WO2010149751A1

WO2010149751A1 - Converter for carrying out exothermic catalytic reactions

Info

Publication number: WO2010149751A1
Application number: PCT/EP2010/059016
Authority: WO
Inventors: Joachim Engelmann; Genrikh Falkevich; Rashid Temirbulatovich Sarsenov
Original assignee: Chemieanlagenbau Chemnitz Gmbh; Sapr - Neftekhim Llc.; Too Techno Trading Ltd.
Priority date: 2009-06-25
Filing date: 2010-06-24
Publication date: 2010-12-29
Also published as: DE102009031765A1; DE102009031765B4

Abstract

The invention relates to a converter for carrying out exothermic catalytic reactions, inter alia, for use in the chemical and petrochemical industry. The converter according to the invention is suitable for a virtually isothermic temperature regime in the reaction chamber (25), and contains in its body a plurality of heat panels (8) which are arranged in the reaction chamber (25). The bottom part (28) of each heat panel (8) in the bottom part (2) of the body has a wedge shape, wherein in each case the pointed part is directed towards the central axis (21) of the body and the upper part (29) of each heat panel projects from the reaction chamber (25) into the upper (2) part of the body and there is in active connection with a heat-exchange device (9). In this case the upper part (29) of each heat panel (8) is connected in each case to the lower part (28) of the heat panels (8) and so the heat carrier that is vaporized in the lower part (28) can ascend to the upper part (29) and condensed heat carrier can flow back from the upper part (29) to the lower part (28).

Description

Converter for carrying out exothermic catalytic reactions

The invention relates to the field of technological equipment for carrying out catalytic processes and can be used in the chemical, petroleum and other industries for carrying out exothermic catalytic reactions.

SU852541 (1981) discloses a reactor intended to carry out reactions of polymerization and copolymerization of gaseous monomers. The mentioned reactor consists of a body with means for supplying and discharging a circulating gaseous medium, the starting components and the finished product, a shaft with mixing blades, which consist of heat pipes, heat exchanger and pump, wherein the heat pipes vertically and concentrically to the shaft in different radii are arranged to the rotation axis. The means for supplying and discharging the gaseous medium are arranged diametrically in the upper part of the reactor, with the upper ends of said heat pipes between said devices. Disadvantages of this known reactor are a design-related low efficiency and associated low yield of target product.

RU2278726 discloses a reactor for carrying out catalytic gas phase processes, which consists of a body, a device for feeding the starting components and a device for the discharge of the finished product, and a device for the dissipation of heat, which is in the form of a plurality of heat pipes , consists. This known reactor also contains a catalyst, which is applied to the heat pipes and / or the body as a coating. The heat pipes are arranged in the space of the carcass in a checkered manner and their entire surface, which is located in the catalytic zone, is chosen so that it ensures the supply or discharge of the amount of heat energy necessary for carrying out the catalytic process. Disadvantages of this known reactor are again a design-related low efficiency and low yield of target product.

It is emphasized in EP2062640A1 that it is desirable in the field of isothermal or pseudoisothermal chemical reactors to use plate heat exchangers, since these advantageously have a high surface area, are relatively inexpensive and are easy to assemble. In this regard, EP2062640A1 discloses such a reactor with plate heat exchangers having two flat walls arranged in parallel, the individual plate heat exchangers being radially arranged in the reactor and embedded in a catalyst layer. The disadvantage is that by this arrangement the distance between the plate heat exchangers, especially at the point where the strongest heat generation takes place, is greatest. An external fluid heat carrier is fed from outside the reactor to the plate heat exchangers and then discharged back to the outside. Similarly constructed isothermal reactors with plate heat exchangers are disclosed in EP1436075B1 and EP1347825B1. US2003 / 0175184A1, DE19754185C1 and US 2005 / 0158217A1 also disclose reactors with plate heat exchangers.

The object of the invention is to provide a converter for carrying out exothermic catalytic reactions, which is characterized by an increased efficiency and an increase in the quality of the product produced.

The converter should be particularly suitable for carrying out catalytic exothermic reactions in the gas phase with a temperature regime in the reaction space, which is almost isothermal.

This object is achieved by a converter according to claim 1. Advantageous embodiments are specified in the dependent claims.

The converter according to the invention for carrying out exothermic catalytic reactions has a body with at least one inlet for the feed of the starting components and at least one outlet for the discharge of the reaction products. The one or more inlets are preferably mounted in the form of nozzles in the side wall of the carcass. The drain or the drains are preferably arranged in the lower part of the carcass.

The body forms the outer wall of the converter and is subsequently split functionally into a lower and an upper part. The body may be made in one piece, but for ease of handling (assembly / disassembly) is preferably made in two parts (an upper, preferably in half-shell shape and a lower, the bottom in the form of a half-shell) or three parts, preferably by flanges can be connected to each other. The body has at least one inlet for the supply of the starting components and at least one outlet for the removal of the reaction products.

In the lower part of the carcass is the reaction space in which the exothermic catalytic reaction takes place. The reaction space is bounded radially by an inner and an outer support structure. In the inner support structure is an (inner) cavity - the inner central tube - which serves for the discharge of the gaseous reaction product to the outside, via a connection in the lower part of the carcass. The reaction space and the inner Cavities are preferably upwards and preferably also solid or detachable closed down. The bottom closure is formed by a bottom plate or a catalyst table mounted thereon. Through the bottom plate protrudes the inner central tube. At the top, the reaction space is limited by a cover, preferably a seal.

Between the outer support structure and the inner wall of the carcass preferably remains an outer cavity, which serves for the distribution of the starting components. The outer cavity is preferably closed at the top and preferably fixed or detachable down. The conclusion to the top is preferably formed by the body wall (in the upper part of the body). The conclusion downwards is preferably also formed by the bottom plate. In the wall of the carcass, the inlet is arranged so that the starting components preferably flow through the outer support structure via this outer cavity into the reaction space. The reaction space forms the reaction zone, d. H. in this the chemical reaction takes place. The reaction products then flow into the internal cavity (inner central tube) connected to the drain. However, it is also possible to exchange inlet and outlet, so that the starting materials are supplied via the inner cavity, flow through the reaction zone and the reaction product is discharged through the outer cavity.

According to the invention, a plurality of heat panels are arranged in the interior of the carcass on the catalyst table or directly on the bottom plate. For the purposes of this application, a heat panel is generally understood to mean a hollow, preferably bar or tubular element or an element of another shape for dissipating the heat of reaction from the reaction space.

The heat panels are mounted on the bottom plate and are additionally fixed by vertical partitions on the bottom plate in position.

Each heat panel (inner cooling circuit) has a lower part located in the reaction space and an upper part protruding from the reaction space into the upper part of the body and operatively connected to a heat exchange device (outer cooling circuit). The lower parts of the heat panels are used to absorb the heat from the reaction space in which the catalyst is located and the exothermic reaction takes place. The upper parts of the heat panels are in operative connection with heat exchange devices inside the converter. By the heat exchange devices and connected lines and possibly collectors, the heat is dissipated using a heat exchange medium to the outside. The lower part of the heat panels is preferably formed as a hollow body with wedge-shaped base, wherein preferably each of the pointed part is directed to the central axis (to the inner central tube) in the lower part of the body. Preferably, the pointed, directed to the central axis of the body lower part of the heat panels forms an angle of 1, 5 to 18 °. The angle is chosen in particular as a function of the dimensions of the converter and the ratio of the heat exchange surface to the volume of the catalyst.

Between the wedge-shaped lower parts of the heat panels catalyst is preferably filled. The catalyst is preferably poured. However, the converter can also be used for reactions without a catalyst (for example neutralization reactions) or for reactions with liquid catalysts. In addition, catalyst is preferably additionally introduced between the heat panels and the inner support structure and / or the outer support structure. The described wedge-shaped construction of the heat panels allows an optimal ratio of the surface of the heat panels to the catalyst volume, whereby the necessary temperature stability is ensured in the catalyst bed.

The reaction space is thereby outward, d. H. shell side towards the body, bounded by the outer support structure, which is arranged around the heat panels, d. H. the outer support structure surrounds both the catalyst and the heat panels. Supporting structure is generally understood to mean a structure which keeps the preferably poured catalyst in the form, i. H. which is impermeable to the catalyst by which, however, a stowage is possible. The outer support structure is a gas-permeable, at least approximately cylindrical structure, preferably a net or grid or also a perforated vessel or a combination thereof.

The reaction space (catalyst bed and heat panels) is preferably arranged radially around the inner support structure, which delimits the inner cavity (inner central tube). The reaction space is preferably cylindrical (preferably straight hollow cylinder with a preferably circular base area). Inside this cylinder is then the inner cavity (inner central tube), limited on the shell side by the inner support structure.

The inner support structure is preferably a perforated vessel or else a mesh or grid or a combination thereof, particularly preferably a perforated vessel which is bounded by a network to the reaction space. The perforated vessel is tightly closed at the top or is covered by a seal and possibly a net.

Both the inner and the outer support structure serve as support elements for the preferably poured catalyst and are (in the contact region to the catalyst) permeable to the starting components (starting materials) and the reaction products which are preferably present in the gas phase under the selected reaction conditions in the converter.

On top of the reaction space, d. H. Above the catalyst bed, the lower parts of the heat panels and the inner central tube (inner cavity) is at least one cover. Through the cover the upper parts of the heat panels protrude. The cover is preferably a seal. The cover preferably has a high hydraulic resistance. The cover ensures that the reaction gases flow radially through the catalyst bed to the inner central tube. The seal preferably contains or consists of mats of thermally stable material. Due to the cover of the catalyst bed and the inner central tube by means of the seal upwards, the gas flow from the outer wall of the converter to the central tube is guided radially through the catalyst bed, which is located between the heat panels, and through the inner central tube to the outlet in the lower part of the carcass ,

In order to increase the efficiency of the converter, the catalyst is preferably introduced not only between the heat panels, but also between the heat panels and the inner and / or the outer support structure. Particularly preferably, the heat panels are completely enclosed by the catalyst to the sides.

As a result, 3 zones are formed in the catalyst layer:

1 . an outer adiabatic zone between outer support structure and the heat panels,

2. an isothermal zone between the heat panels,

3. an inner adiabatic zone between the inner support structure and the heat panels.

In the adiabatic zones, the reaction gas is first heated by the exothermic reaction as it flows into the catalyst bed and receives an additional energy input before flowing out. As a result, an external heating of the gas can advantageously be dispensed with, in particular in the case of a circulation loop, which simplifies the construction of the system and minimizes energy costs. The thickness of the catalyst layer between the heat panels (isothermal zone) corresponds to the distance between the heat panels to each other. The walls of the adjacent heat panels are preferably arranged parallel to one another or at an angle of 170 ° to 190 °, preferably 175 ° to 185 ° to each other. As a result, a uniform layer, ie a catalyst layer of almost constant thickness, preferably results between the heat panels. As a result, the converter can be operated in principle in both directions, ie inlet and outlet can be reversed. The functional terms in the claims which refer to a particular gas flow direction (such as inlet and outlet) are thus to be understood in this context and not by way of limitation.

Both during operation in the gas flow direction (inlet -> external support structure -> catalyst -> inner support structure -> drain) and in the reverse gas flow direction (drain -> inner support structure -> catalyst -> external support structure -> inlet) the following applies:

The volume of the catalyst which is located between the outer support structure and the heat panels is preferably more than 5% and preferably does not exceed 30% of the total volume of the catalyst.

The volume of the catalyst which is located between the inner support structure and the heat panels is preferably more than 5% and preferably does not exceed 30% of the total volume of the catalyst.

The majority of the catalyst, preferably at least 55%, preferably up to 85% and particularly preferably not less than 65% of the total catalyst volume, is thus located between the heat panels.

The distance between the individual heat panels (and thus the thickness of the catalyst layer between them) is preferably 8 mm to 200 mm.

In the area between the heat panels (isothermal zone) is advantageously a nearly constant temperature (temperature fluctuation max. 5 ⁰ C, preferably max. 2 ⁰ C, particularly preferably max. 1 ° C).

According to the invention, in the upper part of the carcass, the heat panels are connected to at least one heat exchange device (heat exchanger). In one embodiment, each individual heat panel (inner cooling circuit) is provided with a single, preferably cylindrical one Heat exchange device (outer cooling circuit) connected. Alternatively, the heat exchange device is designed as a unit for all the heat panels. In this alternative, the upper part of the body preferably forms a space for heat exchange, which is separated from the reaction space by an intermediate bottom. The heat exchange device serves to dissipate the excess heat of reaction from the heat transfer medium in the heat panel (and thus indirectly from the reaction zone) by transferring the heat to a heat exchange medium which passes through the heat exchange device or heat exchange devices. The heat exchange medium enters the upper part of the body of the converter through an inlet port, passes through the heat exchangers or the heat exchange device in the upper part of the heat panels, absorbing the excess heat of reaction to volatilize and leaving the upper part of the body of the converter through an outlet nozzle. Preferably, the converter contains at least one outlet for the gaseous heat exchange medium.

In particular, when using a vaporizable heat exchange medium, the heat exchange device preferably contains a flushing opening in the lower area. This advantageously avoids the deposition of harmful impurities of the heat exchange medium inside the heat exchange device on the heat exchange surface (such as lime and salts when using water as the heat exchange medium). For this purpose, preferably continuously or periodically, part of the heat exchange medium, preferably 5 to 15%, is discharged through the flushing opening. Alternatively, the rinsing is carried out discontinuously with heat exchange medium or rinsing liquid.

If several heat exchange devices are used, the converter preferably contains collectors with which the heat exchange devices are connected to each other. In a collector, the gaseous heat exchange medium is collected from the individual heat panels to co-discharge it from the converter. Other collectors are preferably used for the feed of the heat exchange means to the heat exchange devices and the discharge of the heat exchange medium or the rinsing liquid used for rinsing.

Preferably, the system, in particular in the case of a vaporizable heat exchange means, a level control for the heat exchange medium in the heat exchange devices, preferably outside the converter at the level of Upper part of the body is arranged. This level control preferably has a viewing window.

The energy dissipated with the heat exchange medium can be used for different processes (for example for preheating the starting components or for the bottom heating of the rectification column for product separation). The upper part of the heat panel (heat exchange device) is tubular and preferably has an inner tube and a jacket. The heat exchange medium flows in the jacket. The bottom of the shell is continuously flowed through by low flow rate of the liquid heat exchange medium, or may also be in the jacket pipes during the reaction process, at a subsequent discharge of the reaction process for blowdown and blowdown of the jacket pipes. This ensures avoidance of accumulation of harmful admixtures (salts and others) in the heat exchange means.

The lower parts of the heat panels are in the reaction space as a hollow body, preferably with a wedge-shaped base executed. The outer walls of the lower parts of the heat panels are in contact with the catalyst bed, which gives off heat. Inside the heat panels is a heat carrier, which absorbs the heat of reaction from the catalyst bed. The heat carrier vaporizes and preferably rises through pipes mounted inside the lower parts of the heat panels into the upper part of the heat panels where it releases its heat energy to a heat exchange means located in the shell around the pipe of the upper part of the heat panels , As a result, the heat transfer medium itself becomes liquid again and flows back within the heat panel. Ie. The heat transfer medium is conducted in the heat panels in a closed circuit. Advantageously, the heat transfer medium does not have to be led out of the body of the converter. Preferably, the heat panels are constructed in their interior so that the back-flowing heat transfer medium flows along the inner wall of the heat panels. For this purpose, the heat panels preferably contain internals in the lower region, via which the refluxing heat carrier is distributed. Each heat panel preferably contains at least one tube which receives the gaseous, ascending heat transfer medium.

Due to the evaporation of the heat carrier is advantageously a higher heat dissipation and thus more effective cooling achieved. If the heat energy input into the catalyst layer increases as a result of the exothermic process, this is compensated for by increased evaporation of the heat carrier. This advantageously allows the heat transfer medium (inner cooling circuit) in one closed system to drive. The regulation of the temperature in the inner cooling circuit and thus in the reaction zone is effected by the supply of the heat exchange medium in the outer cooling circuit. Advantageously, can be dispensed with a complex control technology in the inner cooling circuit.

The heat transfer medium is dependent on the process temperature to be reached in the converter, i. H. the temperature in the reaction zone, selected. Not only conventional heat transfer media, such as liquid metals (eg sodium and cesium) or molten salts, but advantageously also simpler and less expensive, such as elemental sulfur, can be used as the heat transfer medium.

Preferably, the heat panels are configured to receive and dissipate all the heat energy transferred from the reaction zone via the heat transfer medium and the heat exchange medium, i. H. the heat exchange surface in the reaction zone (the contact area of the heat panels with the catalyst) is dimensioned according to the heat energy to be absorbed. By the level of the heat exchange medium in the heat exchange devices, the amount of heat to be dissipated from the converter and thus ultimately the temperature in the reaction zone can be advantageously set.

The temperature difference between the temperature in the reaction zone (catalyst layer) and the temperature of the heat transfer medium inside the heat panels in the region of the reaction zone is preferably to below 60 ⁰ C, preferably below 30 ⁰ C, is set.

The ratio of the heat exchange surface in the reaction zone (ie the contact area of the wedge-shaped lower part of the heat panel with the catalyst) to the catalyst volume is dependent on the thermal energy dissipated, the rate of change of temperature and the contact time, ie the reaction to be carried out in the converter. The ratio of the heat exchange surface in the reaction zone to the catalyst volume is preferably at least 10 m ² / m ³ , more preferably 60 m ² / m ³ or more, and is preferably in the range from 10 m ² / m ³ to 250 m ² / m ³ . An oversized heat exchange surface has no negative impact on the process.

The outer surfaces of the heat panels in the reaction zone are preferably coated with a layer of aluminum dioxide and / or enamel. The thickness of this layer (s) total preferably 0.1 to 2 mm, more preferably 0.2 to 1 mm, in particular 0.3 to 0.7 mm. The heat exchange area of the heat exchange devices is preferably 3 to 10 times less than the surface area of the lower panel parts (heat exchange area in the reaction zone). This area corresponds to the possible contact area of the heat panels with the heat exchange medium. By the level of the heat exchange means, this can be advantageously varied and thus the temperature can be set in the converter.

Preferably, the converter additionally contains at least one temperature measuring device, preferably thermocouples. These are preferably introduced through nozzles in the upper region of the body of the converter. The temperature measuring devices are preferably in contact with the catalyst bed and allow the temperature measurement in the reaction zone. Preferably, the converter contains at least one temperature measuring device, more preferably 3 temperature measuring devices, which are distributed uniformly over the cross section and each measuring the temperature in the reaction zone in 3 different heights. The temperature measuring devices thus allow monitoring of the function of the heat panels and control of the temperature in the reaction zone. The temperature measuring devices allow automatic process control by automated control of the level of heat exchange medium in the heat exchange devices, the temperature of the feed at the inlet of the converter, the vapor pressure in the heat exchange device (s).

The converter according to the invention is therefore a reactor which, due to its special structure, is particularly suitable for an isothermal reaction, ie. H. a reaction at a nearly constant temperature throughout the volume of the reaction space. Due to the direct contact of the heat panels with the catalyst layer can advantageously be dissipated by the exothermic reaction heat directly at the origin.

The structure of the converter according to the invention, in particular the arrangement of the heat panels and the catalyst, makes it possible to set an optimum ratio of the surface of the heat panels to the volume of the catalyst, whereby a temperature control near the isothermal conditions in the entire volume of the reaction space is ensured.

Advantageously, in the converter according to the invention, depending on which reaction it is used for, different catalysts (eg a copper-containing catalyst for the synthesis of methanol from synthesis gas or a zeolite-containing catalyst for the reaction from methanol to gasoline). Due to the flexible construction of the body, which is composed of an upper and a lower part, it becomes possible to easily replace the catalyst (if necessary, the renewal of the catalyst after deactivation of the catalyst or when using the converter for another reaction).

Due to its high efficiency, in particular the higher product yield at higher throughputs in relation to the catalyst volume, it becomes possible for certain processes, in which classically several reactors are used (eg in the process of methanol synthesis), three classic from the Technology to replace known reactors by a converter according to the invention.

In addition, it becomes possible to make the converter very compact. For example, dimensions of the body of 1 to 3 m in diameter and heights of 2 to 20 m are possible. However, the size of the converter is determined by the process and throughput to be performed therein.

The almost isothermal reaction regime makes it possible to increase the yield of target product compared to the adiabatic reaction regime and at the same time to increase the product selectivity. Thus, fewer by-products are obtained, which significantly improves the effectiveness of the overall process.

Another object is therefore also the use of the converter according to the invention for carrying out chemical, catalytic reactions in the gas phase, preferably with almost isothermal reaction control. It finds application especially in the chemical and petroleum chemical industries.

The invention also relates to the heat panel as an important component of the converter according to the invention. The heat panel is hollow on the inside and has the following components: a.) A lower part, which is designed as a hollow body with a wedge-shaped base, whose lateral surfaces are formed as heat exchange surfaces, b.) An upper part, which is formed as a tube and with a Heat exchange device is operatively connected or can be brought into operative connection, wherein the tube of the upper part is connected to the upper base of the lower part, so that in the lower part vaporized heat carrier can rise into the tube and the condensed heat carrier from the tube in the lower part can flow back. The lower part of the heat panel preferably includes horizontal internals which are formed so that the refluxing condensed heat transfer medium flows down the inner wall of the panels. The lower part of the heat panel preferably further contains tubes for discharging the vaporized heat carrier in the upper part.

The invention also relates to the use of a heat panel constructed in this way in a converter for carrying out chemical, catalytic reactions in the gas phase, in particular in the chemical and petroleum chemical industries.

Preferred Embodiment of the Converter According to the Invention:

In a preferred embodiment, the converter according to the invention has a body with a nozzle for supplying the starting components and a nozzle for discharging the reaction products. In the lower part of the carcass there is a bottom plate on which a plurality of heat panels are arranged, in the upper part the mentioned heat panels are in operative connection with heat exchanging devices designed so as to allow the passage of a heat exchange medium through them Heat panels is the catalyst filled, which is bounded from the outside by a network as the outer support structure, which is attached to the heat panels and the catalyst bed therebetween, on the inside, the space occupied by the catalyst and heat panels, through a perforated vessel as limited inner support structure. Preferably, a net is mounted on the outer surface of the perforated vessel, which allows to fix the catalyst particles at the place of their use. The interior of this perforated vessel forms a hollow cylinder - the inner central tube - through which the formed gaseous reaction products flow outward.

About catalyst, heat panels and inner central tube is a seal with a high hydraulic resistance. In the preferred variant of the realization, the seal consists of mats of thermally stable material with a high hydraulic resistance, which forces the reaction gases to a radial flow through the catalyst bed in the direction of the central tube.

Preferably, the body comprises a lower part and an upper part, which are connected to each other by use of flanges, which ensures the ease of assembly / disassembly of the converter.

In the upper part of each heat panel may be arranged a cylindrical heat exchange device for removing the heat of reaction from the reaction zone. As a variant, the heat exchange device for dissipating the excess heat of reaction may be a unit for all heat panels.

In the preferred embodiment, the heat panel has a wedge-shaped shape with the pointed portion facing the central axis of the body. Such a panel configuration ensures an optimum ratio of the surface of the heat panels to the catalyst volume. The converter may additionally include thermocouples in the region of the heat panels inserted through sockets located on the body. The use of the mentioned thermocouples makes it possible to control the temperature in the reaction zone.

Another object of the invention are the heat panels, which are characterized by the following structure.

Preferred Embodiment of the Thermal Panel According to the Invention:

Preferably, the lower part of the heat panel has a cylindrical shape with a wedge-shaped base. Inside, the heat panel is hollow. It contains fixtures. With the upper cover of the lower part of the heat panel, a pipe is connected, which forms a unit as the upper part of the heat panel together with the lower part of the heat panel. The surface of the lower part of this heat panel serves as a heat exchange surface between the reaction space located around the heat panel and the heat carrier located in the interior of the heat panel. The heat transfer medium in the interior of the heat panel absorbs the heat generated during an exothermic reaction, whereby it evaporates. The gaseous heat carrier rises in the interior of the heat panel in built-in tubes up and collects in the attached to the lid of the heat panel tube. The tube is in its upper part with a heat exchange device in operative connection to which the amount of heat absorbed by the heat transfer in the reaction chamber, the heat transfer condenses, runs down on the inner wall of the manifold and inside the lower cylindrical panel part via horizontal internals to a is drained flow on the inner wall and flows down. In the reaction space, the condensed heat carrier evaporates again by absorbing the heat of reaction.

Based on the following figures and embodiments, the invention will be explained in more detail without being limited to these.

In Fig. 1 is the side view (vertical section) of a converter according to the invention, in Fig. 2 is the horizontal section of the converter through the reaction space, in Fig. 3 is the horizontal section of a heat panel and in Fig. 4 is the vertical section of a heat panel and a heat exchange device. FIG. 5 shows a detail from FIG. 2, in which the isothermal and adiabatic zones are shown.

The converter shown in FIGS. 1 and 2 for carrying out exothermic catalytic reactions is delimited by a body composed of a lower part 1 and an upper part 2. The body has a central axis 21. In the body, nozzles for feeding the starting components 3 and for discharging the reaction products 4 are attached. The body is assembled with the lower part 1 connected to the upper part 2 by use of flanges 5 and 6. In the lower part 1 of the body of the converter is a bottom plate 7, which forms the bottom of the reaction space 25 and on which heat panels 8 are located. Above the reaction space 25, the upper parts of the heat panels are connected to heat exchanging devices 9 through which the heat exchange means for removing the heat energy from the heat panels 8 flows. The heat exchange medium enters the collector for the heat exchange medium (e.g., feed water) 11 through an inlet port 10, continues to pass through the heat exchangers 9 where it evaporates, collects in the gaseous vaporized heat exchange medium collector 12, and then through the outlet port for the vaporized heat exchange medium 13 is removed in gaseous form. The rinse water collector 14 is used to collect the heat exchange means for flushing the lower parts of the heat exchange devices to avoid salt deposits, and the Spülwasseraustrittsstutzen 15 serves its derivation from the converter. Between the heat panels 8, which have a wedge-shaped shape in the region of the reaction space (see FIG. 3), a catalyst 16 is interspersed. The reaction space 25, including heat panels 8, is bounded on the outside (shell-side) by a net as an outer support structure 24. The volume of the catalyst between the edge of the heat panels 8 and the outer support structure 24 is less than 30% of the total volume of the catalyst. Inside the reaction space 25, an inner cavity 22 is bounded by a perforated vessel as the inner support structure 17, which forms the inner central tube, through which the reaction gases flow. This perforated vessel is also wrapped in a net to avoid entraining catalyst particles outward along with the reaction gas. The volume of the catalyst between the inner support structure 17 and the heat panels 8 is less than 30% of the total catalyst volume.

The reaction space 25 and the inner cavity 22 are bounded at the top by a seal 18, which consist of mats made of a thermally stable material with a high hydraulic resistance. This seal 18 prevents the gaseous Flow starting components at the space between the wedge-shaped parts of the heat panels 8 or flow in the limited by the inner support structure 17 inner cavity 22 (central tube for discharging the reaction gases) or from the catalyst layer from below into the upper converter space. The seal 18 has tight passages for the heat panels 8. The gaseous starting components thus flow only through the catalyst bed 16, which is located between the heat panels 8. Through the nozzle 19 Vielzonenthermoelemente 20 for measuring the temperature in the reaction chamber 25 are performed. In the reaction space 25, the thermocouples 20 extend directly through the catalyst bed 16, parallel to the central axis at a defined distance from the adjacent heat panels eighth

The operating principle of the converter with the heat panels 8 is as follows: In the converter gaseous starting components enter through the nozzle 3, they pass through the outer cavity 23 in the reaction chamber 25. In the reaction chamber 25 takes place an exothermic reaction, the reaction products emerge enter the reaction space 25 through the inner support structure 17 in the inner cavity 22 and then exit through the nozzle 4 from the converter. During the reaction, it is necessary for their normal course to dissipate heat from the reaction space 25. This is ensured by the heat panels 8, which are essentially "heat pipes" and contain a heat transfer medium that vaporizes due to the heat input, ie the lower wedge-shaped part of each heat panel 8 removes heat from the reaction zone in the catalyst bed 16 and carries it to the heat exchanging devices 19 in the upper part 2 of the carcass, the heat is then transferred to a heat exchange medium in the heat exchange device 19. The heat carrier thereby condenses again and flows back into the lower part of the heat panel 8. The heat exchange medium evaporates by the heat energy supplied and then becomes removed via the outlet pipe for the evaporated heat exchange medium 13 and used for other processes.

In Fig. 3 is an enlarged sectional view of the lower part of a heat panel 8 is shown. The heat panel 8 has tubes 26 inside to discharge the vaporized heat carrier. In the heat exchange device 9, this condenses again and then runs downwards on the inner walls of the heat panel 8. Furthermore, the heat panel 8 has inside horizontal struts 27, which mechanically stabilize the heat panel and ensure the mechanical strength of the heat panel 8 at high pressure in the reaction chamber 25. The heat panel 8 is wedge-shaped, wherein the pointed, directed to the central axis 21 of the body lower part of the heat panel 8 forms an angle 35 of 1, 5 to 18 °. FIG. 4 shows the vertical section of a heat panel and a heat exchange device operatively connected to the heat panel. The heat panel consists of the lower cylindrical hollow body with a wedge-shaped base surface 28, to the lid of a vertical pipe 29 is attached. Cylindrical hollow body 28 and vertical pipe 29 form a body with a uniform interior. This space is closed to the outside and contains in the cylindrical hollow body 28 internals. Inside the body, consisting of cylindrical hollow body 28 and vertical tube 29, there is the heat transfer medium, which absorbs the heat released during the exothermic catalytic reaction. In this case, the liquid heat carrier evaporates and rises in a gas upward into the vertical pipe 29. To the upper part of this vertical pipe 29, a jacket tube 30 is attached, which is part of the heat exchange device 9. In the jacket tube 30 is the heat exchange medium, which removes the heat from the heat carrier, which cools and condenses. The condensate of the heat carrier flows on the inner walls of the vertical tube 29 down into the cylindrical hollow body 28 of the heat panel 8, where it is forced by internals to drain on the inner walls down. Subsequently, the heat carrier evaporates again and the process of evaporation and condensation of the heat carrier by heat absorption and heat dissipation is repeated, so that the heat carrier always in the circuit between the lower part of the heat panel 8 - the cylindrical hollow body 28 - and upper part of the heat panel 8 - the vertical Pipe 29 - is located. The system is closed. The heat transfer medium remains inside the heat panel 8.

FIG. 5 shows the adiabatic zones 33 and 34 and the isothermal zone 32 within the catalyst bed 16 on the basis of a detail from FIG. 2. The reaction gas used initially flows through the outer adiabatic zone 34 and is heated here by the exothermic reaction to optimum reaction temperature. Subsequently, the reaction gas flows through between the heat panels 8 and is here - in the isothermal zone 32 - held by the continuous heat removal at a nearly constant optimum reaction temperature. Finally, the mixture of the reaction gases in the inner adiabatic zone 33 is reheated. This additional introduction of energy into the inner adiabatic zone 33 makes it possible to recirculate the circulating reaction gas without an external supply of heat into the converter. Exemplary Embodiment 1 - Application of the Converter for the Methanol Synthesis:

The synthesis of methanol is realized from synthesis gas (CO + H ₂ + H ₂ O + CO ₂ + inerts) at a pressure of 30 to 70 bar and a temperature of 220 ⁰ C to 290 ⁰ C.

The catalyst used is a copper-containing catalyst which is customarily used for methanol synthesis. The amount of catalyst used is 0.45 m ² .

In the converter 24 heat panels are used, as shown in Fig. 2.

Each heat panel has a zone of dissipation of the heat of reaction at the bottom. As a heat carrier n-dodecane is used here. In the upper area, each heat panel has a cooling zone connected to the heat exchange device. As a heat exchange medium here water of a temperature near boiling point is used. The heat of reaction is dissipated by the water vapor formed and used for other processes. The achieved steam pressure is 16 bar.

The temperature difference between the temperature in the reaction zone and the temperature of the heat carrier in the reaction zone is <40 ⁰ C.

The total heat exchange area of all heat panels in the reaction zone (ie the heat exchange area between the catalyst bed and the heat carrier in the heat panels) is 33 m ² .

The ratio of the heat exchange surface in the reaction zone to the catalyst volume is 60 m ² / m ³ .

The heat exchange surface in the reaction zone (i.e., the catalyst contact area) is coated with a layer of 0.2 mm of alumina and enamel of 0.3 mm thickness.

The heat exchange area in the area of the heat exchange device is 5.5 m ² . This corresponds to the possible contact surface with the heat exchange medium. By the level of the heat exchange medium, the amount of heat dissipated and thus the temperature in the reaction space of the converter can be adjusted.

Each heat panel has its own heat exchange device where steam is generated. The heat exchange devices are each as a vertical tube with jacket tube in the upper Area of the heat panels arranged. All heat exchange devices are interconnected by a common collector for feed water, a collector for evaporated heat exchange medium and a rinse water collector with subsequent discharge of the rinse water through the rinse water outlet nozzle (see Fig. 1).

The pressure inside the heat panel is up to 4 bar. The fixing of the heat panels serve partitions with notches of a diameter of 30 mm. The partitions are mounted vertically every 52 mm. The body has a diameter of 2 m and 3 m height.

Embodiment 2 - Application of the Synthetic Gasoline Convertible Converter from Crude Ethanol:

The synthesis is carried out at a pressure of 7 - 50 bar and a temperature in a range between 280 ⁰ C to 420 ⁰ C. In the example, the reaction of the synthesis of gasoline from crude methanol at a pressure of 7 bar and a temperature of 380 ⁰ C and at a pressure of 48 bar and a temperature of 380 ⁰ C is performed.

The catalyst used is a zeolite-containing catalyst, which is usually used for methanol gasoline production. The amount of catalyst used is 0.45 l.

In the converter 24 type elements are arranged, which are shown in Fig. 2.

Each heat panel has a zone of dissipation of the heat of reaction at the bottom. The heat transfer medium used here is sulfur with added iodine. In the upper area, each heat panel has a cooling zone connected to the heat exchange device. As a heat exchange agent here water is used. The heat of reaction is dissipated by the water vapor formed and used for other processes. The achieved steam pressure is 64 bar.

The temperature difference between the temperature in the reaction zone and the temperature of the heat carrier in the reaction zone is <30 ⁰ C.

The total heat exchange area of all the heat panels in the zone of heat of reaction dissipation (ie the contact area to the catalyst in the reaction zone) is 33 m ² . The ratio of heat exchange surface (contact surface to the catalyst) to the catalyst volume is again 60 m ² / m ³ . The heat exchange area in the area of the heat exchange device is 5.1 m ² .

Otherwise, the converter, as described in Example 1, constructed.

The structure of the converter according to the invention makes it possible to set an optimum ratio of the surface of the heat panels to the volume of the catalyst, whereby a nearly isothermal temperature control is ensured with the necessary temperature stability in the catalyst bed.

REFERENCE NUMBER: Lower part of the body Upper part of the body Inlet for supplying the starting components Process for discharging the reaction products Connecting flange Connecting flange Bottom plate Heat panel Heat exchange device Heat exchanger inlet Collector for heat exchange medium Collector for vaporized heat exchange medium Evacuated heat exchange medium outlet Flushing water collector / flushing water collector Flushing water outlet / outlet for Flushing Fluid Catalyst Transmission Inner Support Structure (Inner Central Tube) Seal Socket for Temperature Transmitter Temperature Transducer Central Axle Internal Cavity Outer Cavity External Support Structure Reaction Cavities Tubes for Evaporated Heat Transfer Horizontal Struts Lower part of the heat panel (cylindrical hollow body with wedge-shaped base) Upper part of the heat panel (vertical tube ) Jacket ear (as part of the heat exchange device) Catalyst table Isothermal zone Inner adiabatic zone Outer adiabatic zone Angle of the pointed lower part of the heat panel

Claims

claims

1. converter for carrying out exothermic catalytic reactions with a body (1, 2) having at least one inlet (3) for the feed of the starting components and at least one outlet (4) for discharging the reaction products, wherein in the lower part (2) of the carcass a reaction space (25) bounded by an inner support structure (17) and an outer support structure (24), wherein in the reaction space (25) a plurality of heat panels (8) are arranged, wherein within the inner support structure (17) an inner Cavity (22) is located, wherein the inlet (3) is arranged so that the starting components through the outer support structure (24) into the reaction space (25) flow, and the outlet (4) is connected to the inner cavity (22), the lower part (28) of each heat panel (8) in the lower part (2) of the carcass has a wedge-shaped shape, wherein each of the pointed part is directed to the central axis (21) of the carcass and wherein the upper part (29) each of the heat panel projects out of the reaction space (25) into the upper (2) part of the body and is operatively connected to a heat exchange device (9), the upper part (29) of each heat panel (8) being respectively connected to the lower part (28). the heat panels (8) is connected, so that in the lower part (28) vaporized heat carrier in the upper part (29) rise and condensed heat transfer medium from the upper part (29) in the lower part (28) can flow back.

2. Converter according to claim 1, characterized in that the pointed, directed to the central axis (21) of the body, lower part of the heat panel (8) forms an angle (35) of 1, 5 ° to 18 °.

3. Converter according to claim 1 or 2, characterized in that the ratio of the heat exchange surface in the reaction space (25) to the catalyst volume is 10 to 250 m ² / m ³ .

4. Converter according to one of claims 1 to 3, characterized in that the catalyst bed contains an outer adiabatic zone (34) which is located between the edge of the heat panel (8) and the outer support structure (24), wherein the catalyst volume in the outer adiabatic zone (34) does not exceed 30% of the total volume of the catalyst (16).

5. Converter according to one of claims 1 to 4, characterized in that the catalyst bed contains an inner adiabatic zone (33) which extends between the inner support structure (17) and the heat panels (8), wherein the catalyst volume in the inner adiabatic zone (33) does not exceed 30% of the total volume of the catalyst (16).

6. Converter according to claim 4 or 5, characterized in that there are at least 55%, preferably not less than 65%, of the catalyst volume between the heat panels.

7. Converter according to one of claims 1 to 6, characterized in that the heat exchange device (9) is in the upper part (2) of the body and with individual, several or all heat panels (8) is in contact.

8. Converter according to one of claims 1 to 7, characterized in that the inner support structure (17) has a diameter which allows the operator to have access to any location in the reaction space and the surface of the panels (8).

9. Converter according to one of claims 1 to 8, characterized in that the heat exchange device (9), in particular when using a vaporizable heat exchange means, in the lower region has a flushing opening.

10. Converter according to one of claims 1 to 9, characterized in that when using a plurality of heat exchange devices (9) of the upper part of the body a collector for the heat exchange means (1 1), a collector for the evaporated heat exchange means (12) and a collector for flushing liquid (14), wherein the converter has a level control for the heat exchange means, which is preferably arranged outside the converter at the level of the upper part (2) of the body.

1 1. Use of a heat panel, which is hollow inside and comprising the following components: a.) A lower part (28) which is formed as a hollow body with a wedge-shaped base surface (28) whose lateral surfaces are formed as heat exchange surfaces, b.) A upper part (29), which is formed as a tube and is in operative connection with a heat exchange device or can be brought into operative connection, wherein the tube of the upper part (29) is connected to the upper base of the lower part (28), so that in Bottom part (28) vaporized heat carrier can rise into the tube and condensed heat carrier from the tube in the lower part (28) can flow back in a converter according to one of claims 1 to 10.

12. Use according to claim 1 1, characterized in that the lower part contains internals (27) which are formed so that the refluxing condensed heat transfer medium flows on the inner wall of the heat panel down.