ITRM990702A1 - PROCEDURE FOR THE RECOVERY OF GASEOUS PRODUCTS BY CATALYTIC REACTION IN THE GASEOUS PHASE AND APPARATUS FOR THE EXECUTION OF THE PROCEDURE - Google Patents

Description

DESCRIPTION

accompanying a patent application for an invention entitled:

"Process for the recovery of gaseous products by means of a catalytic reaction in the gas phase and apparatus for carrying out the procedure"

A product, such as for example phthalic anhydride (AF) is recovered in a reactor by finalized partial oxidation of o-xylene or naphthalene or a mixture of these two substances of use. The oxygen required for recovery is taken from the air which simultaneously serves as a carrier gas. With the currently usual dimensions of the systems, the quantity of air sucked in, compressed and preheated to about 180 ° C, ranges from 20,000 to 100,000 Nm3 / h. The substance used is sprayed or evaporated or added in the form of vapor to the preheated hot air stream, before the reactor.

The known reactors are shaped like tubular reactors. In them the mixture of air and the working substance is oxidized on catalysts to give AF. Water, CO, CO2, maleic anhydride, phthalide etc. are thus formed as undesirable by-products of AF. . The reaction is strongly exothermic. For this purpose, in known tubular reactors most of the heat that is created is removed towards the outside through a liquid salt bath. A further part of the heat is removed in the form of the reaction gas heated to about 380 ° C and charged with AF. This reaction gas is cooled in heat exchangers to about 170 ° C after leaving the reactor, and finally passed into separators, in which the AF is recovered by desublimation.

Known tubular reactors have a plurality of exchange tubes (between about 5000 and 25,000) between an upper gas inlet cap and a lower gas outlet cap. These exchange tubes are filled with a catalyst prior to commissioning of the tubular reactors, roughly over the entire overall length. For this purpose, the actual active catalyst mass is usually applied to ceramic support bodies in the form of rings or spheres.

In the upper part of the exchange tubes, the mixture of air and working substances which enters the tubular reactors is heated to the reaction temperature through the hot exchange tubes. Thereafter, oxidation occurs through multiple intermediates to give the desired AF product and the undesirable by-products mentioned above. During this oxidation, the temperature rises at the exchange points up to the so-called "hotspot" and then drops again, at the lower ends of the exchange tubes, to the temperature of the liquid salt bath surrounding the exchange tubes. The reaction gas charged with AF then leaves the tubular reactors via the lower gas outlet caps.

The liquid salt baths which cool the exchange tubes and also the reactor casing must be continuously pumped back in a relatively expensive way and at the same time must be passed around all the exchange tubes, in order to avoid undesirable excessive oxidation in too hot spots or insufficient oxidation in too cold spots. For this reason, liquid brine baths should also have only very modest temperature differences of around 3 ° C.

The heat absorbed by the salt baths is removed externally to the reactor casing in the coolants of the salt bath in the form of high pressure steam.

Due to the fact that the mixture of air and substance of use, but also the reaction gas charged with AF are explosive in the entire temperature range, the reactor cases must be protected in various areas by large and additionally sensitive safety devices from outbursts.

Since the tubular reactors are cooled with liquid salt to practically the same temperature, it is not possible to use optimum reaction temperatures in the state of the art. On the contrary, depending on the catalyst, a typical temperature profile is created over the length of the pipes with a "hotsport" over approximately 40% of the length of the pipes. This results in the creation of unwanted by-products, excessive oxidation and a strictly limited useful life of the catalysts.

To at least partially avoid these drawbacks, it has been proposed to use two tubular reactors inserted in series or a single tubular reactor with two reaction zones and separate cooling with salt bath (European patent applications 0686 633 A1 and 0453 951 A1). Since the construction, production and operation of these tubular reactors are very expensive, they have so far not been able to establish themselves in practice. It is also technically very difficult to achieve the same cooling for all the exchange tubes in the reactor boxes. Consequently, it cannot be excluded that in the known case partly different reactions take place in the many thousands of exchange tubes.

A further problem is that of filling the exchange tubes with a mass of catalyst. This filling must be carried out extremely accurately, so that each exchange tube also receives the same quantity of catalyst mass and has the same pressure loss on the gas side. The cost for filling and testing (about 3 to 4 weeks) is consequently very high and uneconomical.

Furthermore, with the increasing load of the air with the substance used in a tubular reactor, it becomes more difficult and more expensive to remove the heat that forms through the salt bath. The reason is the proportional increase of the reactor heat with the increase of the air load with AF.

Furthermore, it is impossible to avoid a high pressure loss on the air side and consequently high blower costs.

There is also a considerable danger of the formation of salt bath leaks. Furthermore, known tubular reactors need long heating and cooling phases. The inspection of tubular reactors is also linked to a number of problems.

As already mentioned above, with high loads, unwanted by-products are created to a greater extent, which can only be eliminated by distillation in an expensive way. In practice, therefore, a separate subsequent reactor (post-reactor) was sporadically inserted after a main reactor. In this post-reactor a part of the by-products is burned, and a very small part is also converted into AF. Normally the reaction gases then leaving the main reactor are still pre-cooled before entering the post-reactor in an intermediate coolant (patent DE 19807 018 A1).

The invention therefore has the objective, starting from the state of the art, to provide a process for the recovery of products in gaseous form by means of catalytic reactions in the gas phase as well as an apparatus for carrying out the process, which are simpler both under the profile of the production technique which, from the point of view of the operating technique and which allow to recover, at a higher level of safety and with a smaller number of by-products, a greater yield of products.

As for the solution of the procedural technical part of this problem, this is found in the features of claim 1.

Consequently, the entire reaction in a reactor case is divided into several stages. First of all, the gas entering the reactor casing, preheated and loaded with the relative substance of use, is heated in a heating stage to the optimum starting temperature. Immediately after the heating stage, the gas is guided into a first reaction stage over a mass of catalyst, where a first partial reaction takes place. Subsequently, the reaction gas in this reaction stage, now partially loaded with the product, is cooled, and precisely to a temperature which guarantees a further optimal partial reaction when passing through the subsequent catalyst mass.

The number of reaction stages, which are passed through in the reaction gas which is increasingly charged with the product, should be between 5 and 8 for one operation according to practice. The contact time of the reaction gas with the relative mass of catalyst can be the same or even of different length in the individual reaction stages. Furthermore, it is possible to provide for a modification of the number of reaction stages both as regards the catalyst and as regards the cooling, that is, according to the substance used, the filler concentration or the type of catalyst mass used.

After the reaction is over, the reaction gas loaded with the product leaves the reactor case and is fed to the cooling of the gas and to the subsequent desublimation or condensation.

The direction of flow of the charged gas or the reaction gas in the reactor case can be chosen at will. In particular, however, it will be vertical or horizontal.

A substantial advantage of the invention is that a liquid salt bath is now entirely omitted. Consequently, there is also no longer any danger of detonation if salt and organic components of the reaction gas react spontaneously following a leak.

A further significant advantage of the invention consists in the increase in yield of the product, according to some percentile points. The reason lies in the fact that for the individual reaction stages, tailor-made reactor masses produce fewer by-products and more product at the optimum reaction temperature. A smaller quantity of by-products is used simultaneously a simpler distillation of the raw product and consequently lower investment and operating costs.

The quantity of gas to be supplied to the reactor as well as the loading with the substance of use can be made to vary within wide limits, since the reactor mass can be used each time in an optimal manner.

The multistage reaction according to the present invention has, in comparison with the oxidation in a tubular reactor, the advantage of greater flexibility. A tubular reactor can be operated optimally at one point only. This is due to the temperature of the salt bath, with repercussions on the load and yield. Once a catalyst combination has been set, it can no longer be changed. The invention, on the other hand, makes it possible to always guarantee optimal operating modes in the individual reaction stages.

In the context of the process according to the present invention, it is for example the catalytic oxidation of anthracene to anthraquinone.

A particularly advantageous embodiment of the process underlying the present invention is highlighted, however, in the characteristics of claim 2. It is a question here of the recovery of AF.

Also in this case the compressed air entering the reactor casing, preheated and loaded with the relative substance of use, is heated in a heating stage to the optimum starting temperature. Immediately after the heating stage, the charged air is guided in a first oxidation stage over a mass of catalyst, where a first partial oxidation takes place. After this, the reaction gas now partially charged with AF is cooled in this oxidation stage, and precisely to a temperature which guarantees a further optimal partial oxidation when passing through the subsequent catalyst mass.

The number of oxidation stages, which are passed through by the consciously charged reaction gas with AF, should be between 5 and 8 for normal operation. The duration of the contact of the reaction gas with the relative mass of catalyst can be the same or of different length in the individual oxidation stages. Furthermore, it is possible to foresee a change in the number of oxidation stages both as regards the catalysts and as regards the cooling, and precisely according to the substance of use, the filler concentration or the type of catalyst mass used.

After the oxidation is finished, the reaction gas charged with AF leaves the reactor case and is fed to the cooling of the gas and to the subsequent desublimation.

For example, in order to always remain outside the explosion limits of the air / substance mixture, it is possible in accordance with the characteristics of claim 3 to introduce additional use substance into the reaction gas charged with AF in the reactor casing, along its path characterized by variable partial oxidation on a mass of catalyst and subsequent cooling. The introduction site is conveniently located approximately in the middle of the reaction gas flow path in the reactor case.

In order to prevent deposits of the working substance and / or AF on cold parts of the reactor casing, but also to shorten the heating time during the start-up of the reactor, it is possible according to claim 4 to heat the reactor casing and the masses of catalyst before starting the reactor. This can be done by steam. However, thermal oil or electric current can also be used. If steam is used, this must have the highest possible pressure. In this case it is convenient to provide the first oxidation stage after the heating stage with a highly active catalyst mass, so that the necessary temperature is reached here during start-up by means of the reaction heat. Furthermore, the advantage of an easy temperature regulation is realized in the use of thermal oil. Furthermore, thermal oil can be used for heating in distillation. A common starting burner must then be provided for the oil circuit.

Another advantageous feature of the invention is seen in the features of claim 5. According to it, the heat which is created in the cooling can be used to heat the air charged with the use substance in the heating stage. This may be an internal heat shift. An appropriate heat exchange oil is advantageous for this.

The solution of the problem based on the invention which forms the subject of this patent application is found in the characteristics of claim 6.

On the basis of these characteristics, a reactor casing is provided which has a constant section in the direction of flow of the preheated gas and loaded with the substance to be used, in particular air. The air charged with the application substance first reaches a heating device in the heating stage, where the air is heated to the optimum starting temperature. This heating device can also be shaped to act as a rectifier by its resistance. Thanks to it, the catalyst of the first reaction stage, in particular of the oxidation stage, inserted directly after the heating device, is hit over the entire cross section with an almost uniform speed and air temperature, which is demonstrated also advantageous in the subsequent reaction stages.

After the heating device, catalysts are provided which alternate in several reaction stages, for the partial reaction, in particular for the partial oxidation of the product, in particular of AF, and cooling devices for cooling the reaction gas to the temperature of optimal reaction of the immediately following catalyst. The lengths of the beds of the different catalysts can be the same or different.

According to claim 7, the inflow sections of the heating device, catalysts and cooling devices are of equal size. In this way, a simpler structure is obtained for the catalysts and cooling devices, resulting in a desirably uniform gas velocity for the partial catalytic reaction, in particular for the partial oxidation, in all areas of the reactor casing.

A particularly advantageous embodiment of the invention is described by the features of claim 8. According to it, the heating device, the catalysts and the cooling devices are modularly shaped and are interchangeably integrated in the reactor case. This modular type structure allows to incorporate the catalysts and the cooling devices in frames related to the section of the reactor casing, and consequently to create identical inflow sections for both the catalysts and the cooling devices, which is linked to a speed of the reactor. uniform gas, in a simple structure.

The modular type configuration allows to incorporate the catalysts, the cooling devices and the heating device through the frames one by one in the reactor case, so that furthermore the individual frames can be removed as such from the reactor case and used again. . In this way, maintenance, cleaning and even the replacement of a catalyst mass can be carried out very quickly. Furthermore, the modular type configuration allows, in the event that for example the technical development makes it appear logical, to exchange at a later time modules including cooling devices with modules having catalysts, or vice versa. Furthermore, free spaces can be foreseen in an economical way for a subsequent extension or restructuring. It is also possible in the context of the invention to keep aside in an economical way modules with catalysts and / or cooling devices, in order to be able to carry out an exchange in a short time if necessary.

The invention makes it possible to incorporate each catalyst and each cooling device into a frame and manipulate this in itself as a module. According to claim 9, however, it is also conceivable to provide a catalyst and a cooling device jointly in a frame and thus combine them as an exchangeable module. In this way space and bulk are saved, which is linked to a shortening of the reactor casing and consequently to material savings.

Although the manner in which the heating device or the cooling device is designed is generally of secondary importance according to the invention, i.e. that heat exchangers with smooth tubes or other suitable heat exchange surfaces can be used, the claim 10 provides, according to a preferred embodiment, that the heating device and the cooling devices are formed by finned tube heat exchangers.

According to the characteristics of claim 11, it is possible to use as catalysts rings, spheres or similar support bodies reported, provided with a mass of catalyst.

However, according to claim 12, bee nests are also conceivable which have the additional advantage of being able to be assembled and disassembled very quickly as modules.

The heat required for the further preheating of the gas / substance mixture in the heating device can be extracted with heat transfer according to claim 13, preferably by means of one of the cooling devices arranged in the subsequent reaction stages, in particular of the stages of oxidation. This is a matter of internal heat displacement. For example, a suitable heat exchange oil can be used for this purpose, which has the advantage of simple temperature regulation. Furthermore, this hot heat exchange oil can be used for heating in distillation. A common oil circuit with a common starter burner is sufficient for this.

In order that too high pressures are not created in the reactor casing in the event of an explosion or pulsation, burst openings are provided according to claim 14 at several points of the reactor casing suitable for this purpose. Their size depends on the composition of the relevant mixture, the temperatures and the volume to be discharged. The burst openings can be used by removing the safety devices from the actual burst, such as manholes for inspections, maintenance and cleaning of the reactor casing.

In order that the reactor case is not made unnecessarily large due to the bursting openings and to keep the volume to be discharged as low as possible, it may be advantageous according to claim 15 to directly correlate the explosion openings with the catalysts. The blast openings with the blast safety devices then conveniently form a component of a frame with a catalyst which can itself be integrated into the reactor casing.

According to claim 16, the reactor case is heatable. Especially to shorten the warm-up time during start-up, this is advantageous, but it is also advantageous to prevent deposits of use substance or product in cold areas of the case. Steam, thermal oil or electric current can be used for this. For example, heating pipes can be applied to the outer side of the reactor casing, which can be invested with a suitable heat exchanger.

The invention is better illustrated in what follows in the light of embodiments shown in the drawings. In the drawings:

Figure 1 is a schematic vertical longitudinal section of a reactor for the oxidation of AF from an air / substance mixture; Figure 2 represents a trend, referred to the reactor of Figure 1, of the temperature of the reaction gas mixture passing through the reactor;

Figures 3 and 4 are an enlarged schematic presentation of an oxidation step of the reactor of Figure 1 with a catalyst and a cooler and

Figure 5 is also an enlarged schematic representation of a further embodiment of an oxidation stage of the reactor of Figure 1.

1 designates in Figure 1 a reactor, which forms a component of a plant, otherwise not better illustrated, for the recovery of phthalic anhydride (AF). Reactor 1 has a longitudinally extending reactor case 2, square in section, with a constant section up to an inlet cap 3 and an outlet cap 4 on the remaining longitudinal section 5. The outer surfaces of the inlet cap 3 , the outlet cap 4 and the longitudinal section 5 located between them are provided with tubes 6, which can be invested with an appropriate heat exchanger, such as for example thermal oil.

Furthermore, it can be deduced from Figure 1 that in the inlet cap 3, in the outlet cap 4 as well as in the longitudinal section 5 located between them, in the wall of the reactor casing 2, blast openings 7 with safety devices 8 from blast are incorporated. .

The reactor casing 2 has in the direction of flow the mixture 9 of air and the substance of use which enters through the inlet cap 3, such as for example o-xylene, or of the reaction gas 10 leaving the reactor casing through the outlet 4, charged with AF, first in the vicinity of the inlet cap 3 in a heating stage HST a heating device 11 for heating the mixture 9. The heating device 11 is modularly shaped and is formed as a heat exchanger Rahmen tube with fins incorporated in a frame not better represented. The frame is releasably fixed by means of a frame plate 12 on the peripheral side of an opening 12a of the reactor casing 2. The connections for the supply and removal of the heating medium to the heating device 11 are designated 13 and 14 .

In the direction of flow of the mixture 9, the heating device 11 is remotely followed by a catalyst 15 in a first oxidation stage I. The catalyst 15 includes a mass of catalyst, which is applied to rings, spheres, bee nests or similar support bodies. The mass of catalyst is reported in the catalyst 15 incorporated in a frame 16 (see also Figure 3). This catalyst 15 is consequently also shaped in a modular manner and is fixed by means of a frame plate 17 on the peripheral side of an opening 18 in the wall 19 of the reactor casing 2.

Between the heating device 11 and the catalyst 15 there is a temperature measuring point 20.

At a distance from the catalyst 15 a cooling device 21 is integrated in the reactor casing 2 in a releasable manner in the first cooling stage I (see also Figure 4). The cooling device 21 consists of a finned tube heat exchanger. It is fixed in a modular manner by means of a frame plate 22 on the peripheral side of an opening 23 provided in the wall 19 of the reactor case 2. The connections for the supply and removal of the cooling medium are designated with 24 and 25.

A further temperature measurement point 26 is provided between the catalyst 15 and the cooling device 21.

As can also be recognized from Figure 1, in a stepwise insertion one behind the other on the first oxidation stage I with the catalyst 15 and the cooling device 21, in a second oxidation stage II a catalyst 27 and a cooler 28, in a third oxidation stage III a catalyst 29 and a cooler 30, in a fourth oxidation stage IV a catalyst 31 and a cooler 32, and in a fifth oxidation stage V a catalyst 33 as well as a free space 34. The modularly shaped catalysts 27, 29, 31 and 33 as well as the cooling devices 28, 30 and 32 are also releasably fixed by means of frame plates 17, 22 according to Figure 3 on the peripheral side of openings 18, 23 in the wall 19 of the reactor casing 2. However, the lengths of the catalyst beds 15, 27, 29, 31 and 33 located in the direction of flow are of different configuration to. The masses of the catalysts 15, 27, 29, 31 and 33 are of identical configuration in the exemplary embodiment. The cooling devices 28, 30 and 32, like the cooling device 21, are shaped like fin tube heat exchangers and are provided with connections 24, 25 for a heating medium.

Figure 3 also allows it to be recognized that instead of the blast openings 7 located on one side between the catalysts 15, 27 and 31 as well as between the cooling devices 21, 28 and 32 inserted after them on the other side in the wall 19 of the reactor 2, a burst opening 7 of this kind can also be associated, along the dotted lines, directly with a catalyst 15, 27, 29, 31 and 33. The bursting opening 7 is then located in the firing plate frame 17.

While in the presentation of Figures 1, 3 and 4 the catalysts 15, 27, 29, 31 and 33 as well as the cooling devices 21, 28, 30 and 32 are arranged one behind the other at a certain distance and are each integrated releasably in the reactor casing 2, it results from Figure 5 an embodiment in which a catalyst 35 and a cooler 36 are supported as oxidation stage VI in a modular manner only in a frame 37, and are fixed by means of a frame plate 38 on the peripheral side of an opening 39 provided in the wall 19 of the reactor casing 2. Consequently, this catalyst 35 and cooling devices 36 are also jointly extractable from the reactor casing 2 which can again be integrated therein.

Considering Figures 1 and 2 together, it is possible to recognize the trend of the gas temperature from the inlet of the mixture 9 into the inlet cap 3 up to the abandonment of the reaction gas 10 through the outlet cap 4.

It can be seen that the mixture 9 enters the reactor casing with a temperature of about 180 ° C. As it passes through the heating device 11, the mixture 9 is then brought to a temperature of about 270 ° C. This temperature is sufficient as a starting temperature, so that an optimal partial oxidation at about 380 ° C takes place in the subsequent catalyst 15 of the first reaction stage 1.

The reaction gas now partially charged with AF then passes through the cooler 21 of the first oxidation stage I and is cooled here again to about 300 ° C. In this way, a temperature is created which also again guarantees an optimal partial oxidation for the subsequent catalyst 27 of the second oxidation stage II.

The temperature trend according to Figure 2 then also shows with the necessary clarity that each cooling device 28, 30 and 32 inserted after a catalyst 27, 29 and 31 ensures that the immediately following catalyst 29, 31 and 32 ensures that again an optimal partial oxidation, so that ultimately a reaction gas 10 charged with AF with a temperature of about 380 ° C exits from the outlet cap 4.

The temperature measurement points between the first oxidation stage I and the second oxidation stage II, in the second oxidation stage II, between the second oxidation stage II and the third oxidation stage III, in the third oxidation stage III, between the third oxidation stage III and the fourth oxidation stage IV, in the fourth oxidation stage IV, between the fourth oxidation stage IV and the fifth oxidation stage V and after the fifth oxidation stage V are designated with 40-47 .

Figure 1 also allows it to be recognized that the inflow sections for the catalysts 15, 27, 29, 31 and 33 as well as for the coolers 21, 28, 30 and 32 are identical. This also results in identical conformations for the frames 16 and a very simple modular structure, so that ultimately a desirable uniform speed results for the catalytic partial oxidation on the masses of the catalysts 15, 27, 29, 31 and 33.

The same circumstance is valid when the oxidation stage VI according to Figure 5 is applied.

Explanation of the reference marks

1 - reactor

2 - reactor case

3 - entrance cover v. 2

4 - output cap v. 2

5 - longitudinal section or respectively 3 and 4

6 - tubes at 3-5

7 - burst openings

8 - explosion safety devices v. 7

9 - blend

10 - reaction gas

11 - heating device

12 - frame plate f. 11

12 a - opening in 19

13 - link v. 11

14 - link v. 11

15 - catalyst

16 - frames f. 15

17 - frame plate v. 16

18 - opening in 19

19 - wall v. 2

20 - temperature measurement point 21 - cooler

22 - frame plate v. 21

23 - opening in 19

24 - link v. 21

25 - link v. 21

26 - temperature measurement point 27 - catalyst v. II

28 - cooler v. II 29 - catalyst v. III

30 - cooler v. Ill 31 - catalyst v. IV

32 - cooler v. IV 33 - catalyst v. V.

34 - free space v. V.

35 - catalyst v. YOU

36 - cooler v. VI 37 frame f. 35 and 36

38 - frame plate v. 37

39 - opening in 19

40 - temperature measuring point 41 - temperature measuring point 42 - temperature measuring point 43 - temperature measuring point 44 - temperature measuring point 45 - temperature measuring point 46 - temperature measuring point 47 - temperature measurement point I - 1st stage of oxidation

II - 2nd stage of oxidation

III - 3rd stage of oxidation

IV - 4th stage of oxidation

V - 5th stage of oxidation

VI - 6th stage of oxidation

HST - heating stage

Claims (16)

CLAIMS 1. Process for the recovery of gaseous products by means of a catalytic reaction in the gaseous phase of a substance of use, in which a gas preheated and loaded with the substance of use is heated to the starting temperature in a reactor casing in a heating stage and subsequently it is first guided over a mass of catalyst in several reaction stages that follow one another with enrichment of the product, and then it is cooled, after which the reaction gas thus charged with the product is fed from the box of the reactor to desublimation or condensation. 2. Process according to claim 1, wherein for the recovery of phthalic anhydride (AF) by catalytic oxidation in the gas phase of a working substance, such as o-xylene, naphthalene or a mixture of these working substances, compressed air (9 ) preheated and loaded with the substance to be used is heated in a reactor casing (2) in a heating stage (HST) to the starting temperature and is subsequently guided through a mass of catalyst in several oxidation stages (I-VI) one or the other with AF enrichment and then cooled, after which the reaction gas (10) charged in this way with AF is fed from the reactor casing (2) to the desublimation. 3. Process according to claim 2, in which additional use substance is introduced along its path in the reactor casing (2) characterized by alternating partial oxidation on a mass of catalyst and subsequent cooling. Process according to claims 2 or 3, wherein the reactor casing (2) and the catalyst masses are heated before starting the reactor (1). Method according to one of claims 2 to 4, in which the heat generated by the cooling is used to heat the air (9) charged with the application substance in the heating stage (HST). 6. Apparatus for carrying out the process according to one of claims 1 to 5, wherein in a reactor casing (2) having a section which remains constant in the direction of flow of the preheated gas (9) and loaded with the substance to be used are provided with an insertion one behind the other in stages, first a heating device (11) to heat the gas (9) to the optimum starting temperature and then alternatively several catalysts (15, 27, 29, 31, 33 , 35) for the partial reaction of the product and cooling devices (21, 28, 30, 32, 36) for the cooling of the reaction gas (10) loading of the product to the optimal reaction temperature of the catalyst each time successive (27 , 29, 31, 33, 35). 7. Apparatus according to claim 6, in which the inflow sections of the heating device (11), the catalysts (15, 27, 29, 31, 33, 35) and the cooling devices (21, 28, 30, 32 , 36) are sized with the same size. 8. Apparatus according to claim 6 or 7, wherein the heating device (11) the catalysts (15, 27, 29, 31, 33, 35) and the cooling devices (21, 28, 30, 32, 36) are shaped in a modular manner and are integrated in an exchangeable manner in the reactor casing (2). Apparatus according to one of claims 6-8, wherein the catalysts (35) and the cooling devices (36) each inserted behind them are combined in jointly exchangeable modules. Apparatus according to one of claims 6-9, wherein the heating device (11) and the cooling devices (21, 28, 30, 32, 36) are formed by fin tube heat exchangers. Apparatus according to one of claims 6-10, wherein for the catalysts (15, 27, 29, 31, 33, 35) are used applied rings, spheres or similar bearing bodies, equipped with the catalyst mass. Apparatus according to one of claims 6-10, wherein honeycombs equipped with the catalyst mass are used for the catalysts (15, 27, 29, 31, 33, 35). Apparatus according to one of claims 6 to 12, wherein the heating device (11) is coupled for heat exchange with at least one cooling device (21, 28, 30, 32, 36). Apparatus according to one of claims 6 to 13, wherein the reactor casing (2) has burst openings (7) with burst safety device (8). 15. Apparatus according to claim 14, wherein the burst openings (7) are correlated with the catalysts (15, 27, 29, 31, 33). Apparatus according to one of claims 6 to 15, wherein the reactor casing (2) is heatable.