EP1239944B1 - Method and device for production of a homogeneous mixture of a vapour-forming aromatic hydrocarbon and an oxygen-containing gas - Google Patents

Method and device for production of a homogeneous mixture of a vapour-forming aromatic hydrocarbon and an oxygen-containing gas Download PDF

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Publication number
EP1239944B1
EP1239944B1 EP00985245A EP00985245A EP1239944B1 EP 1239944 B1 EP1239944 B1 EP 1239944B1 EP 00985245 A EP00985245 A EP 00985245A EP 00985245 A EP00985245 A EP 00985245A EP 1239944 B1 EP1239944 B1 EP 1239944B1
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Prior art keywords
aromatic hydrocarbon
oxygen
containing gas
xylene
nozzles
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EP00985245A
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German (de)
French (fr)
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EP1239944A1 (en
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Ulrich Block
Rolf Seubert
Bernhard Ulrich
Helmut Wunschmann
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BASF SE
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BASF SE
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20—Mixing gases with liquids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20—Mixing gases with liquids
    • B01F23/21—Mixing gases with liquids by introducing liquids into gaseous media
    • B01F23/213—Mixing gases with liquids by introducing liquids into gaseous media by spraying or atomising of the liquids
    • B01F23/2132—Mixing gases with liquids by introducing liquids into gaseous media by spraying or atomising of the liquids using nozzles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/30—Injector mixers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/30—Injector mixers
    • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
    • B01F25/313—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
    • B01F25/3131—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit with additional mixing means other than injector mixers, e.g. screens, baffles or rotating elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F2025/91—Direction of flow or arrangement of feed and discharge openings
    • B01F2025/916—Turbulent flow, i.e. every point of the flow moves in a random direction and intermixes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/40—Static mixers
    • B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions

Definitions

  • the invention relates to a method and a device for generating a homogeneous mixture of a vaporous aromatic Hydrocarbon and an oxygen-containing gas for catalytic gas phase reactions, especially a homogeneous one Mixture of vaporous o-xylene and / or naphthalene and Air for the production of phthalic anhydride.
  • PSA Phthalic anhydride
  • Equipment for carrying out such a PSA production process consist essentially of the functional units for the production the o-xylene vapor-air mixture, the reactor for the reaction the o-xylene vapor-air mixture and a device for PSA separation and workup.
  • the reaction by catalytic gas phase oxidation is usually carried out on V 2 O 5 -containing catalysts.
  • o-xylene is evaporated, mixed with an excess of air and passed at 340 ° C to 440 ° C over the catalyst in the tubes of a tube bundle reactor.
  • the catalyst consists for example of a mixture of V 2 O 5 and TiO 2 with promoters on ceramic bodies, such as porcelain or SiC spheres or rings, for example, 6 x 6 mm dimension. Large reactors have 10,000 to 40,000 tubes in the tube bundle.
  • the o-xylene is oxidized to PSA with a selectivity of 78% to 80%. This oxidation itself is highly exothermic at -1,110 kJ / mol.
  • the raw materials can be more or less contaminated.
  • the air may include NO x , H 2 S, sulfur oxides such as SO 2 , NH 3 and their salts, eg with CO 2 , which may lead to constrictions of one or more nozzles.
  • corrosion particles can change the droplet size and shape of the atomized o-xylene beam. Similar effects are caused by erosion of the nozzles in long-term operation.
  • the o-xylene may also contain m- and p-xylene, toluene, ethylbenzene, isopropylbenzene, nonane and small amounts of styrene. Such compounds can affect the surface tension of o-xylene.
  • the present invention is therefore based on the object improved method and apparatus for generating a homogeneous mixture of a vaporous aromatic hydrocarbon, such as o-xylene and / or naphthalene, and an oxygen containing gas, in particular air, for catalytic gas phase reactions to provide.
  • a vaporous aromatic hydrocarbon such as o-xylene and / or naphthalene
  • an oxygen containing gas in particular air
  • the invention solves the above-mentioned problems in that in a generic method, the atomization of the liquid aromatic hydrocarbon by using a nozzle for Formation of an atomizing hollow cone, preferably a swirl nozzle, he follows.
  • the atomizing cone may initially be a continuous one Be film from the liquid hydrocarbon, the tearing into small pieces at a greater distance from the swirl nozzle, which by surface forces to single drops with a Contract diameter less than 1 mm.
  • the present invention is therefore a method for Generation of a homogeneous mixture of a vaporous aromatic Hydrocarbon, such as o-xylene and / or naphthalene and an oxygen-containing gas, such as air, for catalytic Gas phase reactions, wherein the liquid aromatic hydrocarbon to drops with a diameter of less than 1 mm atomized and in one above the boiling point of the aromatic hydrocarbon preheated, oxygen-containing gas stream einst, wherein the method is characterized in that the mixture is generated in a room that exceeds the boiling point the hydrocarbon heated side walls is limited, and the liquid aromatic hydrocarbon by means of nozzles for Forming a hollow cone, preferably by means of swirl nozzles, atomized.
  • a vaporous aromatic Hydrocarbon such as o-xylene and / or naphthalene
  • an oxygen-containing gas such as air
  • the inventive method allows the generation of a very homogeneous, strandselle mixture of gaseous oxygen, preferably in air or other oxygen-containing Gas, and a hydrocarbon vapor.
  • the inventive method is preferably used in the Production of carboxylic acids or carboxylic anhydrides by catalytic Gas-phase oxidation of aromatic hydrocarbons, such as xylenes, in particular o-xylene and / or naphthalene, in Fixed bed reactors.
  • aromatic hydrocarbons such as xylenes, in particular o-xylene and / or naphthalene
  • PSA Called phthalic anhydride
  • the aromatic hydrocarbon is o-xylene and the oxygen-containing gas air.
  • the sputtering hollow cone preferably has an opening angle of 30 ° to 70 °.
  • the atomizing hollow cone preferably has an opening angle of about 60 °.
  • the axis of the sputtering hollow cone lies in the flow direction of the oxygen-containing gas, that is about the air, but can to deviate from this by up to 30 °.
  • Another measure can be in particular, be a certain distance, about one third of the Pipe radius of the wall to comply. It is preferably used several nozzles, about 2 to 6, preferably 4 to 6 in about the same Intervals.
  • swirl nozzles for atomizing of the liquid hydrocarbon.
  • Hollow cone nozzles designated vortex nozzles preferably present the outlet opening a guide with oblique flow surfaces on, the liquid to be atomized a twist or a Give rotation around the flow axis.
  • Such swirl nozzles are for other uses, such as fast pulse transmission in water jet pumps, injection condensers, etc. known (see. Grassmann "Physical Principles of Process Engineering", publisher Sauerlander (1970), pages 355 and 805).
  • the use of hollow cone nozzles in the method according to the invention is particularly preferred is, in other embodiments of the invention also full cone nozzles or slot nozzles can be used.
  • the Use of two-fluid nozzles, which with about to be sprayed o-xylene and the propellant air can be charged possible.
  • the liquid hydrocarbon stream to drops with a diameter of less than 1 mm, preferably less than 0.8 mm atomized.
  • the liquid stream is atomized to droplets of 0.02 to 0.2 mm.
  • the formation of the sputtering hollow cone with an opening angle From 30 ° to 70 ° used swirl nozzles are beneficial within a tube through which the oxygen gas flows on a pipe with supply line for the liquid to be atomized arranged. But you can also the annular feed pipe arrange for the liquid around the oxygen pipe and insert the nozzles into the oxygen pipe from the outside. In this case, the nozzle outlet openings are in Directed towards the gas flow.
  • the axis of the hollow cone by up to 30 ° from the Deviate flow direction of the gas. This can be achieved that fewer drops of the hollow cone touch the wall.
  • Axial hollow cone nozzles type KS 1 (Lechler, Metzingen, Germany). Such nozzles enable the production a hollow cone with the preferred cone angle of 60 °. Of the Hollow cone diameter is then at a distance of 250 mm from the outlet about 200 mm. According to the invention form small drops with a diameter of less than 1 mm, preferred less than 0.8 mm, more preferably 0.02 to 0.2 mm. The latter evaporate very fast and are already at a distance from 200 to 500 mm from the nozzle exit opening completely evaporated. However, drops of 0.8 to 1 mm may be up to complete evaporation 50 to 100 cm far and fly while the Touch and moisten the wall.
  • the mixture for example, the o-xylene-air mixture to produce in a room that of above the boiling point of the hydrocarbon heated Sidewalls is limited.
  • a heated tube such as a double-jacket tube, in particular a thermoplate tube formed (such thermal sheets become in Germany for example from the companies BUCO, Geesthacht or DEG, Gelsenmün produced).
  • Hydrocarbon droplets on the heated Pipe meet, can not be deposited as a liquid film, but are evaporated immediately. This eventually creates the desired mixture of hydrocarbon vapor and, for example Air.
  • the tube gap of the double-jacket tube can be heated with high-pressure steam be, preferably with water vapor of about 20 bar with a Temperature of 214 ° C.
  • the aforesaid thermoplates can have a particularly narrow pipe gap. Thermoshelf pipes are relatively simple and thus cheaper. Intensive heating can be used with thermoplate tubes cold spots are excluded.
  • the mixing device used is preferably static mixers. These are attached in the flow-through pipe Baffles that divide the stream to be mixed several times and bring together again, causing complete homogenization he follows.
  • static mixers are used for example by Sulzer, Winterthur, Switzerland.
  • Static mixers are also in the German patent applications DE 25 250 20 A1, DE 196 223 051 A1 and DE 196 23 105 A1.
  • the subject of the present invention is also a device for producing a homogeneous mixture of a vaporous aromatic hydrocarbon and an oxygen-containing Gas with a pipe for a preheated, oxygen-containing Gas stream, an atomizing device opening into the pipe for a stream of a liquid aromatic hydrocarbon, which is characterized in that the atomizing device Having swirl nozzles, and that the tube at least downstream of the swirl nozzles has walls that at least heated to the boiling point of the hydrocarbon are.
  • the tube preferably comprises a double-jacket tube or a tube Thermoshelf. Particularly preferred is downstream of the swirl nozzles a static mixer arranged in the gas channels.
  • the temperature on the hot tube wall is adjusted so that 5 to 50% by weight of the liquid hydrocarbon, especially 5 to 40 wt.%, Particularly preferably 5 to 30 wt.% Of the pipe wall meet and can be evaporated there, with the exact proportion from the impurities of raw materials, from the hollow cone shape and Nozzle change (erosion) during operation depends.
  • functional unit can be more
  • connect functional units to make PSA e.g. the reactor for converting the o-xylene to PSA, and the device for PSA separation and PSA recovery, as they are from the State of the art are known.
  • the device has a tube 11, which a preheated air flow (in the figure Arrow 12 symbolizes) introduce.
  • a sputtering device 13 provided from the supply lines 14th for liquid o-xylene and arranged at the end of the lines Swirl nozzles 15 exist.
  • the supply lines 14 are of a the pipe 11 concentrically surrounding supply pipe (not shown) fed.
  • the swirl nozzles 15 produce a hollow cone 16 from liquid o-xylene, which in finest drops with a middle Diameter between 0.02 and 0.2 mm decays.
  • the apparatus for o-xylene evaporation in a plant for PSA production consisted of a vertical thermobalance pipe of 1200 mm diameter. Through this, the oxidation air preheated to 200 ° C with a preheater was sent to the reactor. The pressure was about 1.5 bar absolute. The air was charged with o-xylene with a loading of 100 g per Nm 3 . The air was sucked without special cleaning, only via an air filter from the environment. The thermoplate tube was heated to 214 ° C with 20 bar steam. The o-xylene was injected via 6 swirl nozzles, which were mounted on a ring of 600 mm diameter and whose axis was pointing vertically upwards. These were axial hollow cone nozzles (KS 1 of type 216.324 made of steel, Lechler). The form was 8 bar. At a distance of 4.5 m behind the nozzles static mixers were mounted in the horizontally extending pipe section.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Hydrogen, Water And Hydrids (AREA)
  • Accessories For Mixers (AREA)

Abstract

A process and an apparatus for producing a homogeneous mixture of a gaseous aromatic hydrocarbon and an oxygen-containing gas for catalytic gas-phase reactions, in particular a homogeneous mixture of gaseous o-xylene and/or naphthalene and air for preparing phthalic anhydride, are provided. The liquid aromatic hydrocarbon is atomized to form droplets having a diameter of less than 1 mm and injected into an oxygen-containing gas stream (12) preheated to above the boiling point of the aromatic hydrocarbon. According to the invention, the liquid aromatic hydrocarbon is atomized by means of nozzles (15) which form a hollow cone (16), preferably by means of swirl nozzles. The o-xylene/air mixture is advantageously produced in a chamber which is bounded by side walls (18) heated to above the boiling point of the hydrocarbon.

Description

Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur Erzeugung eines homogenen Gemisches aus einem dampfförmigen aromatischen Kohlenwasserstoff und einem Sauerstoff enthaltenden Gas für katalytische Gasphasenreaktionen, insbesondere einem homogenen Gemisch aus dampfförmigem o-Xylol und/oder Naphthalin und Luft zur Herstellung von Phthalsäureanhydrid.The invention relates to a method and a device for generating a homogeneous mixture of a vaporous aromatic Hydrocarbon and an oxygen-containing gas for catalytic gas phase reactions, especially a homogeneous one Mixture of vaporous o-xylene and / or naphthalene and Air for the production of phthalic anhydride.

Phthalsäureanhydrid (PSA) ist ein wichtiges zwischenprodukt zur Herstellung von synthetischen Harzen, Phthalatweichmachern, Phthalocyaninfarbstoffen und weiteren Feinchemikalien. PSA wird heutzutage vorwiegend aus o-Xylol hergestellt und zwar überwiegend durch Gasphasenoxidation von o-Xylol mit Luft als Oxidans.Phthalic anhydride (PSA) is an important intermediate to Production of synthetic resins, phthalate plasticizers, Phthalocyanine dyes and other fine chemicals. PSA will Nowadays mainly made of o-xylene and that predominantly by gas-phase oxidation of o-xylene with air as the oxidant.

Anlagen zur Durchführung eines solchen PSA-Herstellungsverfahrens bestehen im wesentlichen aus den Funktionseinheiten für die Herstellung der o-Xyloldampf-Luftmischung, dem Reaktor für die Umsetzung der o-Xyloldampf-Luftmischung und einer Einrichtung zur PSA-Abscheidung und Aufarbeitung.Equipment for carrying out such a PSA production process consist essentially of the functional units for the production the o-xylene vapor-air mixture, the reactor for the reaction the o-xylene vapor-air mixture and a device for PSA separation and workup.

Die Umsetzung durch katalytische Gasphasenoxidation erfolgt meist an V2O5-haltigen Katalysatoren. Dazu wird o-Xylol verdampft, mit einem Überschuß an Luft gemischt und bei 340 °C bis 440 °C über den Katalysator in den Rohren eines Rohrbündelreaktors geleitet. Der Katalysator besteht beispielsweise aus einem Gemisch von V2O5 und TiO2 mit Promotoren auf keramischen Körpern, wie z.B. Porzellan- oder SiC-Kugeln oder -Ringen von beispielsweise 6 x 6 mm Abmessung. Große Reaktoren haben 10.000 bis 40.000 Rohre im Rohrbündel. Üblicherweise wird das o-Xylol mit einer Selektivität von 78% bis 80% zu PSA oxidiert. Diese Oxidation selbst ist mit -1.110 kJ/Mol stark exotherm.The reaction by catalytic gas phase oxidation is usually carried out on V 2 O 5 -containing catalysts. For this purpose, o-xylene is evaporated, mixed with an excess of air and passed at 340 ° C to 440 ° C over the catalyst in the tubes of a tube bundle reactor. The catalyst consists for example of a mixture of V 2 O 5 and TiO 2 with promoters on ceramic bodies, such as porcelain or SiC spheres or rings, for example, 6 x 6 mm dimension. Large reactors have 10,000 to 40,000 tubes in the tube bundle. Usually, the o-xylene is oxidized to PSA with a selectivity of 78% to 80%. This oxidation itself is highly exothermic at -1,110 kJ / mol.

Bei der Verfahrensführung müssen dabei u.a. die folgenden kritischen Punkte beachtet werden: Zum einen befindet sich die Mischung von o-Xylol mit Luft (Sauerstoffüberschuß) im Explosionsbereich (Ullmann's Encyclopedia of Industrial Chemistry, 5. Auflage, Band A 20, Seite 85), des weiteren muß die große Zahl von 10.000 - 40.000 Rohren mit einer im gesamten Querschnitt gleichen und zeitlich konstanten Gasmischung angeströmt werden, damit die Reaktion in allen Rohren gleich schnell und nicht etwa in einigen besonders schnell oder besonders langsam abläuft. Außerdem kann die stark negative Reaktionsenthalpie dazu führen, daß der Katalysator bei Abweichungen von den eingestellten Bedingungen in einzelnen Rohren sintert, schmilzt oder inaktiv wird. Dies ist mit beträchtlichen Risiken für die Anlage verbunden.In the process management u.a. the following critical Points to note: First, there is the mixture of o-xylene with air (oxygen excess) in the explosion area (Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Volume A 20, page 85), furthermore, the large number of 10,000 - 40,000 tubes with one in the entire cross-section same and time constant gas mixture are flown, so that the Reaction in all tubes equally fast and not in some runs particularly fast or very slowly. In addition, can the strong negative reaction enthalpy cause the catalyst in case of deviations from the set conditions in individual pipes sinters, melts or becomes inactive. This is associated with considerable risks to the plant.

Durch Inhomogenitäten in der Beaufschlagung werden außerdem die Reaktionsbedingungen in den Rohren unterschiedlich. Dadurch entstehen in erhöhtem Maße Nebenprodukte, die die Ausbeuten verringern,und die in späteren Reinigungsstufen vom PSA abgetrennt und entsorgt werden müssen.Inhomogeneities in the admission are also the Reaction conditions in the tubes differently. This creates to an increased degree by-products which reduce yields, and separated in later purification stages of the PSA and must be disposed of.

Aus der DE-A 1 793 453 ist ein Verfahren zur Herstellung eines homogenen Gemisches aus dampfförmigen o-Xylol und Luft für die katalytische Oxidation zu Phthalsäureanhydrid bekannt. Bei dem bekannten Verfahren wird ein o-Xylolstrom zu Tropfen mit einem Durchmesser von unter 1 mm, beispielsgemäß in einer Größe von überwiegend unter 0,3 mm verstäubt und in einen über den Siedepunkt von o-Xylol vorgewärmten Luftstrom eingeleitet. Dieser Luftstrom ist turbulent; es wird eine Reynoldszahl über 200.000 empfohlen. Die Verweilzeit von der o-Xyloleindüsung bis zum Reaktor muß mindestens 0,2 Sekunden betragen, um ein homogenes Gasgemisch und damit eine gleichmäßige Beaufschlagung aller Rohre zu erhalten.From DE-A 1 793 453 a process for the preparation of a homogeneous mixture of vaporous o-xylene and air for the catalytic oxidation to phthalic anhydride known. In which Known method is a o-xylene to drip with a Diameter of less than 1 mm, for example in a size of mostly dusted below 0.3 mm and in one above the boiling point initiated by o-xylene preheated air stream. This Airflow is turbulent; there will be a Reynolds number over 200,000 recommended. The residence time from the o-xylene injection to the reactor must be at least 0.2 seconds to a homogeneous gas mixture and thus a uniform admission of all pipes too receive.

Trotz dieser Verbesserung, die das Verfahren gemäß DE-A 1 793 453 darstellt, können - besonders bei Schwankungen der Betriebsbedingungen - Veränderungen der Tropfengröße und Störungen der Verdampfung stattfinden. Unterschiedliche Ursachen können hierfür in Frage kommen:Despite this improvement, the process according to DE-A 1 793 453 can - especially with fluctuations in operating conditions - Changes in drop size and disturbances of evaporation occur. Different causes can be found in this Question come:

Die Rohstoffe können mehr oder weniger verunreinigt sein. Die Luft kann unter anderem NOx, H2S, Schwefeloxide wie SO2, NH3 und deren Salze, z.B. mit CO2, enthalten, was zu Verengungen einer oder mehrerer Düsen führen kann. Auch Korrosionspartikel können die Tropfengröße und Form des zerstäubten o-Xylolstrahls verändern. Ähnliche Auswirkungen entstehen durch Erosion der Düsen im Langzeitbetrieb. Des weiteren kann das o-Xylol auch m- und p-Xylol, Toluol, Ethylbenzol, Isopropylbenzol, Nonan sowie geringe Mengen an Styrol enthalten. Derartige Verbindungen können die Oberflächenspannung des o-Xylols beeinflussen. Es können Tropfen entstehen, die weiter fliegen als die vorstehend genannten Tropfen mit einer Größe von beispielsweise überwiegend unter 0,3 mm. Diese können die Wand des Reaktionsrohres benetzen und dort einen Flüssigkeitsfilm bilden. Als weitere Schwierigkeit kommt noch hinzu, daß es in der Praxis nicht möglich ist, die Düsen, die zur Zerstäubung des o-Xylolstroms dienen, so zu installieren, daß keine Tropfen des zerstäubten o-Xylolstroms mit der Wand des Führungsrohres in Kontakt kommen. The raw materials can be more or less contaminated. The air may include NO x , H 2 S, sulfur oxides such as SO 2 , NH 3 and their salts, eg with CO 2 , which may lead to constrictions of one or more nozzles. Also corrosion particles can change the droplet size and shape of the atomized o-xylene beam. Similar effects are caused by erosion of the nozzles in long-term operation. Furthermore, the o-xylene may also contain m- and p-xylene, toluene, ethylbenzene, isopropylbenzene, nonane and small amounts of styrene. Such compounds can affect the surface tension of o-xylene. It can produce drops that fly further than the above-mentioned drops with a size of, for example, predominantly below 0.3 mm. These can wet the wall of the reaction tube and form a liquid film there. As a further difficulty is added that it is not possible in practice, the nozzles that serve to atomize the o-xylene, install so that no drops of the atomized o-xylene come into contact with the wall of the guide tube.

Auch kann es bei dem Verfahren gemaß DE-A 1 793 453 zu unbeabsichtigten, negativ wirkenden Veränderungen der eingestellten Parameter wie Druck und Temperatur und der Luftmenge kommen. Des weiteren können in den Ausgangsstoffen Luft und o-Xylol enthaltene Beimengungen eingetragen werden und die Tropfen des zerstäubten o-Xylolstroms können die Rohrwand berühren. Insofern ist das vorstehend genannte Verfahren nach wie vor verbesserungsbedürftig.Also, in the method according to DE-A 1 793 453 it may be inadvertent, Negative changes in the set parameters how pressure and temperature and the amount of air come. Of others may contain air and o-xylene in the starting materials Add admixtures and the droplets of the atomized o-xylene flow can touch the pipe wall. So far the above-mentioned method still needs to be improved.

Der vorliegenden Erfindung liegt daher die Aufgabe zugrunde, ein verbessertes Verfahren und eine Vorrichtung zur Erzeugung eines homogenen Gemisches aus einem dampfförmigen aromatischen Kohlenwasserstoff, wie o-xylol und/oder Naphthalin, und einem Sauerstoff enthaltenden Gas, insbesondere Luft, für katalytische Gasphasenreaktionen zur Verfügung zu stellen. Insbesondere sollen die oben beschriebenen Nachteile vermieden oder zumindest minimiert werden.The present invention is therefore based on the object improved method and apparatus for generating a homogeneous mixture of a vaporous aromatic hydrocarbon, such as o-xylene and / or naphthalene, and an oxygen containing gas, in particular air, for catalytic gas phase reactions to provide. In particular, should avoids or at least minimizes the disadvantages described above become.

Die Erfindung löst die vorstehend genannten Probleme dadurch, daß bei einem gattungsgemäßen Verfahren die Zerstäubung des flüssigen aromatischen Kohlenwasserstoffs durch Verwendung einer Düse zur Bildung eines Zerstäubungshohlkegels, vorzugsweise einer Dralldüse, erfolgt. Der Zerstäubungshohlkegel kann anfangs ein zusammenhängender Film aus dem flüssigen Kohlenwasserstoff sein, der bei größerem Abstand von der Dralldüse in kleine Fetzen zerreißt, die sich durch Grenzflächenkräfte zu einzelnen Tropfen mit einem Durchmesser von weniger als 1 mm zusammenziehen.The invention solves the above-mentioned problems in that in a generic method, the atomization of the liquid aromatic hydrocarbon by using a nozzle for Formation of an atomizing hollow cone, preferably a swirl nozzle, he follows. The atomizing cone may initially be a continuous one Be film from the liquid hydrocarbon, the tearing into small pieces at a greater distance from the swirl nozzle, which by surface forces to single drops with a Contract diameter less than 1 mm.

Gegenstand der vorliegenden Erfindung ist daher ein Verfahren zur Erzeugung eines homogenen Gemisches aus einem dampfförmigen aromatischen Kohlenwasserstoff, wie o-Xylol und/oder Naphthalin und einem Sauerstoff enthaltenden Gas, wie Luft, für katalytische Gasphasenreaktionen, wobei man den flüssigen aromatischen Kohlenwasserstoff zu Tropfen mit einem Durchmesser von weniger als 1 mm zerstäubt und in einen über den Siedepunkt des aromatischen Kohlenwasserstoffs vorgewärmten, Sauerstoff enthaltenden Gasstrom eindüst, wobei das Verfahren dadurch gekennzeichnet ist, daß man das Gemisch in einem Raum erzeugt, der von über den Siedepunkt des Kohlenwasserstoffs beheizten Seitenwänden begrenzt ist, und den flüssigen aromatischen Kohlenwasserstoff mittels Düsen zur Ausbildung eines Hohlkegels, vorzugsweise mittels Dralldüsen, zerstäubt.The present invention is therefore a method for Generation of a homogeneous mixture of a vaporous aromatic Hydrocarbon, such as o-xylene and / or naphthalene and an oxygen-containing gas, such as air, for catalytic Gas phase reactions, wherein the liquid aromatic hydrocarbon to drops with a diameter of less than 1 mm atomized and in one above the boiling point of the aromatic hydrocarbon preheated, oxygen-containing gas stream einst, wherein the method is characterized in that the mixture is generated in a room that exceeds the boiling point the hydrocarbon heated side walls is limited, and the liquid aromatic hydrocarbon by means of nozzles for Forming a hollow cone, preferably by means of swirl nozzles, atomized.

Das erfindungsgemäße Verfahren ermöglicht die Erzeugung eines sehr homogenen, strähnenfreien Gemischs aus gasförmigem Sauerstoff, vorzugsweise in Luft oder einem anderen Sauerstoff enthaltenden Gas, und einem Kohlenwasserstoffdampf. The inventive method allows the generation of a very homogeneous, strandsfreien mixture of gaseous oxygen, preferably in air or other oxygen-containing Gas, and a hydrocarbon vapor.

Das erfindungsgemäße Verfahren wird bevorzugt verwendet bei der Herstellung von Carbonsäuren oder Carbonsäureanhydriden durch katalytische Gasphasenoxidation von aromatischen Kohlenwasserstoffen, wie Xylolen, insbesondere o-Xylol und/oder Naphthalin, in Festbettreaktoren. Beispielhaft sei hier die Herstellung von Phthalsäureanhydrid (PSA) genannt.The inventive method is preferably used in the Production of carboxylic acids or carboxylic anhydrides by catalytic Gas-phase oxidation of aromatic hydrocarbons, such as xylenes, in particular o-xylene and / or naphthalene, in Fixed bed reactors. As an example, the production of Called phthalic anhydride (PSA).

Im folgenden wird, rein exemplarisch, auf die besonders bevorzugte Verwendung des erfindungsgemäßen Verfahrens bei der Herstellung von PSA durch katalytische Gasphasenoxidation Bezug genommen. Dabei ist der aromatische Kohlenwasserstoff o-Xylol und das sauerstoffhaltige Gas Luft.In the following, purely by way of example, the most preferred Use of the method according to the invention in the production of PSA by catalytic gas phase oxidation. The aromatic hydrocarbon is o-xylene and the oxygen-containing gas air.

Bei dem erfindungsgemäßen Verfahren weist der Zerstäubungshohlkegel bevorzugt einen Öffnungswinkel von 30° bis 70° auf. Besonders bevorzugt besitzt der Zerstäubungshohlkegel einen Öffnungswinkel von ungefähr 60°.In the method according to the invention, the sputtering hollow cone preferably has an opening angle of 30 ° to 70 °. Especially The atomizing hollow cone preferably has an opening angle of about 60 °.

Die Achse des Zerstäubungshohlkegels liegt in der Strömungsrichtung des sauerstoffhaltigen Gases, also etwa der Luft, kann aber um bis zu 30° von dieser abweichen. Dies bedeutet, daß die Mittelachse des Zerstäubungshohlkegels des Kohlenwasserstoffstroms in einem Winkel von -30° bis +30° zur Mittelachse des vorgewärmten Gasstroms steht. Man erreicht dadurch, daß weniger Tropfen des Hohlkegels die Wand berühren. Eine weitere Maßnahme dazu kann insbesondere sein, einen bestimmten Abstand, etwa ein Drittel des Rohrradius von der Wand einzuhalten. Man verwendet vorzugsweise mehrere Düsen, etwa 2 bis 6, bevorzugt 4 bis 6 in etwa gleichen Abständen.The axis of the sputtering hollow cone lies in the flow direction of the oxygen-containing gas, that is about the air, but can to deviate from this by up to 30 °. This means that the central axis of atomizing hollow cone of hydrocarbon stream in an angle of -30 ° to + 30 ° to the central axis of the preheated Gas stream stands. This achieves that fewer drops of the Hollow cones touching the wall. Another measure can be in particular, be a certain distance, about one third of the Pipe radius of the wall to comply. It is preferably used several nozzles, about 2 to 6, preferably 4 to 6 in about the same Intervals.

Erfindungsgemäß werden vorzugsweise sog. Dralldüsen zum Zerstäuben des flüssigen Kohlenwasserstoffs verwendet. Diese auch als Hohlkegeldüsen bezeichneten Dralldüsen weisen vorzugsweise vor der Austrittsöffnung einen Leitkörper mit schrägen Anströmflächen auf, die der zu zerstäubenden Flüssigkeit einen Drall oder eine Rotation um die Strömungsachse verleihen. Derartige Dralldüsen sind für andere Verwendungszwecke, wie schnelle Impulsübertragung bei Wasserstrahlpumpen, Einspritzkondensatoren etc. bekannt (vgl. Grassmann "Physikalische Grundlagen der Verfahrenstechnik", Verlag Sauerländer (1970), Seite 355 und 805). Obwohl die Verwendung von Hohlkegeldüsen im erfindungsgemäßen Verfahren besonders bevorzugt ist, können in anderen Ausführungsformen der Erfindung auch Vollkegeldüsen oder Schlitzdüsen verwendet werden. Auch die Verwendung von zweistoffdüsen, welche etwa mit dem zu versprühenden o-Xylol und dem Treibmittel Luft beschickt werden können, ist möglich. According to the invention, it is preferable to use so-called swirl nozzles for atomizing of the liquid hydrocarbon. This as well Hollow cone nozzles designated vortex nozzles preferably present the outlet opening a guide with oblique flow surfaces on, the liquid to be atomized a twist or a Give rotation around the flow axis. Such swirl nozzles are for other uses, such as fast pulse transmission in water jet pumps, injection condensers, etc. known (see. Grassmann "Physical Principles of Process Engineering", publisher Sauerlander (1970), pages 355 and 805). Although the use of hollow cone nozzles in the method according to the invention is particularly preferred is, in other embodiments of the invention also full cone nozzles or slot nozzles can be used. Also the Use of two-fluid nozzles, which with about to be sprayed o-xylene and the propellant air can be charged possible.

Wenn man zum Erzeugen des erfindungsgemäßen Zerstäubungshohlkegels eine Drall- oder Hohlkegeldüse verwendet, so wird diese bevorzugt mit einem Vordruck von 2 bis 20 bar betrieben, damit sichergestellt ist, daß ein Zerstäubungshohlkegel mit dem erfindungsgemäß bevorzugten Öffnungswinkel von 30° bis 70° entsteht.When it comes to producing the Zerstäubungshohlkegels invention used a swirl or Hohlkepfüse, it is preferred operated with a pre-pressure of 2 to 20 bar, thus ensuring is that a sputtering hollow cone with the invention preferred opening angle of 30 ° to 70 ° is formed.

Bei dem erfindungsgemäßen Verfahren wird der flüssige Kohlenwasserstoffstrom zu Tropfen mit einem Durchmesser von kleiner als 1 mm, bevorzugt kleiner als 0,8 mm zerstäubt. Besonders bevorzugt wird der Flüssigkeitsstrom zu Tropfen von 0,02 bis 0,2 mm zerstäubt.In the process according to the invention, the liquid hydrocarbon stream to drops with a diameter of less than 1 mm, preferably less than 0.8 mm atomized. Especially preferred the liquid stream is atomized to droplets of 0.02 to 0.2 mm.

Die zur Bildung des Zerstäubungshohlkegels mit einem Öffnungswinkel von 30° bis 70° verwendeten Dralldüsen werden vorteilhaft innerhalb eines von dem Sauerstoffgas durchströmten Rohres kranzförmig auf einem Rohr mit Zuleitung für die zu zerstäubende Flüssigkeit angeordnet. Man kann aber auch das ringförmige Zuleitungsrohr für die Flüssigkeit um das Sauerstoffleitungsrohr anordnen und die Düsen von außen in das Sauerstoffleitungsrohr hineinführen. In diesem Fall sind die Düsenaustrittsöffnungen in Richtung der Gasströmung gerichtet. Wie vorstehend bereits gesagt, kann jedoch die Achse des Hohlkegels um bis zu 30° von der Strömungsrichtung des Gases abweichen. Dadurch kann erreicht werden, daß weniger Tropfen des Hohlkegels die Wand berühren.The formation of the sputtering hollow cone with an opening angle From 30 ° to 70 ° used swirl nozzles are beneficial within a tube through which the oxygen gas flows on a pipe with supply line for the liquid to be atomized arranged. But you can also the annular feed pipe arrange for the liquid around the oxygen pipe and insert the nozzles into the oxygen pipe from the outside. In this case, the nozzle outlet openings are in Directed towards the gas flow. As already stated above, However, the axis of the hollow cone by up to 30 ° from the Deviate flow direction of the gas. This can be achieved that fewer drops of the hollow cone touch the wall.

Für die Zwecke des erfindungsgemäßen Verfahrens sind insbesondere Axial-Hohlkegeldüsen des Typs KS 1 (Firma Lechler, Metzingen, Deutschland) geeignet. Derartige Düsen ermöglichen die Erzeugung eines Hohlkegels mit dem bevorzugten Kegelwinkel von 60°. Der Hohlkegeldurchmesser beträgt dann in einer Entfernung von 250 mm von der Austrittsöffnung ca. 200 mm. Erfindungsgemäß bilden sich kleine Tropfen mit einem Durchmesser von kleiner als 1 mm, bevorzugt kleiner als 0,8 mm, besonders bevorzugt 0,02 bis 0,2 mm. Letztere verdampfen sehr schnell und sind bereits in einer Entfernung von 200 bis 500 mm von der Düsenaustrittsöffnung vollständig verdampft. Tropfen von 0,8 bis 1 mm können aber bis zur völligen Verdampfung 50 bis 100 cm weit fliegen und dabei die Wand berühren und benetzen.For the purposes of the method according to the invention are in particular Axial hollow cone nozzles type KS 1 (Lechler, Metzingen, Germany). Such nozzles enable the production a hollow cone with the preferred cone angle of 60 °. Of the Hollow cone diameter is then at a distance of 250 mm from the outlet about 200 mm. According to the invention form small drops with a diameter of less than 1 mm, preferred less than 0.8 mm, more preferably 0.02 to 0.2 mm. The latter evaporate very fast and are already at a distance from 200 to 500 mm from the nozzle exit opening completely evaporated. However, drops of 0.8 to 1 mm may be up to complete evaporation 50 to 100 cm far and fly while the Touch and moisten the wall.

Wegen dieser Benetzungsmöglichkeit ist vorgesehen, das Gemisch, beispielsweise das o-Xylol-Luft-Gemisch, in einem Raum zu erzeugen, der von über den Siedepunkt des Kohlenwasserstoffs beheizten Seitenwänden begrenzt ist. Vorteilhaft werden die Seitenwände des Raums von einem beheizten Rohr, etwa einem Doppelmantelrohr, insbesondere einem Thermoblechrohr gebildet (derartige Thermoblechrohre werden in Deutschland beispielsweise von den Firmen BUCO, Geesthacht oder DEG, Gelsenkirchen hergestellt). Kohlenwasserstofftröpfchen, die auf das beheizte Rohr treffen, können sich nicht als flüssiger Film ablagern, sondern werden sofort verdampft. Dadurch entsteht schließlich das gewünschte Gemisch aus Kohlenwasserstoffdampf und beispielsweise Luft.Because of this wetting possibility is provided, the mixture, for example, the o-xylene-air mixture to produce in a room that of above the boiling point of the hydrocarbon heated Sidewalls is limited. Advantageously, the side walls of the Space of a heated tube, such as a double-jacket tube, in particular a thermoplate tube formed (such thermal sheets become in Germany for example from the companies BUCO, Geesthacht or DEG, Gelsenkirchen produced). Hydrocarbon droplets on the heated Pipe meet, can not be deposited as a liquid film, but are evaporated immediately. This eventually creates the desired mixture of hydrocarbon vapor and, for example Air.

Der Rohrspalt des Doppelmantelrohres kann mit Hochdruckdampf beheizt werden, vorzugsweise mit Wasserdampf von ca. 20 bar mit einer Temperatur von 214 °C. Die vorstehend genannten Thermoblechrohre können einen besonders engen Rohrspalt aufweisen. Thermoblechrohre sind relativ einfach aufgebaut und dadurch kostengünstiger. Durch ein intensive Beheizung können bei Thermoblechrohren kalte Stellen ausgeschlossen werden.The tube gap of the double-jacket tube can be heated with high-pressure steam be, preferably with water vapor of about 20 bar with a Temperature of 214 ° C. The aforesaid thermoplates can have a particularly narrow pipe gap. Thermoshelf pipes are relatively simple and thus cheaper. Intensive heating can be used with thermoplate tubes cold spots are excluded.

Zu einer vollständigen Homogenisierung wird die Dampf-Luftmischung anschließend gemäß einer weiteren vorteilhaften Verfahrensvariante durch eine Mischeinrichtung geleitet.Complete homogenization becomes the vapor-air mixture subsequently according to a further advantageous variant of the method passed through a mixing device.

Als Mischeinrichtung werden bevorzugt statische Mischer eingesetzt. Dabei handelt es sich um im durchströmten Rohr angebrachte Leitbleche, die den zu durchmischenden Strom mehrfach teilen und wieder zusammen führen, wodurch die vollständige Homogenisierung erfolgt. Derartige statische Mischer werden beispielsweise von der Fa. Sulzer, Winterthur, Schweiz, hergestellt. Statische Mischer werden auch in den deutschen Patentanmeldungen DE 25 250 20 A1, DE 196 223 051 A1 und DE 196 23 105 A1 beschrieben.The mixing device used is preferably static mixers. These are attached in the flow-through pipe Baffles that divide the stream to be mixed several times and bring together again, causing complete homogenization he follows. Such static mixers are used for example by Sulzer, Winterthur, Switzerland. Static mixers are also in the German patent applications DE 25 250 20 A1, DE 196 223 051 A1 and DE 196 23 105 A1.

Gegenstand der vorliegenden Erfindung ist außerdem eine Vorrichtung zur Erzeugung eines homogenen Gemisches aus einem dampfförmigen aromatischen Kohlenwasserstoff und einem Sauerstoff enthaltenden Gas mit einem Rohr für einen vorgewärmten, Sauerstoff enthaltenden Gasstrom, einer in das Rohr mündenden Zerstäubungseinrichtung für einen Strom eines flüssigen aromatischen Kohlenwasserstoffs, die dadurch gekennzeichnet ist, daß die Zerstäubungseinrichtung Dralldüsen aufweist, und daß das Rohr zumindest stromabwärts von den Dralldüsen Wände aufweist, die wenigstens bis auf die Siedetemperatur des Kohlenwasserstoffs beheizbar sind.The subject of the present invention is also a device for producing a homogeneous mixture of a vaporous aromatic hydrocarbon and an oxygen-containing Gas with a pipe for a preheated, oxygen-containing Gas stream, an atomizing device opening into the pipe for a stream of a liquid aromatic hydrocarbon, which is characterized in that the atomizing device Having swirl nozzles, and that the tube at least downstream of the swirl nozzles has walls that at least heated to the boiling point of the hydrocarbon are.

Bevorzugt umfasst das Rohr ein Doppelmantelrohr oder ein Rohr aus Thermoblech. Besonders bevorzugt ist stromabwärts von den Dralldüsen ein statischer Mischer in den Gaskanälen angeordnet. The tube preferably comprises a double-jacket tube or a tube Thermoshelf. Particularly preferred is downstream of the swirl nozzles a static mixer arranged in the gas channels.

Die Temperatur an der heißen Rohrwand wird so eingestellt, daß 5 bis 50 Gew.% des flüssigen Kohlenwasserstoffs, insbesondere 5 bis 40 Gew.%, besonders bevorzugt 5 bis 30 Gew.% auf die Rohrwand treffen und dort verdampft werden können, wobei der genaue Anteil von den Verunreinigungen der Rohstoffe, von der Hohlkegelform und Düsenveränderung (Erosion) während des Betriebs abhängt.The temperature on the hot tube wall is adjusted so that 5 to 50% by weight of the liquid hydrocarbon, especially 5 to 40 wt.%, Particularly preferably 5 to 30 wt.% Of the pipe wall meet and can be evaporated there, with the exact proportion from the impurities of raw materials, from the hollow cone shape and Nozzle change (erosion) during operation depends.

An die vorstehend genannte Funktionseinheit können sich weitere Funktionseinheiten etwa zur Herstellung von PSA anschließen, z.B. der Reaktor zur Umsetzung des o-Xylols zu PSA, und die Vorrichtung zur PSA-Abscheidung und PSA-Reingewinnung, wie sie aus dem Stand der Technik bekannt sind.To the above-mentioned functional unit can be more For example, connect functional units to make PSA, e.g. the reactor for converting the o-xylene to PSA, and the device for PSA separation and PSA recovery, as they are from the State of the art are known.

Die Erfindung wird im folgenden anhand einer in der beigefügten Zeichnung schematisch dargestellten Ausführungsform und durch ein Anwendungsbeispiel näher erläutert.The invention is described below with reference to one in the attached Drawing schematically illustrated embodiment and by a Application example explained in more detail.

In der Figur der Zeichnung ist eine Vorrichtung 10 zur Erzeugung eines homogenen Gemisches aus dampfförmigem o-Xylol und/oder Naphthalin und Luft dargestellt. Die Vorrichtung weist ein Rohr 11 auf, welches einen vorgewärmten Luftstrom (in der Figur durch Pfeil 12 symbolisiert) heranführen. In dem Rohr 11 ist eine Zerstäubungseinrichtung 13 vorgesehen, die aus Zufuhrleitungen 14 für flüssiges o-Xylol und aus am Ende der Leitungen angeordneten Dralldüsen 15 bestehen. Die Zufuhrleitungen 14 werden von einem das Rohr 11 konzentrisch umgebenden (nicht dargestellten) Versorgungsrohr gespeist. Die Dralldüsen 15 erzeugen einen Hohlkegel 16 aus flüssigem o-Xylol, der in feinste Tropfen mit einem mittleren Durchmesser zwischen 0,02 und 0,2 mm zerfällt. Die feinen Tropfen verdampfen in dem vorgewärmten Luftstrom sehr schnell, so daß ein homogenes Gemisch aus Luft und o-Xyloldampf entsteht. Zur weiteren Verbesserung der Homogenität ist in dem Rohr 11 ein statischer Mischer 17 angeordnet, durch den das Dampf/Luft-Gemisch geleitet wird. Stromabwärts von den Dralldüsen 15 ist das Rohr 11 als beheizbares Doppelmantelrohr 18 ausgebildet. Das Rohr wird mit Wasserdampf auf eine Temperatur oberhalb des Siedepunktes von o-Xylol erhitzt. Tröpfchen aus zerstäubtem o-Xylol, die auf die Rohrwand treffen, werden somit dort sofort verdampft und lagern sich nicht als Flüssigkeitsfilm ab. Bei 19 mündet das Rohr 11 in einen Rohrbündelreaktor, in welchem Phthalsäureanhydrid durch katalytische Gasphasenoxidation des o-Xylols hergestellt wird.In the figure of the drawing is a device 10 for the production a homogeneous mixture of vaporous o-xylene and / or Naphthalene and air shown. The device has a tube 11, which a preheated air flow (in the figure Arrow 12 symbolizes) introduce. In the tube 11 is a sputtering device 13 provided from the supply lines 14th for liquid o-xylene and arranged at the end of the lines Swirl nozzles 15 exist. The supply lines 14 are of a the pipe 11 concentrically surrounding supply pipe (not shown) fed. The swirl nozzles 15 produce a hollow cone 16 from liquid o-xylene, which in finest drops with a middle Diameter between 0.02 and 0.2 mm decays. The fine drops evaporate very quickly in the preheated air flow, so that a homogeneous mixture of air and o-xylene vapor is formed. To further Improvement of homogeneity is a static one in the tube 11 Mixer 17 is arranged, passed through the steam / air mixture becomes. Downstream of the swirl nozzles 15, the tube 11 formed as a heatable double-jacket tube 18. The pipe will with water vapor to a temperature above the boiling point of o-xylene heated. Droplets of atomized o-xylene on the Pipe wall meet, are therefore immediately evaporated and store there not as a liquid film from. At 19, the pipe 11 opens in a tube bundle reactor in which phthalic anhydride by catalytic Gas phase oxidation of o-xylene is produced.

Beispielexample

Die Vorrichtung zur o-Xylolverdampfung bei einer Anlage zur PSA-Herstellung bestand aus einem senkrechten Thermoblechrohr von 1200 mm Durchmesser. Durch dieses wurde die Oxidationsluft, die mit einer Vorwärmvorrichtung auf 200°C vorgewärmt war, zum Reaktor geleitet. Der Druck betrug ungefähr 1,5 bar absolut. Die Luft wurde mit o-Xylol mit einer Beladung von 100 g je Nm3 beaufschlagt. Die Luft wurde ohne besondere Reinigung, lediglich über einen Luftfilter aus der Umgebung angesaugt. Das Thermoblechrohr war mit 20 bar-Dampf auf 214 °C beheizt. Das o-Xylol wurde über 6 Dralldüsen, die auf einem Kranz von 600 mm Durchmesser angebracht waren und deren Achse senkrecht nach oben wies, eingedüst. Es handelte es sich dabei um Axial-Hohlkegeldüsen (KS 1 vom Typ 216.324 aus Stahl, Firma Lechler). Der Vordruck betrug 8 bar. Im Abstand von 4,5 m hinter den Düsen waren im waagerecht verlaufenden Rohrstück statische Mischer angebracht.The apparatus for o-xylene evaporation in a plant for PSA production consisted of a vertical thermobalance pipe of 1200 mm diameter. Through this, the oxidation air preheated to 200 ° C with a preheater was sent to the reactor. The pressure was about 1.5 bar absolute. The air was charged with o-xylene with a loading of 100 g per Nm 3 . The air was sucked without special cleaning, only via an air filter from the environment. The thermoplate tube was heated to 214 ° C with 20 bar steam. The o-xylene was injected via 6 swirl nozzles, which were mounted on a ring of 600 mm diameter and whose axis was pointing vertically upwards. These were axial hollow cone nozzles (KS 1 of type 216.324 made of steel, Lechler). The form was 8 bar. At a distance of 4.5 m behind the nozzles static mixers were mounted in the horizontally extending pipe section.

Mit diesem Dralldüsen-Heißwand-Mischer-System wurde eine homogene, strähnenfreie o-Xyloldampf-Luft-Mischung erzeugt, deren Homogenität auch durch schwankende Betriebsparameter nicht gestört wurde. Dies wurde an der langzeitkonstanten PSA-Ausbringung festgestellt. Ferner wurden keine die Anlagensicherheit beeinträchtigende, durch Gemischinhomogenitäten verursachte Zündungen innerhalb der Produktionsanlage beobachtet. Schäden oder Notabschaltungen durch hohe Temperaturen in einzelnen Reaktorbereichen oder in Reaktorrohren wurden nicht beobachtet. Zwischen den jährlichen wartungsbedingten Routineabschaltungen lag die Anlagenverfügbarkeit bei über 99%.With this swirl hot-wall mixer system, a homogeneous, strands-free o-xylene vapor-air mixture produces its homogeneity also not disturbed by fluctuating operating parameters has been. This was determined by the long-term constant PSA application. Furthermore, no plant safety, ignitions caused by mixture inhomogeneities within the production plant observed. Damage or emergency shutdowns by high temperatures in individual reactor areas or in reactor tubes were not observed. Between the annual maintenance-related routine shutdowns lay the plant availability at over 99%.

Claims (11)

  1. A process for producing a homogeneous mixture of a gaseous aromatic hydrocarbon and an oxygen-containing gas for catalytic gas-phase reactions, by
    atomizing the liquid aromatic hydrocarbon to form droplets having a diameter of less than 1 mm and injecting it into an oxygen-containing gas stream preheated to above the boiling point of the aromatic hydrocarbon,
    wherein the mixture is produced in a chamber which is bounded by side walls heated to above the boiling point of the hydrocarbon, the liquid aromatic hydrocarbon is atomized by means of nozzles which form a hollow cone.
  2. A process as claimed in claim 1, wherein the hollow atomization cone has an opening angle of from 30° to 70°.
  3. A process as claimed in claim 1 or 2, wherein the central axis of the hollow atomization cone is at an angle of from -30° to +30° to the central axis of the preheated gas stream.
  4. A process as claimed in any of claims 1 to 3, wherein the liquid aromatic hydrocarbon is atomized by means of swirl nozzles.
  5. A process as claimed in any of claims 1 to 4, wherein the side walls of the chamber are formed by a heated tube.
  6. A process as claimed in claim 4 or 5, wherein from 5 to 50% by weight of the atomized hydrocarbon are vaporized on the heated side walls.
  7. A process as claimed in any of the preceding claims, wherein the mixture after vaporization of the aromatic hydrocarbon is passed through a static mixer.
  8. A process as claimed in any of the preceding claims for use in the synthesis of phthalic anhydride, where the aromatic hydrocarbon is o-xylene and/or naphthalene and the oxygen-containing gas is air.
  9. An apparatus for producing a homogeneous mixture of a gaseous aromatic hydrocarbon and an oxygen-containing gas having
    a channel (11) for a preheated, oxygen-containing gas stream (12) and
    an atomization device (13) for a stream of a liquid aromatic hydrocarbon opening into the channel (11),
    wherein the atomization device (13) has swirl nozzles (15) and the channel (11) has, at least downstream of the swirl nozzles (15), walls (18) which can be heated to at least the boiling point of the hydrocarbon.
  10. An apparatus as claimed in claim 9, wherein the channel (11) comprises a double-walled tube or a tube made of "Thermoblech".
  11. An apparatus as claimed in claim 9 or 10, wherein a static mixer is installed in the channel downstream of the swirl nozzles.
EP00985245A 1999-12-23 2000-12-22 Method and device for production of a homogeneous mixture of a vapour-forming aromatic hydrocarbon and an oxygen-containing gas Expired - Lifetime EP1239944B1 (en)

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DE19962616A DE19962616A1 (en) 1999-12-23 1999-12-23 Production of a homogeneous mixture of an aromatic hydrocarbon vapor and an oxygen containing gas for catalytic gas phase reactions, comprises spraying the hydrocarbon in the form of a hollow cone
DE19962616 1999-12-23
PCT/EP2000/013165 WO2001047622A1 (en) 1999-12-23 2000-12-22 Method and device for production of a homogeneous mixture of a vapour-forming aromatic hydrocarbon and an oxygen-containing gas

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FR2835443B1 (en) * 2002-02-01 2004-03-05 Commissariat Energie Atomique METHOD AND DEVICE FOR MIXING GAS
DE102004052827B4 (en) * 2004-11-02 2010-05-06 Lurgi Gmbh Apparatus for producing an o-xylene-air mixture for phthalic anhydride production
DE102005030416B4 (en) * 2005-06-30 2007-06-21 Stockhausen Gmbh Arrangement and method for heating and fumigation of a polymerizable material and apparatus and method for producing high-purity (meth) acrylic acid
DE102005059971A1 (en) * 2005-12-15 2007-06-21 Fisia Babcock Environment Gmbh Smoke gases at high flow-rates are treated, to destroy nitrogen oxides, by injection of liquid reducing agents with high efficiency dispersal by vortex shedding from an inclined planar baffle
DE102006004068A1 (en) * 2006-01-28 2007-08-09 Fisia Babcock Environment Gmbh Method and device for mixing a fluid with a large gas flow rate
GB0718995D0 (en) * 2007-09-28 2007-11-07 Exxonmobil Chem Patents Inc Improved vaporisation in oxidation to phthalic anhydride
GB0718994D0 (en) * 2007-09-28 2007-11-07 Exxonmobil Chem Patents Inc Improved mixing in oxidation to phthalic anhydride
US8648007B2 (en) * 2008-04-22 2014-02-11 Fina Technology, Inc. Vaporization and transportation of alkali metal salts
CN103949171A (en) * 2014-04-28 2014-07-30 德合南京智能技术有限公司 Rapid gas-solution mixing method and device
EP2955219B1 (en) * 2014-06-12 2020-03-25 The Procter and Gamble Company Water soluble pouch comprising an embossed area
JP6941473B2 (en) * 2017-04-26 2021-09-29 株式会社日本製鋼所 Display manufacturing method, display and LCD TV
CN107096405A (en) * 2017-06-08 2017-08-29 江苏天宇石化冶金设备有限公司 A kind of high efficient gas and liquid blender
CN112546889B (en) * 2020-11-16 2021-07-20 哈尔滨工业大学 Gas mixing device for thermal stability output of heat storage and release system
KR102469555B1 (en) * 2020-11-26 2022-11-22 현대제철 주식회사 Treatment apparatus of particle and gas material

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1350202A (en) * 1918-07-05 1920-08-17 G A Buhl Company Liquid and gas contact apparatus
FR2019460A1 (en) * 1968-09-19 1970-07-03 Zieren Chemiebau Gmbh Dr A Control apparatus for bore pipes and similar bodies
DE2517756A1 (en) * 1975-04-22 1976-11-04 Christian Coulon PROCESS AND EQUIPMENT FOR DUSTING AND BURNING LIQUID FUELS
US4157241A (en) * 1976-03-29 1979-06-05 Avion Manufacturing Co. Furnace heating assembly and method of making the same
CH608587A5 (en) * 1977-03-16 1979-01-15 Michel Suaton Swirl device for burner using liquid fuel atomised at high pressure
DE3044518A1 (en) * 1980-11-26 1982-07-01 Basf Ag, 6700 Ludwigshafen METHOD FOR PRODUCING PHTHALIC ACID ANHYDRIDE
JPS5895103A (en) * 1981-11-30 1983-06-06 ガデリウス株式会社 Pressure atomizing system porous type temperature reducer
EP0085445B1 (en) * 1982-01-29 1987-05-20 Shell Internationale Researchmaatschappij B.V. Process for contacting a gas with atomized liquid
JPS63248445A (en) * 1987-04-03 1988-10-14 Kawasaki Steel Corp Regeneration of catalyst for producing phthalic anhydride
US5108583A (en) * 1988-08-08 1992-04-28 Mobil Oil Corporation FCC process using feed atomization nozzle
DE3925580A1 (en) * 1989-08-02 1991-02-07 Hoechst Ag METHOD AND DEVICE FOR PRODUCING GAS / VAPOR MIXTURES
JPH0775658B2 (en) * 1990-05-10 1995-08-16 株式会社新潟鐵工所 Gas mixing device
US5242577A (en) * 1991-07-12 1993-09-07 Mobil Oil Corporation Radial flow liquid sprayer for large size vapor flow lines and use thereof
JPH06509823A (en) * 1992-06-18 1994-11-02 アモコ・コーポレーション Method for producing aromatic carboxylic acid
JPH07332847A (en) * 1994-06-03 1995-12-22 Mitsubishi Chem Corp Spray-drying method
JPH08198807A (en) * 1995-01-30 1996-08-06 Mitsubishi Chem Corp Production of terephthalic acid
JP4025891B2 (en) * 1997-02-27 2007-12-26 ビーエーエスエフ アクチェンゲゼルシャフト Method for producing shell catalyst for catalytic gas phase oxidation of aromatic hydrocarbons
JP3745489B2 (en) * 1997-03-18 2006-02-15 富士写真フイルム株式会社 Method for producing emulsion
DE19755275A1 (en) * 1997-12-12 1999-06-17 Basf Ag Complete vaporization of liquid in gas stream without reducing gas velocity
JP4026784B2 (en) * 1998-01-08 2007-12-26 富士重工業株式会社 In-cylinder injection engine

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MY125936A (en) 2006-09-29
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AU2172001A (en) 2001-07-09
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EP1239944A1 (en) 2002-09-18
JP4669184B2 (en) 2011-04-13
ES2218265T3 (en) 2004-11-16
DE19962616A1 (en) 2001-06-28
ATE262372T1 (en) 2004-04-15
WO2001047622A1 (en) 2001-07-05
CN1174793C (en) 2004-11-10
CN1411392A (en) 2003-04-16
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MXPA02005852A (en) 2002-10-23
KR100655339B1 (en) 2006-12-08
TW581710B (en) 2004-04-01

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