WO2007082790A1 - Process for regenerating a dehydrogenation catalyst - Google Patents
Process for regenerating a dehydrogenation catalyst Download PDFInfo
- Publication number
- WO2007082790A1 WO2007082790A1 PCT/EP2007/050061 EP2007050061W WO2007082790A1 WO 2007082790 A1 WO2007082790 A1 WO 2007082790A1 EP 2007050061 W EP2007050061 W EP 2007050061W WO 2007082790 A1 WO2007082790 A1 WO 2007082790A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- catalyst
- dehydrogenation
- regeneration
- temperature
- reactor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- 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
- B01J38/00—Regeneration or reactivation of catalysts, in general
- B01J38/04—Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst
- B01J38/12—Treating with free oxygen-containing gas
- B01J38/14—Treating with free oxygen-containing gas with control of oxygen content in oxidation gas
-
- 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
- B01J23/90—Regeneration or reactivation
- B01J23/92—Regeneration or reactivation of catalysts comprising metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
-
- 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
- B01J23/06—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of zinc, cadmium or mercury
-
- 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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/20—Carbon compounds
- B01J27/232—Carbonates
-
- 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
Definitions
- the present invention relates to a process for the regeneration of a catalyst for the dehydrogenation of secondary cyclic alcohols.
- DE-A 1 443,462 discloses a process for the dehydrogenation of primary and secondary alcohols in which the alcohol used is dehydrogenated at elevated temperature in the gas phase over catalysts predominantly consisting of zinc oxide to give the corresponding aldehyde or ketone.
- the catalyst may contain both copper compounds and alkaline earths.
- the dehydrogenation of cyclohexanol to cyclohexanone is described.
- DE-AS 1,296,625 describes a process for preparing cyclohexanone from cyclohexanol contaminated with organic acids and esters at elevated temperatures in the presence of a zinc-containing catalyst consisting of zinc oxide-zinc carbonate or mixtures of zinc oxide-zinc carbonate with calcium oxide-calcium carbonate or with magnesium oxide magnesium carbonate.
- EP 0 888 273 B1 describes a process for the dehydrogenation of secondary alcohols, in particular of cyclohexanol in the presence of a catalyst containing zinc oxide and calcium carbonate, at elevated temperature in the gas phase.
- No. 6,376,422 discloses a catalyst for the dehydrogenation of cyclohexanol to cyclohexanone which, in addition to zinc oxide and calcium carbonate or calcium oxide, also contains chromium (III) oxide.
- Cyclohexanone an important intermediate for the production of caprolactam, is prepared, inter alia, from a cyclohexanol / cyclohexanone mixture in a gas phase dehydrogenation on a fixed bed catalyst.
- This reaction is carried out for example in a tube bundle reactor at about 300 to 400 ° C, wherein the liquid cyclohexanol / cyclohexanone mixture is evaporated in a preheater and then passed through the heated catalyst bed. The reaction mixture is cooled and condensed after leaving the reactor. In a multi-stage distillation then heavy and low boilers are separated. In this way, the major portion of the cyclohexanone is separated from the product stream.
- the incompletely separated cyclohexanol is subsequently combined with the feed stream comprising cyclohexanol / cyclohexanone and fed back into the dehydrogenation stage.
- the feed stream may contain impurities that are not completely separated in the distillation. These impurities can be up to 20% of the feed stream and are circulated through the poor separation.
- This object has been achieved by a process for the regeneration of a catalyst for the dehydrogenation of secondary cyclic alcohols, characterized in that the catalyst at a temperature in the range of 350 ° C to 420 ° C with a gas stream, the 0.1 to 5 vol. - Contains% oxygen in contact.
- secondary cyclic alcohols are meant cycloaliphatic alcohols having 5 to 16 carbon atoms such as cyclopentanol, cyclohexanol, 4-methylcyclohexanol, cyclooctanol, cyclododecanol and cyclohexadecanol, preferably cyclohexanol.
- the regeneration process according to the invention is particularly suitable for zinc oxide-containing catalysts.
- These include u.a. also catalysts containing zinc oxide zinc carbonate or mixtures of zinc oxide zinc carbonate with calcium oxide calcium carbonate or magnesium oxide magnesium carbonate.
- Preference is given to those dehydrogenation catalysts which contain zinc oxide and calcium carbonate.
- Particular preference is given to catalysts whose active components contain from 30 to 60, preferably from 40 to 50,% by weight of zinc oxide and from 40 to 70, preferably from 50 to 60,% by weight of calcium carbonate, very particularly preferably such dehydrogenation catalysts as calcium carbonate contained in the calcite modification.
- the catalysts may also be 0.2 to
- chromium (III) oxide preferably 1, 5 to 20 wt .-%, particularly preferably 2.5 to 15 wt .-% chromium (III) oxide.
- the gas stream used for the regeneration of the dehydrogenation catalyst contains less than 10% by volume, preferably less than 5% by volume, particularly preferably less than 2% by volume, of steam.
- the regeneration process according to the invention is characterized in that the regeneration of the catalyst can take place in the same fixed bed reactor as the dehydrogenation itself, preferably in a tube bundle reactor.
- a particularly preferred embodiment of the method is characterized in that the regeneration takes place in two stages, wherein the catalyst in the first stage i) as long as with an air-nitrogen mixture having an oxygen content of 0.1 to 1, 0 vol .-% , preferably 0.4 to 0.6 vol .-% at a temperature in the range of 350 ° C to 400 ° C, preferably in the range of 380 ° C to 400 ° C is brought into contact until no more volatile condensable organic compounds can be detected and then in the second stage ii) with an air-nitrogen mixture having an oxygen content of 1 to 5 vol .-% at a temperature in the range of 405 ° C to 420 ° C, preferably at a temperature in the range from 410 ° C to 415 ° C is brought into contact until the oxygen content in the gas stream at the reactor outlet is as large as at the reactor inlet.
- the catalyst in the tube bundle reactor is brought to a temperature of 390.degree. C. by means of an accompanying heating (gas or salt bath). Subsequently, hot nitrogen is passed over the catalyst.
- air is metered in, so that the oxygen content is about 0.5% by volume. This value is kept constant until no more volatile, condensable organic compounds are found in the condensation tank. After that, the actual burnup reaction sets in. This increases the
- the Oxygen content and the CO 2 content in the exhaust gas determined. After a temperature wave has completely migrated through the reactor (about 20 h with strong coking), the oxygen concentration can be slowly increased to 5 vol .-% in 1 vol .-% steps. It should be noted, however, that the temperature in the reactor does not rise above 20 ° C. The regeneration is finished (usually after 36h) when the oxygen content in the outlet is exactly the same as in the inlet.
- the forehead compressive strength of the regenerated tablets is preferably 500 to 4000 N / cm 2 , especially 1000 to 2500 N / cm 2 and the lateral compressive strength is preferably between 5 and 20 N, preferably 10 to 15 N.
- Temperature 1 regeneration temperature [° C.] temperature 2: dehydrogenated temperature [° C.] conversion 1: conversion achieved with catalyst deactivated [%] conversion 2: conversion achieved with regenerated catalyst [%] * ) duration of regeneration [h]
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
Verfahren zur Regenerierung eines DehydrierkatalysatorsProcess for the regeneration of a dehydrogenation catalyst
Beschreibungdescription
Die vorliegende Erfindung betrifft ein Verfahren zur Regenerierung eines Katalysators zur Dehydrierung von sekundären cyclischen Alkoholen.The present invention relates to a process for the regeneration of a catalyst for the dehydrogenation of secondary cyclic alcohols.
Es ist bekannt, dass sekundäre Alkohole bei erhöhter Temperatur in der Gasphase an Katalysatoren zu Aldehyden oder Ketonen dehydriert werden können.It is known that secondary alcohols can be dehydrogenated at elevated temperature in the gas phase over catalysts to give aldehydes or ketones.
So ist in der DE-A 1 ,443,462 ein Verfahren zur Dehydrierung von primären und sekundären Alkoholen offenbart, in dem der eingesetzte Alkohol bei erhöhter Temperatur in der Gasphase an vorwiegend aus Zinkoxid bestehenden Katalysatoren zum entsprechenden Aldehyd bzw. Keton dehydriert wird. Der Katalysator kann sowohl Kupferverbindungen als auch Erdalkalien enthalten. Insbesondere wird die Dehydrierung von Cyclohexanol zu Cyclohexanon beschrieben.For example, DE-A 1 443,462 discloses a process for the dehydrogenation of primary and secondary alcohols in which the alcohol used is dehydrogenated at elevated temperature in the gas phase over catalysts predominantly consisting of zinc oxide to give the corresponding aldehyde or ketone. The catalyst may contain both copper compounds and alkaline earths. In particular, the dehydrogenation of cyclohexanol to cyclohexanone is described.
DE-AS 1 ,296,625 beschreibt ein Verfahren zur Herstellung von Cyclohexanon aus mit organischen Säuren und Estern verunreinigtem Cyclohexanol bei erhöhten Temperatu- ren in Gegenwart eines zinkhaltigen Katalysators, bestehend aus Zinkoxid-Zinkcarbo- nat oder Mischungen von Zinkoxid-Zinkcarbonat mit Calciumoxid-Calciumcarbonat oder mit Magnesiumoxid-Magnesiumcarbonat.DE-AS 1,296,625 describes a process for preparing cyclohexanone from cyclohexanol contaminated with organic acids and esters at elevated temperatures in the presence of a zinc-containing catalyst consisting of zinc oxide-zinc carbonate or mixtures of zinc oxide-zinc carbonate with calcium oxide-calcium carbonate or with magnesium oxide magnesium carbonate.
EP 0 888 273 B1 beschreibt ein Verfahren zur Dehydrierung von sekundären Alkoho- len, insbesondere von Cyclohexanol in Gegenwart eines Katalysators, enthaltend Zinkoxid und Calciumcarbonat, bei erhöhter Temperatur in der Gasphase.EP 0 888 273 B1 describes a process for the dehydrogenation of secondary alcohols, in particular of cyclohexanol in the presence of a catalyst containing zinc oxide and calcium carbonate, at elevated temperature in the gas phase.
Aus US 6,376,422 ist ein Katalysator zur Dehydrierung von Cyclohexanol zu Cyclohexanon bekannt, der neben Zinkoxid und Calciumcarbonat oder Calciumoxid noch Chrom(lll)oxid enthält.No. 6,376,422 discloses a catalyst for the dehydrogenation of cyclohexanol to cyclohexanone which, in addition to zinc oxide and calcium carbonate or calcium oxide, also contains chromium (III) oxide.
Cyclohexanon, ein wichtiges Zwischenprodukt für die Herstellung von Caprolactam, wird u.a. aus einem Cyclohexanol/Cyclohexanon-Gemisch in einer Gasphasendehydrierung an einem Festbettkatalysator hergestellt. Diese Reaktion wird beispielsweise in einem Rohrbündelreaktor bei ca. 300 bis 400°C durchgeführt, wobei das flüssige Cyclohexanol/Cyclohexanon Gemisch in einem Vorheizer verdampft wird und anschließend durch das beheizte Katalysatorbett geleitet wird. Das Reaktionsgemisch wird nach Austritt aus dem Reaktor gekühlt und kondensiert. In einer mehrstufigen Destillation werden dann Schwer- und Leichtsieder abgetrennt. Auf diese Weise wird auch der Hauptanteil des Cyclohexanons vom Produktstrom abgetrennt. Das nicht vollständig abgetrennte Cyclohexanol wird anschließend mit dem Cyclohe- xanol/Cyclohexanon enthaltenden Feedstrom vereinigt und wieder der Dehydrierstufe zugeführt. Je nach Prozessdesign kann der Feedstrom Verunreinigungen enthalten, die nicht vollständig in der Destillation abgetrennt werden. Diese Verunreinigungen können bis zu 20 % des Feedstroms betragen und werden durch die schlechte Abtrennung im Kreis gefahren.Cyclohexanone, an important intermediate for the production of caprolactam, is prepared, inter alia, from a cyclohexanol / cyclohexanone mixture in a gas phase dehydrogenation on a fixed bed catalyst. This reaction is carried out for example in a tube bundle reactor at about 300 to 400 ° C, wherein the liquid cyclohexanol / cyclohexanone mixture is evaporated in a preheater and then passed through the heated catalyst bed. The reaction mixture is cooled and condensed after leaving the reactor. In a multi-stage distillation then heavy and low boilers are separated. In this way, the major portion of the cyclohexanone is separated from the product stream. The incompletely separated cyclohexanol is subsequently combined with the feed stream comprising cyclohexanol / cyclohexanone and fed back into the dehydrogenation stage. Depending on the process design, the feed stream may contain impurities that are not completely separated in the distillation. These impurities can be up to 20% of the feed stream and are circulated through the poor separation.
Aufgrund der hohen Temperaturen bei der Dehydrierung können diese Verunreinigungen auf dem aktiven Dehydrierkatalysator zu einer Verkokung und damit zu einer Deaktivierung des Katalysators führen.Due to the high temperatures in the dehydrogenation, these impurities on the active dehydrogenation catalyst can lead to coking and thus to deactivation of the catalyst.
Es war daher die Aufgabe der vorliegenden Erfindung, ein Verfahren bereitzustellen, dass es ermöglicht, den Katalysator möglichst schnell und wirkungsvoll von dem entstehenden Kohlenstoff zu befreien und zu reaktivieren.It was therefore the object of the present invention to provide a process which makes it possible to liberate and reactivate the catalyst as quickly and effectively as possible from the carbon formed.
Diese Aufgabe wurde gelöst durch ein Verfahren zur Regenerierung eines Katalysators zur Dehydrierung von sekundären cyclischen Alkoholen, dadurch gekennzeichnet, dass man den Katalysator bei einer Temperatur im Bereich von 350°C bis 420°C mit einem Gasstrom, der 0,1 bis 5 Vol.-% Sauerstoff enthält in Kontakt bringt.This object has been achieved by a process for the regeneration of a catalyst for the dehydrogenation of secondary cyclic alcohols, characterized in that the catalyst at a temperature in the range of 350 ° C to 420 ° C with a gas stream, the 0.1 to 5 vol. - Contains% oxygen in contact.
Als sekundäre cyclische Alkohole sind cycloaliphatische Alkohole mit 5 bis 16 Kohlenstoffatomen wie Cyclopentanol, Cyclohexanol, 4-Methylcyclohexanol, Cyclooctanol, Cyclododecanol und Cyclohexadecanol, bevorzugt Cyclohexanol gemeint.As secondary cyclic alcohols are meant cycloaliphatic alcohols having 5 to 16 carbon atoms such as cyclopentanol, cyclohexanol, 4-methylcyclohexanol, cyclooctanol, cyclododecanol and cyclohexadecanol, preferably cyclohexanol.
Das erfindungsgemäße Regenerierverfahren eignet sich insbesondere für Zinkoxid- haltige Katalysatoren. Darunter fallen u.a. auch Katalysatoren, enthaltend Zinkoxid- Zinkcarbonat oder Mischungen von Zinkoxid-Zinkcarbonat mit Calciumoxid- Calciumcarbonat oder mit Magnesiumoxid-Magnesiumcarbonat. Bevorzugt sind solche Dehydrierkatalysatoren, die Zinkoxid und Calciumcarbonat enthalten. Besonders bevorzugt handelt es sich dabei um Katalysatoren, deren aktive Komponenten 30 bis 60, bevorzugt von 40 bis 50 Gew.-% Zinkoxid und 40 bis 70, bevorzugt 50 bis 60 Gew.- % Calciumcarbonat enthalten, ganz besonders bevorzugt solche Dehydrierkatalysatoren, die Calciumcarbonat in der Calcit-Modifikation enthalten.The regeneration process according to the invention is particularly suitable for zinc oxide-containing catalysts. These include u.a. also catalysts containing zinc oxide zinc carbonate or mixtures of zinc oxide zinc carbonate with calcium oxide calcium carbonate or magnesium oxide magnesium carbonate. Preference is given to those dehydrogenation catalysts which contain zinc oxide and calcium carbonate. Particular preference is given to catalysts whose active components contain from 30 to 60, preferably from 40 to 50,% by weight of zinc oxide and from 40 to 70, preferably from 50 to 60,% by weight of calcium carbonate, very particularly preferably such dehydrogenation catalysts as calcium carbonate contained in the calcite modification.
In einer weiteren Ausführungsform können die Katalysatoren außerdem 0,2 bisIn a further embodiment, the catalysts may also be 0.2 to
30 Gew.-%, bevorzugt 1 ,5 bis 20 Gew.-%, besonders bevorzugt 2,5 bis 15 Gew.-% Chrom(lll)oxid enthalten.30 wt .-%, preferably 1, 5 to 20 wt .-%, particularly preferably 2.5 to 15 wt .-% chromium (III) oxide.
Die Herstellung dieser Katalysatoren wird u.a. beschrieben in EP 0 888 273 B1 und US 6,376,422 und dem darin zitierten Stand der Technik. Dabei wird der pulverförmige Katalysator zu Formkörpern wie Tabletten, Ringen, Zylinder etc. verpresst. Bevorzugt liegt der Dehydrierkatalysator in gepresster Form als Tablette oder Ring vor.The preparation of these catalysts is described, inter alia, in EP 0 888 273 B1 and US Pat. No. 6,376,422 and the prior art cited therein. This is the powdery Catalyst to moldings such as tablets, rings, cylinders, etc. pressed. The dehydrogenation catalyst is preferably present in compressed form as a tablet or ring.
Der für die Regenerierung des Dehydrierkatalysators verwendete Gasstrom enthält dabei weniger als 10 Vol.-%, bevorzugt weniger als 5 Vol.-%, besonders bevorzugt weniger als 2 Vol.-% Wasserdampf.The gas stream used for the regeneration of the dehydrogenation catalyst contains less than 10% by volume, preferably less than 5% by volume, particularly preferably less than 2% by volume, of steam.
Das erfindungsgemäße Regenerierverfahren zeichnet sich dadurch aus, dass die Regenerierung des Katalysators im selben Festbettreaktor wie die Dehydrierung selbst erfolgen kann, vorzugsweise in einem Rohrbündelreaktor.The regeneration process according to the invention is characterized in that the regeneration of the catalyst can take place in the same fixed bed reactor as the dehydrogenation itself, preferably in a tube bundle reactor.
Eine besonders bevorzugte Ausführungsform des Verfahrens ist dadurch gekennzeichnet, dass die Regenerierung in zwei Stufen erfolgt, wobei der Katalysator in der ersten Stufe i) solange mit einem Luft-Stickstoff-Gemisch mit einem Sauerstoffgehalt von 0,1 bis 1 ,0 Vol.-%, bevorzugt 0,4 bis 0,6 Vol.-% bei einer Temperatur im Bereich von 350°C bis 400°C, bevorzugt im Bereich von 380°C bis 400°C in Kontakt gebracht wird, bis keine flüchtigen kondensierbaren organischen Verbindungen mehr nachgewiesen werden können und anschließend in der zweiten Stufe ii) solange mit einem Luft-Stickstoff-Gemisch mit einem Sauerstoffgehalt von 1 bis 5 Vol.-% bei einer Temperatur im Bereich von 405°C bis 420°C, bevorzugt bei einer Temperatur im Bereich von 410°C bis 415°C in Kontakt gebracht wird, bis der Sauerstoffgehalt im Gasstrom am Reaktorausgang so groß ist wie am Reaktoreingang.A particularly preferred embodiment of the method is characterized in that the regeneration takes place in two stages, wherein the catalyst in the first stage i) as long as with an air-nitrogen mixture having an oxygen content of 0.1 to 1, 0 vol .-% , preferably 0.4 to 0.6 vol .-% at a temperature in the range of 350 ° C to 400 ° C, preferably in the range of 380 ° C to 400 ° C is brought into contact until no more volatile condensable organic compounds can be detected and then in the second stage ii) with an air-nitrogen mixture having an oxygen content of 1 to 5 vol .-% at a temperature in the range of 405 ° C to 420 ° C, preferably at a temperature in the range from 410 ° C to 415 ° C is brought into contact until the oxygen content in the gas stream at the reactor outlet is as large as at the reactor inlet.
Bei der erfindungsgemäßen Regenerierung wird der Katalysator im Rohrbündelreaktor durch eine Begleitbeheizung (Gas oder Salzbad) auf eine Temperatur von 390°C gebracht. Im Anschluss wird heißer Stickstoff über den Katalysator geleitet. Im ersten Regenerationsschritt wird Luft zudosiert, so dass der Sauerstoffanteil ca. 0,5 Vol.-% beträgt. Dieser Wert wird so lange konstant gehalten, bis keine flüchtigen, kondensierbaren organischen Verbindungen mehr in dem Kondensationsbehälter gefunden werden. Im Anschluss setzt die eigentlich Abbrandreaktion ein. Hierbei steigt dieIn the regeneration according to the invention, the catalyst in the tube bundle reactor is brought to a temperature of 390.degree. C. by means of an accompanying heating (gas or salt bath). Subsequently, hot nitrogen is passed over the catalyst. In the first regeneration step, air is metered in, so that the oxygen content is about 0.5% by volume. This value is kept constant until no more volatile, condensable organic compounds are found in the condensation tank. After that, the actual burnup reaction sets in. This increases the
Temperatur auf ca. 410°C im oberen Teil des Betts. Dieser Hotspot wandert durch den Reaktor (ca. 5 h pro 25 % Betthöhe). Nach 20h ist die Temperaturfront am Ende des Reaktors angekommen. Die Temperatur wird über den Sauerstoffgehalt kontrolliert. Solange die erste Temperaturfront den Reaktor nicht verlassen hat, muss der Sauer- stoffgehalt bei 0,5 Vol.-% bleiben. Damit die Reaktionswärme (stark exotherm) den Katalysator nicht schädigt, muss die Temperatur im Katalysatorbett während der gesamten Regenerationszeit überwacht werden. Hierbei ist besonders wichtig, dass das Delta T im Reaktor auf maximal 20°C ansteigt. Wenn dieser Wert größer wird, kann es zu einer Schädigung des Katalysators und des Reaktors kommen. Im Fall eines zu schnellen, unkontrollierten Temperaturanstiegs muss der Sauerstoffgehalt schrittweise unter 0,5 Vol.-% abgesenkt werden. Während der Regeneration wird der Sauerstoffgehalt und der Cθ2-Gehalt im Abgas bestimmt. Nachdem eine Temperaturwelle komplett durch den Reaktor durchgewandert ist (ca. 20 h bei starker Verkokung) kann die Sauerstoffkonzentration langsam auf 5 Vol.-% in 1 Vol.-% Schritten angehoben werden. Es ist jedoch zu beachten, dass die Temperatur im Reaktor nicht mehr als 20°C ansteigt. Die Regeneration ist beendet (normalerweise nach 36h), wenn der Sauerstoffgehalt im Ausgang genau so groß ist wie im Eingang.Temperature to about 410 ° C in the upper part of the bed. This hotspot moves through the reactor (about 5 hours per 25% bed height). After 20 hours, the temperature front has arrived at the end of the reactor. The temperature is controlled by the oxygen content. As long as the first temperature front has not left the reactor, the oxygen content must remain at 0.5% by volume. So that the heat of reaction (strongly exothermic) does not damage the catalyst, the temperature in the catalyst bed must be monitored during the entire regeneration time. It is particularly important that the Delta T in the reactor rises to a maximum of 20 ° C. As this value increases, damage to the catalyst and reactor may result. In the case of too rapid, uncontrolled temperature rise, the oxygen content must be gradually lowered below 0.5 vol .-%. During regeneration, the Oxygen content and the CO 2 content in the exhaust gas determined. After a temperature wave has completely migrated through the reactor (about 20 h with strong coking), the oxygen concentration can be slowly increased to 5 vol .-% in 1 vol .-% steps. It should be noted, however, that the temperature in the reactor does not rise above 20 ° C. The regeneration is finished (usually after 36h) when the oxygen content in the outlet is exactly the same as in the inlet.
Besonders überraschend hat sich gezeigt, dass solch ein regenerierter Katalysator im Anschluss die gleiche Performance wie ein frischer Katalysator besitzt. Außerdem konnte bei der speziellen Abbrennungsprozedur keine Verschlechterung der mechanischen Härte festgestellt werden, was bei einer Abbrennungsprozedur unter reiner Luftzufuhr normalerweise der Fall ist.It has been found, particularly surprisingly, that such a regenerated catalyst subsequently has the same performance as a fresh catalyst. In addition, the special burn-up procedure did not detect any deterioration of the mechanical hardness, which is normally the case with a clean-air burn-off procedure.
Die Stirndruckfestigkeit der regenerierten Tabletten beträgt vorzugsweise 500 bis 4000 N/cm2, insbesondere 1000 bis 2500 N/cm2 und die Seitendruckfestigkeit liegt bevorzugt zwischen 5 und 20 N, vorzugsweise 10 bis 15 N.The forehead compressive strength of the regenerated tablets is preferably 500 to 4000 N / cm 2 , especially 1000 to 2500 N / cm 2 and the lateral compressive strength is preferably between 5 and 20 N, preferably 10 to 15 N.
Es konnte gezeigt werden, dass die Regeneration die ursprüngliche Aktivität des Katalysators wieder herstellt. Dabei konnte kein negativer Einfluss auf die Selektivität oder die Nebenproduktbildung festgestellt werden.It could be shown that the regeneration restores the original activity of the catalyst. No negative influence on the selectivity or by-product formation could be determined.
Die folgende Tabelle zeigt, dass nach mehrmaligem Regenerieren des Katalysators unter den oben genannten Bedingungen, jeweils wieder die Anfangswerte (erzielt mit frisch hergestelltem Katalysator) bezüglich Umsatz, Selektivität und Produktivität bei der Dehydrierung von Cyclohexanol zu Cyclohexanon erreicht wurden.The following table shows that after repeated regeneration of the catalyst under the abovementioned conditions, in each case the initial values (achieved with freshly prepared catalyst) with respect to conversion, selectivity and productivity were achieved in the dehydrogenation of cyclohexanol to cyclohexanone.
Temperatur 1 : Regeneriertemperatur [°C] Temperatur 2: Dehydriertem peratur [°C] Umsatz 1 : erzielter Umsatz mit deaktiviertem Katalysator [%] Umsatz 2: erzielter Umsatz mit regeneriertem Katalysator [%] *) Dauer der Regeneration [h] Temperature 1: regeneration temperature [° C.] temperature 2: dehydrogenated temperature [° C.] conversion 1: conversion achieved with catalyst deactivated [%] conversion 2: conversion achieved with regenerated catalyst [%] * ) duration of regeneration [h]
Claims
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP06100326 | 2006-01-13 | ||
| EP06100326.5 | 2006-01-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2007082790A1 true WO2007082790A1 (en) | 2007-07-26 |
Family
ID=37907635
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2007/050061 Ceased WO2007082790A1 (en) | 2006-01-13 | 2007-01-04 | Process for regenerating a dehydrogenation catalyst |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2007082790A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020104991A1 (en) * | 2018-11-21 | 2020-05-28 | Nova Chemicals (International) S.A. | Oxidative dehydrogenation catalyst regeneration and integration with an air separation unit |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3149082A (en) * | 1959-12-14 | 1964-09-15 | Baugh Chemical Company | Calcium phosphate catalysts and method of production |
| GB1142402A (en) * | 1965-11-05 | 1969-02-05 | Gulf Research Development Co | Process for dehydrogenating oxygenated hydroaromatics |
| DE1443462A1 (en) * | 1962-12-18 | 1969-08-14 | Basf Ag | Process for the dehydration of primary or secondary alcohols |
| US4380673A (en) * | 1980-06-26 | 1983-04-19 | Institut Francais Du Petrole | Catalyst and process for manufacturing a ketone by dehydrogenation of a secondary alcohol |
| US5075268A (en) * | 1990-05-25 | 1991-12-24 | Agency Of Industrial Science And Technology | Regeneration method for methanol-reforming catalyst |
| WO2002026668A1 (en) * | 2000-09-26 | 2002-04-04 | Basf Aktiengesellschaft | Method for the dehydrogenation of hydrocarbons |
-
2007
- 2007-01-04 WO PCT/EP2007/050061 patent/WO2007082790A1/en not_active Ceased
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3149082A (en) * | 1959-12-14 | 1964-09-15 | Baugh Chemical Company | Calcium phosphate catalysts and method of production |
| DE1443462A1 (en) * | 1962-12-18 | 1969-08-14 | Basf Ag | Process for the dehydration of primary or secondary alcohols |
| GB1142402A (en) * | 1965-11-05 | 1969-02-05 | Gulf Research Development Co | Process for dehydrogenating oxygenated hydroaromatics |
| US4380673A (en) * | 1980-06-26 | 1983-04-19 | Institut Francais Du Petrole | Catalyst and process for manufacturing a ketone by dehydrogenation of a secondary alcohol |
| US5075268A (en) * | 1990-05-25 | 1991-12-24 | Agency Of Industrial Science And Technology | Regeneration method for methanol-reforming catalyst |
| WO2002026668A1 (en) * | 2000-09-26 | 2002-04-04 | Basf Aktiengesellschaft | Method for the dehydrogenation of hydrocarbons |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020104991A1 (en) * | 2018-11-21 | 2020-05-28 | Nova Chemicals (International) S.A. | Oxidative dehydrogenation catalyst regeneration and integration with an air separation unit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE60001592T2 (en) | Process for the purification of (meth) acrylic acid | |
| DE60026844T2 (en) | PROCESS FOR THE PREPARATION OF 3,3-DIMETHYLBUTANAL | |
| DE69108860T2 (en) | Removal of carbonyl contaminants from the carbonylation process stream. | |
| DE60316930T2 (en) | OXIDATIVE TREATMENT OF A RECYCLING CURRENT IN THE PROCESS OF ACETIC ACID BY METHANOL CARBONYLATION | |
| DE3313573A1 (en) | METHOD FOR PRODUCING AN UNSATURATED ALDEHYDE FROM THE CORRESPONDING ALKAN | |
| DD289554A5 (en) | CONVERSION OF SUBSTANCES ENRICHED WITH OXYGEN IN PETROL AT CHANGING ROOM SPEED | |
| EP3339276A1 (en) | Method and assembly for manufacturing an olefin | |
| WO2016015972A1 (en) | Process for preparing acrylic acid from methanol and acetic acid | |
| EP4021882A1 (en) | Simplified workup of the reactor discharge of an oxidative esterification | |
| EP0008412B1 (en) | Process for preparing esters of butanedicarboxylic acids | |
| DD283990A5 (en) | IMPROVED METHOD FOR THE PRODUCTION OF N, N-DIMETHYL ALKYLAMINES BY CATALYTIC HYDROGENATION OF N, N-DIMETHYL ALKYLAMIDES | |
| DE19709471A1 (en) | Process for the preparation of (meth) acrylic acid | |
| DE60117908T2 (en) | Process for the preparation of lower alkyl fatty acid esters | |
| EP0053335A1 (en) | Process for the preparation of 1,2-dichloroethane | |
| WO2007082790A1 (en) | Process for regenerating a dehydrogenation catalyst | |
| DE2748050C2 (en) | Process for the preparation of methacrylic acid | |
| DE2361098A1 (en) | PROCESS FOR THE PRODUCTION OF CARBONIC ACID ESTERS FROM UNSATATULATED ALCOHOLS | |
| DE2340929A1 (en) | METHOD FOR PRODUCING MALEIC ACID ANHYDRIDE | |
| DE2923681B1 (en) | Process for the recovery and reuse of heavy metal oxidation catalyst from the Wittem DMT process | |
| EP1658258A1 (en) | Method for the production of maleic anhydride | |
| DE2719745B2 (en) | Catalytic low pressure process for the production of butynediol | |
| DE2558164C2 (en) | Process for decomposing a complex consisting of an aromatic aldehyde, hydrogen fluoride and boron trifluoride | |
| DE2658191C2 (en) | Process for the production of maleic anhydride | |
| DE2045169B2 (en) | ||
| DE2625273A1 (en) | METHOD OF MANUFACTURING CYCLOAL CANNONS AND CYCLOAL CANOLS |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 07703624 Country of ref document: EP Kind code of ref document: A1 |