Reactor for thermal cracking of a gaseous, hydrocarbonaceous feedstock stream

Abstract

The invention relates to a reactor (1) for thermal cracking of a gaseous, hydrocarbonaceous feedstock stream (2) in an electrically heated moving bed (3) composed of electrically conductive granules (4) with elemental carbon deposited on the granules (4), comprising an upper reactor section (5) in which a feed conduit (6) for the granules (4) and a discharge conduit (7) for a hydrogen-containing product stream (8) are disposed, a middle reactor section (9), and a lower reactor section (13) in which a feeding device (14) for the gaseous, hydrocarbonaceous feedstock stream (2) is disposed and on the bottom side of which a discharge conduit (15) for the granules (4) is provided, wherein the discharge conduit (15) comprises at least one funnel-shaped vibrating base (16) which can be made to vibrate in the vertical and / or horizontal direction by means of at least one first vibration generator (17) and is connected to the lower reactor section (13) via a vibration-decoupling suspension (18).

Description

[0001] Reactor for the thermal cracking of a gaseous, hydrocarbon-containing feed stream

[0002] State of the art

[0003] The invention relates to a reactor for the thermal cracking of a gaseous, hydrocarbon-containing feed stream according to the preamble of claim 1.

[0004] The pyrolysis of gaseous, hydrocarbon-containing feedstock streams, particularly natural gas or methane, represents an economically and ecologically advantageous method of hydrogen production. To date, the majority of industrially produced and consumed hydrogen is generated through steam reforming of natural gas, which releases large amounts of the greenhouse gas CO2 (so-called "grey" hydrogen). The transition to a climate-friendly hydrogen economy requires alternative production processes that reduce or even completely avoid the amount of CO2 released. This can be achieved by capturing and storing the CO2 produced during the conventional steam reforming process (also known as "blue" hydrogen), or by electrolyzing water using renewable electricity ("green" hydrogen).

[0005] The pyrolysis of natural gas or methane offers advantages over these two alternatives. During pyrolysis, the hydrocarbons are directly separated into their constituents, elemental carbon and hydrogen. If the energy required to carry out this endothermic reaction is supplied using renewable energy, the process is carbon-neutral. Compared to "blue" hydrogen, this offers the advantage of avoiding the expense of capture and the costs, including the potential risks, of underground CO2 storage. The resulting elemental carbon, on the other hand, is climate-neutral and can be partially reused as a valuable product or easily disposed of.

[0006] Compared to the electrolysis of water, there is the advantage of a significantly reduced energy consumption per ton of hydrogen produced, since water has a significantly higher binding energy per hydrogen atom:

[0007] CH4C + 2 H2AH RO= 37.8 kJ / mol H2

[0008] 2 H2O O2 + 2 H2AH RO = 285.8 kJ / mol H2 Under ideal conditions, only about 13% of the energy required to produce hydrogen by pyrolysis is needed compared to the energy required to produce it by water electrolysis.

[0009] For these reasons, the pyrolysis of carbon-containing feedstock streams appears to be a promising technology for the energy-efficient production of hydrogen.

[0010] Various processes are already known for the pyrolysis of hydrocarbon-containing feed streams. Firstly, pyrolysis can be carried out by electron beam plasma pyrolysis, in which the hydrocarbon molecules are dissociated using the kinetic energy of accelerated electrons. A device for carrying out such a plasmalysis is known, for example, from DE 102020 116 950 A1. Furthermore, the feed stream can be introduced into a liquid metal bath in which pyrolysis takes place. The resulting carbon then remains in the metal bath and must subsequently be extracted. Such a device is known from EP 3 521 241 A1.

[0011] Another alternative process involves the purely thermal cracking of gaseous, hydrocarbon-containing feed streams in an electrically heated moving bed made of electrically conductive granules. In a columnar reactor, the moving bed is guided from top to bottom under the influence of gravity. The hydrocarbon-containing feed stream flows countercurrently through the reactor from bottom to top. The moving bed is directly heated electrically by at least two electrodes arranged in the moving bed, which conduct an electric current through the moving bed. The majority of the heat is generated by resistance heating at the contact points between the individual grains of the granules. With a uniform current flow, a reaction volume is created between the electrodes, in which a temperature sufficient for pyrolysis, in the range of 1,000°C - 1,500°C, is reached.The feed stream is thermally cracked, with the released gaseous hydrogen being discharged upwards and the elemental carbon precipitating on the granulate. Such reactors are known, for example, from WO 2019 / 145279 A1 and WO 2020 / 244803 A1.

[0012] A disadvantage of these reactors is that the precipitation of elemental carbon on the granules can lead to the formation of electrically conductive bridges between the granules. This problem becomes more pronounced the larger the reactor, as the granules then remain within the reaction volume for longer and experience greater deposition. The formation of bridges between the granules leads to a drop in the electrical resistance between the electrodes and thus to a lower heating output of the reactor. Gradually, a path of reduced electrical resistance forms between the electrodes, through which the electrical current flows preferentially. As the granules continue to caking together, the hydrogen yield decreases until the co-heating concept ultimately fails. In addition, the caking together granules hinder the transport of the moving bed through the reactor.

[0013] One possible measure to reduce bridging is to accelerate the flow of the moving bed through the reactor. This can reduce the amount of carbon deposited on the granules and, consequently, the tendency to bridging. A disadvantage, however, is the increased energy required to heat the faster-circulating moving bed to the required temperature, which increases the volume of granules entering the reaction volume per unit of time. Furthermore, energy losses occur due to the moving bed exiting the reactor at a higher temperature, and further cooling of the granules outside the reactor may even be necessary.

[0014] Disclosure of the invention

[0015] The object of the invention is therefore to provide a reactor for the thermal cracking of a gaseous, hydrocarbon-containing feed stream in an electrically heated moving bed, in which the tendency to bridge formation between the granules of the moving bed is reduced while at the same time ensuring energy-efficient operation.

[0016] This object is achieved by a reactor having the features of claim 1.

[0017] This creates a reactor for the thermal cracking of a gaseous, hydrocarbon-containing feed stream in an electrically heated moving bed of electrically conductive granules, with the deposition of elemental carbon on the granules. The reactor comprises an upper, a middle, and a lower reactor section. The upper reactor section contains an inlet for the granules and an outlet for a hydrogen-containing product stream. The lower reactor section contains a feed device for the gaseous, hydrocarbon-containing feed stream, and a outlet for the granules is provided at the bottom.According to the invention, the discharge comprises at least one funnel-shaped vibrating floor which can be set into vibration in the vertical and / or horizontal direction by means of at least one first vibration generator and is connected to the lower reactor section via a vibration-decoupling suspension.

[0018] Thanks to the vibration-decoupling suspension on the lower reactor section, the funnel-shaped vibrating floor is designed to vibrate relative to the lower reactor section. This transfers the vibration particularly efficiently to the granules resting on the vibrating floor in the reactor. The vibrating granules exhibit improved flow properties, which evens out the residence time of the granules in the reactor. The vibrating floor thus supports the formation of plug flow in the reactor. Local granule blockages in the reactor are avoided, and the tendency for bridging between the granules is consequently reduced.

[0019] Secondly, the vibration transmitted to the granules through collisions between neighboring granules causes them to rotate in place. Even if neighboring granules do not temporarily move relative to each other in the granule flow, the rotation of the granules caused by the vibrating floor ensures a regular change in the contact points of neighboring granules. Since the carbon produced during pyrolysis primarily deposits at the resistance-heated contact points, regularly rotating the contact points is particularly effective in preventing bridging.

[0020] The granulate used preferably contains grains of a carbon-containing material. Suitable materials include granules made of pure carbon or coke. However, the use of granules made of materials such as silicon carbide or boron carbide is also conceivable.

[0021] Preferably, at least two electrodes for heating the moving bed are arranged in the middle reactor section. The positioning of the electrodes in the reactor and the flow rate of the granules, as well as the flow rate of the feedstock stream, indirectly define a reaction volume in the reactor in which the reaction conditions for pyrolysis are present. The reaction volume is preferably arranged at least partially in the middle reactor section. However, the reaction volume can also extend into the upper and / or lower reactor sections. In some embodiments, the electrodes comprise an upper electrode and a lower electrode, each of which extends along a horizontal cross-sectional area of ​​the reactor. In this case, the electrodes introduce an electric field into the moving bed in a vertical direction parallel to the direction of movement of the granules.

[0022] In other embodiments, the electrodes are arranged on opposite side walls of the reactor. The lateral arrangement of the electrodes reduces the interference with the movement of the moving bed. Furthermore, the electrodes do not impede the transmission of vibrations from the vibrating bed to the granules. This embodiment is preferably used in combination with a reactor with a rectangular or square cross-section. This allows a particularly homogeneous electric field to be generated in the moving bed perpendicular to its direction of movement.

[0023] Alternatively, or in addition to the electrodes, at least one coil for inductive heating of the moving bed can be arranged outside the central reactor section. Inductive heating of the moving bed from the outside has the advantage of introducing heat into the granules without the need to install heating elements inside the reactor, which could lead to carbon deposits and impair granule flow.

[0024] In preferred embodiments, a lower displacement body is arranged in the lower reactor section, which is attached to the vibrating floor by means of a strut and can be set into vibration together with the vibrating floor. By using a displacement body in the lower reactor section, the vibrations of the vibrating floor can additionally be introduced at a position in the reactor that is closer to the reaction volume. Such an embodiment is particularly advantageous in large-sized reactors in which the vertical distance between the vibrating floor and the reaction volume causes considerable damping of the induced granule movements. The displacement body attached to the vibrating floor forms a second vibration source in the moving bed, which increases the volume of the fluidized portion in the moving bed.The lower displacement body preferably extends over at least 50%, particularly preferably over at least 75%, of the cross-sectional area of ​​the reactor in order to introduce the vibration as uniformly as possible across the reactor cross-section. The lower displacement body is preferably arranged above the feed device. Since the feed device can create resistance to the propagation of vibrational oscillations in the moving bed, it is advantageous to introduce the vibrations by using a displacement body only above the feed device in order to achieve the most unhindered propagation of the oscillations into the reaction volume in the central reactor section.

[0025] The lower displacement body is preferably arranged entirely within a preheating volume of the reactor defined by the feed device and the lowest point of the electrodes. In particular, it is preferred if the displacement body is arranged entirely in the upper half of the preheating volume. The lower displacement body is thus preferably positioned close to the reaction volume, but without protruding into it. If the displacement body were to extend into the reaction volume, increasing deposition of elemental carbon on the displacement body would be expected. This would impede the flow of the granules and require regular maintenance of the reactor.

[0026] The displacement body can also have extensions that extend into recesses in a lower electrode. Such extensions can transmit the vibration of the vibrating floor into the space above the electrode. Furthermore, the vibrating electrodes can promote the flow of granules through the recesses of the electrode.

[0027] In other preferred embodiments, the displacement body forms the lower electrode. This has the advantage that the vibration is introduced into the moving bed as close as possible to the reaction volume and that the displacement body does not represent an additional obstacle to the granule flow.

[0028] The displacement body preferably has a conical or truncated cone-shaped surface. Conical surfaces cause the granules to vibrate more strongly, also with a horizontal movement component, which promotes relative movements between neighboring grains of the granules. Furthermore, conical surfaces act as baffles and ensure improved flow around the displacement body in the granule flow. The cone angle of the surface is preferably in the range between 90° and 160°, particularly preferably between 120° and 152°. The displacement body can preferably have openings for the flow of the granules, which, in a vertical projection, make up between 10% and 60%, particularly preferably between 30% and 50% of the total surface of the displacement body.For such an opening ratio of the displacement body, a preferred compromise is found between the desired excitation of the granules and excessive flow obstacles in the granule flow.

[0029] In individual embodiments of the invention, in addition to the vibrating floor and alternatively or in addition to the lower displacement body, an upper displacement body can be arranged in the upper reactor section, which can be set into vibration by means of at least one second vibration generator. The upper displacement body can be used to stimulate an upper part of the moving bed to vibrate in an improved manner.

[0030] Preferably, the at least one vibration generator is configured to generate vibrations of the vibrating floor with a frequency in the range of 25 Hz to 75 Hz and / or a vibration speed in the range of 10 mm / s to 40 mm / s.

[0031] Further advantageous embodiments can be found in the following description and the subclaims.

[0032] The invention is explained in more detail below with reference to the embodiments shown in the attached figures.

[0033] Brief description of the drawings

[0034] Fig. 1 shows schematically a reactor according to a first embodiment of the invention with a displacement body and electrodes extending in the horizontal direction,

[0035] Fig. 2 shows schematically a reactor according to a second embodiment of the invention, wherein the displacement body forms the lower electrode,

[0036] Fig. 3 shows schematically a reactor according to a third embodiment of the invention with electrodes arranged on opposite side walls,

[0037] Fig. 4 schematically shows a reactor according to a fourth embodiment of the invention, in which the displacement body is arranged entirely in an upper half of the preheating volume, Fig. 5A schematically shows a reactor according to a fifth embodiment of the invention with a lower and an upper displacement body, each of which has extensions that project into recesses of the associated electrodes,

[0038] Fig. 5B shows schematically a cross-section of the reactor as in Fig. 5A in a horizontal section plane at the level of the lower electrode,

[0039] Fig. 6A-6E show schematically different embodiments of displacement bodies with a conical or frustoconical surface,

[0040] Fig. 6F-6G show schematically the displacement bodies according to Fig. 6C to 6E in a vertical projection and

[0041] Fig. 7 shows schematically a reactor according to a sixth embodiment of the invention with inductive heating of the moving bed.

[0042] Embodiments of the invention

[0043] In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

[0044] Fig. 1 shows a reactor 1 for the thermal cracking of a gaseous, hydrocarbon-containing feed stream 2 in an electrically heated moving bed 3 of electrically conductive granules 4 with deposition of elemental carbon on the granules 4. The reactor 1 is preferably generally cylindrical and extends along a vertical direction V. The cylinder can have, for example, a circular, rectangular, square, or polygonal cross-section. To carry out the thermal cracking, the reactor 1 is designed for temperatures of the moving bed 3 in the range of 1,000°C to 1,500°C and gas pressures of up to 40 bar (g).

[0045] The reactor 1 comprises three sections arranged one above the other, each providing different functions of the reactor 1: an upper reactor section 5, a middle reactor section 9 and a lower reactor section 13.

[0046] In the upper reactor section 5, an inlet 6 for the granulate 4 and an outlet 7 for a hydrogen-containing product stream 8 are arranged. The granulate 4 is therefore fed in at the top during operation of the reactor 1 and migrates as a moving bed 3 in the vertical direction V through the reactor 1. In addition to the carbon deposited on the granulate 4, further elemental carbon in the form of soot particles is generally also produced during operation of the reactor 1, some of which leave the reactor 1 downwards with the moving bed 3 and some of which are discharged with the hydrogen-containing product stream 8.

[0047] In the middle reactor section 9, at least two electrodes 10, 11; 10', 11' are preferably arranged for heating the moving bed 3. The electrodes 10, 11; 10', 11' create a reaction volume 12 within the reactor 1 during operation. The reaction volume 12 of the reactor 1 is defined as the space in which a sufficient temperature is reached for the thermal cracking of the hydrocarbon-containing feed stream. Since the electrodes cause the electrical resistance heating of the moving bed 3 during operation, the reaction volume 12 is generally located between the electrodes 10, 11 and is delimited by them. During operation, the electrical current flows through the moving bed 3 between the electrodes 10, 11; 10', 11' and dissipates into thermal energy due to the electrical resistance of the moving bed 3. The electrical resistance results from the contact points between the granules orthe small transfer surfaces, while the granules themselves preferably have a comparatively high conductivity. As shown in Fig. 1, the electrodes 10, 11 can, for example, comprise an upper electrode 10 and a lower electrode 11, each of which extends along a cross-sectional area in the horizontal direction H of the reactor 1.

[0048] However, the position and extent of the reaction volume 12 are also determined by the flow of the granulate 4 and the flow of the feed stream 2 in the reactor 1, since the materials, due to their inherent heat capacity, transport the thermal energy generated in the reactor 1. By appropriately selecting the flow conditions in the reactor, the reaction volume can also extend outside the space delimited by the electrodes 10, 11; 10', 1T.

[0049] A feed device 14 for the gaseous, hydrocarbon-containing feed stream 2 is arranged in the lower reactor section 13. The gaseous feed stream 2 is passed upwards in the vertical direction V in countercurrent to the moving bed 3. Between the feed device 14 and the lowest point of the electrodes 10, 11, a preheating volume is thus formed, in which the feed stream 2 is preheated with the thermal energy of the moving bed 3 emerging from the reaction volume 12, but does not yet reach the temperature required for thermal pyrolysis. The preheating volume forms a lower of two heat integration zones of the reactor 1. In the lower heat integration zone, thermal energy from the moving bed 3 emerging from the reaction volume is transferred, preferably as completely as possible, to the feed stream 2.The second, upper heat integration zone forms in the upper reactor section 5, in which thermal energy of the gaseous product stream 8 is transferred, preferably as completely as possible, to the moving bed 3 before it enters the reaction volume 12 from above. By forming two heat integration zones within the reactor 1, the thermal energy can be largely retained within the reactor 1, and the need for external heat exchangers is correspondingly reduced.

[0050] Furthermore, a discharge 15 for the granulate 4 is provided on the bottom side of the lower reactor section 13. According to the invention, the discharge 15 comprises at least one funnel-shaped vibrating floor 16. The vibrating floor 16 can be set into vibration by means of at least one first vibration generator 17 in the vertical direction V and / or horizontal direction H. Preferably, the vibration generator 17 is designed to set the vibrating floor 16 in a circular movement in the horizontal direction H and vertical direction V. Particularly preferably, the horizontal component of the movement of the vibrating floor 16 is greater than the vertical component of the movement.

[0051] The discharge 15 can preferably have a housing on the outer side of the vibrating floor 16, facing away from the moving bed 3. The housing allows the external application of gas pressure from a pressure source to the vibrating floor 16. This can reduce pressure loads on the vibrating floor 16. The gas pressure preferably corresponds to the pressure prevailing in the reactor 1 with a tolerance of + / - 50%, particularly preferably + / - 25%.

[0052] The vibrating floor 16 is connected to the lower reactor section 13 via a vibration-decoupling suspension 18, for example, a freely oscillating ring buffer suspension. At the bottom, the vibrating floor 16 is preferably also connected in a vibration-decoupled manner via an outlet sleeve 29 to a discharge device, typically a screw conveyor (not shown).

[0053] Unbalance motors, such as electric unbalance vibrators, are preferably used as vibration generators 17. Alternatively or additionally, other vibration generators, such as hydraulically or pneumatically acting vibrators, can also be used. The at least one vibration generator 17 can preferably be configured to generate vibrations of the vibrating floor 16 at a frequency in the range of 25 Hz to 75 Hz and / or a vibration speed in the range of 10 mm / s to 40 mm / s.

[0054] During operation of reactor 1, the vibrating floor 16 sets the granules of the moving bed 3 in motion, which preferably includes rotations of the granules in addition to translational components. This motion promotes the outflow of the granules 4 through the discharge 15, so that a uniform downward movement of the moving bed 3, similar to a plug flow, preferably develops in the reactor 1. Furthermore, the movement of the granules in the area of ​​the reaction volume 12 leads to constantly changing contact points between the granules, thereby reducing the tendency for bridging by deposited carbon.

[0055] The movement of the granules introduced by the vibrating floor 16 is dampened by internal components in the reactor 1, such as the feed device 14 or a horizontally extending electrode 11, but also by the granules 4 themselves. Depending on the extent of the lower reactor section 13 and the positioning of the aforementioned internal components, it can therefore be advantageous if a lower displacement body 21 is arranged in the lower reactor section 13, which is attached to the vibrating floor 16 by means of a strut 22 and can be set into vibration together with the vibrating floor 16. The strut can, for example, consist of a central strut or several struts distributed over the circumference of the vibrating floor 16. As shown in Fig.1, the displacement body 21 is preferably arranged above the feed device 14 and particularly preferably arranged entirely in the preheating volume of the reactor between the feed device 14 and the lowest point of the electrode 10.

[0056] In the embodiment shown in Fig. 1, the displacement body 21 has a frustoconical surface that tapers downwards. At least in the central region, the surface has an opening to allow the granulate 4 to pass through. Further possible shapes of the displacement body are explained in more detail with reference to Fig. 6.

[0057] Fig. 2 shows a second embodiment of a reactor 1 according to the invention. The reactor 1 differs from the first embodiment according to Fig. 1 in that the displacement body 21 forms the lower electrode 11. This has the advantage that the lower electrode 11 does not constitute an obstacle to the movement of the granules induced by the vibrating floor 16, but rather itself stimulates the granules 4 to move. In this way, the granules 4 can be set in motion particularly effectively in the reaction volume 12. If the displacement body 21 simultaneously forms the lower electrode 11, the design of the displacement body 21 / the electrode 11 should also consider ensuring that the reaction volume continues to be heated homogeneously across the cross-sectional area of ​​the reactor 1. This criterion preferably leads to a flat, grid-like structure of the displacement body 21.

[0058] A further, independent difference from the first embodiment is the positioning of the suspension 18. As can be seen from Fig. 2, the suspension 18 does not necessarily have to be arranged at the interface between the lower reactor section 13 and the discharge 15. Particularly for load-related reasons, it may be advantageous to arrange the suspension 18 in the region of a funnel-shaped taper of the discharge 15, as shown in Fig. 2.

[0059] Otherwise, the statements regarding the first embodiment apply accordingly to the second embodiment.

[0060] The third embodiment shown in Fig. 3 differs from the first embodiment in the arrangement of the electrodes 10', 11'. In Fig. 3, the electrodes 10', 11' are arranged on opposite side walls 19, 20 of the reactor. This arrangement of the electrodes 10', 11' is advantageous because, due to their lateral positioning, the electrodes 10', 11' cause significantly less damping of the movements introduced into the moving bed 3 by the vibrating floor 16. In this way, the vibrations are transported more effectively into the reaction volume 12. To form a homogeneous electric field, this arrangement of electrodes 10', 11' is preferably used in combination with a reactor 1 with a rectangular, square, or polygonal cross-section.

[0061] Furthermore, the statements regarding the first two embodiments apply accordingly to the third embodiment.

[0062] The fourth embodiment shown in Fig. 4 is a variant of the third embodiment with a displacement body having a conical surface. In this case, the displacement body 21 is not only arranged entirely within the preheating volume Vv, but is even located entirely in its upper half H2, while the lower half H1 is only penetrated by the preferably vertical strut 22. Otherwise, the statements regarding the first three embodiments apply accordingly to the fourth embodiment.

[0063] Fig. 5A shows a fifth embodiment of the invention, which differs from the first embodiment in the type and arrangement of the displacement body 21. According to Fig. 5A, the displacement body 21 is formed with extensions 23 that protrude into recesses 24 of the lower electrode 11. The arrangement of extensions 23 and recesses 24 of the lower electrode 11 is shown in cross-section in Fig. 5B. To ensure reliable granulate flow in the region of the recesses 24, the gap width between the extension 23 and the edge of the recess 24 should correspond to at least 5 times the grain size of the granulate 4.

[0064] A further difference from the first embodiment is that an upper displacement body 27 is arranged in the upper reactor section 5, which can be set into vibration by means of at least one second vibration generator 28. In the example shown, the shape and arrangement of the upper displacement body 27 corresponds to the lower displacement body 21. However, any other shapes and combinations of lower and upper displacement bodies can also be used according to the invention.

[0065] Fig. 6 shows various other shapes of displacement bodies 21 that can be used according to the invention. Fig. 6A shows an upwardly tapered displacement body 21 and Fig. 6B shows a downwardly tapered displacement body 21 with a frustoconical surface and a central opening 25. Fig. 6C and Fig. 6D show displacement bodies with conical surfaces that, in addition to a central opening 25, also have annular openings 26. The annular openings 26 are larger in the case of Fig. 6D. Fig. 6E shows the displacement body 21 that corresponds to a vertical mirror image of the displacement body 21 according to Fig. 6C. In all cases, the cone angle ß of the surface is preferably in the range between 90° and 160°, particularly preferably between 120° and 152°.

[0066] Fig. 6F and 6G show the displacement bodies according to Fig. 6C and 6D in a vertical projection, in which the area of ​​the openings 25, 26 can be seen in relation to the total area of ​​the displacement body 21. The displacement body 21 preferably has openings 25, 26 for the flow of the granulate 4, which in such a vertical projection make up between 10% and 60%, preferably between 30% and 50%, of the total area of ​​the displacement body 21. The shapes of displacement bodies shown in Fig. 6A to 6G can each also be used as the upper displacement body 27.

[0067] Through testing, the specialist is able to further optimize the shape of the displacement body. The focus is on minimizing particle flow in the moving bed, allowing a uniform flow of the gaseous feed stream, and ensuring the most effective vibration transmission possible.

[0068] Fig. 7 shows a sixth embodiment of the invention, which differs from the third embodiment in that, instead of electrodes in reactor 1, a coil 30 for inductive heating of the moving bed 3 is arranged outside the central reactor section 9. The coil 30 generates an alternating magnetic field in reactor 1, which induces eddy currents in the conductive granules 4. Due to the intrinsic electrical resistance of the moving bed 3, the ohmic losses of the eddy currents lead to the heating of the moving bed 3. The sixth embodiment is characterized by a particularly small number of components arranged in the interior of the reactor 1. This minimizes carbon deposits in the reactor 1 and achieves the most undisturbed flow of the moving bed 3 possible.

[0069] Otherwise, the statements regarding the previous embodiments apply accordingly.

[0070] List of reference symbols

[0071] 1 reactor

[0072] 2 feedstock stream

[0073] 3 hiking bed

[0074] 4 granules

[0075] 5 upper reactor section

[0076] 6 Feed for granulate

[0077] 7 Discharge for gas product stream

[0078] 8 Product flow

[0079] 9 middle reactor section

[0080] 10, 10', 11 , 1 T electrodes

[0081] 12 reaction volumes

[0082] 13 lower reactor section

[0083] 14 Feeding device

[0084] 15 Discharge for granulate

[0085] 16 sprung floor

[0086] 17 first vibration generators

[0087] 18 Suspension

[0088] 19, 20 side walls

[0089] 21 lower displacement body

[0090] 22 Bracing

[0091] 23 extensions

[0092] 24 recesses

[0093] 25, 26 Breakthroughs in the displacement body

[0094] 27 upper displacement body

[0095] 28 second vibration generator

[0096] 29 Outlet cuff

[0097] 30 coil

[0098] H Horizontal direction

[0099] H1 lower half of the preheating volume

[0100] H2 upper half of the preheating volume

[0101] V Vertical direction

[0102] Vv Preheating volume ß Cone angle

Claims

PATENT CLAIMS 1. Reactor for the thermal cracking of a gaseous, hydrocarbon-containing feed stream (2) in an electrically heated moving bed (3) of an electrically conductive granulate (4) with deposition of elemental carbon on the granulate (4), comprising: an upper reactor section (5) in which a feed (6) for the granulate (4) and a discharge (7) for a hydrogen-containing product stream (8) are arranged, a middle reactor section (9), a lower reactor section (13) in which a feed device (14) for the gaseous, hydrocarbon-containing feed stream (2) is arranged, and on which a discharge (15) for the granulate (4) is provided on the bottom side, characterized in that the discharge (15) comprises at least one funnel-shaped vibrating bottom (16) which can be set into vibration in the vertical and / or horizontal direction by means of at least one first vibration generator (17) and is connected to the lower reactor section (13) via a vibration-decoupling suspension (18).

2. Reactor according to claim 1, characterized in that at least two electrodes (10, 11; 10', 1 T) for heating the moving bed (3) are arranged in the central reactor section (9).

3. Reactor according to claim 2, characterized in that the electrodes (10, 11) comprise an upper electrode (10) and a lower electrode (11), each extending along a horizontal cross-sectional area of ​​the reactor (1).

4. Reactor according to claim 2, characterized in that the electrodes (10', 1 T) are arranged on opposite side walls (19, 20) of the reactor.

5. Reactor according to one of claims 1 to 4, characterized in that at least one coil (30) for inductive heating of the moving bed (3) is arranged on the outside of the central reactor section (9).

6. Reactor according to one of claims 1 to 5, characterized in that in the lower reactor section (13) a lower displacement body (21) is arranged, which is fastened to the vibrating base (16) by means of a strut (22) and can be set into vibration together with the vibrating base (16). Reactor according to claim 6, characterized in that the lower displacement body (21) is arranged above the feed device (14). Reactor according to claim 6 or 7, characterized in that the lower displacement body (21) is arranged completely in a preheating volume (Vv) of the reactor (1) defined by the feed device (14) and the lowest point of the electrodes (10, 11; 10', 11'). Reactor according to one of claims 6 to 8 and claim 3, characterized in that the displacement body (21) has extensions (23) which project into recesses (24) in the lower electrode (11). Reactor according to one of claims 6 to 8 and claim 3, characterized in that the displacement body (21) forms the lower electrode (11).Reactor according to one of claims 6 to 10, characterized in that the displacement body (21) has a conical or frustoconical surface. Reactor according to claim 11, characterized in that a cone angle (ß) of the surface is in the range between 90° and 160°, preferably between 120° and 152°. Reactor according to one of claims 6 to 12, characterized in that the displacement body (21) has openings (25, 26) for the flow of the granulate (4), which, in a vertical projection, make up between 10% and 60%, preferably between 30% and 50%, of a total surface of the displacement body (21). Reactor according to one of claims 1 to 13, characterized in that an upper displacement body (27) is arranged in the upper reactor section (5), which can be set into vibration by means of at least one second vibration generator (28).Reactor according to one of claims 1 to 14, characterized in that the at least one vibration generator (17) is designed to generate vibrations of the. vibrating floor (16) with a frequency in the range of 25 Hz to 75 Hz and / or a vibration speed in the range of 10 mm / s to 40 mm / s.

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