Abstract: A process for charging a reactor with a fixed catalyst bed which comprises at least one annular shaped support catalyst body K, in which, before the charging, fragments formed in the preparation of the shaped catalyst bodies K are removed by screening.

Abstract: A process for starting up a separating process for purifying removal of acrylic acid crystals from a suspension S of crystals thereof in mother liquor with a hydraulic wash column which has a crystal melt circuit including crystal melt space, and a process space and a distributor space which are separated by an end with passages connecting the two spaces, in which the crystal bed is formed for the first time by first filling the crystal melt circuit and, at least partly, the process space with an acrylic acid-comprising startup liquid whose acrylic acid crystal formation temperature is less than or equal to the temperature of the suspension S increased by 15° C.

Abstract: The present invention relates to a process for preparing acrylic acid by two-stage heterogeneously catalyzed partial gas phase oxidation of propylene, in which the propylene source used is a preceding propane dehydrogenation and in which the first oxidation stage is operated with restricted propylene conversion, and unconverted propane and propylene present in the product gas mixture of the second partial oxidation stage are recycled substantially into the preceding propane dehydrogenation.

Abstract: A process for producing a ringlike oxidic shaped body by mechanically compacting a pulverulent aggregate introduced into the fill chamber of a die, wherein the outer face of the resulting compact corresponds to that of a frustocone.

Abstract: A process for preparing (meth)acrolein by heterogeneously catalyzed gas phase partial oxidation of a precursor compound, in which the reaction gas mixture which comprises at least 3% by volume of precursor compound is passed through a fresh fixed catalyst bed whose active material is a multielement oxide which comprises the elements Mo, Fe and Bi and at least one of the elements Ni and Co, and the fixed catalyst bed is loaded with at least 40 l (STP)/l·h of precursor compound, and the precursor compound is converted to an extent of at least 90 mol %, wherein, over the first 8000 operating hours, during X=10 to 500 operating hours, the highest temperature of the reaction gas mixture in the fixed catalyst bed is 400 to 450° C. and, during the remaining 8000?X operating hours, is 300 to <400° C., and the loading of the fixed catalyst bed with organic precursor compound, averaged over the time, for the X=10 to 500 operating hours is greater than for the 8000?X operating hours.

Abstract: A process for preparing an organic target compound by heterogeneously catalyzed gas phase partial oxidation of an organic precursor compound with molecular oxygen in two oxidation reactor lines operated in parallel and removal of the target compound from the mixture of the product gas streams in a workup line, wherein the catalysts charge of one of the oxidation lines comprises a portion of catalyst over which the heterogeneously catalyzed gas phase partial oxidation has already been carried out for longer than over the portions of catalyst of the catalyst charge of the other oxidation reactor line.

Abstract: Mo-, Bi- and Fe-comprising multimetal oxide compositions of the general stoichiometry I, Mo12BiaCobFecKdSieOx??(I), where a=0.5 to 1, b=7 to 8.5, c=1.5 to 3.0, d=0 to 0.15, e=0 to 2.5 and x=the stoichiometric coefficient of O2? which guarantees the electric neutrality of the multimetal oxide, and 12?b?1.5·c=A and 0.5?A?1.5, 0.2?a/A?1.3, and 2.5?b/c?9, and the use thereof.

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 heterogeneously catalyzed partial direct oxidation of propane and/or isobutane, in which target product is removed in a workup stage from the product gas mixture obtained in the reaction stage, the remaining residual product gas mixture is divided into two portions of the same composition, one portion is recycled into the reaction stage and the other portion is discharged, and both the reaction stage and the workup stage are operated at elevated pressure.

Abstract: A process for preparing a coated catalyst in which a finely divided mixture of a multielement oxide comprising the elements Mo and V and a molybdenum oxide or a molybdenum oxide former is applied to the surface of a support body as an active composition.

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 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 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 mixing a liquid or mixture of a liquid and a fine solid present in a vessel, in which the vessel is supplied with the same liquid or the same mixture as a motive jet of a jet nozzle which is present in the vessel and has a motive jet and a momentum exchange chamber, the suction region between motive nozzle and momentum exchange chamber being provided with a sheath which has a suction orifice below the central jet leading from the motive nozzle into the momentum exchange chamber.

Abstract: A redissociating apparatus to carry out 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 is provided. The apparatus 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 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 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 heterogeneously catalyzed partial gas phase oxidation of propylene to acrylic acid, in which the starting reaction gas mixture comprises cyclopropane as an impurity and the acrylic acid, after conversion from the product gas mixture into the condensed phase, is removed with the aid of a crystallative removal.

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 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.