Abstract: The present invention relates to a system (1) for operating a liquid gas evaporator (3), comprising an evaporator (3) for evaporating a liquid gas into its gaseous aggregation state, a trough (5) carrying the evaporator (3), a housing (7) which surrounds the evaporator (3) on three sides and which terminates flush with the trough (5), at least one detector (9) which is sensitive to the liquid gas and its gaseous aggregation state and which is arranged in the trough (5), a line (11) for the distribution of vapor D, which is provided on the fourth, non-housed side of the evaporator (3) and which is arranged at that margin of the trough (5) which is not closed off by the housing (7), a feed (13), connected to the line (11), for the vapor D, and a regulating valve (15) provided on the feed (13) and connected to the detector (9) and at least one shut-off valve (17). The present invention relates furthermore, to a method for operating a liquid gas evaporator (3).

Abstract: The present invention relates to an apparatus (1) for separation of a target product from a liquid phase P comprising the target product, comprising at least one primary space (3) for a heat transfer medium W, at least one first feed unit (5a) and one first removal unit (5b) for the heat transfer medium W, at least one secondary space (7) for the liquid phase P, at least one second feed unit (9) for the liquid phase P, at least one crystallization surface (13) which divides the primary space (3) and the secondary space (7), at least one second removal unit (15) for the target product and at least one application unit (11) for a liquid phase P0 essentially directly to the crystallization surface (13) or the surfaces of lines that conduct the heat transfer medium W. The present invention further relates to a process for removing a target product from a liquid phase P comprising the target product.

Abstract: The present invention relates to a plant (1) for performance of heterogeneously catalyzed gas phase reactions, comprising a reactor (3), at least one line (11) leading into the reactor (3) for introduction of reactants into the reactor (3), at least one first feed (5) for providing at least one first reactant A, which leads into the line (11), at least one second feed (7) for providing at least one second reactant B, which leads into the line (11), at least one third feed (9) for providing a cycle gas G, which leads into the line (11), a temperature control unit (13) which is disposed in the line (11) upstream of the reactor (3) and is for controlling the temperature of the first reactant A and/or second reactant B and/or cycle gas G prior to entry into the reactor (3) and at least one outlet (15) for products, by-products and/or unreacted reactants from the gas phase reaction. The present invention further relates to a process for performing heterogeneously catalyzed gas phase reactions.

Abstract: An ?,?-unsaturated aldehyde and/or an ?,?-unsaturated carboxylic acid are prepared by gas phase oxidation of alkene with molecular oxygen over a fixed catalyst bed comprising a bed of hollow cylindrical shaped catalyst bodies having a multimetal oxide active composition. The fixed catalyst bed comprises at least three successive reaction zones; the highest local temperature in the fixed catalyst bed does not occur in the reaction zone closest to the reactor outlet; the highest local temperature in the fixed catalyst bed does not occur in the reaction zone closest to the reactor inlet; and the value WT=(ED?ID)/2 in the reaction zone in which the highest local temperature in the fixed catalyst bed occurs is lower than in the other reaction zones, in which ED is the external diameter and ID is the internal diameter of the shaped catalyst body. The yield of the products of value is enhanced in this way.

Abstract: The present invention relates to a reactor system (1) comprising a reactor 3, at least one cooler (5) connected to the reactor (3), at least one pump (7) for circulating at least some of a liquid heat-transfer medium (9), wherein the pump (7) is connected to the reactor (3) and/or the at least one cooler (5), and a container (11) for collecting the liquid heat-transfer medium (9), wherein the container (11) is connected to the reactor (3) and/or the at least one cooler (5), wherein the container (11) is disposed substantially below the reactor (3) and/or the at least one cooler (5). Moreover, the use of the reactor system (1) according to the invention for carrying out exothermic reactions is described.

Abstract: The present invention relates to a heat exchanger (1) comprising a bundle of at least two heat exchanger tubes (3), a heat exchanger housing (5) surrounding the bundle of heat exchanger tubes (3), wherein a liquid heat-transfer medium (7) is passed around the bundle of heat exchanger tubes (3) in the heat exchanger housing (5), a heat exchanger cap (9) sealing the top of the heat exchanger housing (5), a heat exchanger bottom (11) sealing the bottom of the heat exchanger housing (5), a feed point (13) for the heat-transfer medium (7), an outlet (15) for the heat-transfer medium (7), an emergency relief port (17) disposed in proximity to the heat exchanger cap (9). The heat exchanger (1) comprises a safety device (19) disposed in proximity to the heat exchanger bottom (11). The present invention further relates to a reactor arrangement (101).

Abstract: The present invention describes a system (1) for recovering liquid or free-flowing chemicals in a chemical plant (3), comprising at least two plant sections (3a, 3b), for each plant section (3a, 3b) at least one connecting device (5a, 5b) arranged at the lowest point, at least one common collecting line (7) which runs beneath the connecting devices (5a, 5b) and connects them to one another, at least one collecting vessel (9) arranged at the same height as or higher than the at least two plant sections (3a, 3b) and above the collecting line (7), at least one pump (11) provided in the collecting line (7) between the connecting devices (5a, 5b) and the collecting vessel (9) for drawing off the at least one liquid or free-flowing chemical combined in the collecting line (7) and introducing it into the collecting vessel (9).

Abstract: The invention relates to an oxidation catalyst comprising at least one inorganic, oxidic or ceramic, shaped support body having a BET surface area of less than 0.5 m2/g, based on the support, which is at least partly coated with a catalytically active multielement oxide, the catalyst being precious metal-free and the shaped support body having the form of a saddle whose saddle surface is curved oppositely in the two principal directions, to a process for producing it, to its use in various catalytic gas phase oxidations, and to corresponding processes for catalytic gas phase oxidation.

Abstract: The present invention relates to an extraction column 1 having a vertically aligned column body 2 which is cylindrical at least in sections and forms a column cavity 3 having a horizontal maximum extent, with provision in the column body 2 of at least one first feed 4 for an extractant, at least one second feed 5 for the fluid to be extracted and at least one outlet 6 for the extract mixture and at least one outlet for the raffinate. In the inventive extraction column 1, a vertically aligned divider 7 arranged within the column cavity 3 subdivides the column cavity 3 into a plurality of vertically aligned and horizontally divided regions, the horizontal maximum extent of each region being less than the horizontal maximum extent of the column cavity 3. The invention further relates to a process for extracting a constituent from a fluid by means of such an extraction column 1.

Abstract: A thermal separation process between a gas ascending in a separating column and a liquid descending in the separating column, which comprise (meth)acrylic monomers, wherein the separating column comprises a sequence of crossflow mass transfer trays, the crossflow mass transfer trays of which have passage orifices for the ascending gas in crossflow direction both in front of and beyond a downcomer for the descending liquid, and such crossflow mass transfer trays and one such crossflow mass transfer tray in a sequence of crossflow mass transfer trays present in a separating column.

Abstract: A hollow cylindrical shaped catalyst body for gas phase oxidation of an alkene to an ?,?-unsaturated aldehyde and/or an ?,?-unsaturated carboxylic acid comprises a compacted multimetal oxide having an external diameter ED, an internal diameter ID and a height H, wherein ED is in the range from 3.5 to 4.5 mm; the ratio q=ID/ED is in the range from 0.4 to 0.55; and the ratio p=H/ED is in the range from 0.5 to 1. The shaped catalyst body is mechanically stable and catalyzes the partial oxidation of an alkene to the products of value with high selectivity. It provides a sufficiently high catalyst mass density of the catalyst bed and good long-term stability with acceptable pressure drop.

Abstract: An ?,?-unsaturated aldehyde and/or an ?,?-unsaturated carboxylic acid are prepared by gas phase oxidation of alkene with molecular oxygen over a fixed catalyst bed comprising a bed of hollow cylindrical shaped catalyst bodies having a multimetal oxide active composition. The fixed catalyst bed comprises at least three successive reaction zones; the highest local temperature in the fixed catalyst bed does not occur in the reaction zone closest to the reactor outlet; the highest local temperature in the fixed catalyst bed does not occur in the reaction zone closest to the reactor inlet; and the value WT=(ED?ID)/2 in the reaction zone in which the highest local temperature in the fixed catalyst bed occurs is lower than in the other reaction zones, in which ED is the external diameter and ID is the internal diameter of the shaped catalyst body. The yield of the products of value is enhanced in this way.

Abstract: A thermal separation process between a gas ascending in a separating column and a liquid descending in the separating column, which comprise (meth)acrylic monomers, wherein the separating column comprises a sequence of crossflow mass transfer trays, the crossflow mass transfer trays of which have passage orifices for the ascending gas in crossflow direction both in front of and beyond a downcomer for the descending liquid, and such crossflow mass transfer trays and one such crossflow mass transfer tray in a sequence of crossflow mass transfer trays present in a separating column.

Abstract: What is described is a catalyst for preparation of an ?,?-unsaturated carboxylic acid by gas phase oxidation of an ?,?-unsaturated aldehyde, comprising a shaped support body with an active composition applied thereto, wherein the active composition coverage q q = Q ( 100 - Q ) ? S m is at most 0.3 mg/mm2, where Q is the active composition content of the catalyst in % by weight and Sm is the specific geometric surface area of the shaped support body in mm2/mg. Also described are a process for preparing the catalyst and a process for preparing an ?,?-unsaturated carboxylic acid by gas phase oxidation of an ?,?-unsaturated aldehyde over a fixed catalyst bed comprising a bed of the catalyst. The catalyst, with constantly high conversion of acrolein, reduces overoxidation to COx and increases the selectivity of acrylic acid formation.

Abstract: A process for transporting a liquid monomer phase which has been withdrawn from a storage vessel and comprises methacrylic monomers to an extent of ?90% by weight, in a tank truck or in a tanker ship, in which the liquid monomer phase is subjected to a separating operation on the route from the storage vessel into the tank of a tank truck or of a tanker ship in order to separate polymer of the monomer present in dissolved form in the liquid monomer phase.

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 mixing a liquid stored in a vessel, in which gas is sucked in from the gas phase present above the liquid interface with a suction apparatus present in the liquid, and released into it again for the gas-induced mixing of the liquid.

Abstract: A process for mixing a liquid stored in a vessel, in which gas is sucked in from the gas phase present above the liquid interface with a suction apparatus present in the liquid, and released into it again for the gas-induced mixing of the liquid.

Abstract: A thermal separation process between a gas ascending in a separating column and a liquid descending in the separating column, which comprise (meth)acrylic monomers, wherein the separating column comprises a sequence of crossflow mass transfer trays, the crossflow mass transfer trays of which have passage orifices for the ascending gas in crossflow direction both in front of and beyond a downcomer for the descending liquid, and such crossflow mass transfer trays and one such crossflow mass transfer tray in a sequence of crossflow mass transfer trays present in a separating column.

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.