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 for heterogeneously catalyzed partial gas phase oxidation of propylene to acrylic acid in the absence of propane as an inert diluent gas, in which, in the starting reaction gas mixture, cyclopropane is substantially avoided as an impurity and crude propylene is used additionally as a propylene source.

Abstract: A method for the heterogeneously catalyzed partial direct oxidation of propane to acrylic acid in the gas phase, in which the reaction gas inlet mixture comprises cyclopropane as an impurity and the acrylic acid, after it has been converted from the product gas mixture into the liquid phase, is operated from the other constituents of the liquid phase with the aid of a separation by crystallization.

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 for purifying removal of a chemical target compound from a suspension of crystals thereof in mother liquor in a wash column with forced transport of the crystal bed from the top downward, in which crystals are removed from the lower end of the crystal bed with a rotating removal device and melted, and a portion of the crystal melt is conducted back toward the crystal bed as wash melt, the removal device being secured with a drive shaft conducted into the wash column from the bottom through an inlet having a seal, said drive shaft being driven about its longitudinal axis by a drive unit for rotation and being mounted so as to be rotatable about its longitudinal axis in more than one bearing, such that the mounting in one of the bearings absorbs the downward force acting on the drive shaft, the mounting in two or more bearings absorbs forces acting radially outward from the drive shaft, and the mounting in one bearing is additionally capable of absorbing an upward force acting on the drive shaft.

Abstract: A process for preparing annular unsupported catalysts by thermally treating annular shaped unsupported catalyst precursor bodies, wherein the side crushing strength of the annular shaped unsupported catalyst precursor bodies is ?12 N and ?23 N; such precursor bodies per se; annular unsupported catalysts having a specific pore structure; and a method of using such annular unsupported catalysts for the catalytic partial oxidative preparation in the gas phase of (meth)acrolein.

Abstract: An annular unsupported catalyst for the heterogeneously catalyzed partial gas phase oxidation of propene to acrolein at a propene hourly space velocity on the fixed catalyst bed of ?120 1 (STP)/1·h and a total CO2 and saturated hydrocarbon content of the starting reaction gas mixture of below 15 mol %, the catalysts of the fixed catalyst bed are the annular unsupported catalysts whose active composition is a multimetal oxide in which the molar Co/Fe ratio=from 2 to 4 and the molar Co/Mo ratio=from 0.3 to 0.7.

Abstract: A method of charging catalyst tubes of a bundle of catalyst tubes in a structured fashion, in which uniformly predispensed portions of formulations of shaped catalyst bodies are used for producing a section of charge.

Abstract: An apparatus for separating crystals from their suspension in contaminated crystal melt with purification, in which a hydraulic wash column has distributor aids in a distributor space.

Abstract: A process for redissociating Michael adducts which are present in a liquid F with a proportion by weight of ?10% by weight and have been formed in the preparation of acrylic acid or esters thereof in a redissociating apparatus which comprises a pump P, a separating column K with separating internals and a circulation heat exchanger UW, wherein, for the purpose of supplying the cleavage energy, the pump P sucks in bottoms liquid from the bottom space of the separating column K and, via the circulation heat exchanger UW, continually recycles it into the bottom space above the level of the bottoms liquid, and wherein the pump P is a radial circulation pump with an open impeller.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide which comprises the element Mo, the elements Bi and/or V and one or more of the elements Co, Ni, Fe, Cu and alkali metals, in which sources of the different elements are used to obtain a finely divided mixture which is coarsened to a powder by press agglomeration, the coarsened powder is used to form, by press agglomeration, shaped bodies V which are separated into undamaged shaped bodies V+ and into damaged shaped bodies V?, the undamaged shaped bodies V+ are converted by thermal treatment to the shaped catalyst bodies K, and the damaged shaped bodies V? are comminuted and recycled into the obtaining of the finely divided mixture.

Abstract: A process for continuously removing a target product X in the form of fine crystals from a liquid phase P comprising the target product X and constituents other than the target product X by cooling suspension crystallization in an indirect heat transferer, in which the crystal suspension formed is conducted out of the heat transferer first into a mixed buffer tank and, from there, fed to an apparatus for separating the crystal suspension into crystals and liquid phase, and wherein external measures dissipade the oversaturation of the crystal suspension fed to the buffer vessel with target product X.

Abstract: A method of charging catalyst tubes of a bundle of catalyst tubes in a structured fashion, in which uniformly predispensed portions of formulations of shaped catalyst bodies are used for producing a section of charge.

Abstract: A process for removing methacrylic acid from liquid phase P comprising acrylic acid as a main constituent and target product, and methacrylic acid as a secondary component in which the removal is effected by crystallization, the acrylic acid accumulating in the crystals formed and the methacrylic acid in the remaining mother liquor.

Abstract: A process for transferring heat to a liquid mixture comprising at least one (meth)acrylic monomer in an indirect heat exchanger, wherein a quaternary ammonium salt, a tertiary amine or a salt thereof with a Brønsted acid is added to the liquid mixture to reduce fouling.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [BiaZ1bOx]p[BicMo12FedZ2eZ3fZ4gZ5hZ6iOy]1, in which a finely divided oxide BiaZ1bOx and, formed from element sources, a finely divided mixture of stoichiometry BicMo12FedZ2eZ3fZ4gZ5hZ6i are mixed in a ratio of p:1, this mixture is used to form shaped bodies and these are treated thermally, where 0<c?0.8.

Abstract: A process for making acrylic acid from acrolein; a process for making methacrylic acid from methacrolein; and a process for making acrylic acid from propane.

Abstract: A process for separating acrylic acid present as a main product and glyoxal present as a by-product in a product gas mixture of a partial gas phase oxidation of a C3 precursor compound, in which a liquid phase P is obtained, which consists of acrylic acid to an extent of at least 70% of its weight and, based on the molar amount of acrylic acid present therein, comprises at least 200 molar ppm of glyoxal, in which the glyoxal is separated from the acrylic acid in the liquid phase P by crystallization.

Abstract: A process for operating a hydraulic wash column, in which the position of the buildup front in the wash column is positioned by means of the flow rates of control liquor conducted into the wash column and/or by means of the flow rate of the suspension conducted into the wash column, and the flow rate determination is with the aid of the pressure difference which exists in the column between points in the suspension zone disposed upstream of the buildup front and points in the zone projecting from the buildup front up to the end of the crystal bed.

Abstract: A process for transferring heat to a liquid F comprising dissolved monomeric acrylic acid, Michael acrylic acid oligomers, and acrylic acid polymer with the aid of an indirect heat exchanger to which are supplied the liquid F with a temperature TF of ?150° C. and a fluid heat carrier W with a temperature of TW>TF, wherein the formation of gas bubbles and/or of thin layers of liquid F adjoining a gas phase is brought about in the liquid F during the flow through the heat exchanger.