DE10047693A1 - Process for lengthening the service life of catalysts comprises using a charge of inert material in the contact tubes, the tubular base and between the base and gas inlet and outlet - Google Patents

Abstract

A process for lengthening the service life of catalysts comprises using a charge of inert material in the contact tubes, the tubular base and between the base and gas inlet and outlet hood of the reactor. Independent claims are also included for: (a) a container for stabilizing an inert material against drifting; (b) a tubular reactor comprising a reactor casing, bases (11, 12), contact tubes (4), gas inlet and outlet hoods (1, 2), and inlet and outlet openings for process gas and heat carriers. The lower hood is connected to a hydraulic lowering device; and (c) a process for burning off deposits on the insert material comprising treating the deposits with an oxygen-containing gas containing 0.1-50 vol.% oxygen at 200-800 deg C and 0.01-5.0 MPa pressure.

Description

The present invention relates to a method for extension the service life of catalysts in tube bundle reactors and containers ter to stabilize an inert material fill against usage hung.

Shell and tube reactors are used for processes for highly exothermic, temperature-sensitive reactions (see e.g. Ullmann's Encyclopedia of Industrial Chemistry, 6 ^th ed, 1999 Electronic Release. Chapter: Catalysis and Catalysts-Reactors for Two-Phase Systems) and are also analogous for endothermic Procedure can be used.

Shell and tube reactors have a inside of a reactor jacket a heat pump pumped in the circuit, e.g. B. water, heat transfer oil or eutectic salt mixtures, washed contact tube bundle that is between a reaction gas inlet side and extends a tube sheet on the reaction gas outlet side, and the gas inlet spanning the two tube plates at the end process gas, generally a gas mixture, is over the Gas inlet hood in the contact containing catalyst mass pipes introduced and after passing through the gas out discharge hood removed from the reactor. The gas can entry is on the top or bottom and the heat transfer medium holistically seen in cocurrent or countercurrent with respect to pass the process gas stream through the reactor. Can too the reactor can be designed in several stages.

Usually the process gas stream is made up of two or more shortly before entering the reactor, d. H. its gas inlet hood, get merged material flows. It can, above all in the immediate vicinity of the usually relatively hot pipe soil, come to adverse reactions for the process. This is particularly the case with such tube bundle reactors which the tube sheet has tube-free areas in which the Heat transfer medium is deflected so that the tube sheet is about the Has temperature of the heat transfer medium. This effect is special during the start-up phase, e.g. B. after a shutdown, pronounced.

Another disadvantage of such reactors is that, according to Ullmann's Encyclopedia of Industrial Chemistry (6 ^th ed, 1999 Electronic Release. Chapter: Catalysis and Catalysts-Filling Fixed-Bed Reactors), catalyst distribution and particle size must be uniform in order to avoid channel formation, which leads to an inadequate heat transfer and an impairment of the catalyst performance. The pressure loss in each contact tube should be the same so that the gas flow is evenly distributed across all tubes.

Slight changes in the packing density in the tubes can be inconsistent heat transfer and, in the case of a strongly exothermic reak ions, so-called hot spots and selectivity ver result in lust.

Since a change of catalyst in tube bundle reactors means a shutdown for several weeks and the pressure loss adjustment in tube bundle reactors is a manual process (Ullmann's Encyclopedia of Industrial Chemistry, 6 ^th ed, 1999 Electronic Release. Chapter: Oxidation-Process Technology of Heterogeneously Catalyzed Oxidations) endeavors to provide the catalyst with the longest possible service life, ie the period in which the catalyst achieves certain conversion and selectivity values under acceptable process parameters.

Partial oxides are examples of exothermic reaction processes tion such as B. the production of maleic anhydride, phthal acid anhydride, acrolein, methacrolein, methacrylic acid and acrylic acid, but also ethylene oxide and propylene oxide and as examples for endothermic processes the production of hydrocyanic acid and vinyl formamide.

Partial oxidations in the sense of this document are such gases phase oxidations, in which a hitherto during the reaction bond between a carbon that is not present in the target molecule Substance atom and an oxygen atom is linked, the Oxygen atom from the molecular oxygen of the process gas comes.

Examples of such partial oxidations are those per se known preparations of maleic anhydride from n-butane or 2-butene, phthalic anhydride from o-xylene, acrolein from propane or propene, methacrolein from isobutane, isobutene, or tert. Butanol, methacrylic acid from isobutane, isobutene, tert-butanol, Methyl tert-butyl ether, methacrolein or isobutyraldehyde, Acrylic acid from acrolein, propane or propene, ethylene oxide Ethene and propylene oxide from propene.  

For reasons of economy and safety technology at least part of the non-condensable reactor inert after extensive separation of the reaction products, as Recycle gas is returned to the reactor to those inside Recycle components of value or around this cycle gas as a inert inert gas to use.

With these, as well as with the process gas that passes through the reactor has, however, to some extent also contaminants, e.g. B. higher molecular weight organic substances, dirt particles and Verko products, carried on the tube sheet and / or can precipitate the catalyst mass. This is particularly so the case for reactions in multi-stage reaction zones, for example play with several reactors connected in series, at de when moving from one reaction zone to the next on. Value, intermediate or by-product unselective reactions can perform e.g. B. coking, polymerization, condensation of high-boiling components etc., and thus as a further pollution Cleaning for deposits on the tube sheet, the catalyst and / or lead in individual contact tubes, which these at least at least partially clogged. In addition to the previous ones Impurities listed can also be a catalyst inventory part of a previous stage, z. B. by abrasion or sublimation, and in the following procedure disrupt stage.

Depending on the inflow to the tube sheet on the gas inlet side such partially or completely blocked reaction tubes or Pipe bundle areas no longer as desired by the process gas flows through and therefore no longer optimally participate in the reaction part. To the same extent, the other contact tubes and inside contained catalyst loaded more, causing the local Temperature is increased, which also leads to a faster des activation can lead. A partial flow partially clogged Pipes can not only because of the changed flow rate digkeit- and residence time ratios in this reaction space cause unselective reactions, it can also, as described above ben, by the changed heat dissipation to local overheating (hot spots) lead the catalyst z. T. about its tole heat the temperature range or its thermal stability and irreversibly damage and thus shorten its service life or to ignitions or deflagrations of the reaction gas mixture being able to lead. Such deflagration caused in a tube or ignition can occur at low gas flow rates the gas inlet space between the tube sheet and the gas inlet hood kick back and there to further hot spots or pressure surges that the catalyst or the reactor and the associated apparatus  damage or at least a response to security tech African facilities can cause what a shutdown of System and thus result in loss of production.

Possible deposits of coking or polymer sation are often in practice by burning, d. H. Behan with an oxygen-containing gas at an elevated temperature, away. As a result, high lo kale temperatures occur, which in the worst case the inte can affect the quality of the catalyst or reactor components.

The use of inert beds in reactors has been around for a long time known.

W. Bauer, Jr., in "Kirk-Othmer, Encyclopedia of Chemical Technology ", 4th ed., 1994, chapter" Acrylic Acid and De rivatives ", page 298, that in the stage of partial oxidation of propene as a small amount of an inert material Preheater acts for the feed gas.

DE-A 30 42 468 describes the two- Stage oxidation of propylene a cooling area in the form of a bed tes of an inert solid in the contact tubes gas outlet described later in connection with the catalyst bed. On the use of such a cooling area to reduce Deposits or as a flame arrester are not accepted.

In DE-A1 198 06 810 a tube reactor with a Pipe cross-sections saving heat insulation layer in the area of the tube sheet on the reaction gas inlet side. A such a heat insulation layer causes the gas inlet side that Process gas entering is kept away from the hot tube sheet and heat transfer side that the tube sheet in relation to the Heat transfer medium is kept cool.

The underlying task of DE-A1 198 06 810 was the prevention of side reactions, especially ignitions and deflagrations, in inside the gas inlet hood. It is suggested the Rohrbo compared to the heat transfer medium or the incoming process gas Insulate heat so that the tube sheet is relatively cool will hold, or the process gas is prevented from to come into contact with the hot tube sheet.

The heat insula applied to the heat transfer medium on the tube sheet tion layer consists for example of ceramic, such as a glass frit, or a corresponding heat-dissipating solid and encloses the individual pipes as tightly as they fit together  connect the reactor jacket and spares the pipe cross sections. In addition to the insulation of the tube plate on the gas inlet side can be a filling made of ceramic material, a wire mesh braid or the like may be included.

A disadvantage of this heat insulation layer is that it Layer especially complex due to the cut-out of the pipe cross-sections must be adapted to the tube bundle reactor. A heat transfer medium side thermal insulation is still within the scope of the usual setting lungs not for control or exchange purposes accessible, this requires opening the heat transfer chamber. moreover the proposed thermal insulation of the catalyst not protected from contamination.

WO 00/51962 describes a process for the production of vinyl Acetate from ethylene, oxygen and acetic acid in one tube Bundle reactor described in the liquid acetic acid, inhibitor residues and polymers in an inert material that can be over entire volume has interconnected cavities are filtered out of the feed gas. Another effect of this Inert material is the feed gas that this comes out contains filtering substances, more evenly on the tubes of the Distribute reactor and prevent a flashback countries. Furthermore, removable grids or supporting ones Structures such as B. frame, for storage and protection of the Inertbettes proposed to access personnel ensure without crushing the inert bed, or an An bring the inert bed to the bottom of the reactor.

The disadvantage is that such removable grids or sub support structures the change of the inert bed is difficult.

Furthermore, in WO 00/51962 only inert beds on the Gas inlet side described to vinegar contained in the feed gas filter out acid or non-volatile components. problema However, the process gas on the gas outlet side, ie. H. after passage of a catalyst. In this are conditional through the reaction, polymerizable substances of the above-mentioned partial oxidations, e.g. B. acrylic acid, meth acrylic acid, maleic anhydride, acrolein, methacrolein etc., as well as lower aldehydes, but also catalyst components, such as z. B. abrasion or sublimate, enriched so that the process gas the gas outlet side of the reactor a much higher risk the formation of impurities or impurities may include, so that subsequent process stages thereof can be affected.  

The object of the present invention was to provide a method for to provide partial oxidation, which is equally to reduce deposits on the catalyst or appa advice components, as gas distribution and as flame relationship wise explosion barrier on the gas inlet and / or outlet side serves.

It has now been found that the service life of catalysts extend for partial oxidation in tube bundle reactors can if you have a bed of an inert material in the area of the tube sheet in the contact tubes and in the area between the tube floor and gas inlet and / or outlet hood used.

The inert material, consisting of suitable moldings, is filled in a random bed ( 5 ) above and / or below (not shown) the catalyst bed ( 4 ) located in the catalyst tubes ( FIG. 1). This generally includes, in addition to the thickness of the tube sheet (11 or 12), a fill height between the catalyst bed and the heat transfer side of the tube sheet of 1 to 50 cm, particularly 2 to 20 cm and particularly preferably 5 to 10 cm.

Thus, the inert material bed in the contact tubes in the region of the tube sheet ( 5 ) on the top of the reactor comprises the volume between the top edge of the catalyst bed and the top of the tube sheet or on the bottom of the reactor analogously the volume between the bottom edge of the catalyst bed and the bottom of the tube sheet.

If desired, the catalyst on the Ga entry and / or exit side mixed with inert material become.

Bodies known per se to the person skilled in the art come as molded bodies high geometric ("outer") surface into consideration, e.g. B. Balls, rings, spirals, saddle bodies, braids, irregular Granules, tablets, cylinders or strands, optionally as Compacts or extrudates.

The size of the moldings, i.e. H. in the context of this document greatest spatial extension, is generally up to 15 mm, preferably between 0.5 and 10 mm, particularly preferably between 1 and 7 mm and very particularly preferably between 1 and 5 mm.

The area of the tube sheet in the contact tubes is general mean not loaded with catalyst mass, because in this Area that is not washed with heat transfer medium, the removal of the  generated by the exothermic reaction within the catalyst tubes Heat of reaction is insufficient.

Such materials are suitable as inert materials, as long as the dimensions Satisfy that they do not we under the reaction conditions significant chemical reactions to the present reaction gas mixture result, for example oxides, sulfides, Ni trides, carbides, carbonates and silicates of alkali, alkaline earth and transition metals, as well as metals, semi - and non - metals the III., IV. and V. main group of the periodic table of the chemi elements and their mixtures. Magnesium is preferred oxide, calcium oxide, α-aluminum oxide, γ-aluminum oxide, silicon di oxide, titanium dioxide, zinc oxide, silicon nitride and silicon carbide as well as containing at least one of these substances in nature occurring or artificial mixtures, such as B. aluminum silicates, ceramic materials, common refractory materials and glasses. Α-aluminum oxide, silicon carbide, Bentonite, steatite, mullite, kyanite, pumice stone, diatomaceous earth and / or Kaolin.

Inert materials are preferably used which, in addition to their outer surface due to the geometry of the molded body surface increased porosity and / or inner surface have, preferably those with coarse and / or fine pores the latter are those with macro and / or mesopores.

Of course, steels and stainless steels are also in the tech nisch common alloys possible, but have essentially just a geometric surface.

Due to a large geometric and inner surface, generally a higher adsorption effect and consequently a higher cleaning effect in the process gas stream achieved than without be or such an inert material fill with less Surface.

The inert material bed ( 5 ) located in the contact tubes should be such that it prevents a flashback in the contact tubes, for example by a hot spot or the like, resulting or arising flame formation in the space between the gas inlet side tube sheet and the gas inlet hood. This is preferably the case when the inert material consists essentially of shaped bodies whose size is up to 3 mm, particularly preferably between 0.5 and 2 mm, balls with a size between 0.5 and 2 mm are very particularly preferred ,

The flames fight back into the space between the tube sheets (11 or 12) and hood (1 or 2) is in generally the more effectively prevented, the smaller the shape body, or the spaces between the forms are bodies, or the lower in networks or Braiding the mesh size is.

However, since this increases the pressure loss, this flame barrier is preferably used only in the area of the contact tubes ( 5 ). In addition, the small gaps tend to be clogged by impurities, so that a separation of such contaminations by an additional inert material bed ( 6 ) between the tube sheet and hood is advantageous.

The area between the tube sheet and the gas inlet or outlet hood is also filled with inert material ( 6 ) according to the invention. The inert material bed located in this area is essentially such that it intercepts impurities contained in the reaction gas, for. B. by adsorption or filter action, and / or that it causes a uniform distribution of the incident reaction gas on the contact tubes to compensate for local occupancy of the inert material bed, and / or that it causes an adjustment of the temperature of the gas inlet-side reaction gas to the temperature of the tube sheet , and / or that they with little pressure loss along the contact tubes, for. B. in the case of relatively short contact tubes, in which even small differences between the individual contact tubes can have a strong effect, brings about an approximation of the pressure loss between the individual contact tubes.

The same inert material fill as in the contact tubes are used, is preferred in the area between the tube sheet and the gas inlet or outlet hood, however a bed of larger shaped bodies than that in contact tubes used, particularly preferably a bulk tion, the size of the molded body is between 2 and 8 mm and very particularly preferably between 3 and 5 mm. It can also in the area between the tube sheet and gas inlet or gas outlet Inert material used from the same or one suitable other material and / or the same and or ande ren shaped bodies exist.

The filling level of the inert material bed ( 6 ) in the area between the tube sheet and the gas inlet or outlet hood can be, for example, between 5 and 100 cm, preferably between 5 and 80 cm, particularly preferably between 10 and 50 cm and very particularly preferably between 10 and 30 cm.

Of course, the use of a bed of inert material is not only limited to the gas inlet side, but can also be located on the gas outlet side of the contact tubes and / or between the reactor and the gas outlet hood (not shown in FIG. 1). In this case, the purpose of such an inert material bed is mainly to remove the impurities contained in the reaction gas in order to remove its deposits in a downstream process stage, such as, for. B. Re actuator, absorber, heat exchanger or quench to reduce, be particularly such deposits in a heat exchanger, for. B. an intercooler. In this case, the inert material bed is to be secured in a suitable manner against slipping, since the gas outlet side is usually located on the underside of the described reactors.

In this case or in the case of flow through the reactor from the bottom up, it may be advantageous for the hood ( 2 ) on the underside of the reactor, optionally with components thereon, such as, for. B. a quench or heat exchanger, e.g. B. an intercooler to provide a lowering device ( Fig. 4, 13) with which the accessibility of the inert material by lowering the hood ( 2 ), as shown in Fig. 4b, he is facilitated. The type of lowering is not limited. B. done hydraulically.

For this purpose, the lower hood ( 2 ) is permanently connected to a known, for example hydraulic device, with which the hood controls after loosening the connection to the reactor jacket, for. B. can be lowered for cleaning or maintenance work. After completing the above-mentioned work, the hood ( 2 ) can be brought back to the initial state by the same device and connected again to the reactor jacket.

In this case, the inert material fill is placed on a suitable th bracket, through which the moldings do not escape can, e.g. B. perforated plates, sieves, sieve plates, fabrics, nets or Combinations of these. Furthermore, of course, the stabilization options described below who used the.

The above applies to the filling level of the inert material fill Said.  

The method according to the invention includes guiding the Reaction gas to be brought through the reactor from above down or from the bottom up. The process gas is preferred passed through the reactor from top to bottom.

The guidance of the heat transfer medium is not restricted. According to the invention, the heat transfer medium can be based on the process gas be carried out in cocurrent or countercurrent, is preferred the lead in direct current.

It may also be expedient to increase the distance between the tube sheet ( 12 ) and the hood ( 2 ) in the manner shown in FIG. 5, so as to create an area ( 14 ) between the hood and the tube sheet for a larger amount of inert material. This area ( 14 ) can be located on the top or bottom of the reactor, or on the gas inlet or outlet side and, if it is on the bottom, can also be provided for a lowering.

Since the inert material bed in the reactors is exposed to relatively high gas speeds, there is a risk that the individual moldings due to gas flows and Verwirbelun conditions such. B. as a result of the flow line through a baffle plate ( 3 ), but also without a baffle plate, in the bed, which can cause drifts. Such drifts affect the effectiveness of the inert material filling by changing the desired bed height. Depending on the type, size and weight of the molded body, this can be the case from gas speeds of approx. 5 to 8 m / s.

In order to counteract such drifts, it can furthermore make sense according to the invention to stabilize the pouring in against at least one of the following measures against drift:

• - A substantially parallel to the tube sheet cover ( 7 ) can stabilize the inert material on the gas inlet or outlet side, if desired, several layers of inert material can be stabilized by such che covers ( Fig. 2).
• - The inert material fill can be filled into suitable containers ( 9 ) in which at least the bottom ( 15 ) and the cover ( 18 ), if present, are made of a cover ( Fig. 3, 3a, 3b, 6a, 6b).

As covers, i.e. H. walls permeable to the process gas, can perforated plates, sieves, sieve plates, fabrics or nets the mesh size or hole size is that the shaped body is not ge through the mesh or holes long or clog them. This is for example at a mesh or hole width of up to Half the size of the moldings used, preferably one Tenths to a third and particularly preferably one Tenths to a quarter.

The covers can be conveniently on the tube sheet or Gas inlet or outlet hood in a manner known per se be consolidated, for example by hooks or screw connections.

As containers for receiving the inert material fill, those can be used in which at least the bottom (15 in FIGS. 6a, b) consists of one or more of the covers mentioned. Advantageously, the side walls ( 16 ) and / or ( 17 ) consist of one or more of the above-mentioned covers, the same cover as used for the bottom ( 15 ). However, the side walls ( 16 ) and / or ( 17 ) can also be solid, ie have no holes and / or meshes.

Furthermore, a lid ( 18 ) can advantageously form the top of the container, which likewise consists of one or more of the covers mentioned, the same cover as for the bottom ( 15 ) being able to be used. The lid ( 18 ) can be present separately from the container as in Fig. 6a, but it can also be fixed to the container in a manner known per se, e.g. B. by hinges, rings or pins.

For the purpose of closing the top of the container, the lid ( 18 ) can be connected to the side walls of the container in a manner known per se, e.g. B. via locks, hooks, flexible rods or springs. If the lid ( 18 ) is dispensed with, the containers which are open at the top can also be covered, for example, with a cover which can first stretch over the entire reactor diameter.

In addition, the container can be placed on spacers ( 19 ) so that, for. B. for temperature compensation, a distance from the tube sheet is maintained.

The containers preferably have any essentially rectangular or square bottom surface ( 15 ), but any other geometries, such as, for example, are also conceivable. B. Hexagons, Tra peze etc.

The containers, which are located on the edge region of the tube sheet to the reactor jacket, preferably have a curved side wall (20, Fig. 6b) which are adapted to the curvature of the reactor wall or the reactor jacket. The same applies to the bottom ( 15 ) and the optional cover ( 18 ).

Typical edge lengths for the floor surfaces ( 15 ) with the side surfaces (16) and / or (17) are between 20 and 200 cm, before given between 30 and 150 cm and particularly preferably between 40 and 100 cm.

The height of the container is typically 5 to 110 cm before draws 5 to 90 cm, particularly preferably 10 to 60 cm and completely particularly preferably 10 to 35 cm.

The distance between the upper fill level of the inert material fill in the containers and the upper edge of the side walls ( 16 ) and / or ( 17 ), or the lid, if applicable, is typically at most 20 cm, preferably at most 10 cm and particularly preferably at most 5 cm.

The spacers ( 19 ) of the containers, if present, are typically 5 to 100 mm long.

The number of spacers is at least four or, in the case of curved containers, as in FIG. 6b, at least three, but any number can be added.

Furthermore, devices such as. B. handles, eyelets or hooks, which allow easy replacement of the container, for example when changing the inert material bed (not shown in Fig. 6a, 6b).

Thus, the container together with the inert material to be exchanged can be easily removed and, if necessary after opening the optional lid ( 18 ), emptied and, if desired, filled with fresh inert material and used again in the gas inlet or outlet space. Such an inert material bed can of course also be removed from the containers, for example by suction or scooping.

The material from which the covers or containers are made not restricted, preferably steels or stainless steels used.

The containers can, for example, be arranged regularly or have a shape adapted to certain partial areas of the tube sheet, such as pipe-free zones or the edge area (10 in FIG. 3b).

The bed height of the inert material can be in the individual containers be the same or different, as well as the inert used material. Preferably in the said pipe-free Teilbe reach the tube sheet with smaller moldings and / or such a higher inner or outer surface, you can but also with a solid component consisting of a suitable inert material, e.g. B. the inert materials mentioned above lien, for example firebrick.

By using the cover according to the invention wise containers, the drift is effectively reduced, too In addition, the removal of the inert material fill is made easier tert by the material together with the containers or the Ab cover is removed.

If different areas of inert material are used in the areas in the contact tube ( 5 ) and between the tube sheet and the gas inlet or outlet hood ( 6 ), it can make sense to cover these areas with a cover according to the invention, which is applied directly to the tube sheet (8 in Fig. 2) to separate 1. This has the advantage that when the inert material bed ( 6 ) is suctioned off in the region between the tube sheet and the gas inlet or outlet hood, the inert material bed ( 5 ) in the contact tubes is not accidentally removed.

Furthermore, it can be useful to use the inert material, the Deposits located on the catalyst and / or reactor components, ent ent in the course of a process of partial oxidation stood by burning, d. H. essentially more complete Oxidation to e.g. B. carbon oxides and water to remove. To do this, the deposits are mixed with an oxygen-containing gas an oxygen content of 0.1 to 50% by volume, preferably 0.5 to 25% by volume, particularly preferably 1 to 20 vol% at a temperature of 200 to 800 ° C, preferably 200 to 600 ° C, particularly preferably 250 up to 500 ° C and very particularly preferably 300 to 450 ° C and at one Pressure from 0.01 to 5.0 MPa, especially 0.05 to 1.0 MPa, especially  preferably 0.09 to 0.15 MPa and very particularly preferably at nor thermal pressure.

Nitrogen, water vapor, and coal can be used as the inert gas for dilution Dioxide and / or noble gases, such as. B. helium, neon or argon, are used, nitrogen and / or water vapor are preferred.

To make an uncontrolled during the strongly exothermic regeneration Temperature rise and thus possible damage to the catalytic converter avoiding a goal, you advantageously start with one never low oxygen concentration. Among them is, for example To understand oxygen concentration of 0.1 to 5 vol .-%. The on 100% by volume of missing parts become clogged as previously described together. Air with nitrogen and / or what is advantageous diluted to the desired oxygen concentration. ever according to the embodiment, it is possible to start at the beginning of the to set the desired final temperature or a lower temperature. It is only when the burning progresses advantageous under control of the temperature gradient, the Sauer substance concentration and / or the temperature successively or continuously to increase it. At the end of the burn it is too possible to pass undiluted air over the catalyst. The Burn-off oxygen treatment generally takes several Minutes to a few days and depends, among other things, on the Type of deposits, the type of catalyst and especially of the amount of impurities on the catalyst. Too short thermal treatment leads to insufficient burning of the Deposits, prolonged treatment generally hurts Not. The progress of the burning procedure can be done via the Exo thermal of the reaction, d. H. the temperature profile along the Catalyst bed ("hot spot"), and the content of carbon foxides in the exhaust gas are tracked.

The gas flow through the reactor is chosen so that the Temperature in an individual security area that can. If this security area is left, so the temperature can be lowered and / or the proportion of inert gas be raised.

The method according to the invention enables an improved host Efficiency through a simplified technical feasibility speed, as well as an extension of the service life of catalysts in Tube bundle reactors and a reduction in downtimes an easier change of the inert material filling. Farther becomes a simplified and less safety-related ch burning of receipts, since they mostly on  the inert material filling and only subordinate to the Catalyst and / or reactor components are deposited.

Claims (18)

1. A method for extending the service life of catalysts for partial oxidation in tube bundle reactors, characterized in that a bed made of an inert material is used in the contact tubes and in the area of the tube sheet and in the area between the tube sheet and the gas inlet and / or outlet hood. 2. The method according to claim 1, characterized in that one in the contact tubes in the area of the tube sheet and in the area between the tube sheet and the gas inlet and / or outlet hood different inert material fillings used. 3. The method according to any one of the preceding claims, characterized characterized in that the inert material is molded in Shape of rings, tablets, saddles or balls used. 4. The method according to any one of the preceding claims, characterized characterized in that magnesium oxide, cal ziumoxid, α-aluminum oxide, γ-aluminum oxide, silicon dioxide, Titanium dioxide or silicon carbide or at least one of these Substances containing, occurring in nature or artificial Mixtures used. 5. The method according to any one of the preceding claims, characterized characterized in that the inert material is pumice, pebble gur, silicon carbide or steatite used. 6. The method according to any one of the preceding claims, characterized characterized in that the shaped bodies in the contact tubes in Area of the tube sheet preferably a size of at most 3 mm, particularly preferably have between 0.5 and 2 mm. 7. The method according to any one of the preceding claims, characterized characterized in that the process gas from top to bottom through the reactor is led. 8. The method according to any one of the preceding claims, characterized characterized in that the heat transfer medium in direct current is led to the process gas stream through the reactor.   9. The method according to any one of claims 1 to 7, characterized records that the heat transfer medium in counterflow with respect to the Process gas stream is passed through the reactor. 10. The method according to any one of the preceding claims, characterized characterized in that the inert material or inert material material fillings are stabilized against drift. 11. The method according to claim 10, characterized in that we at least one essentially parallel to the tube sheet brought cover is used. 12. The method according to claim 10 or 11, characterized in that cover the area of the tube sheet in contact pipes and the area between the tube sheet and gas inlet and / or outlet hood separates from each other. 13. Container for stabilizing an inert material pouring against drift, consisting of a bottom ( 15 ), side walls ( 16 ) and ( 17 ), optionally a curved side wall ( 20 ) and optionally a lid ( 18 ), characterized in that at least bottom ( 15 ) and the cover ( 18 ), if present, consist of a cover. 14. The method according to any one of claims 1 to 12, characterized records that the inert material in containers according to An saying 13 is filled. 15. The method according to claim 14, characterized in that the Filling level of the inert material in the containers fill is the same or different. 16. The method according to claim 14 or 15, characterized in that that another inert in tube-free areas of the tube sheet bulk material and / or another inert material than in the other areas. 17. tube bundle reactor with reactor jacket, tube sheets ( 11 ) and ( 12 ), contact tubes ( 4 ), gas inlet and outlet hood ( 1 ) and ( 2 ) and inlet and outlet openings for process gas and heat transfer medium, characterized in that the lower hood ( 2 ) is connected to a hydraulic lowering device ( 13 ). 18. Process for burning off deposits from a partial Oxidation process on inert material, catalyst and / or Reactor components, characterized in that the deposits  with an oxygen-containing gas with an oxygen content of 0.1 to 50 vol% at a temperature of 200 to 800 ° C and thermal at a pressure of 0.01 to 5.0 MPa treated.