Abstract: A process for the continuous recovery of (meth)acrylic acid from the reaction gas of a catalytic gas-phase oxidation comprising the following process stages is proposed: I quenching of the reaction gas by evaporative cooling using a high-boiling solvent, II separation of the (meth)acrylic acid from the quenched reaction gas by absorption into the high-boiling solvent, III separation of the solvent laden with (meth)acrylic acid by rectification into a first part-stream IIIA), which contains predominantly (meth)acrylic acid, and into a second part-stream IIIB) which contains predominantly the solvent, IV recycling of the stream IIIB) to process stage II and V distillative production of (meth)acrylic acid from stream IIIA), all liquid residual streams obtained in process stage V being recycled to process stage I.

Abstract: In a process for the heterogeneously catalyzed dehydrogenation in one or more reaction zones of one or more dehydrogenatable C2-C30-hydrocarbons in a reaction gas mixture comprising them, with at least part of the heat of dehydrogenation required being generated directly in the reaction gas mixture in at least one reaction zone by combustion of hydrogen, the hydrocarbon or hydrocarbons and/or carbon in the presence of an oxygen-containing gas, the reaction gas mixture comprising the dehydrogenatable hydrocarbon or hydrocarbons is brought into contact with a Lewis-acid dehydrogenation catalyst which has essentially no Brönsted acidity.

Abstract: C2–C30-alkanes are dehydrogenated in a process in which (i) ethylbenzene is dehydrogenated to styrene in a first part process to give a hydrogen-containing offgas stream, and (ii) one or more C2–C30-alkanes are dehydrogenated in the presence of a heterogeneous catalyst in one or more reaction zones in a second part process to give the corresponding olefins, with a hydrogen-containing gas stream being mixed into the reaction gas mixture of the dehydrogenation in at least one reaction zone, wherein at least part of the hydrogen-containing offgas stream obtained in the dehydrogenation of ethylbenzene is mixed into the reaction gas mixture of the alkane dehydrogenation.

Abstract: Disclosed is a method for jointly producing (i) formic acid (III); (ii) a carboxylic acid comprising at least two carbon atoms (II) and/or the derivatives thereof; and (iii) a carboxylic acid anhydride (VII). According to said method, (a) a formic acid ester (I) is transesterfied to formic acid (III) and the corresponding carboxylic acid ester (IV) by means of a carboxylic acid comprising at least two carbon atoms (II); (b) at least one portion of the carboxylic acid ester (IV) formed in step (a) is carbonylated in order to obtain the carboxylic acid anhydride (V); and (c) at least one portion of the carboxylic acid anhydride (V) formed in step (b) is further dehydrated by means of a carboxylic acid (VI) so as to form a carboxylic acid anhydride (VII) and the carboxylic acid (II).

Abstract: A process for preparing acrolein or acrylic acid or a mixture thereof from propane, in which the propane is initially dehydrogenated under heterogeneous catalysis to give propene, secondary components are removed and the remaining gas mixture, comprising propane and propene, is subjected to the heterogeneously catalyzed partial oxidation to acrolein or acrylic acid or a mixture thereof as the target product, target product is removed from the product gas mixture and the remaining residual gas, comprising excess oxygen and unconverted propane, is recycled into the propane dehydrogenation in such a way that the other propane fed to the dehydrogenation is at least partly converted under dehydrogenating conditions at the recycle point.

Abstract: The present invention relates to an integrated process for the synthesis of propylene oxide, which comprises at least the following steps: (i) dehydrogenation of propane to give a substream T (0) comprising at least propane, propene and hydrogen; (ii) fractionation of the substream T (0) to give at least one gaseous hydrogen-rich substream T (2) and a substream T (1) comprising at least propene and propane; (iii) synthesis of hydrogen peroxide using the substream T (2), giving a substream T (4) which is rich in hydrogen peroxide and a gaseous substream T (6); (iv) fractionation of the substream T (1) to give at least one propane-rich substream T (5) and at least one propene-rich substream T (3); (v) reaction of the at least one substream T (3) with substream T (4) to give propylene oxide.

Abstract: A process for the continuous heterogeneously catalyzed partial dehydrogenation of a hydrocarbon in the gas phase and in the presence of molecular oxygen, in which part of the product gas is recirculated to the reaction zone, and a reactor for carrying out such a process.

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: C2-C30-alkanes are dehydrogenated in a process in which

Abstract: A process for preparing at least one partial oxidation and/or ammoxidation product of a hydrocarbon by partially dehydrogenating at least one saturated hydrocarbon H under heterogeneous catalysis and using the resulting product gas mixture A, which comprises the partially dehydrogenated hydrocarbon H, as such or in modified form for heterogeneously catalyzed partial oxidation and/or ammoxidation of the partially dehydrogenated hydrocarbon present in the product gas mixture A, said process including at least one mechanical separating operation inserted between the product gas mixture A and the heterogeneously catalyzed partial oxidation and/or ammoxidation.

Abstract: Partial oxidation products and/or ammoxidation products of an olefinic hydrocarbon A′ are prepared by a process in which said olefinic hydrocarbon is produced during normal operation by partial dehydrogenation and/or oxydehydrogenation of hydrocarbon A and fed in from another source during partial or complete nonoperation of the dehydrogenation and/or oxydehydrogenation.

Abstract: In a process for the preparation of acrolein or acrylic acid or a mixture thereof from propane, the propane is subjected, in a first reaction stage, to a partial dehydrogenation under heterogeneous catalysis to give propene, of the components contained in the product gas mixture formed in the first reaction stage other than propene and propane at least a portion of the molecular hydrogen present is then separated off from said mixture and the product gas mixture is then used for the preparation of acrolein and/or acrylic acid by gas-phase catalytic propylene oxidation, molecular nitrogen being present for diluting the reaction gas mixture during the propylene oxidation.

Abstract: A process for the continuous recovery of (meth)acrylic acid from the reaction gas of a catalytic gas-phase oxidation comprising the following process stages is proposed:

Abstract: In a process for the two-stage catalytic gas-phase oxidation of propene to acrylic acid, the reaction gas starting mixture is passed, in a tube-bundle reactor, with a propene loading of ≧160 l (S.T.P.) of propene/l·h, first over a fixed catalyst bed 1 present in two successive temperature zones A, B and then over a fixed catalyst bed 2 which is housed either in one further temperature zone C or in two further temperature zones D, E, the temperature of the zone A being kept at a lower temperature than the zone B and the temperature of the zone D at a lower temperature than the zone E.

Abstract: A process for the preparation of acrylic acid or methacrylic acid is described, in which propane or isobutane is reacted with molecular oxygen in the gas phase in a fluidized-bed reactor containing a catalyst, the catalyst containing a multimetal oxide comprising molybdenum, tellurium and/or antimony, vanadium and niobium, and a catalyst activator which comprises at least one tellurium compound being added to the reactor during the reaction.

Abstract: A process for preparing acrylic acid and/or acrylates which comprises the following stage A and, if desired, B and C: A: cooling a gaseous reaction mixture which comprises acrylic acid and is obtained in the gas-phase oxidation to prepare acrylic acid, using oligomeric acrylic acid or a mixture of acrylic acid and oligomeric acrylic acid, to give a gaseous mixture comprising acrylic acid and a quench bottom product which comprises oligomeric acrylic acid; B: separating the gaseous mixture comprising acrylic acid, to give a low-boiling fraction, a crude acrylic acid, and a bottom product, which comprises oligomeric acrylic acid; C: esterifying the crude acrylic acid obtained in stage B by means of one or more alkanols.

Abstract: In a process for preparing at least one partial oxidation and/or ammoxidation product of propylene, the propylene is obtained from crude propane by dehydrogenating and subjected in the presence of unconverted propane as a constituent of a gas mixture 2 which comprises a total C4-hydrocarbon content of ≦3% by volume to a heterogeneously catalyzed gas phase partial oxidation and/or partial gas phase ammoxidation.

Abstract: Process for preparing at least one partial oxidation and/or ammoxidation product of propylene, in which the propylene is produced from crude propane by dehydrogenation and is subjected to a heterogeneously catalyzed gas-phase partial oxidation and/or partial gas-phase ammoxidation in the presence of unreacted propane as constituent of a gas mixture 2 containing <1% by volume of 1-butene.

Abstract: In a process for the heterogeneously catalyzed dehydrogenation in one or more reaction zones of one or more dehydrogenatable C2-C30-hydrocarbons in a reaction gas mixture comprising them, with at least part of the heat of dehydrogenation required being generated directly in the reaction gas mixture in at least one reaction zone by combustion of hydrogen, the hydrocarbon or hydrocarbons and/or carbon in the presence of an oxygen-containing gas, the reaction gas mixture comprising the dehydrogenatable hydrocarbon or hydrocarbons is brought into contact with a Lewis-acid dehydrogenation catalyst which has essentially no Bronsted acidity.

Abstract: A process for the fractional condensation of a gas mixture which, in addition to acrylic acid or methacrylic acid, also contains at least one further condensable component and additionally a high proportion of one or more noncondensable components, wherein the gas mixture is passed through a column having separatory internals and the condensable components are condensed by cooling.