摘要:
A process for removing methacrolein from liquid phase P comprising acrylic acid as a main constituent and target product, and methacrolein as a secondary component in which the removal is effected by crystallization, the acrylic acid accumulating in the crystals formed and the methacrolein in the remaining mother liquor.
摘要:
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 catalyst 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.
摘要:
A process for long-term operation of a continuous heterogeneously catalyzed partial dehydrogenation of a hydrocarbon to be dehydrogenated, in which a reaction gas mixture stream comprising the hydrocarbon to be dehydrogenated in a molar starting amount KW is conducted through an overall catalyst bed comprising the total amount M of dehydrogenation catalyst and the deactivation of the overall catalyst bed is counteracted in such a way that, with increasing operating time, the contribution to the conversion in the first third of the total amount M of dehydrogenation catalyst in flow direction decreases, the contribution to the conversion in the last third of the total amount M of dehydrogenation catalyst in flow direction increases, and the contribution to the conversion in the second third of the total amount M of dehydrogenation catalyst in flow direction passes through a maximum.
摘要:
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.
摘要:
The present invention relates to a process for charging a reactor with a catalyst, to the resulting charged reactors, and to the use thereof for carrying out catalytic gas phase reactions.
摘要:
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.
摘要:
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.
摘要:
In a process for partially oxidizing acrolein to acrylic acid in the gas phase under heterogeneous catalysis, the starting reaction gas mixture is oxidized at an acrolein loading of ≦145 and ≧70 l (STP) of acrolein/l of fixed catalyst bed·h over a fixed catalyst bed which is accommodated in two successive reaction zones A, B, the highest temperature of the reaction gas mixture within reaction zone A being above the highest temperature of the reaction gas mixture within reaction zone B.
摘要:
A process for the long-term operation of a heterogeneously catalyzed gas phase partial oxidation of acrolein to acrylic acid, in which the temperature of the fixed catalyst bed is increased over time and partial oxidation is interrupted and an oxygen-containing gas is conducted through the fixed catalyst bed before the temperature increase is 8° C.
摘要:
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.