摘要:
The invention relates to a process for preparing 1,3-butadiene by heterogeneously catalysed oxidative dehydrogenation of n-butene, in which a butene mixture comprising at least 2-butene is provided. The problem that it addresses is that of specifying a process for economically viable preparation of 1,3-butadiene on the industrial scale, which is provided with a butene mixture as raw material, wherein the 1-butene content is comparatively low compared to the 2-butene content thereof, and in which the ratio of 1-butene to 2-butene is subject to variation. This problem is solved by a two-stage process in which, in a first stage, the butene mixture provided is subjected to a heterogeneously catalysed isomerization to obtain an at least partly isomerized butene mixture, and in which the at least partly isomerized butene mixture obtained in the first stage is then subjected, in a second stage, to oxidative dehydrogenation. The two-stage process leads to higher butadiene yields compared to the one-stage process.
摘要:
A process for the combined preparation of a butene and an octene from ethene, proceeds by: a) providing a solvent having a boiling point or boiling range above the boiling points of the butenes and below the boiling points of the octenes and wherein the solvent is an inert solvent or is hexene alone or is hexene admixed with pentane or hexane or heptane or is a mixture of pentane, hexane, and heptane; b) providing a first feed mixture containing at least the solvent and ethene dissolved therein; c) providing a second feed mixture containing at least hexene, the solvent and also ethene dissolved in the solvent and/or in the hexene; d) transferring the first feed mixture into a first synthesis and the second feed mixture into a second synthesis, wherein the first and second syntheses are physically separated from one another; e) oligomerising of at least part of the ethene present in the first feed mixture in the presence of a first heterogeneous catalyst and in the presence of the solvent in the first synthesis to give a first reaction mixture comprising at least the solvent, butene and hexene; f) separating a butene-containing low boiler fraction from the first reaction mixture or from a stream based on the first reaction mixture; g) separating an intermediate boiler fraction containing hexene and the solvent from the first reaction mixture or from a stream based on the first reaction mixture; h) using at least part of the intermediate boiler fraction in the course of providing the second feed mixture; and i) reacting at least part of the ethene present in the second feed mixture with at least part of the hexene present in the second feed mixture in the presence of a second heterogeneous catalyst and in the presence of the solvent in the second synthesis to give a second reaction mixture comprising at least octene and the solvent.
摘要:
A process for the combined preparation of at least butene and octene from ethane, proceeds by a) providing an inert solvent having a boiling point or boiling range below the boiling point of butene; b) providing a first feed mixture comprising at least the inert solvent and ethene dissolved therein; c) converting the first feed mixture in a first synthesis; d) in the first synthesis, oligomerizing at least a portion of the ethene present in the first feed mixture in the presence of a first heterogeneous catalyst and in the presence of the inert solvent to obtain a first reaction mixture comprising at least the inert solvent, butene, hexene and octene; e) working-up of the first reaction mixture and/or a substance stream based thereon into a low boiler fraction comprising the inert solvent, at least one C4-fraction comprising butenes, a C6-fraction comprising hexenes, a C8-fraction comprising octenes and into a C8+-fraction comprising hydrocarbons having more than eight carbon atoms; f) using at least a portion of the low boiler fraction for providing the first feed mixture; g) providing a second feed mixture comprising at least hexene and ethene dissolved in the hexene using at least a portion of the C6-fraction; h) converting the second feed mixture in a second synthesis, wherein the second synthesis is spatially separated from the first synthesis; i) in the second synthesis, reacting at least a portion of the ethene present in the second feed mixture with at least a portion of the hexene present in the second feed mixture in the presence of a second heterogeneous catalyst to obtain a second reaction mixture comprising at least octene; and k) joint working-up of the second reaction mixture with the first reaction mixture or with the substance stream based thereon.
摘要:
The invention relates to a method for producing a carboxylic acid amide from a carbonyl compound and hydrocyanic acid, comprising the steps of A) reacting a carbonyl compound with hydrocyanic acid to produce a hydroxycarboxylic acid nitrile, B) hydrolysis of the hydroxycarboxylic acid nitrile obtained in step A) in the presence of a catalyst comprising manganese dioxide, wherein a molar excess of carbonyl compound is used in relation to the hydrocyanic acid to react the carbonyl compound with hydrocyanic acid according to step A), and the reaction mixture obtained in step A) is not purified by distillation before the hydrolysis according to step B) is carried out. The invention furthermore relates to a method for producing alkyl(meth)acrylates from polymers, moulding compounds and moulded bodies, wherein a method for producing a carboxylic acid amide from a carbonyl compound and hydrocyanic acid is carried out in accordance with the method described above.