding the core and composed of at least one further substance, in a streaming system, to nanoparticles which can be produced according to this process, to nanoparticles comprising a nonporous core comprising at least one first substance and at least one porous envelope at least partly surrounding the core and composed of at least one further substance, the nanoparticles having a narrow particle size distribution, to the use of such nanoparticles in photocatalysis and to apparatus for carrying out the process.

Abstract: A process for continuous heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated in a reactor which is manufactured from a steel with specific elemental composition on its side in contact with the reaction gas, and also partial oxidations of the dehydrogenated hydrocarbon and the reactor itself.

Abstract: A process is described for hydrocyanating 1,3-butadiene over at least one nickel(0) complex having phosphorus ligands as a catalyst, wherein the 1,3-butadiene is used in a mixture with n-butane and the mixture contains from 60 to 90% by volume of 1,3-butadiene and from 40 to 10% by volume of n-butane.

Abstract: A process for preparing o-xylene comprises the steps of a) dimerizing 2-butenes to 3,4- and/or 2,3-dimethylhexenes and b) aromatizing the 3,4- and/or 2,3-dimethylhexenes under dehydrogenating conditions to give o-xylene and is suitable for the selective preparation of o-xylene.

Abstract: The invention relates to a process for preparing propene from propane, comprising the steps: A) a feed gas stream a comprising propane is provided; B) the feed gas stream a comprising propane and an oxygenous gas stream are fed into a dehydrogenation zone and propane is subjected to a nonoxidative catalytic, autothermal dehydrogenation to propene to obtain a product gas stream b comprising propane, propene, methane, ethane, ethene, C4+ hydrocarbons, carbon monoxide, carbon dioxide, steam and hydrogen, C) the product gas stream b is cooled and steam is removed by condensation to obtain a steam-depleted product gas stream c, D) carbon dioxide is removed by gas scrubbing to obtain a carbon dioxide-depleted product gas stream d, E) the product gas stream d is cooled and a liquid hydrocarbon stream e1 comprising propane, propene, methane, ethane, ethene and C4+ hydrocarbons is removed by condensation to leave a residual gas stream e2 comprising methane, hydrogen and carbon monoxide, F) the liquid hydrocarbon stre

Abstract: A process for preparing 1-butene from 1-butane, which includes providing a n-butane-containing feed gas stream; introducing of the n-butane-containing feed gas stream into at least one dehydrogenation zone and nonoxidative catalytic dehydrogenation of n-butane; removing hydrogen, the low-boiling secondary constituents and optionally water vapor to give a C4 product gas stream containing 10-80% by volume of n-butane, 5-40% by volume of 1-butene, 10-50% by volume of 2-butene, 0-40% by volume of butadiene and 0-10% by volume of further gas constituents; introducing the C4 product gas stream containing 10-80% by volume of n-butane, 10-60% by volume of 1-butene, 15-60% by volume of 2-butene, 0-5% by volume of butadiene and 0-10% by volume of further gas constituents, into a selective hydrogenation zone and selective hydrogenation of butadiene to 1- and/or 2-butene to give stream consisting essentially of n-butane, 1-butene and 2-butene; and separating of the stream distillation into a desired product.

Abstract: A process for preparing butadiene, comprising nonoxidatively dehydrogenating n-butane from a stream (a) in a first dehydrogenation zone to obtain stream (b) comprising 1-butene, 2-butene, and butadiene; oxidatively dehydrogenating the 1-butene and 2-butene of (b) in the presence of an oxygenous gas in a second dehydrogenation zone to obtain stream (c) comprising n-butane, butadiene, hydrogen, and steam; compressing and cooling (c) to obtain stream (d2) comprising n-butane, butadiene, hydrogen, and steam; extractively distilling (d2) into stream (e1) comprising butadiene and stream (e2) comprising n-butane, hydrogen, and steam; optionally compressing and cooling (e2) to obtain stream (f1) comprising n-butane and water and stream (f2) comprising n-butane and hydrogen and optionally recycling (f1) into the first dehydrogenation zone; separating (f2) into stream (g1) comprising n-butane and stream (g2) comprising hydrogen by contacting (f2) with a high boiling absorbent and subsequently desorbing the gas constitu

Abstract: The disclosure involves a process for preparing butadiene from n-butane. In the process, n-butane is first dehydrogenated autothermally under nonoxidative conditions to form a gas stream. The gas stream is then oxidatively dehydrogenated to form a second gas stream. From the second gas stream, a third gas stream containing n-butane, 2-butene and butadiene is obtained. From the third gas stream, a butadiene/butaine product stream is obtained and remaining n-butane and 2-butene is recycled into the first dehydrogenation zone.

Abstract: The disclosure involves a process for the preparation of butadiene and 1-butene. The process includes at least a first catalytic dehydrogenation of n-butane to obtain a gas stream which is followed by at least a second oxidative dehydrogenation to form a second gas stream. The second gas stream is then subjected to distillation and isomeration steps to obtain butadiene and 1-butene.

Abstract: A process for preparing 1-butene, which includes nonoxidatively, catalytically dehydrogenating n-butane to obtain a product gas stream of n-butane, 1-butene, 2-butene, butadiene, hydrogen, and secondary constituents; removing hydrogen and the secondary constituents to obtain a C4 product gas stream; separating the C4 product stream into a recycle stream of n-butane and a stream of 1-butene, 2-butene and butadiene by extractive distillation, and recirculating the recycle stream to the dehydrogenation zone; introducing the 1 -butene, 2-butene and butadiene stream into a selective hydrogenation zone and selective hydrogenation of butadiene to 1-butene and/or 2-butene to obtain a stream of 1-butene and 2-butene; introducing the 1-butene and 2-butene stream, and a circulating stream of 1-butene and 2-butene into a distillation zone and isolation of a product stream; and introducing the 2-butene-containing stream into an isomerization zone to obtain a circulating stream of 1-butene and 2-butene, and recirculating t

Abstract: The disclosure relates to a process for preparing butadiene. The process involves nonoxidatively catalytically dehydrogenating butane to obtain a product gas stream containing butane, 1-butene, 2-butene, butadiene, hydrogen and secondary constituents. The 1-butene and 2-butene of the product gas stream is then oxidatively dehydrogenated to give a second gas stream containing butane,2-butene, butadiene, hydrogen, steam and secondary constituents. Next, the butane,2-butene and butadiene are separated from the second gas stream and the butane and 2-butene are then separated from the butadiene product. The butane and 2-butene are then recycled into the nonoxidative catalytic dehydrogenating zone.