摘要:
A process for the dissociation of methyl tert-butyl ether (MTBE), which includes at least a) catalytic dissociation of MTBE which is present in two streams I and VII over a catalyst to give a dissociation product II, b) separation by distillation of the dissociation product II obtained in a) into an overhead stream III containing more than 90% by mass and a bottom stream IV containing diisobutene, MTBE and more than 80% of the methanol present in the dissociation product II, c) separation by distillation of the bottom stream IV obtained in b) into a methanol-containing bottom stream V, a side stream VI containing diisobutene, methanol and MTBE and an overhead stream VII containing MTBE and methanol and d) recirculation of the overhead stream VII to a).
摘要:
A reactor for carrying out catalyzed liquid reactions in which the catalyst is present as a dispersion in the reaction zone. The reactor includes at least one inlet and outlet, with all starting materials being fed in via the inlet and all products being discharged via the outlet. The inlet and outlet can be switched so that an exit previously serving as the outlet is utilized as an entrance serving as the inlet and at the same time an entrance previously serving as the inlet is utilized as an exit serving as the outlet. The inlet and outlet each include a filter element that keeps the catalyst in the reactor. The reactor also includes a device that ensures homogeneous distribution of the catalyst and the starting materials in the reactor. This reactor can carry out reactions at a high solids content without the catalyst having to be separated off from a product stream in an extra process step and without regular cleaning and thus shutdown of the process being necessary.
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:
Silicon-aluminum mixed oxide powder having a weight ratio of (Al2O3/SiO2)ttl in the total primary particle of from 0.003 to 0.05, a weight ratio (Al2O3/SiO2)surface of the primary particles in a surface layer having a thickness of about 5 nm which is less than in the total primary particle and a BET surface area of from 50 to 250 m2/g. It is prepared by igniting one or more silicon compounds selected from the group consisting of CH3SiCl3, (CH3)2SiCl2, (CH3)3SiCl and (n-C3H7)SiCl3, a hydrolysable and oxidizable aluminum compound, at least one fuel gas and air and burning the flame into a reaction chamber, subsequently separating the solid from gaseous materials and subsequently treating the solid with water vapor. The silicon-aluminum mixed oxide powder can be used as catalyst.
摘要:
Provided is a process for producing an aldehyde from an alkylene. The process includes (a) photocatalytically dehydrogenating at least one alkane to obtain a mixture comprising at least one olefin and hydrogen, (b) adding carbon dioxide and hydrogen to the mixture, and (c) hydroformylating the olefin to at least one aldehyde. The process also includes converting carbon dioxide and hydrogen into water and carbon monoxide prior to the hydroformylating. In addition, the conversion of carbon dioxide and hydrogen into water and carbon monoxide is performed by a reverse water gas shift reaction.
摘要:
The present invention relates to a process for preparing unsaturated aldehydes or unsaturated carboxylic acids by heterogeneous catalytic gas phase oxidation of unsaturated or saturated hydrocarbons, comprising the process steps of: i) providing a gas mixture comprising a saturated hydrocarbon and catalytically dehydrogenating the saturated hydrocarbon in the gas phase to obtain a gas mixture comprising an unsaturated hydrocarbon in a dehydrogenation reactor having a dehydrogenation catalyst material; or ii) providing a gas mixture comprising oxygen and an unsaturated hydrocarbon; iii) catalytically oxidizing the unsaturated hydrocarbon obtained in process step i) or provided in process step ii) in the gas phase to obtain a gas mixture comprising an unsaturated aldehyde in a first oxidation reactor having a first oxidation catalyst material; wherein at least one of the reactors selected from the dehydrogenation reactor, the first oxidation reactor and the second oxidation reactor comprises at least one foam body.
摘要:
Isobutene is prepared by dissociation of MTBE in the gas phase, by a) fractional distillation of an MTBE-containing stream comprising feed MTBE (I) and a recycle stream (VIII) to give an MTBE-containing overhead stream (II) and a bottom stream (III) having a boiling point higher than MTBE, b) catalytic dissociation of the overhead stream (II) obtained in step a) to give a dissociation product (IV), c) separation by distillation of the dissociation product (IV) obtained in step b) into an overhead stream (V) comprising more than 90% by mass of isobutene and a bottom stream (VI) comprising diisobutene, MTBE and more than 50% of the methanol present in the dissociation product (IV), d) fractional distillation of the bottom stream obtained in step c) under conditions under which the methanol is obtained as bottom product (VII) and more than 99% of the MTBE is obtained in the overhead product (VIII), and e) recirculation of the overhead product (VIII) to step a).
摘要:
The present invention refers to a catalyst for the manufacture of methyl mercaptan from carbon oxides comprising Mo and K compounds and oxides or sulfides of metals chosen from the manganese group. The improvement of the present process consists of the fact that carbon dioxide can be converted with higher conversions and selectivities to methyl mercaptan as compared to state-of-the-art technologies, with only minor amounts of carbon monoxide being formed as side product. Simultaneously, carbon monoxide can be easily converted into carbon dioxide and hydrogen by reaction with water using established water-gas-shift-technologies thus increasing the overall selectivity to methyl mercaptan.
摘要:
A continuous process for preparing an isoolefin having 4 to 6 carbon atoms is performed by cleaving a compound of the formula I R1—O—R2 (I) wherein R1=a tertiary alkyl radical having 4 to 6 carbon atoms, and R2=H or an alkyl radical, in a gas phase over a solid catalyst, in the temperature range of 200 to 400° C., at a pressure of 0.1 to 1.2 MPa, in a reactor which is equipped with a heating jacket and is heated with a liquid heat carrier, wherein the cleavage is carried out in such a way that a temperature drop in the catalyst zone at any point in relation to the entrance temperature is less than 50° C., wherein (i) a reaction mixture in the reactor and (ii) the heat carrier in the jacket flow through the reactor in cocurrent, and wherein a temperature difference of the heat carrier between a feed point to the reactor and an outlet from the reactor is adjusted to less than 40° C.