Abstract: A method for resistance welding includes performing a plurality of resistance welding processes during which welding electrodes are pressed against respective welding spots of respective workpieces. The welding electrodes are energized with a respective welding current for each of the plurality of resistance welding processes, and for each of the plurality of resistance welding processes, a respective at least one characteristic value that characterizes a quality of the welding is determined. A statistical analysis of the determined at least one characteristic value for each of the plurality of resistance welding processes is performed, and based upon the analysis, an adaptation of the prescribed welding parameters is determined.

Abstract: The invention relates to a process (10) for the production of propylene which comprises carrying out a process (1) for propane dehydrogenation to obtain a first component mixture (A), carrying out a further propylene production method (2) to obtain a second component mixture (B), and forming a separation product (P2) containing predominantly propane using one or more propane separation steps (S1), wherein at least part of the first component mixture (A) is supplied to the propane separation step or steps (S1). It is envisaged that the separation product (P2), which mainly contains propane, will at least partly be returned to the further propylene production method (2). A corresponding plant and a process for converting a steam cracking plant are also the subject of the invention.

Abstract: The invention concerns a process (10) for the production of propylene, which comprises carrying out a process (1) for propane dehydrogenation to obtain a first component mixture (A), carrying out a steam cracking process (2) to obtain a second component mixture (B), forming a first separation product (P1) which contains at least predominantly propylene using one or more first separation steps (S1), forming a second separation product (P2) containing at least predominantly propane using the first separation step(s) (S1), forming a third separation product (P3) containing at least predominantly ethylene using one or more second separation steps (S2) and forming a fourth separation product (P4) containing at least predominantly ethane using the second separation step(s) (S1).

Abstract: The present invention relates to a catalyst for the dehydrogenation of hydrocarbons which is based on iron oxide and a process for producing it. The catalyst comprises at least one iron compound, at least one potassium compound and from 11 to 24% by weight of at least one cerium compound, calculated as CeO2, wherein the at least one iron compound and the at least one potassium compound are at least partly present in the form of one or more K/Fe mixed oxide phases of the general formula KxFeyOz, where x is from 1 to 17; y is from 1 to 22 and z is from 2 to 34, and comprises at least 50% by weight, based on the total catalyst, of the K/Fe mixed oxide phases, and also a process for producing it.

Abstract: The present invention relates to a catalyst based on iron oxide for the dehydrogenation of hydrocarbons and also a process for producing it. The catalyst comprises at least one iron compound, at least one potassium compound and at least one cerium compound, wherein the at least one iron compound and the at least one potassium compound are at least partly present in the form of one or more K/Fe mixed oxide phases of the general formula KxFeyOz, where x is from 1 to 17; y is from 1 to 22 and z is from 2 to 34, where the catalyst comprises at least 20% by weight, based on the total catalyst, of the K/Fe mixed oxide phases and comprises crystalline cerium dioxide having a crystallite size in the range from 10 nm to 30 nm.

Abstract: Production plant (1) for producing at least one end product (3) from at least one primary starting material (2), comprising at least one processing station (41-43) which processes at least one starting material (21-23) to form at least one product (31, 32, 33), and a process controller (51-53) which can control at least one variable (71-73), which is a measure of a quality feature of the product (31-33) and/or is correlated with a quality feature of the product (31-33), by influencing at least one manipulated variable (61-63) acting on the processing station (41-43), wherein the process controller (51-53) is additionally designed to control the production rate (31a-33a) of the processing station (41-43) for the product (31-33) and/or the consumption rate (21a-23a) of the processing station (41-43) with regard to starting material (21-23) by acting on the manipulated variable (61-63).

Abstract: The present invention relates to a catalyst for the dehydrogenation of hydrocarbons which is based on iron oxide and additionally comprises at least one potassium compound, at least one cerium compound, from 0.7 to 10% by weight of at least one manganese compound, calculated as Mn02, and from 10 to 200 ppm of at least one titanium compound, calculated as TiO2, and also to a process for the production thereof. Furthermore, the present invention relates to a process for the catalytic dehydrogenation of hydrocarbons using the catalyst of the invention.

Abstract: The present invention relates to a process for preparing acrylic acid from acetic acid and formaldehyde, which comprises (a) provision of a stream S1 comprising acetic acid and formaldehyde, where the molar ratio of acetic acid to formaldehyde in the stream S1 is in the range from 0.5:1 to 2:1; (b) contacting of the stream S1 with an aldol condensation catalyst comprising vanadium, phosphorus and oxygen to give a stream S2 comprising acrylic acid, where, in (b), the space velocity WHSV is in the range from 0.35 to 7.0 kg/kg/h.

Abstract: Provided are selective catalytic reduction catalytic articles, emission treatment systems and methods for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The catalytic articles have a Selective Catalytic Reduction (SCR) catalyst uniformly coated over the outlet portion of wall flow filter walls resulting in reduction of NO2 and combustion of the soot without substantially increasing the system backpressure.

Abstract: An oxidic composition comprising vanadium, tungsten, phosphorus, oxygen and optionally tin, where the molar ratio of phosphorus to the sum total of vanadium, tungsten and any tin in the oxidic composition is in the range from 1.4:1 to 2.4:1.

Abstract: The present invention relates to a catalyst based on iron oxide for the dehydrogenation of hydrocarbons and also a process for producing it. The catalyst comprises at least one iron compound, at least one potassium compound and at least one cerium compound, wherein the at least one iron compound and the at least one potassium compound are at least partly present in the form of one or more K/Fe mixed oxide phases of the general formula KxFeyOz, where x is from 1 to 17; y is from 1 to 22 and z is from 2 to 34, where the catalyst comprises at least 20% by weight, based on the total catalyst, of the K/Fe mixed oxide phases and comprises crystalline cerium dioxide having a crystallite size in the range from 10 nm to 30 nm.

Abstract: The present invention relates to a catalyst for the dehydrogenation of hydrocarbons which is based on iron oxide and a process for producing it. The catalyst comprises at least one iron compound, at least one potassium compound and from 11 to 24% by weight of at least one cerium compound, calculated as CeO2, wherein the at least one iron compound and the at least one potassium compound are at least partly present in the form of one or more K/Fe mixed oxide phases of the general formula KxFeyOz, where x is from 1 to 17; y is from 1 to 22 and z is from 2 to 34, and comprises at least 50% by weight, based on the total catalyst, of the K/Fe mixed oxide phases, and also a process for producing it.

Abstract: Catalytic articles, methods and emissions treatment systems for treating an engine exhaust gas stream containing NOx and particulate matter are disclosed and include a particulate filter comprising a first SCR catalyst for NOx conversion disposed downstream of the injector. The particulate filter is a partial filter with a particle filtration efficiency between about 30% and 60% and an SCR catalyst loading in the range of 0.1 g/in3-3.5 g/in3.

Abstract: The present invention relates to a process for preparing acrylic acid from acetic acid and formaldehyde, which comprises (a) provision of a stream S1 comprising acetic acid and formaldehyde, where the molar ratio of acetic acid to formaldehyde in the stream S1 is in the range from 0.5:1 to 2:1; (b) contacting of the stream S1 with an aldol condensation catalyst comprising vanadium, phosphorus and oxygen to give a stream S2 comprising acrylic acid, where, in (b), the space velocity WHSV is in the range from 0.35 to 7.0 kg/kg/h.

Abstract: The catalyst comprises from 0.01 to 0.5% by weight of platinum, based on the catalyst, and optionally tin, with the weight ratio of Sn:Pt being from 0 to 10, on zeolite A as support.

Abstract: Described is a catalyst, preferably for use in selective catalytic reduction (SCR), said catalyst comprising one or more zeolites of the MFI structure type, and one or more zeolites of the CHA structure type, wherein at least part of the one or more zeolites of the MFI structure type contain iron (Fe), and wherein at least part of the one or more zeolites of the CHA structure type contain copper (Cu). An exhaust gas treatment system is described, comprising said catalyst as well as a process for the treatment of a gas stream comprising NOx using said catalyst as well.

Abstract: A process for charging a longitudinal section of a catalyst tube with a homogeneous fixed catalyst bed section whose active composition is at least one multielement oxide or comprises elemental silver on an oxidic support body and whose geometric shaped catalyst bodies and shaped inert bodies have a specific inhomogeneity of their longest dimensions.

Abstract: In a process for removing oxygen from a C4-hydrocarbon stream comprising free oxygen by catalytic combustion, in which the hydrocarbon stream comprising free oxygen is reacted by catalytic combustion over a catalyst bed in the presence or absence of free hydrogen to give an oxygen-depleted hydrocarbon stream, the catalytic combustion is carried out continuously, the entry temperature in the catalyst bed is at least 300° C. and the maximum temperature in the catalyst bed is not more than 700° C.

Abstract: A shell which encloses an interior and has at least one first orifice for feeding at least one gas stream into the interior and at least one second orifice for withdrawing a gas stream fed to the interior beforehand via the at least one first orifice from the interior, the surface of the shell, on its side in contact with the interior, being manufactured at least partly, in a layer thickness of at least 1 mm, from a steel which has a specific elemental composition, and in the interior, a process for continuous heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated is carried out in a reactor which is manufactured from the steel on its side in contact with the reaction gas.

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.