WO2006082215A2 - Catalyst system for catalytic gas phase reactions featuring an increasing catalyst activity in the direction of flow of the gas - Google Patents

Catalyst system for catalytic gas phase reactions featuring an increasing catalyst activity in the direction of flow of the gas Download PDF

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WO2006082215A2
WO2006082215A2 PCT/EP2006/050616 EP2006050616W WO2006082215A2 WO 2006082215 A2 WO2006082215 A2 WO 2006082215A2 EP 2006050616 W EP2006050616 W EP 2006050616W WO 2006082215 A2 WO2006082215 A2 WO 2006082215A2
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catalyst
catalyst system
gas phase
activity
gas
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German (de)
French (fr)
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WO2006082215A3 (en
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Ruprecht Meissner
Hans-Martin Allmann
Michael Hesse
Jürgen ZÜHLKE
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Basf Aktiengesellschaft
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/19—Catalysts containing parts with different compositions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/0015—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor
    • B01J8/003—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor in a downward flow
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
    • B01J8/06—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds in tube reactors; the solid particles being arranged in tubes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C17/00—Preparation of halogenated hydrocarbons
    • C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
    • C07C17/15—Preparation of halogenated hydrocarbons by replacement by halogens with oxygen as auxiliary reagent, e.g. oxychlorination
    • C07C17/152—Preparation of halogenated hydrocarbons by replacement by halogens with oxygen as auxiliary reagent, e.g. oxychlorination of hydrocarbons
    • C07C17/156—Preparation of halogenated hydrocarbons by replacement by halogens with oxygen as auxiliary reagent, e.g. oxychlorination of hydrocarbons of unsaturated hydrocarbons
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/002—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by dehydrogenation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
    • C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
    • C07C51/215—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of saturated hydrocarbyl groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
    • C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
    • C07C51/25—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of unsaturated compounds containing no six-membered aromatic ring
    • C07C51/252—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of unsaturated compounds containing no six-membered aromatic ring of propene, butenes, acrolein or methacrolein
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
    • C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
    • C07C51/255—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting
    • C07C51/265—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting having alkyl side chains which are oxidised to carboxyl groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
    • C07C51/31—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation of cyclic compounds with ring-splitting
    • C07C51/313—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation of cyclic compounds with ring-splitting with molecular oxygen
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00743—Feeding or discharging of solids
    • B01J2208/00752—Feeding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/02—Processes carried out in the presence of solid particles; Reactors therefor with stationary particles
    • B01J2208/023—Details
    • B01J2208/024—Particulate material
    • B01J2208/025—Two or more types of catalyst
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/002—Mixed oxides other than spinels, e.g. perovskite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/04—Mixing

Definitions

  • the present invention relates to catalyst systems for catalytic gas phase reactions, characterized in that the catalyst activity increases in the direction of flow of the gas, wherein the catalyst activity is controlled by mixtures of low active and highly active catalysts.
  • the invention furthermore relates to processes for the preparation of phthalic anhydride, ethylene dichloride, cyclohexanone, acrylic acid and maleic anhydride, the starting materials being reacted in the said catalyst system.
  • a variety of catalytic gas phase reactions are carried out in a fixed bed reactor.
  • a mixture of a gas containing molecular oxygen and the starting material to be oxidized is passed through a plurality of tubes arranged in a reactor, in which there is a bed of at least one catalyst.
  • the tubes are surrounded by a heat transfer medium, for example a molten salt.
  • a heat transfer medium for example a molten salt.
  • DE-A 25 46268 two-layer catalyst system
  • DE-A 198 23 262 three-layer catalyst system
  • DE-A 103 23 818 discloses an increase in activity due to an increasing BET surface area of the titanium dioxide used.
  • Activity-structured catalyst beds are used not only in the preparation of carboxylic acids or carboxylic anhydrides, but also, for example, in the gas-phase oxychlorination of ethylene to ethylene dichloride or in the dehydrogenation of cyclohexanol to cyclohexanone (K. Weissermel, H. -J. Arpe, Industrielle Organische Chemie, VCH Verlag Weinheim).
  • the number of activity levels is limited by the expense of catalyst preparation and catalyst filling. Despite a multi-layered catalyst system, pronounced hot spots can still form, which have a negative effect on the yield and accelerate the aging of the catalyst.
  • the object was therefore to find a catalyst system whose activity increases in the direction of flow of the catalyst, without a variety of different types of catalysts must be used.
  • the object was to show a simplified activity-structured catalyst system that has a continuous increase in activity.
  • the object was to show catalyst systems that have longer lifetimes compared to the prior art.
  • the object was to provide processes for the preparation of phthalic anhydride, ethylene dichloride, cyclohexanone, maleic anhydride and acrylic acid, which have a higher yield compared to the prior art. It has surprisingly been found that a catalyst system whose catalyst activity increases in the direction of flow of the gas, wherein the catalyst activity is controlled by mixtures of low active and highly active catalysts, can be used advantageously for exothermic and endothermic gas phase reaction.
  • Two different catalysts are particularly preferably used for controlling the activity, one of which (catalyst A) having a low activity and the other (catalyst B) having a high activity.
  • the catalyst A is highly selective.
  • the catalyst B is advantageously highly active and optionally less selective.
  • the activity of the catalysts A and B is adjusted such that mainly the catalyst A is present at the gas inlet of the catalyst bed and the catalyst B mainly at the gas outlet.
  • the different activity of the catalysts A and B can be adjusted by all measures known to the person skilled in the art. For example, different activity can be obtained by a different active mass content, by a different component composition in the active composition, by a different content of inert substances or by a different surface of a catalyst component.
  • a zone of higher activity can be arranged at the gas inlet in front of the point of lowest catalyst activity in order to facilitate the initiation of the reaction.
  • the increase in activity in the catalyst bed is advantageously carried out continuously. Consequently, the catalyst system according to the invention is no longer divided into individual zones of different activity, but has a continuous transition from areas of lower activity to areas of higher activity.
  • This continuous increase in activity is achieved by a continuous increase in the mixing ratio of catalyst A: B from 1: 0 to 0: 1.
  • the exact mixing ratios must be adapted to the respective reaction and the associated temperature profile. This optimization can be carried out by a person skilled in the art without any further effort, for example on the basis of the temperature profiles, by-product spectra or the total combustion CO-CO 2 analysis.
  • the catalyst system according to the invention is advantageously in a fixed bed reactor, in particular in a tube bundle reactor.
  • Tube bundle reactors are at Performing gas phase reactions known.
  • Typical tube bundle reactors have up to 40,000 individual tubes, the individual tubes usually having a diameter of 1 to 10 cm.
  • the filling of the tubes can advantageously be carried out so that from two storage containers (i) containing catalyst A and (ii) containing catalyst B continuously flow catalysts into a mixing tank.
  • the way in which mixing ratio the catalysts A and B are used, d. H. in what speed / amount the catalysts A and B are supplied to the mixing tank is controlled in dependence on the filling level. For example, if the gas inlet side is filled, mainly the catalyst A is supplied to the mixing tank. In the middle region of the catalyst beds, the catalysts are approximately in the same ratio, i. the mixing tank is typically filled with equal parts of catalyst A and B. If, however, the gas outlet side is filled, mainly the catalyst B is supplied to the mixing tank.
  • the mixing container is advantageously not a reservoir, but from there the catalysts pass directly, as described for example in US-A 4,402,643 or in the German application with the application number 102004012754.9, via a conveyor trough with drain funnel into the tubes.
  • the catalyst system according to the invention is particularly advantageous for exothermic gas-phase reactions, in particular for the preparation of phthalic anhydride, ethylene dichloride, acrylic acid, maleic anhydride or cyclohexanone.
  • the catalyst system according to the invention can also be used advantageously for endothermic reactions.
  • the invention further relates to a process for the production of phthalic anhydride by gas phase oxidation of xylene, naphthalene or mixtures thereof, wherein xylene, naphthalene or mixtures thereof and a gas containing molecular oxygen are reacted in the catalyst system of the invention.
  • the invention further relates to a process for the production of ethylene dichloride by gas phase oxychlorination of ethylene wherein ethylene is reacted with hydrochloric acid and air or oxygen to produce ethylene dichloride in the catalyst system of the invention.
  • the invention further relates to a process for the preparation of cyclohexanone by gas-phase dehydrogenation of cyclohexanol, wherein cyclohexanol is converted to cyclohexanone and hydrogen in the catalyst system according to the invention.
  • the invention further relates to a process for the preparation of maleic anhydride by benzene, butane or butene oxidation, wherein benzene, butane or butene and air or oxygen are converted to maleic anhydride in the catalyst system of the invention.
  • the invention further relates to a process for the preparation of acrylic acid by gas phase oxidation of propene and steam or air to acrolein in a first catalyst system and the further oxidation of acrolein in a second catalyst system to acrylic acid, wherein the first or the second or both catalyst systems according to the invention are designed.
  • one of the two prior art reactors may be equipped.
  • the high costs incurred by the preparation of many different catalysts and by the complicated filling of the individual catalyst layers, can be saved.
  • the lifetime of the catalyst system according to the invention is extended in comparison to catalyst systems from the prior art, since the hot spot in the catalyst system of the invention is distributed more uniformly over the entire catalyst bed.
  • catalytic gas phase reactions at lower, i. catalyst-sparing reaction temperatures are carried out as in the prior art.
  • the ability to carry out catalytic gas phase reactions at low reaction temperatures also has the advantage that fewer by-products are formed. Consequently, the catalyst system according to the invention is more selective and has a higher yield than the catalyst systems of the prior art.
  • the increase in the charge of the reactant stream in the catalyst system according to the invention can be carried out more rapidly than, for example, in a 2-layer catalyst system from the prior art.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
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  • Catalysts (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Abstract

The invention relates to catalyst systems for catalytic gas phase reactions which are characterized in that the catalyst activity increases in the direction of flow of the gas, the catalyst activity being controlled using mixtures of low activity and high activity catalysts. The invention further relates to methods for producing phthalic anhydride, ethylene dichloride, cyclohexanone, maleic anhydride, and acrylic acid.

Description

Katalysatorsystem für katalytische Gasphasenreaktionen mit einer in Flussrichtung des Gases zunehmenden KatalysatoraktivitätCatalyst system for catalytic gas phase reactions with an increasing catalyst activity in the direction of flow of the gas
Beschreibungdescription
Die vorliegende Erfindung betrifft Katalysatorsysteme für katalytische Gasphasenreaktionen, die dadurch gekennzeichnet sind, dass die Katalysatoraktivität in Flussrichtung des Gases zunimmt, wobei die Katalysatoraktivität durch Mischungen aus niedrig aktiven und hoch aktiven Katalysatoren gesteuert wird. Ferner betrifft die Erfindung Ver- fahren zur Herstellung von Phthalsäureanhydrid, Ethylendichlorid, Cyclohexanon, Ac- rylsäure und Maleinsäureanhydrid, wobei die Edukte in dem genannten Katalysatorsystem umgesetzt werden.The present invention relates to catalyst systems for catalytic gas phase reactions, characterized in that the catalyst activity increases in the direction of flow of the gas, wherein the catalyst activity is controlled by mixtures of low active and highly active catalysts. The invention furthermore relates to processes for the preparation of phthalic anhydride, ethylene dichloride, cyclohexanone, acrylic acid and maleic anhydride, the starting materials being reacted in the said catalyst system.
Bekanntermaßen wird eine Vielzahl von katalytischen Gasphasenreaktionen in einem Festbettreaktor durchgeführt. Dazu wird beispielsweise ein Gemisch aus einem molekularen Sauerstoff enthaltenden Gas und das zu oxidierende Ausgangsmaterial durch eine Vielzahl in einem Reaktor angeordneter Rohren geleitet, in denen sich eine Schüttung mindestens eines Katalysators befindet. Zur Temperaturregelung sind die Rohre von einem Wärmeträgermedium, beispielsweise einer Salzschmelze umgeben. Trotz dieser Thermostatisierung kann es in der Katalysatorschüttung zur Ausbildung sogenannter „hot spots" kommen, in denen eine höhere Temperatur herrscht als im übrigen Teil der Katalysatorschüttung. Diese hot spots geben Anlass zu Nebenreaktionen, wie beispielsweise der Totalverbrennung des Ausgangsmaterials oder führen zur Bildung schwer abtrennbarer Nebenprodukte. Ferner beschleunigen die hot spots die Alterung der Katalysatoren.As known, a variety of catalytic gas phase reactions are carried out in a fixed bed reactor. For this purpose, for example, a mixture of a gas containing molecular oxygen and the starting material to be oxidized is passed through a plurality of tubes arranged in a reactor, in which there is a bed of at least one catalyst. For temperature control, the tubes are surrounded by a heat transfer medium, for example a molten salt. Despite this thermostatting, so-called "hot spots" can occur in the catalyst bed, in which a higher temperature prevails than in the remaining part of the catalyst bed These hot spots give rise to side reactions, such as the total combustion of the starting material or lead to the formation of hard separable In addition, the hot spots accelerate the aging of the catalysts.
Zur Abschwächung dieser hot spots wurde in der Technik dazu übergegangen, unterschiedlich aktive Katalysatoren schichtweise in der Katalysatorschüttung anzuordnen, wobei sich in der Regel der weniger aktive Katalysator zum Gaseintritt hin befindet und folglich das Reaktionsgemisch zuerst mit ihm in Kontakt kommt, wohingegen sich der aktivere Katalysator zum Gasaustritt aus der Katalysatorschüttung hin befindet.In order to mitigate these hot spots has been adopted in the art to arrange different active catalysts in layers in the catalyst bed, which is usually the less active catalyst for gas inlet out and thus the reaction mixture first comes into contact with him, whereas the more active catalyst is located to the gas outlet from the catalyst bed out.
Die Art und Weise der Aktivitätsstrukturierung ist vielfältig. Nach dem unter anderem in der EP-A 1 063 222 auf dem Gebiet der Herstellung von Phthalsäureanhydrid zusam- mengefassten Stand der Technik kann die Aktivitätssteigerung auf sehr verschiedenen Wegen erfolgen:The way of structuring the activity is manifold. According to the state of the art summarized inter alia in EP-A 1 063 222 in the field of the preparation of phthalic anhydride, the increase in activity can be carried out in very different ways:
(1) durch stetigen Anstieg des Phosphor-, Vanadiumpentoxid- oder Antimonoxidgehalts, (2) durch stetigen Anstieg des Aktivmassengehalts,(1) by a steady increase in the phosphorus, vanadium pentoxide or antimony oxide content, (2) by a steady increase in the active mass content,
(3) durch stetige Abnahme des Alkaligehalts,(3) by steady decrease of the alkali content,
(4) durch stetige Abnahme des Leerraumes zwischen den einzelnen Katalysatoren,(4) by a steady decrease in the void space between the individual catalysts,
(5) durch stetige Abnahme des Gehalts an Inertstoffen, (6) durch stetige Zunahme der Temperatur oder(5) by steadily decreasing the content of inert materials, (6) by steady increase in temperature or
(7) durch stetige Zunahme der Titandioxid-Oberfläche(7) by continuous increase of titanium dioxide surface
von der Oberschicht (Reaktoreingang) zur Unterschicht (Reaktorausgang). Beispiel- weise seien hier DE-A 25 46268 (Zwei-Lagen-Katalysatorsystem) und DE-A 198 23 262 (Drei-Lagen-Katalysatorsystem) genannt. DE-A 103 23 818 offenbart eine Aktivitätssteigerung durch eine zunehmende BET-Oberfläche des eingesetzten Titandioxids.from the upper layer (reactor inlet) to the lower layer (reactor outlet). For example, DE-A 25 46268 (two-layer catalyst system) and DE-A 198 23 262 (three-layer catalyst system) may be mentioned here. DE-A 103 23 818 discloses an increase in activity due to an increasing BET surface area of the titanium dioxide used.
Aktivitätsstrukturierte Katalysatorschüttungen werden nicht nur bei der Herstellung von Carbonsäuren oder Carbonsäureanhydriden eingesetzt, sondern beispielsweise auch bei der Gasphasenoxychlorierung von Ethylen zu Ethylendichlorid oder bei der Dehydrierung von Cyclohexanol zu Cyclohexanon (K. Weissermel, H. -J. Arpe, Industrielle Organische Chemie, VCH Verlag Weinheim).Activity-structured catalyst beds are used not only in the preparation of carboxylic acids or carboxylic anhydrides, but also, for example, in the gas-phase oxychlorination of ethylene to ethylene dichloride or in the dehydrogenation of cyclohexanol to cyclohexanone (K. Weissermel, H. -J. Arpe, Industrielle Organische Chemie, VCH Verlag Weinheim).
Die Anzahl der Aktivitätsstufen ist durch den Aufwand der Katalysatorpräparation und des Katalysatorbefüllens limitiert. Trotz eines mehrlagigen Katalysatorsystems können sich immer noch ausgeprägte hot spots ausbilden, die sich negativ auf die Ausbeute auswirken und die Alterung des Katalysators beschleunigen.The number of activity levels is limited by the expense of catalyst preparation and catalyst filling. Despite a multi-layered catalyst system, pronounced hot spots can still form, which have a negative effect on the yield and accelerate the aging of the catalyst.
Um ein mehrlagiges Katalysatorsystem zu befüllen, wurde in der Technik dazu übergegangen, das manuelle Befüllen, in dem über ein Trichter in jedes einzelne Rohr eine abgemessene Menge Katalysatormaterial eingefüllt wurde, durch automatisches Befüllen zu ersetzen. Eine automatische Befüllung von Rohren mit Katalysatoren ist beispielsweise aus der US-A 4 402 643 bekannt. Dieses Dokument beschreibt ein auf Rollen verfahrbares Rahmengestell mit sich in Granulataustragungsrichtung verjüngenden Behältern. Aus diesem gelangt das Schüttgut in einen mittels einer Vibrationseinheit rüttelbaren Trog, der in nebeneinander liegenden Längsrinnen unterteilt ist. An der Seite des Trogs sind Anschlusselemente vorgesehen, an denen flexible Schläuche befestigt sind, über welche das Schüttgut den Rohrbündelreaktoren zugeführt werden kann.In order to fill a multilayer catalyst system, it has been adopted in the art to replace the manual filling in which a metered amount of catalyst material was introduced into each individual tube via a funnel by means of automatic filling. Automatic filling of tubes with catalysts is known, for example, from US Pat. No. 4,402,643. This document describes a rolling on frame frame with tapering in Granulataustragungsrichtung containers. For this, the bulk material passes into a vibratable by means of a vibration unit trough, which is divided into adjacent longitudinal channels. On the side of the trough connection elements are provided, to which flexible hoses are attached, via which the bulk material can be supplied to the tube bundle reactors.
Die Aufgabe bestand demnach darin, ein Katalysatorsystem aufzufinden, dessen Aktivität in Flussrichtung des Katalysators zunimmt, ohne dass eine Vielzahl von verschiedenen Katalysatortypen eingesetzt werden muss. Insbesondere bestand die Aufgabe darin, ein vereinfachtes aktivitätsstrukturiertes Katalysatorsystem aufzuzeigen, dass eine kontinuierliche Aktivitätssteigerung aufweist. Ferner bestand die Aufgabe darin, Katalysatorsysteme aufzuzeigen, die im Vergleich zum Stand der Technik längere Lebenszeiten aufweisen. Darüber hinaus bestand die Aufgabe darin, Verfahren zur Herstellung von Phthalsäureanhydrid, Ethylendichlorid, Cyclohexanon, Maleinsäurean- hydrid und Acrγlsäure aufzuzeigen, die eine höhere Ausbeute im Vergleich zum Stand der Technik aufweisen. Es wurde überraschender Weise gefunden, dass sich ein Katalysatorsystem dessen Katalysatoraktivität in Flussrichtung des Gases zunimmt, wobei die Katalysatoraktivität durch Mischungen aus niedrig aktiven und hoch aktiven Katalysatoren gesteuert wird, vorteilhaft für exotherme und endotherme Gasphasenreaktion einsetzen lässt.The object was therefore to find a catalyst system whose activity increases in the direction of flow of the catalyst, without a variety of different types of catalysts must be used. In particular, the object was to show a simplified activity-structured catalyst system that has a continuous increase in activity. Furthermore, the object was to show catalyst systems that have longer lifetimes compared to the prior art. In addition, the object was to provide processes for the preparation of phthalic anhydride, ethylene dichloride, cyclohexanone, maleic anhydride and acrylic acid, which have a higher yield compared to the prior art. It has surprisingly been found that a catalyst system whose catalyst activity increases in the direction of flow of the gas, wherein the catalyst activity is controlled by mixtures of low active and highly active catalysts, can be used advantageously for exothermic and endothermic gas phase reaction.
Zur Steuerung der Katalysatoraktivität werden vorteilhaft weniger als vier verschiedene Katalysatoren eingesetzt. Besonders bevorzugt werden zur Steuerung der Aktivität zwei verschiedenen Katalysatoren eingesetzt, wobei der eine davon (Katalysator A) eine niedrige Aktivität und der andere (Katalysator B) eine hohe Aktivität aufweist.To control the catalyst activity less than four different catalysts are advantageously used. Two different catalysts are particularly preferably used for controlling the activity, one of which (catalyst A) having a low activity and the other (catalyst B) having a high activity.
Vorteilhaft ist der Katalysator A hoch-selektiv. Der Katalysator B ist vorteilhaft hochaktiv und gegebenenfalls weniger selektiv.Advantageously, the catalyst A is highly selective. The catalyst B is advantageously highly active and optionally less selective.
Vorteilhaft wird die Aktivität der Katalysatoren A und B so eingestellt, dass am Gasein- tritt der Katalysatorschüttung hauptsächlich der Katalysator A und am Gasaustritt hauptsächlich der Katalysator B vorliegt.Advantageously, the activity of the catalysts A and B is adjusted such that mainly the catalyst A is present at the gas inlet of the catalyst bed and the catalyst B mainly at the gas outlet.
Die unterschiedliche Aktivität der Katalysatoren A und B kann nach allen den Fachmann bekannten Maßnahmen eingestellt werden. Beispielsweise kann unterschiedli- che Aktivität durch einen unterschiedlichen Aktivmassengehalt, durch eine unterschiedliche Komponentenzusammensetzung in der Aktivmasse, durch einen unterschiedlichen Gehalt an Inertstoffen oder durch eine unterschiedliche Oberfläche einer Katalysatorkomponente erhalten werden.The different activity of the catalysts A and B can be adjusted by all measures known to the person skilled in the art. For example, different activity can be obtained by a different active mass content, by a different component composition in the active composition, by a different content of inert substances or by a different surface of a catalyst component.
Gegebenenfalls kann am Gaseintritt vor der Stelle der geringsten Katalysatoraktivität eine Zone höherer Aktivität angeordnet sein, um das Anspringen der Reaktion zu herleichtern.Optionally, a zone of higher activity can be arranged at the gas inlet in front of the point of lowest catalyst activity in order to facilitate the initiation of the reaction.
Die Aktivitätssteigerung in der Katalysatorschüttung erfolgt vorteilhaft kontinuierlich. Folglich ist das erfindungsgemäße Katalysatorensystem nicht mehr in einzelne Zonen unterschiedlicher Aktivität aufgeteilt, sondern weist einen kontinuierlichen Übergang von Bereichen geringerer Aktivität zu Bereichen höherer Aktivität auf.The increase in activity in the catalyst bed is advantageously carried out continuously. Consequently, the catalyst system according to the invention is no longer divided into individual zones of different activity, but has a continuous transition from areas of lower activity to areas of higher activity.
Diese kontinuierliche Aktivitätssteigerung ist durch einen kontinuierlichen Anstieg des Mischungsverhältnisses von Katalysator A: B von 1 :0 bis 0:1 zu erreichen. Die genauen Mischungsverhältnisse sind an die jeweilige Reaktion und den dazugehörigen Temperaturverlauf anzupassen. Diese Optimierung kann vom Fachmann ohne weiteren Aufwand beispielsweise anhand der Temperaturprofile, Nebenproduktspektren oder der Totalverbrennungs-CO-CO2-Analyse durchgeführt werden.This continuous increase in activity is achieved by a continuous increase in the mixing ratio of catalyst A: B from 1: 0 to 0: 1. The exact mixing ratios must be adapted to the respective reaction and the associated temperature profile. This optimization can be carried out by a person skilled in the art without any further effort, for example on the basis of the temperature profiles, by-product spectra or the total combustion CO-CO 2 analysis.
Das erfindungsgemäße Katalysatorsystem befindet sich vorteilhaft in einem Festbettreaktor, insbesondere in einem Rohrbündelreaktor. Rohrbündelreaktoren sind bei der Durchführung von Gasphasenreaktionen bekannt. Typische Rohrbündelreaktoren weisen bis zu 40 000 einzelne Rohre auf, wobei die einzelnen Rohre in der Regel einen Durchmesser von 1 bis 10 cm aufweisen.The catalyst system according to the invention is advantageously in a fixed bed reactor, in particular in a tube bundle reactor. Tube bundle reactors are at Performing gas phase reactions known. Typical tube bundle reactors have up to 40,000 individual tubes, the individual tubes usually having a diameter of 1 to 10 cm.
Die Befüllen der Rohre kann vorteilhaft so erfolgen, dass aus zwei Vorratsbehältern (i) beinhaltend Katalysator A und (ii) beinhaltend Katalysator B kontinuierlich Katalysatoren in einen Mischungsbehälter fließen. Die Art und Weise, in welchem Mischungsverhältnis die Katalysatoren A und B verwendet werden, d. h. in welcher Geschwindigkeit/Menge die Katalysatoren A und B dem Mischungsbehälter zugeführt werden, wird in Abhängigkeit von der Füllhöhe gesteuert. Wird beispielsweise die Gaseintrittsseite befüllt, wird hauptsächlich der Katalysator A dem Mischungsbehälter zugeführt. Im mittleren Bereich der Katalysatorschüttungen liegen die Katalysatoren ungefähr im selben Verhältnis vor, d.h. der Mischungsbehälter wird typischerweise mit gleichen Teilen Katalysator A und B gefüllt. Wird hingegen die Gasaustrittsseite befüllt, wird hauptsächlich der Katalysator B dem Mischungsbehälter zugeführt. Der Mischungsbehälter ist vorteilhaft kein Vorratsbehälter, sondern aus ihm gelangen die Katalysatoren direkt, wie beispielsweise in der US-A 4,402,643 oder in der deutschen Anmeldung mit dem Anmel- de-Aktenzeichen 102004012754.9 beschrieben, über eine Förderrinne mit Ablauftrichter in die Rohre.The filling of the tubes can advantageously be carried out so that from two storage containers (i) containing catalyst A and (ii) containing catalyst B continuously flow catalysts into a mixing tank. The way in which mixing ratio the catalysts A and B are used, d. H. in what speed / amount the catalysts A and B are supplied to the mixing tank is controlled in dependence on the filling level. For example, if the gas inlet side is filled, mainly the catalyst A is supplied to the mixing tank. In the middle region of the catalyst beds, the catalysts are approximately in the same ratio, i. the mixing tank is typically filled with equal parts of catalyst A and B. If, however, the gas outlet side is filled, mainly the catalyst B is supplied to the mixing tank. The mixing container is advantageously not a reservoir, but from there the catalysts pass directly, as described for example in US-A 4,402,643 or in the German application with the application number 102004012754.9, via a conveyor trough with drain funnel into the tubes.
Besonders vorteilhaft ist das erfindungsgemäße Katalysatorsystem für exotherme Gasphasenreaktionen, insbesondere zur Herstellung von Phthalsäureanhydrid, Ethy- lendichlorid, Acrylsäure, Maleinsäureanhydrid oder Cyclohexanon.The catalyst system according to the invention is particularly advantageous for exothermic gas-phase reactions, in particular for the preparation of phthalic anhydride, ethylene dichloride, acrylic acid, maleic anhydride or cyclohexanone.
Allerdings lässt sich das erfindungsgemäße Katalysatorsystem auch für endotherme Reaktionen vorteilhaft einsetzen.However, the catalyst system according to the invention can also be used advantageously for endothermic reactions.
Die Erfindung betrifft ferner ein Verfahren zur Herstellung von Phthalsäureanhydrid durch Gasphasenoxidation von XyIoI, Naphthalin oder Gemischen davon, wobei XyIoI, Naphthalin oder Gemische davon und ein molekularen Sauerstoff enthaltendes Gas in dem erfindungsgemäßen Katalysatorsystem umgesetzt werden.The invention further relates to a process for the production of phthalic anhydride by gas phase oxidation of xylene, naphthalene or mixtures thereof, wherein xylene, naphthalene or mixtures thereof and a gas containing molecular oxygen are reacted in the catalyst system of the invention.
Die Erfindung betrifft ferner ein Verfahren zur Herstellung von Ethylendichlorid durch Gasphasen-Oxychlorierung von Ethylen, wobei Ethylen mit Salzsäure und Luft oder Sauerstoff zu Ethylendichlorid in dem erfindungsgemäßen Katalysatorsystem umgesetzt werden.The invention further relates to a process for the production of ethylene dichloride by gas phase oxychlorination of ethylene wherein ethylene is reacted with hydrochloric acid and air or oxygen to produce ethylene dichloride in the catalyst system of the invention.
Die Erfindung betrifft ferner ein Verfahren zur Herstellung von Cyclohexanon durch Gasphasen-Dehydrierung von Cyclohexanol, wobei Cyclohexanol zu Cyclohexanon und Wasserstoff in dem erfindungsgemäßen Katalysatorsystem umgesetzt wird. Die Erfindung betrifft ferner ein Verfahren zur Herstellung von Maleinsäureanhydrid durch Benzol-, Butan- oder Butenoxidation, wobei Benzol, Butan oder Buten und Luft bzw. Sauerstoff zu Maleinsäureanhydrid in dem erfindungsgemäßen Katalysatorsystem umgesetzt werden.The invention further relates to a process for the preparation of cyclohexanone by gas-phase dehydrogenation of cyclohexanol, wherein cyclohexanol is converted to cyclohexanone and hydrogen in the catalyst system according to the invention. The invention further relates to a process for the preparation of maleic anhydride by benzene, butane or butene oxidation, wherein benzene, butane or butene and air or oxygen are converted to maleic anhydride in the catalyst system of the invention.
Die Erfindung betrifft ferner ein Verfahren zur Herstellung von Acrylsäure durch Gas- phasenoxidation von Propen und Dampf oder Luft zu Acrolein in einem ersten Katalysatorsystem und die Weiteroxidation von Acrolein in einem zweiten Katalysatorsystem zu Acrylsäure, wobei das erste oder das zweite oder beide Katalysatorsysteme erfin- dungsgemäß ausgelegt sind. Gegebenenfalls kann einer der zwei Reaktoren nach dem Stand der Technik ausgestattet sein.The invention further relates to a process for the preparation of acrylic acid by gas phase oxidation of propene and steam or air to acrolein in a first catalyst system and the further oxidation of acrolein in a second catalyst system to acrylic acid, wherein the first or the second or both catalyst systems according to the invention are designed. Optionally, one of the two prior art reactors may be equipped.
Durch den Einsatz des erfindungsgemäßen Katalysatorsystems können die hohen Kosten, die durch die Präparation vieler verschiedener Katalysatoren und durch das aufwendige Befüllen der einzelnen Katalysatorlagen anfallen, eingespart werden.By using the catalyst system according to the invention, the high costs incurred by the preparation of many different catalysts and by the complicated filling of the individual catalyst layers, can be saved.
Ferner verlängert sich die Lebenszeit des erfindungsgemäßen Katalysatorsystems im Vergleich zu Katalysatorsystemen aus dem Stand der Technik, da sich der hot spot im erfindungsgemäßen Katalysatorsystem gleichmäßiger über das gesamte Katalysator- bett verteilt. Somit können katalytische Gasphasenreaktionen bei niedrigeren, d.h. ka- talysator-schonenden Reaktionstemperaturen durchgeführt werden als im Stand der Technik. Die Möglichkeit, katalytische Gasphasenreaktionen bei niedrigen Reaktionstemperaturen durchzuführen, bringt darüber hinaus den Vorteil, dass weniger Nebenprodukte gebildet werden. Folglich ist das erfindungsgemäße Katalysatorsystem selek- tiver und weist eine höhere Ausbeute auf als die Katalysatorsysteme aus dem Stand der Technik.Furthermore, the lifetime of the catalyst system according to the invention is extended in comparison to catalyst systems from the prior art, since the hot spot in the catalyst system of the invention is distributed more uniformly over the entire catalyst bed. Thus, catalytic gas phase reactions at lower, i. catalyst-sparing reaction temperatures are carried out as in the prior art. The ability to carry out catalytic gas phase reactions at low reaction temperatures also has the advantage that fewer by-products are formed. Consequently, the catalyst system according to the invention is more selective and has a higher yield than the catalyst systems of the prior art.
Weiterhin kann die Erhöhung der Beladung des Eduktstroms im erfindungsgemäßen Katalysatorsystem schneller durchgeführt werden als beispielsweise in einem 2-Lagen Katalysatorsystem aus dem Stand der Technik. Dies hat den Vorteil, dass das erfindungsgemäße Katalysatorsystem die volle Produktionskapazität in weniger als der halben Zeit erreicht wie genanntes 2-Lagen Katalysatorsystem aus dem Stand der Technik. Furthermore, the increase in the charge of the reactant stream in the catalyst system according to the invention can be carried out more rapidly than, for example, in a 2-layer catalyst system from the prior art. This has the advantage that the catalyst system according to the invention achieves the full production capacity in less than half the time, as mentioned in the prior art 2-layer catalyst system.

Claims

Patentansprüche claims
1. Katalysatorsystem für katalytische Gasphasenreaktionen, dadurch gekennzeichnet, dass die Katalysatoraktivität in Flussrichtung des Gases zunimmt, wobei die Katalysatoraktivität durch Mischungen aus niedrig aktiven und hoch aktiven Katalysatoren gesteuert wird.A catalyst system for catalytic gas phase reactions, characterized in that the catalyst activity increases in the direction of flow of the gas, wherein the catalyst activity is controlled by mixtures of low active and highly active catalysts.
2. Katalysatorsystem nach Anspruch 1 , dadurch gekennzeichnet, dass die Katalysatoraktivität kontinuierlich in Flussrichtung des Gases zunimmt.2. Catalyst system according to claim 1, characterized in that the catalyst activity increases continuously in the direction of flow of the gas.
3. Katalysatorsystem nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Katalysatoraktivität mit einem niedrig aktiven und mit einem hoch aktiven Katalysator gesteuert wird.3. Catalyst system according to claim 1 or 2, characterized in that the catalyst activity is controlled with a low active and with a highly active catalyst.
4. Katalysatorsystem nach den Ansprüchen 1 bis 3, dadurch gekennzeichnet, dass die katalytische Gasphasenreaktion in einem Festbettreaktor durchgeführt wird.4. Catalyst system according to claims 1 to 3, characterized in that the catalytic gas phase reaction is carried out in a fixed bed reactor.
5. Verfahren zur Herstellung von Phthalsäureanhydrid durch Gasphasenoxidation von XyIoI, Naphthalin oder Gemischen davon, dadurch gekennzeichnet, dass Xy- lol, Naphthalin oder Gemische davon und ein molekularen Sauerstoff enthaltendes Gas in einem Katalysatorsystem nach den Ansprüchen 1 bis 4 umgesetzt werden.5. A process for the preparation of phthalic anhydride by gas phase oxidation of xylene, naphthalene or mixtures thereof, characterized in that xylol, naphthalene or mixtures thereof and a molecular oxygen-containing gas are reacted in a catalyst system according to claims 1 to 4.
6. Verfahren zur Herstellung von Ethylendichlorid durch Gasphasen-Oxychlorierung von Ethylen, dadurch gekennzeichnet, dass Ethylen mit Salzsäure und Luft oder6. A process for the preparation of ethylene dichloride by gas phase oxychlorination of ethylene, characterized in that ethylene with hydrochloric acid and air or
Sauerstoff in einem Katalysatorsystem nach den Ansprüchen 1 bis 4 umgesetzt werden.Oxygen in a catalyst system according to claims 1 to 4 implemented.
7. Verfahren zur Herstellung von Cyclohexanon durch Gasphasen-Dehydrierung von Cyclohexanol, dadurch gekennzeichnet, dass Cyclohexanol zu Cyclohexanon und Wasserstoff in einem Katalysatorsystem nach den Ansprüchen 1 bis 4 umgesetzt wird.7. A process for the preparation of cyclohexanone by gas phase dehydrogenation of cyclohexanol, characterized in that cyclohexanol is converted to cyclohexanone and hydrogen in a catalyst system according to claims 1 to 4.
8. Verfahren zur Herstellung von Maleinsäureanhydrid durch Gasphasenoxidation von Benzol, Butan oder Buten, dadurch gekennzeichnet, dass Benzol, Butan o- der Buten und Luft bzw. Sauerstoff in einem Katalysatorsystem nach den Ansprüchen 1 bis 4 umgesetzt werden.8. A process for the preparation of maleic anhydride by gas phase oxidation of benzene, butane or butene, characterized in that benzene, butane or butene o and air or oxygen are reacted in a catalyst system according to claims 1 to 4.
9. Verfahren zur Herstellung von Acrylsäure durch Gasphasenoxidation von Pro- pen, dadurch gekennzeichnet, dass Propen und Dampf oder Luft zu Acrolein in einem ersten Katalysatorsystem umgesetzt werden und die Weiteroxidation von Acrolein in einem zweiten Katalysatorsystem durchgeführt wird, wobei das erste oder das zweite oder beide Katalysatorsysteme nach den Ansprüchen 1 bis 4 ausgelegt sind. 9. A process for the preparation of acrylic acid by gas phase oxidation of propene, characterized in that propene and steam or air are converted to acrolein in a first catalyst system and the further oxidation of acrolein is carried out in a second catalyst system, wherein the first or the second or both catalyst systems according to claims 1 to 4 are designed.
PCT/EP2006/050616 2005-02-02 2006-02-02 Catalyst system for catalytic gas phase reactions featuring an increasing catalyst activity in the direction of flow of the gas WO2006082215A2 (en)

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