KR101431365B1 - Method for structurally filling contact tubes of a bank of contact tubes - Google Patents

Abstract

The present invention relates to a method of filling a catalyst tube of a catalyst tube bundle in a structured manner, wherein a composition of a preformed catalyst preform is used to form a fill zone.

Description

Technical Field [0001] The present invention relates to a method for filling a catalyst tube bundle of a catalyst tube bundle in a structured manner,

The present invention relates to a method for structurally filling a catalyst tube of a catalyst tube bundle, wherein the individual catalyst tubes of the catalyst tube bundle are filled in the same manner from below to above in the zone having different shaped catalyst preparation.

A heterogeneous catalyzed gas on a fixed bed of catalyst, usually located in a vertical tube in a shell / tube reactor, such as a shell / tube reactor (shell / tube reactor; reactor with a bundle of catalyst tubes in the reactor shell) Processes for carrying out the phase reaction are known (see for example DE-A 44 31 949, EP-A 700 714). These may be either endothermic or exothermic gas phase reactions. In both cases, the reactant gas mixture passes through a fixed bed of catalyst located in the catalyst tube of the shell / tube reactor and the reactants react partially or completely during the time the reactants remain on the catalyst surface. The reaction temperature in the catalyst tube is controlled by passing energy through the reaction system or by passing the liquid heat transfer medium around the catalyst tube of the tube bundle located within the shell to remove energy from the reaction system. The heat transfer medium and the reactant gas mixture may travel in the same or opposite direction through the shell / tube reactor.

Unlike the possibility of passing the heat transfer medium in a simple manner in a longitudinal direction substantially perpendicular to the catalyst tube, this longitudinal transfer may only be realized on the entire reaction shell, Can form a layer in the longitudinal direction within the reactor shell by a series of straining plates arranged along the length of the tube bundle so that the serpentine flow of the heat transfer medium can form a longitudinal zone through the tube bundle -A 44 31 949, EP-A 700 714, DE-A 28 30 765, DE-A 22 01 528, DE-A 22 31 557 and DE-A 23 10 517).

If desired, the heat transfer media, which are substantially spatially separated from each other, can travel around the catalyst tube in tube zones disposed at different locations along the tubes. The tube zone of a particular heat transfer medium usually forms a separate reaction zone. Preferred variants of such multi-zone shell / tube reactors are described, for example, in DE-C 28 30 765, DE-C 25 13 405, US-A 3,147,084, DE-A 22 01 528, EP-A 383 224 and DE- 582 < / RTI > or the like.

Suitable heat transfer media are, for example, melts of salts such as potassium nitrate, potassium nitrite, sodium nitrite and / or sodium nitrate, metals of low melting point such as sodium, mercury and alloys of various metals, ionic liquids Is a conventional liquid such as water or a mixture of high boiling organic solvents (e.g., a mixture of Diphyl (R) and dimethylphthalate) as well as one or more of the ions charged to at least one carbon atom.

The catalyst tube is usually made of ferritic steel or stainless steel and often has a wall thickness of a few mm, for example 1 to 3 mm. Their internal diameter is usually several centimeters, for example 10 to 50 mm, often 20 to 30 mm. The length of the tube is usually in the range of a few meters (the catalyst tube length is typically 1 to 8 m, often 2 to 6 m, often 2 to 4 m). The number of catalyst tubes (working tubes) accommodated in the shell is preferably 1000 or more, often 3000 or more, often more than 10,000, from the viewpoint of operation. The number of catalyst tubes housed within the reactor shell is often 15,000 to 30,000 or 40,000 or 50,000. Shell / tube reactors with more than 50,000 catalyst tubes are exceptional. The catalyst tubes are usually distributed substantially uniformly within the shell and are preferably distributed such that the distance between the center axes of the nearest neighboring catalyst tubes (catalyst tube spacing) is between 25 and 55 mm, often between 35 and 45 mm (see, for example, EP- A 468 290).

In general, at least a portion of the catalyst tube (working tube) of the shell / tube reactor is uniform in terms of operation, preferably over the entire length (within the limits of manufacturing accuracy). I.e. their inner diameter, their wall thickness and their length are the same within a narrow tolerance (see WO 03/059857).

The aforementioned required profile may often be applied to fill a uniformly prepared catalyst tube with a shaped catalyst body as described above to ensure a substantially defect-free optimum operation of the shell / tube reactor (see, for example, WO 03 / 057653). In order to achieve the optimum yield and selectivity of the reactions to be carried out, in particular in the shell / tube reactor, it is of importance that all working tubes of the reactor are preferably homogeneously filled with the catalyst bed if possible.

The working tube and the heat tube are distinguished, for example, as described in EP-A 873 783. The heat tube serves to first and eventually monitor and control the reaction temperature in the catalyst tube, whereas the working tube is a catalytic tube in which the chemical reaction to be performed is substantially carried out. For this purpose, the thermal tube generally comprises a centrally located thermocouple sheath which, in addition to the fixed bed of the catalyst, comprises only a temperature sensor and extends longitudinally in the thermal tube. Generally, the number of heat tubes in the shell / tube reactor is much less than the number of working tubes. The number of heat tubes is generally 20 or less.

The above applies to heterogeneously catalyzed gaseous phase partial oxidation of one or more organic compounds, particularly those which are carried out in a shell / tube reactor, where relatively high amounts of heat are generated.

Examples which may be mentioned are the conversion of propene to acrolein and / or acrylic acid (see, for example, DE-A 23 51 151), methyl ethers of t-butanol, isobutene, isobutane, isobutyraldehyde or t- (For example, DE-A 25 26 238, EP-A 92 097, EP-A 58 927, DE-A 41 32 263, DE-A 41 32 684 and DE- A 40 22 212), conversion of acrolein to acrylic acid, conversion of methacrolein to methacrylic acid (see, for example, DE-A 25 26 238), conversion of o-xylene or naphthalene to phthalic anhydride (See for example DE-A 21 06 796 and DE-A 16 24 921), the conversion of n-butane to maleic anhydride (see, for example, GB- A 1 464 198 and GB-A 1 291 354), the conversion of an indane to, for example, anthraquinone (see, for example, DE-A 20 25 430), ethylene oxide of ethylene Conversion of propylene to propylene oxide (see for example DE-B 12 54 137, DE-A 21 59 346, EP-A 372 972, WO 89/0710, DE-A 43 11 608) Conversion of rhenitrile (see for example DE-A 23 51 151), conversion of isobutene and / or methacrolein to methacrylonitrile (i. E., The term partial oxidation is referred to as Ammoxidation ), Oxidative dehydrogenation of hydrocarbons (see, for example, DE-A 23 51 151), conversion of propane to acrylonitrile or acrolein and / or acrylic acid (for example, DE-A 101 31 297, EP-A 1 09 0684, EP-A 608 838, DE-A 100 46 672, EP-A 529 853, WO 01/96270 and DE-A 100 28 582).

The catalyst used to perform the heterogeneously catalyzed gas phase reaction on the fixed bed of catalyst located within the tube of the shell / tube reactor is generally an active composition that can be shaped to produce shaped bodies of various geometric shapes Quot; sieve "). Examples of such molded articles are spheres, pellets, extrudates, rings, helices, pyramids, cylinders, prisms, straight-parallel hexahedrons, and cubes.

The shaped body may be composed of only the catalytically active composition which, in the simplest case, can be suitably diluted with an inert material. Such a shaped catalyst body is generally referred to as an all-active catalyst.

In the case of a fully active catalyst, the shaping may be accomplished by, for example, squeezing a catalytically active powder (e. G., Powdered active multi-element oxidation composition) to produce the desired catalytic geometry (e.g., tableting, sintering, screw extrusion or ram extrusion) can do. A molding aid may be added during this process.

Alternatively, the shaping can be accomplished by coating the geometry of the catalytically inactive material (inactive material) with the active composition. As with all-active shaped catalyst bodies, such inert supports may have a regular or irregular shape. In the simplest case, the coating can be performed, for example, by wetting the surface of an inert support with a liquid binder and then applying the active composition in powder form to the wetted surface to attach to the surface. The resulting catalyst is referred to as a coated catalyst.

Suitable inert supports for many heterogeneous catalyzed gas phase reactions include porous or nonporous aluminum oxide, silicon dioxide, thorium dioxide, zirconium dioxide, silicon carbide or silicates such as magnesium or aluminum silicates (e.g., CeramTec) C220 type steatite) and a metal such as stainless steel or aluminum.

Inactivity (in this context, inert means that the reaction conversion rate is 5 mol% or less, generally 2 mol% or less, when the reaction gas mixture is passed through the packed bed composed of only dilute shaped bodies under the reaction conditions) , It is often possible to impregnate the support with a solution of the catalytically active material and then evaporate the solvent. The shaped catalyst bodies obtained by such a process are generally referred to as supported catalysts or impregnated catalysts.

The longest dimension of the shaped catalyst body (the longest possible dimension of the straight line between two points on the surface of the shaped catalyst body) is generally 1 to 20 mm, often 2 to 15 mm, usually 3 or 4 to 10 or 8 or 6 mm. In the case of rings, the wall thickness is additionally generally 0.5 to 6 mm, often 1 to 4 or 3 or 2 mm.

The active composition used is typically an oxidizing composition (for example, a multi-element oxidizing composition, such as a multi-metal oxide composition) comprising oxygen together with a noble metal (e.g., Ag) or one or more other elements.

Only in very rare cases of heterogeneously catalyzed gas phase reactions on the fixed bed of catalysts present in the tubes of the shell / tube reactor, the fixed bed of catalyst is homogeneous along the individual catalyst tubes and a single bed of shaped catalysts .

Rather, in most cases, the catalyst tube packing constitutes a different section of the catalyst packing, which is installed on top of each other. Each individual bed zone constitutes a uniform bed of shaped catalyst bodies. However, their composition (composition) generally changes suddenly from one bed zone to the next bed zone. This forms a fixed catalyst bed having a heterogeneous structure along individual catalyst tubes. This is also referred to as structured packing (or bed) in the catalyst tube.

Examples of such structured packings in catalytic tubes are described in particular in EP-A 979 813, EP-A 90 074, EP-A 456 837, EP-A 1 106 598, US-A 5,198,581 and US-A 4,203,903 have.

In the simplest case, two different catalyst loading zones in one reaction tube may differ from each other only in that the shaped catalyst comprising a single type of active composition is diluted with a different proportion of the inert shaped bodies without the active composition In the simplest case, they may be inactive supports, but may also be shaped bodies made of metal). The molding diluent may have the same geometry or different geometry as the shaped catalyst body (their maximum possible dimension range is generally the same as in the case of a molded catalyst body). Various types of dilution profiles (dilution structures) can be created by aligning the zones of the catalyst charge, diluted to different degrees, in series along the catalyst tubes (in each case, specifically adapted to the requirements of the gas phase reaction to be performed). In many cases, the dilution structure is selected such that the degree of dilution decreases with the flow direction of the reactant gas mixture (i.e., the volume-specific active composition increases with the flow direction and the volume-specific activity is low at a high reactant concentration And vice versa). However, it may be selected if an opposite or completely different dilution profile (active structuring) is required. In the simplest case, the structured packing in the catalytic tube is formed by placing a catalytic filling zone (which may be diluted with a molded diluent) consisting of a shaped catalyst body comprising the active composition, for example at the bottom of the catalyst tube, (Such a filling zone consisting solely of a forming diluent, hereinafter also referred to as a filling zone comprising a forming catalyst body). It is also possible that two filling zones consisting of the same shaped catalyst body comprising the active composition are cut off by the zone consisting only of the molding diluent.

Of course, active structuring may also be produced by a mixture which does not change along the region of two or more different shaped catalyst bodies comprising the active composition present in one filling zone in the catalyst tube. Here, the shaping catalyst bodies may be formed only of their geometric shape or only the chemical structure of their active composition or only the physical properties of their active composition (e.g., pore distribution, specific surface area, etc.) or the weight ratio of active composition applied to the inert molding diluent . However, these may be different in many or all of the above-mentioned differentiation features. In addition, they may include a molding diluent. Instead of active structuring, the filler in the catalyst tube may be selectively structured. Specifically, the latter is advantageous when the gas phase reaction takes place in a subsequent reaction, and the individual active compositions can catalyze customized various successive reaction steps.

Overall, the uniformly packed zone in the reaction tube in the case of structured packings in the zones (bottom to top) in the catalyst tube is only a type of shaped catalyst body, only one type of molded diluent, , A mixture of a molding catalyst and a molding diluent, or a mixture of various molding diluents.

Thus, the catalyst tubes packed in a structured manner clearly have more than one, often three or four, often five or six, or seven or eight to ten or more filling zones, The shaping catalyst body preparation is different in terms of type and / or amount of catalyst body (i. E., Generally not identical).

The uniform filling of the catalyst tubes so packed in such a structured manner requires only that the same shaped catalyst bed preparation, which does not vary along the catalyst tube section, is present in the corresponding catalyst tube section. However, secondly, it is also necessary that the same amount of the same shaped catalyst preparation is present in the corresponding catalyst tube zone.

In order to achieve this goal in the case of a large number (more than a thousand) of catalyst tubes (working tubes), a catalyst which introduces a defined proportion of individual shaped catalyst bed preparations directly into a separate catalyst tube from a storage vessel containing the preparation Fillers have been used in the prior art (see, for example, DE-A 199 34 324, WO 98/14392 and US-A 4,402,643). The type of primary parameter sought here is a constant introduction rate (i. E., A very uniform amount of individual shaped catalyst preparation introduced per unit time during filling). And the dimensions of the filling zone and the portion into which the product of the introduction rate and the introduction time are introduced.

However, the method of the prior art has several disadvantages. First, the introduction rate is not completely satisfactorily constant over time, which causes a deviation in the introduced part. This is particularly because the molded body to be introduced is located laterally and thus occasionally blocks the molded body outlet of the filling machine. When individual shaped catalyst body preparations are composed of more than one type of shaped body, partial solution demixing can occur in the storage vessel, which eventually results in some compositional change compared to the corresponding filler zone in the other catalyst tubes . Even with one and the same filling zone in an individual catalyst tube, compositional variations can occur along the filling zone. Also, the filling rate obtained is often not completely satisfactory. The latter is particularly important because the formation, i.e., the gas phase reaction, is intermittent during the filling of the catalyst tube.

It is therefore an object of the present invention to provide an improved method of filling a catalyst tube of a catalyst tube bundle in a structured manner.

The inventors have found a method of filling a catalyst tube of a catalyst tube bundle in a structured manner wherein the individual catalyst tubes of the catalyst tube bundle are filled in the same manner from the bottom up in the zone having the different shaped catalyst preparation, First, a uniform packed volume of the shaped catalyst catalyst preparation is produced by creating a uniform portion of a suitable shaped catalyst catalyst preparation, placing the portion into the packaging material and transferring several packets to each individual catalyst tube. The number of packets transferred into one catalyst tube is usually at least one.

According to the invention, the difference in the uniformity of said parts is generally less than ± 1% by weight or less than ± 0.3% by weight, or less than ± 0.1% by weight, based on the number average of all parts uniformly produced, Less than 0.01% by weight. The difference in relative uniformity is smaller for larger portions present in individual packets.

The method of the present invention is generally applicable to molded catalyst bodies whose maximum dimension L is (significantly) smaller than the inner diameter D of the reaction tube. However, the longest dimension is generally the same as the diameter. The ratio D / L is often 2: 1 or 3: 1 to 20: 1, or 4: 1 to 10: 1.

The amount present in the packet filled with the shaped catalyst body may preferably be from 50 g to 5 kg, which is predetermined in the injection test in a transparent tube of the appropriate geometry, which corresponds to the desired length of the filling zone. The amount of the part is often from 100 g to 3 kg and often from 200 g or 300 g to 2 kg, such as 400 g, 600 g, 800 g, 1000 g, 1200 g, 1400 g, 1600 g and 1800 g. This generally corresponds to a numerically similar filling volume in l or ml (i.e. 25 or 50 ml to 5 or 10 l).

According to the present invention, the amount in the packet is very particularly preferred when it is transferred into the reaction tube, to the extent that it produces all of the desired filling zones in the tube. However, for the purpose of achieving improved uniformity of the filling zone, it may be necessary to have one or more (often 2 to 10, often 2 to 5) packets in which an amount corresponding to a portion is transferred to the creation of the desired filling zone .

The packaging means may be a paper bag, a bag made of other materials, a color, a box, a can, a partition, a bucket, a wooden box, a basket, a drum, As the packaging material, it is possible to use paper, cardboard, wood, glass, ceramic material, metal (sheet and foil), plastic, foam or the like depending on the active composition. The choice of packaging means and packaging method depends on the type of active composition as well as on the type of external influence expected (e.g., storage) after packaging. For example, heat resistance, non-sensitivity to impact, opacity to light, impermeability to air, and impermeability to water vapor may be required.

For example, it may also be desirable to package the part using a shrink film that tightly encapsulates the shaped catalyst body packed under reduced pressure and enable the packet to be particularly simple to laminate. Care must be taken to ensure that the packaging material does not adversely affect the quality of the catalyst, for example, by releasing exogenous substances such as volatile plasticizers or residual monomers that can occupy and block the catalytically active surface during storage of the packet.

Transparent polyethylene (high, low or medium density) is a particularly preferred packaging material according to the present invention, particularly when the active composition is a multi-element oxide, such as a multi-metal oxide. It is generally preferred that the moisture (water vapor) permeability of the package at 25 占 폚 is 1.0 gm ^-2 d ^-1 (d = day) or less. For this purpose, it is possible to use, for example, a bag comprising an aluminum-coated bag or a liquid-crystalline polyester film. Bag is a preferred means, especially when it is made of plastic (e.g. polyethylene) and can be tightly closed in an airtight manner.

The production of packets filled with a uniform amount of a shaped catalyst bed preparation and used in accordance with the present invention can be performed very efficiently and at high speed by using a wrapper prior to the actual filling procedure. A distributor is particularly advantageous in the process according to the invention. In the case of this lower concept wrapper, it is packaged in a form ready for dispensing (for example, a wrapper that produces the package itself from a film provided in roll form is often used). These include, but are not limited to, metering devices that divide the material to be filled by weight or number of pieces, a substantial filling unit and a closing unit (e.g., by twisting, rotating, folding, lt; RTI ID = 0.0 > loosely < / RTI > tightly closed by application of closure.

When the shaped catalyst body preparation introduced according to the present invention comprises one or more types of shaped bodies, the production of a uniform part of the preparation according to the present invention is preferably carried out as follows.

First, each type of shaped body having the maximum possible uniformity is mass-produced.

A metering device is then applied to a particular type of shaped body to continuously produce a uniform portion of each type of shaped body according to the weight or number of pieces and place it on the conveyor belt. Individual conveyor belts convey a uniform portion of a particular type of shaped body at a moderate speed. The conveyor belt comes together at its end and discharges a desired amount of a particular type of molding into the packet. This creates a packet whose contents can not be distinguished in terms of both quantity and composition.

Then, from the length of the catalyst tube and the pre-calculated length of the filling zone of the packed packing with the shaped catalyst bed preparation to be transferred to each catalyst tube (and from the injection experiments on mobile reaction tubes with the corresponding geometry geometry By shifting the determined number, the filling of the catalyst tube can be carried out in a simple manner. In the method of the present invention, the amount packed in each packet is always less than or equal to the amount introduced into each catalyst tube. It is common for the same number of packets to be transferred to each catalyst tube. According to the invention, the number to be transferred to the catalyst tube is preferably an integer. According to the invention, particularly uniform filling zones across the various catalyst tubes can be produced in a short time, since each packet provided in the filling zone contains the same formulation and amount.

The simplest way to transfer a packet into a catalyst tube is by hand. However, in order to transfer the packets into the catalyst tube so as to obtain a very uniform bulk density, DE-A 19934324 may also be transferred using a device as described to fill the tube with a soft material. This includes a certain number of distribution tubes that can be simultaneously lowered into the catalyst tube to be filled. The machine includes one storage vessel per distribution tube, which is connected to each distribution tube via an injection port and a transfer path. By means of the individually operable metering zones, the stream of ductile material exiting each storage vessel into the transfer path is limited to the desired introduction rate into the catalyst tube. Instead of transferring packed packets directly into each catalyst tube according to the present invention, these packets can be transferred to each storage container of the described filling mechanism, the capacity of the storage container preferably being limited to the content of one packet or the content of one or two packets The catalyst can be transferred continuously into each catalyst tube at a very constant rate of movement depending on the consumption through the catalyst bed. This naturally suppresses the mixing of the catalyst in the storage vessel and the constant rate of introduction results in a very uniform bulk density because the storage vessel does not contain large amounts of shaping catalyst preparation that can be charged at any time do. A typical moving speed may be 500 to 3000 moldings per minute.

Particularly preferred fillers include cascades of storage vessels which are interconnected and enable substantially continuous execution of the process of the present invention.

On each of the storage vessels so arranged is a second storage vessel which can be filled with a portion corresponding to one packet before the contents of the underlying storage vessel are completely discharged.

The storage vessels arranged above one another may be connected to different distribution tubes.

For example, the method of the present invention is particularly advantageous if the active composition of the shaped catalyst body present in the packet contains Mo-, Bi- and Fe- containing polymetal oxides (such as oxides of the general formula II of DE-A 4442346) and / -Containing multimetal oxide (for example, an oxide of the general formula I of DE-A 4442346). However, if the active composition of the shaped catalyst body present in the packet is a V- and P-containing multi-element oxide (for example, for producing maleic anhydride, for example EP-A 302509) or a V- and Cs-containing multi- -A 1084115, EP-A 1117484 or EP-A 1311467, for example for the preparation of phthalic anhydrides) or Mo- and P-containing multielement oxides (for example for the production of methacrylic acid, DE-A 4329907) The case is also appropriate.

The process proposed here is described in documents EP-A 700893, EP-A 700714, DE-A 10337788, DE-A 10313210, DE-A 10313214, DE-A 10313213, DE-A 10313212, DE-A 10313211, DE -A 10313208, DE-A 10313209, which is proposed for non-homogeneous catalytic partial oxidation of propene and / or acrolein to acrylic acid. The packaging material used should be a material that is very impermeable to water vapor and closes tightly in an airtight manner. For this purpose, we can follow the proposal of JP-A 2003-10695. If desired, additional fillers may be used as suggested in DE-A 10 337 998. This also applies to the filling means proposed in the prior art cited herein.

The method of the present invention is both impressive in terms of a high degree of filling uniformity achievable using the method and in view of the fast filling rate achievable with the filling uniformity. The uniformity and fast filling rate are natural when there is little metering in that the dispensing and filling are separated from each other in space and time. The length of the uniform filling zone when the method of the present invention is used is typically 20 cm to 800 cm, often 50 cm to 200 cm.

According to the present invention, it is particularly advantageous to provide packets containing the same shaped catalyst body preparation with a particular color. After they have been transferred into individual reaction tubes for the production of the desired filling zone, each reaction tube can advantageously be closed with the same colored stopper indicating that the step has been completed. This is a very simple way to prevent the reaction tube from being filled more than once with one and the same shaped catalyst preparation. Alternatively, the filling height in the reaction tube can be checked by a measuring stick.

Example  And Comparative Example

A) Using the method described in Example 1 of DE-A 10046957, 70 kg of a fully active catalytic ring with a geometry of 5 mm x 3 mm x 2 mm (outer diameter x length x inner diameter) was prepared.

The stoichiometry of the active composition was as follows.

_{[Bi 2 W 2 O 9 x} 2WO 3] 0.5 x [Mo 12 Co 5 .5 Fe 2 .94 Si 1 .59 K 0 .08 O x] 1

70 kg of the entire active catalytic ring was homogeneously mixed with 30 kg of a stearate ring having a geometry of 7 mm x 7 mm x 4 mm and a 6 m long transparent plastic tube with an internal diameter of 35 mm was extruded in accordance with DE-A 19934324 Was filled with the mixture until the plastic tube was completely filled with the catalyst filler described in < RTI ID = 0.0 > J. < / RTI > In this filling process, all homogeneous mixtures were placed in a storage container and the plastic tube was filled therefrom.

Visual inspection of plastic tubing filled in this way resulted in uneven areas at multiple fill heights.

B) 70 g of the fully active catalytic ring and 30 g of the stearate ring of A) were introduced into the polyethylene bag. The 55 filled polyethylene bags were successively transferred into a storage vessel of the same catalytic filler as in A) and transferred to the same plastic tube as in A) at the same rate as in A) by a catalytic filler.

Visual inspection of the plastic tube filled in this way showed no uneven areas.

C) A total of 357 g of Formulation I (5 mm x 3 mm x 2 mm) was obtained using the entire active catalytic ring (geometric shape: 5 mm x 3 mm x 2 mm) and geometric shaped steatite rings Quot; portion of the entire active catalyst ring / 153 g of the statorite ring "was packed into a polyethylene bag using a packing machine (Packet I). The total amount of the packaged preparation I was 5.685 metric tons.

Also, a portion of 835 g of Preparation II consisting solely of the entire active catalytic ring of A) was packed in a polyethylene bag (Packet II). The total amount of the packaged preparation II was 9.308 metric tons.

11148 catalyst tubes made of ferrite steel and having an internal diameter of 25.4 mm (wall thickness; 2 mm) and a length of 3.20 m were first packed with one packet II (all tubes) with a catalyst bed described in DE-A 19934324 ), And then filling one packet I by successive transfer (to all tubes). The difference in uniformity of filling time for individual tubes was less than ± 5 seconds on a time-averaged basis. The average filling time was 45 seconds. Pressure drop measurements on 200 randomly selected tubes at an air throughput of 3000 l / l · h of air were performed, and the difference in uniformity over a number average pressure drop was less than ± 3%.

The filled tube is suitable for partial oxidation of propene to acrolein. No refilling was required to improve uniformity as suggested in WO 03/057653.

U.S. Provisional Patent Application No. 60 / 568,699 (filed on May 7, 2004) is incorporated herein by reference. Many modifications and variations of the present invention are possible in light of the above teachings. Accordingly, the invention may be considered variously practiced within the scope of the appended claims, other than those specifically described herein.

Claims (2)

A part of the shaped catalyst body determined by the weight of the shaped catalyst body or the number of pieces is filled in a shrinkable film under reduced pressure or in a plastic white packing material which is tightly closed in close contact with air and is stacked and transferred into the catalyst tube A packet for filling the catalyst tube. The packet of claim 1, wherein the packaging material has a vapor permeability of less than or equal to 1.0 gm ^-2 d ^-1 at 25 ° C.