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  • B01J8/06—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds in tube reactors; the solid particles being arranged in tubes
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  • B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
  • B01J8/0446—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical
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  • B01J8/06—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds in tube reactors; the solid particles being arranged in tubes
  • B01J8/065—Feeding reactive fluids
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  • C07C1/04—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon from carbon monoxide with hydrogen
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• • C—CHEMISTRY; METALLURGY
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  • C07C1/04—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon from carbon monoxide with hydrogen
  • C07C1/0455—Reaction conditions
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• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
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  • C07C1/12—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon from carbon dioxide with hydrogen
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  • B01J2204/00—Aspects relating to feed or outlet devices; Regulating devices for feed or outlet devices
  • B01J2204/002—Aspects relating to feed or outlet devices; Regulating devices for feed or outlet devices the feeding side being of particular interest
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
  • B01J2208/00017—Controlling the temperature
  • B01J2208/00026—Controlling or regulating the heat exchange system
  • B01J2208/00035—Controlling or regulating the heat exchange system involving measured parameters
  • B01J2208/00044—Temperature measurement
  • B01J2208/00061—Temperature measurement of the reactants
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  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
  • B01J2208/00017—Controlling the temperature
  • B01J2208/00106—Controlling the temperature by indirect heat exchange
  • B01J2208/00168—Controlling the temperature by indirect heat exchange with heat exchange elements outside the bed of solid particles
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  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
  • B01J2208/00017—Controlling the temperature
  • B01J2208/0053—Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
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  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
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  • B01J2208/00663—Concentration
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  • B01J2208/02—Processes carried out in the presence of solid particles; Reactors therefor with stationary particles
  • B01J2208/023—Details
  • B01J2208/024—Particulate material
  • B01J2208/025—Two or more types of catalyst
• • B—PERFORMING OPERATIONS; TRANSPORTING
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  • B01J2208/06—Details of tube reactors containing solid particles
  • B01J2208/065—Heating or cooling the reactor
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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  • Y02P20/10—Process efficiency
  • Y02P20/133—Renewable energy sources, e.g. sunlight

Definitions

• the invention relates to a method and a tube reactor for carrying out catalytic gas phase reactions according to the preamble of claim 1 and 11 and to a reactor system for carrying out catalytic gas phase reactions.
• the invention relates to the performance of exothermic catalytic gas phase reactions with pronounced temperature maxima. An example of such reactions are methanation reactions.
• substitute natural gas essentially contains methane and minor amounts of unreacted and other gases which must comply with the feed-in specification of the relevant gas network if the SNG is there is to be fed.
• SNG can be produced on the basis of coal or other carbonaceous substances such as waste or biomass via synthesis gas - a mixture of CO and / or CO2, H2 and possibly other constituents such as water.
• methanation is used for chemical storage of e.g. Excess electricity used, which arises in the generation of electricity by renewable energy. By electrolysis hydrogen is generated with this stream.
• Carbon dioxide is preferably recovered from exhaust gases from industrial processes or from biogas plants.
• the methanation feed gas in this case consists almost exclusively of CO2 and H2.
• the reactions are i.d.R. catalyzed with elements of VIII. Subgroup, preferably with nickel.
• Equations (1) and (2) result in a decrease in volume on the product side. Both reactions are also highly exothermic. This causes a high pressure and a low temperature to shift the reaction equilibrium to the product side. As pressure increases, however, its influence on the reaction equilibrium becomes smaller and smaller. In addition, the wall thicknesses of all pressurized parts of the apparatus are getting ever larger and demands on the tightness, reinforced by the small molecular size of the hydrogen, rise. The reaction temperature is limited downwards by the minimum working temperature of the catalyst.
• reaction equilibrium can be further shifted to the product side by removing the product component water H2O from the reaction system.
• this promotes soot formation by the Boudouard reaction according to equation (4).
• this reaction is suppressed.
• a feed gas with a nearly stoichiometric composition otherwise the superstoichiometric component remains. This is unproblematic as long as this component is still within the specification of the feed gas. In the other case, a separation is necessary, which leads to increased costs.
• thermometers if they are installed in individual reaction tubes.
• feed gas The gases participating in the chemical reactions are referred to below as “feed gas”, as long as they are still before entering a tube bundle reactor or in a reactor system. From entry into a tube bundle reactor or into a reactor system, the gases are referred to as “reaction gas”, from the completion of the chemical reactions as “product gas”.
• GB472629 proposes to continuously or stepwise alter one or more of the surface, thickness, or activity of the catalyst, gas velocity, turbulence, or flow area. So z. B. in areas with strong heat development, a correspondingly large reduction of the flow cross-section required, which in turn has correspondingly high pressure losses result. Such pressure losses necessitate more powerful compressors and thus lead to increased investment and operating costs.
• each reaction tube coaxially supervise a metering tube in the catalyst bed and initiate the reaction gas in the metering tube.
• the metering tube extends from the gas inlet-side end of the reaction tube into the catalyst filling, is free of catalyst material and has a plurality of axially distributed outflow openings, all of which open into the catalyst bed.
• the reaction is distributed over the length of the reaction tube, whereby the reaction intensity is reduced and the temperature temperature increase is lowered.
• the metering tube causes a reduction of the hydraulic diameter of the catalyst bed and thus a reduction of the radial transport path for the heat of reaction and thus their faster removal.
• a reaction gas component A can be fed into the metering tube and a reaction gas component B in the beginning of the catalyst bed.
• DE 102010040757 A1 proposes a tube bundle reactor whose catalyst-filled reaction tubes provided with metering tubes extend through two heat transfer zones, the outflow openings of the metering tubes all opening into the catalyst bed within the first heat transfer zone.
• the reaction gas is passed in each reaction tube simultaneously both in the inlet of the catalyst bed and in the metering.
• a widely used method for methanation are reactor systems with at least two reactor stages, wherein the first reactor stage is a high-temperature methanation in which high reaction rates are achieved at high temperature. In a second reactor stage, the reaction is continued in a low-temperature methanation to the desired conversion.
• the feed gas is fed completely to the first reactor, it is often diluted with circulating gas from downstream reaction stages to avoid excessively high reaction temperatures.
• the feed gas is tempered with a preheater to the minimum working temperature of the catalyst.
• a corresponding method is shown in DE2549439A.
• the feed gas is split and fed in parallel to the inlet of a plurality of adiabatic fixed bed reactors connected in series.
• the feed gas can additionally be diluted by adding steam.
• the process is exemplarily operated at about 35 bar, the inlet temperature in the reactors is between 240 ° C and 300 ° C, the outlet temperature at about 600 ° C.
• the heat of reaction is used in-process for gas tempering and in other parts of the plant.
• Hydrogen is removed from the product gas and returned to the feed gas.
• DE1645840A proposes a two-stage methanation process in which after the first methanation stage so much water vapor is removed from the reaction gas that carbon deposition on the catalyst is prevented.
• a partial condensation is carried out after the reaction gas has passed through two methanization reactors.
• DE102009059310A1 in the case of two reactors connected in series with external cooling, such a partial condensation is carried out between these two reactors.
• the invention has the object to improve a method, a tube reactor and a reactor system of the type mentioned so that catalytic gas phase reactions with pronounced tempera rmaxima safer, faster and can be carried out with a small size and at the same time extends the life of the catalyst becomes.
• this object is achieved by a method according to claim 1, a tube bundle reactor according to claim 11 and a reactor system according to claim 16.
• catalyst activity is known to those of skill in the art, e.g. in the article "Reschetilowski W .: Introduction to heterogeneous catalysis, Springer Verlag Berlin Heidelberg 2015, pp. 11-20, DOI 10.1007 / 978-3-662-46984-2_2.
• the effectiveness of catalytic gas phase reactions is considerably improved with increased operational reliability, since a more precise control or guidance of the reaction temperature is achieved and a higher throughput is achieved.
• the measures according to the invention are based on the finding that in a tube bundle reactor in which a metering tube is embedded in the catalyst bed of the reaction tubes, the interior of which is catalyst-free, not only the radial heat transport path is shortened but also the flow cross-section of the catalyst bed in the flow direction of the reaction gas is reduced and in this reduced flow cross-section reaction gas is introduced at axially different locations as part streams in the catalyst bed, whereby the heat load of the catalyst bed is made uniform and thus the temperature maximum is reduced.
• the activity of the first catalyst layer is reduced. Since the chemical reactions take place under the influence of catalysts, as a precondition, first of all the conversion decreases. On the other hand, however, there are several influences that lead to an increase in sales and thus approximately cancel the sales-reducing effect of reduced catalyst activity.
• the reduced catalyst activity initially results in less heat of reaction, which leads to a reduction in the height of the temperature of the hot spot.
• a reduced gas temperature now reduces the volume flow and thus the dependent of the gas velocity speed pressure loss, which in turn has an increased mass flow through the first catalyst layer result. It establishes a balance with the parallel gas flow inside the metering tube.
• the conversion at the end of the reaction tube thus remains essentially constant.
• the temperature control in the initial region of the catalyst bed is significantly improved, with the conversion, the flow cross-section and the pressure loss remain essentially unchanged.
• the decisive advantage of the measure according to the invention is that the lifetime of the catalyst is significantly increased by the improved control of the temperature of the hot spot in the first catalyst layer.
• the reactor of the invention has a significantly higher catalyst activity than a reactor designed according to the prior art with undiluted catalyst, so that more product can be produced in a given production period.
• the degree of conversion achieved with a tube bundle reactor according to the invention is already sufficient for certain purposes.
• the product gas can be used with the achieved methane concentration for feeding into an L-gas network or for combustion in combined heat and power plants.
• the reaction conditions can be adapted relatively easily to different requirements and in particular to changing conditions in the tube bundle reactor.
• a particularly effective temperature control is possible at any time.
• a controlled hot spot damped according to a specification, is formed. This sounds out and the temperature in the catalyst layer changes only slightly.
• This last range of the small temperature change preferably accounts for a proportion of 10 to 40% of the first catalyst layer.
• a further advantage of the method according to the invention is that the need for recycling partial product streams for cooling or dilution is eliminated.
• the method is suitable for all heterogeneously catalyzed exothermic gas phase reactions that form a hot spot in the beginning of the catalyst bed.
• the invention is suitable for those reactions in which this hot spot is particularly pronounced and is correspondingly difficult to control.
• the catalytic gas phase reaction includes methanation reactions as an example of such reactions.
• the feed gas for carrying out the process according to the invention preferably consists of CO and H. at Use of CO 2 and H 2 as components of the feed gas in stoichiometric composition after water separation at the end of the process a product gas with a composition according to the equilibrium conditions at a given pressure and temperature is to be expected.
• the methane content will be slightly lower, perhaps because the reactant gas is not exactly in stoichiometric composition. If the feed gas composition is not stoichiometric, one or the other component will always remain after the reaction.
• the choice of the feed gas composition depends on the respective feed conditions for the SNG.
• the process is preferably run in a range between the stoichiometric composition of CO2 / H2 and a slight excess of CO2.
• the preferred range of ratios of CO2 / H2 in this case is between 0.25: 1 and 0.26: 1.
• the activity of the first catalyst layer is preferably adjusted to 5% to 90% and particularly preferably to 10% to 40% of the activity of the at least one further catalyst layer.
• the first and the second catalyst bed can each be subdivided into even further catalyst layers having different catalyst activities, the catalyst activity preferably increasing from catalyst layer to catalyst layer.
• the reaction parameters in the tube bundle reactor in particular the heat carrier temperature, the bed heights of the individual catalyst layers, the axial distances of discharge points of the partial streams, the partial flow amounts and the catalyst activation are set so that the maximum temperatures in the first and second catalyst layer in a Range of 300 ° C to 900 ° C, preferably between 500 ° C and 700 ° C.
• the controlled high temperatures within the catalyst bed lead to an optimum in terms of reaction rates and conversion.
• the tube bundle reactor requires only a relatively small reaction space.
• the heat of reaction generated in the process is preferably used internally in the process and more preferably also inside the apparatus.
• the cooling may be more favorable with a heat transfer medium which is liquid under operating conditions.
• the pressureless operation offers, for example with liquid salt, ionic liquids or a thermal oil.
• materials for the tube bundle reactor are usually all customary in pressure vessel construction heat-resistant steels into consideration, such. the material with the short name 16Mo3 or similar materials. Depending on the location and the type of stress, other materials may also be used.
• thermometers To control the temperature of individual reaction tubes are equipped with thermometers, which allow a Temperaturmessu ng along the reaction tubes.
• the reaction gas is preferably introduced into the crude reactor at a pressure of from 5 bara to 50 bara and preferably from 10 bara to 30 bara and more preferably from 15 bara to 25 bara.
• This pressure range is optimal in terms of influencing the reaction equilibrium, taking into account the design effort, which consists primarily in the strength design, and the investment and operating costs for compression of the feed gas at the entrance of the tube bundle reactor.
• the heat carrier temperature of the tube bundle reactor is adjusted so that it is in the range of 240 ° C to 300 ° C.
• This temperature range is optimal in terms of influencing the reactions in terms of reaction rate and conversion.
• the inventive method can also be carried out at temperatures in the range between 200 ° C and 350 ° C. Decisive for the lower temperature is always the light-off temperature of the catalyst, which should not be undercut.
• the tube bundle reactor forms a first reactor stage of a reactor system, which further comprises a condenser, a heating zone and a second reactor stage, all in the flow direction of a reactor system flowing through Reaction gases are arranged one behind the other, with the further steps following step b):
• step c) heating the reaction gas, from which part of the condensed constituents was derived in step c);
• the basic idea in these measures is to optimize one reaction parameter in each individual reactor stage.
• the aim of the first reactor stage is a controlled high reaction rate.
• the reactor dimensions are minimized and extended the life of the catalyst.
• the second reactor stage the residual conversion takes place at low temperature. At this residual conversion only little heat of reaction is generated.
• the structural design of the second reactor stage can be considerably simplified and is usually sufficient for a simple adiabatic catalytic fixed bed reactor.
• the conversion of the educts at the end of the first reactor stage is in the range of 90% to 99%.
• the residual conversion takes place in the second reactor stage.
• the conversion in the first reactor stage is limited by the reaction product water because of the equilibrium reaction. Due to the partial condensation after the first reactor stage, water is removed from the reaction system, so that the reaction equilibrium is further shifted to the product side. Due to the high conversion of the first reactor stage, the heat of reaction in the second reactor stage is so low that i.d.R. a simple adiabatic fixed bed reactor is sufficient for the remaining methanation.
• the reaction gas is passed through exactly two reactor stages.
• the reaction parameters can be adjusted so that in the second reactor stage, the remaining reaction of the starting materials takes place and thus the total conversion of the reactants is completed and another reactor stage is no longer required.
• methanation reactions that after the second reactor stage, the product gas, after condensation of the water content, meets the feed specification of the respective gas network into which it is to be fed.
• the main objective is to achieve a methane concentration according to the feed specification. This is achieved by a high conversion at a relatively low temperature.
• the lower temperature limit is determined by the minimum working temperature of the catalyst, also referred to as "light-off temperature”.
• the upper temperature limit is determined by the temperature resistance of the catalyst and the turnover to be maintained. Conveniently continues to have a high pressure.
• the reaction gas is cooled to a temperature below the dew point of water in step c) and at least a portion of the condensed water derived. Due to the partial condensation and dissipation of the reaction product water between the first reactor stage and the second reactor stage, the reaction equilibrium is shifted to the product side in a favorable manner.
• the reaction gas after deriving at least a portion of the condensed water advantageously contains a residual water vapor content of 0% to 30% and preferably from 15% to 25%.
• a residual water vapor amount in the reaction gas soot formation is prevented, thus stabilizing the process.
• the reaction gas Before entering the second reactor stage, the reaction gas is heated to something above the light-off temperature analogous to the feed gas in a preheater. With this residual steam content, an optimum is achieved with respect to the shift of the reaction equilibrium on the product side and the prevention of soot deposits.
• the entire reactor system with a space velocity (GHSV) of 5000 1 / h to 20,000 1 / h, particularly preferably from 8000 1 / h to 15000 1 / h, operated.
• GHSV space velocity
• a high space velocity leads to a smaller reactor volume at the same reactor power. This results in reduced investment costs and constructive advantages by reducing space requirements.
• the reduction of the catalyst activity in a tube bundle reactor according to the invention is preferably achieved by diluting the catalyst with an inert material.
• the dilution ratio of catalyst to inert material is preferably in a range of 1: 1 to 1:10 and more preferably in a range of 1: 2.5 to 1: 4.
• the ratios relate to the bulk volumes of the individual components.
• the degree of dilution of the first catalyst layer with the aim of a reduced catalyst activity depends in particular on the basic activity of the undiluted catalyst, the flow rate, the GHSV and the inlet temperature.
• the shape of the usable particles for the catalyst is not particularly limited. In principle, all known shaped bodies can be used, e.g. Balls, pellets, saddles or cylinder rings.
• the particles should have good flow behavior and not settle after filling, i.
• the height of the bed should ideally not change during operation. They should be such that the flow behavior in the annular space between the reaction tube inner wall and Dosierrohrau touchwand only slightly deviates from the flow behavior of a particle bed with a large flow area. With the flow behavior in particular the pressure loss and the Randauerkeit meant.
• cylinder pieces with a diameter in the range of 1, 2 mm to 3.0 mm, a length in the range of 3.0 mm to 8.0 mm and a length / diameter ratio in the range of 1: 1 to 8: 1.
• the particles are preferred for use as a full catalyst.
• the size and shape of the catalyst particles and inert particles are usually about the same. As a result, segregation of the two types of particles is prevented.
• catalyst particles and inert particles are different in size and / or in shape.
• This embodiment can be particularly advantageous if, for example, inert particles such as catalyst particles are difficult to obtain or inert particles of a different type are significantly more economical.
• the individual parameters of this training can not be determined in advance. They must be examined and determined separately in individual cases.
• a filling method is preferably used, which is particularly designed to prevent segregation.
• the proportion of the first catalyst layer at the (first) catalyst bed is preferably 5% by volume and 50% by volume.
• the proportion of the first catalyst layer with reduced activity on the total catalyst volume is the result of the process simulation. In general, a proportion in a range of 10 vol .-% to 35 vol .-% of the total catalyst volume of the (first) catalyst bed. In the first catalyst layer and in the initial region of the second catalyst layer, a high conversion is achieved at high temperature. The following hot spots following each additional gas discharge point are preferably weaker in their height.
• the tube bundle reactor is flowed through from bottom to top, d. H. the reaction tubes are flowed through from bottom to top. Accordingly, the metering tube of a reaction tube is attached at the lower end and ends within the catalyst bed.
• the filling of the catalyst is greatly simplified in the reaction tubes, since the upper ends of the reaction tubes in this arrangement are free of internals.
• reaction tubes having an outside diameter in the range from 20 mm to 100 mm, preferably in the range from 20 mm to 40 mm, have proven particularly useful with wall thicknesses in the range of 1.5 mm to 3.0 mm.
• the metering tube preferably has an outer diameter in a range of 6 mm to 85 mm, particularly preferably 6 mm to 15 mm, with a wall thickness in the range of 1, 0 mm to 2.0 mm.
• the cross-sectional shape of the metering tubes is arbitrary.
• the cross section may for example be circular or oval or quadrangular.
• Several parallel metering tubes in a reaction tube are possible.
• the at least two catalyst layers preferably contain the same catalyst material and the first catalyst layer contains 5% by volume to 90% by volume, preferably 10% to 40% by volume, of the catalyst material of the at least one further catalyst layer.
• the catalyst activity of the first catalyst layer can be adjusted flexibly by dilution with inert material.
• process optimization is first performed by numerical simulation. This results in a first, possibly even relatively further optimal range of the degree of dilution. Further optimization can be achieved through pilot plant trials.
• the first, already determined area is checked and, if necessary, further optimized, ie defined more precisely.
• the axial distance between the at least one gas inflow and the first gas outflow in the flow direction of the reaction gas the axial distance between the Gasausströmstellen and the axial distance between the last Gasausströmstelle and the end of the metering tube and the number chosen so that a heating surfaces belastu ng by the liberated reaction heat between the Gaseinström- or Gasausströmstellen in the range of 10 kW / m 2 to 150 kW / m 2 , preferably in the range of 20 kW / m 2 to 50 kW / m 2 results.
• Reference surface here is the tube outer surface.
• the quadratic ratio of the inner diameter of the reaction tube to the outside diameter of the metering tube is in a range from 2 to 6. With these preferred ratios, an annular gap results, which particularly meets the requirements for a reaction control.
• the reactor system according to the invention has several components which influence one another.
• the individual components are designed using a simulation program.
• a simulation program can be a commercially available program or a program which can be created with known process engineering contexts.
• the catalysts have different activities depending on the composition.
• the parameters of the catalyst to be used are determined for this purpose in laboratory experiments and thus adapted to the simulation parameters.
• the sizes of the first and second reactor stages influence each other. The larger the first reactor stage, ie the more catalyst volume is present there, the greater is the conversion there. The second reactor stage will be less. Conversely, a smaller first reactor stage requires a larger second reactor stage.
• the reactor system can be optimized, for example, to a minimum total amount of catalyst given given given boundary conditions for mass flow rate and methane concentration.
• the conversion of the first reaction stage is too low, then it may come in the second reactor stage to a critical operating case in which locally so much heat of reaction is released that the temperature rises so high that, firstly, the catalyst is damaged and secondly, the turnover under one specified value, which is normally at least equal to the feed-in specification. There is also the risk of damage to the reactor.
• the second reaction stage is therefore preferably dimensioned so that even with a decrease in the conversion in the first reaction stage to a worst-case expected value of the limit in the second Reaction stage, which leads to a critical operating case is not achieved.
• an adiabatic catalytic fixed bed reactor is preferably used. Its simple structural design increases the efficiency of the reactor system.
• At least two of the units of the first reactor stage, condenser, heating zone and second reactor stage form a structural unit. If the first and second reactor stages are arranged in a reactor housing, then the two reactor stages can be arranged either sequentially or in parallel. The combination of individual units in a constructive unit leads to a compact production plant. More compact design units increase the clarity of the system and lead to cost savings. In internal heat utilization heat losses are minimized.
• the second reactor stage can also be designed as an isothermal catalytic reactor. This can be advantageous if both reaction stages are arranged in a reactor housing.
• the second reactor stage is a cooled reactor whose average heat transfer temperature is 0 K to 30 K lower than the heat carrier temperature of the first reactor stage. This temperature range is optimal in terms of reaction rate, recoverable conversion and overall size of the individual units of the reactor system.
• the second reactor stage is preferably a tube bundle reactor with a bundle of reaction tubes which are filled with the second catalyst bed and, during operation, are operated by a reaction vessel. gas flows through and are cooled by a heat transfer medium.
• This variant increases the flexibility of the overall system, because it is possible to reduce the conversion of the first reactor stage and to increase the heat of reaction in the second reactor stage accordingly. This procedure may be useful if, for example, two identical reactors represent an alternative to two different reactors for constructional or economic reasons or offer joint heat utilization.
• the reaction tubes of the two reactors are located in a common heat carrier space.
• a reactor is saved.
• the reactions of both reactor stages can be controlled simultaneously. Nevertheless, very different adapted reaction conditions can be set by the metering tubes in the first reactor stage.
• FIG. 1 shows a vertical section through a first embodiment of a tube bundle reactor according to the invention
• FIG. 2 shows on an enlarged scale a sectional view through an exemplary embodiment of a reaction tube from the tube bundle reactor from FIG. 1, FIG.
• FIG. 3 shows a vertical section through a second exemplary embodiment of a tube bundle reactor according to the invention
• FIG. 4 shows a diagram of a first embodiment of a reactor system according to the invention
• FIG. 5 shows a diagram of a second exemplary embodiment of a reactor system according to the invention, with first and second reactor stages in the same reactor housing,
• Figure 6 shows a vertical section through a reactor housing of a third embodiment of a tube bundle reactor according to the invention, with first and second reactor stage in the same reactor housing and
• Figure 7 shows a vertical section through a reactor housing of a fourth embodiment of a tube bundle reactor according to the invention, with first and second reactor stage and capacitor and heating zone in the same reactor housing.
• FIG. 1 shows a boiling water reactor as an exemplary embodiment of a tube bundle reactor according to the invention.
• the tube bundle reactor 12 has a bundle 13 with a multiplicity of catalyst-filled reaction tubes 14, which are located between an upper tube plate 15 and a lower tube plate 16 extend vertically and are enclosed by a cylindrical reactor shell 17. The two
• reaction tubes 14 are gas-tight welded to the respective tube sheet 15,16.
• the reaction tubes 14 by a reaction gas 1 1 - in the illustrated embodiment, from top to bottom - flows through and cooled by a heat carrier 18.
• the two tube sheets 15, 16 together with the jacket 17 a heat transfer chamber 18 A, in which the heat transfer medium 18 enters through an inlet line 52 in the lower end region of the reactor shell 17 and from the heat transfer medium 18 through an outlet line 53 in the upper end region of the reactor shell 17 exit.
• the upper tube sheet 15 is from a gas inlet hood
• reaction tubes 14 are filled with a catalyst bed 4, wherein in each reaction tube 14 coaxially to this a metering tube 21 is arranged, whose interior 22 is free of catalyst.
• FIG. 2 shows a catalyst-filled reaction tube 14 with metering tube 21 in detail.
• the reaction tube 14 and the metering tube 21 are not shown to scale there and in Figure 1.
• the length / diameter ratio of reaction tubes 14 and metering tubes 21 is much larger in reality.
• the metering tube 21 extends by a predetermined length into the reaction tube 14 and is fixed by spacers 23 in its central position.
• the metering tube 21 is attached in a manner not shown here at its gas inlet end 24 on the reaction tube 14 or on the adjacent upper, gas inlet side tube plate 15.
• an annular gap 27 is formed whose size is dimensioned so that the square ratio of the inner diameter 28 of the reaction tube 14 to the outer diameter 29 of the metering tube 21 is in a range of 2 to 6 ,
• a catalyst holder 31 is arranged, on which the catalyst bed 4 rests. This extends from the catalyst holder 31 to the metering tube 21 and then further into the annular space 32 between the reaction tube 14 and metering 21 into a predetermined distance from the gas inlet end 33 of the reaction tube 14.
• a catalyst-free space 34 is formed , This prevents the way bubbles of catalyst material, because at the gas inlet of the reaction tubes 14, turbulence in the reaction gas stream 1 1 can form.
• a gas-permeable element for example a perforated plate or a wire mesh, can be arranged in order to fix the catalyst in its position.
• the ratio of the annular gap 27 between the inner wall 25 of the reaction tube 14 and the outer wall 26 of the metering tube 21 to the particle diameter of the catalyst bed 4 is in the range of 2 to 6.
• the gas inlet-side end 24 of the metering tube 21 forms an inflow opening 35 for the reaction gas 11.
• a first Gasausströmstelle 37 A is arranged and in the example shown at further predetermined axial distances from this still a second and a third, last Gasausströmstelle 37 B, 37 C.
• a Gasausströmstelle is formed by one or more Gasausströmöffn openings 38, which are preferably evenly distributed on the circumference of the metering tube 21.
• the Gasausströmö réelleen 38 a Gasausströmstelle 37 A, 37 B, 37 C may be offset in the circumferential direction against each other.
• the size and number of these Gasausströmö réelleen 38 are dimensioned so that sets a predetermined gas flow.
• 21 throttle openings may be arranged in the manner not shown here within the metering tube.
• the metering tube 21 has three functions. It reduces the flow cross-section of the catalyst bed 4 in the reaction tube 14 to the cross-section of the annular space 32 between the reaction tube 14 and metering tube 21, whereby the heat of reaction is reduced. Further, the reaction gas 11 is introduced axially stepped, whereby the total heat of reaction is divided into several smaller proportions. And finally, transverse to the flow direction of the reaction gas 11, the heat dissipation path is shortened to the size of the annular gap 27 between the reaction tube 14 and metering tube 21, so that not only less reaction heat is created, but this is also derived even faster.
• the catalyst bed 4 is divided into two catalyst layers 4a, 4b.
• the first catalyst layer 4a in the flow direction of the reaction gas 11 has a lower activity than the subsequent second catalyst layer 4b. It, 4a, starts at the gas inlet-side end 36 of the catalyst bed 4 in the annular space 32 and ends upstream of the first gas discharge point 37A.
• the two catalyst layers 4a, 4b contain the same catalyst material, the first catalyst layer 4a being a mixture comprising 5% by volume to 90% by volume, preferably 10% by volume to 40% by volume of the catalyst material of the second catalyst layer 4b and otherwise contains inert material.
• the particle sizes of the catalyst material and the inert material are preferably the same in order to avoid segregation, in particular when filling the reaction tubes 14.
• a preheated feed gas 10 enters the gas inlet hood 19 of the crude reactor 12 through the gas inlet nozzle 50 and distributes there - now referred to as reaction gas 11 - onto the reaction tubes 14.
• each reaction tube 14 the reaction gas stream entering there is subdivided into a first substream 11.1, which enters directly into the catalyst bed 4 located in the annular space 32 between metering tube 21 and reaction tube 14, and into a second substream 11.2, which enters the inflow opening 35 of the metering tube 21 and there is guided in the bypass to the catalyst bed 4 until it emerges from the gas outflow points 37A, 37B, 37C as part streams 11.2A, 11.2B, 1 1.2C in the catalyst bed 4.
• the gas inlet-side end 36 of the catalyst bed 4 thus forms the point of introduction for the partial flow 11.1 and the gas outlet points 37A, 37B, 37C form the points of introduction for the partial flows 11.2A, 11B, 11C into the catalyst bed 4.
• the reaction tube section 14.2 is subdivided into a reaction tube section 14.2a, which contains the first catalyst layer 4a (with a lower activity), and a reaction tube section 14.2b, which contains part of the second catalyst layer 4b.
• the downstream end 40 of the first catalyst layer 4a is located at a predetermined distance upstream of the first gas discharge point 37A or the second catalyst layer 4b projects upstream from the first gas discharge point 37A by this distance and forms the reaction tube section 14.2b.
• This reaction tube section 14.2b fulfills the main function of reacting the reaction gas 1 1 almost to the reaction equilibrium until it reaches the first gas discharge point 37A. Another function is to provide a safety zone in the event of possible settling of the catalyst, so that it is ensured that the reaction gas 11, which flows through the first gas outlet 37 A in the catalyst bed 4, flows into an undiluted catalyst layer 4 b and so on optimal conditions.
• the reaction forms a temperature profile within the first catalyst layer 4a with a hot spot and has progressed far to the downstream end 40 of the first catalyst layer 4a, which is to be understood as a degree of conversion in the range of about 70% to 85%.
• the required axial extent of the catalyst layer 4a is determined by means of simulation calculations.
• the reaction tube section 14.3 adjoining the reaction tube section 14.2 is a series of gas outlet points 37A, 37B, 37C and subsequent reaction sections. It starts with the first gas discharge point 37A and ends with the downstream end 39 of the metering tube 21.
• 11.2B, 1 1.2C of the reaction gas 11 react in the respectively following catalyst layer 4b to the next gas outlet 37B, 37C or to the downstream end 39 of the metering tube 21.
• the axial distances of the gas outlet 37A, 37B, 37C are dimensioned such that the reaction of the respectively added substreams 1 1 2A, 1 1 2B to the beginning of the next gas outflow point 37B, 37C has progressed far, this also being understood as meaning a degree of conversion in the range from about 70% to 85%. In this case, the conversion of the reaction sections at their downstream ends in the downstream direction from reaction section to reaction section increases.
• a last reaction tube section 14.4 connects to the last part of the catalyst layer 4b of the catalyst bed 4, in which a residual conversion takes place up to the reactive weight. Because of the small amount of heat of reaction generated there, the effects of the dosing tube 21 are no longer needed.
• the residence time of the reaction gas 11 is extended, whereby the reaction can be performed almost to the same weight as the reaction weight.
• the conversion is in the range of 90% to 99%.
• the reaction gas 11 flows out of the reaction tubes 14 into the
• FIG. 3 shows a further exemplary embodiment of a tube bundle reactor according to the invention.
• the heat transfer medium is circulated by means of a pump (not shown).
• a cooler 350 is connected directly to the tube bundle reactor 12, so that together they form a structural unit 300.
• the tube bundle reactor 12 has - as the tube bundle reactor shown in Figure 1 - a bundle 13 reaction tubes 14 which are filled with the catalyst bed 4 and in each of which a metering tube 21 is at least partially embedded in the catalyst bed 4.
• the reaction tubes 14 with the metering tubes 21 are flowed through from top to bottom. They correspond to the embodiment shown in Figures 1 and 2, d. H. the catalyst bed 4 is divided into two catalyst layers 4a and 4b as described therein.
• the upper, gas inlet-side ends of the reaction tubes 14 are gas-tightly secured in an upper tube plate 15, which is spanned by an upper reactor hood or gas inlet hood 19 with a gas inlet nozzle 50.
• the lower, gas inlet-side ends of the reaction tubes 14 are gas-tightly secured in a lower tube plate 16, on which on the side facing away from the reaction tubes 14 side of the radiator 350 is attached.
• reaction tubes 14 are also enclosed here by a cylindrical reactor jacket 17, which forms a heat carrier chamber 18A together with the upper and lower tubesheet 15, 16.
• the reaction tubes 14 are flowed around by a heat carrier 18, the heat carrier 18A supplied from a lower annular channel 352 and in the heat transfer chamber 18A through disc and annular baffles 353 meandering in each radial direction from outside to inside and vice versa and from below above - ie transversely to the reaction tubes 14 and in countercurrent to the reaction gas 1 1 - passed through the tube bundle 13 and is derived from an upper annular channel 354 again from the heat carrier chamber 18A.
• the annular channels 352, 354 enclose the reactor jacket 17 on the outside thereof and are in fluid communication with the heat carrier chamber 18A through jacket openings 355.
• the heat transfer medium 18 is via a heat exchanger and a heat transfer pump, both not shown here, led in a circle.
• the heat carrier 18 is a well-known liquid salt, but other heat transfer can be used, such as thermal oil or ionic liquids.
• the cooler 350 has a bundle 356 of cooling tubes 357, the number of which may be smaller than the number of reaction tubes 14.
• the cooling tubes 357 extend from an upper radiator tube bottom 358 vertically to a lower bulb tube bottom 359 and are of one cylindrical radiator sheath 360 enclosed. The ends of the cooling tubes 357 are welded gastight to the respective radiator tube plate 358, 359.
• the cooling tubes 357 are catalyst-free and are flowed through by the reaction gas 11 from top to bottom.
• a gas transfer chamber 361 is arranged, into which the reaction gas 11 exits the reaction tubes 14 and from which it enters the cooling tubes 357.
• the cooling tube bundle 356 is traversed transversely by a heat carrier 362 in a heat carrier circuit independent of the heat transfer medium circuit of the tube bundle reactor 12.
• the heat transfer fluid enters through an in the lower end region of the radiator 350 arranged inlet nozzle 363 in the radiator 350 and through an upper end of the radiator 350 arranged outlet nozzle 364 from this again.
• a baffle 365 is arranged between the inlet and the outlet nozzle 363, 364, which extends horizontally through the entire cooling tube bundle 356, so that the heat carrier flow coming from the inlet nozzle 363 and after its deflection to the outlet nozzle 364 out across the entire cooling tube bundle 356 is performed.
• the lower radiator tube plate 359 is spanned on its side facing away from the cooling tubes 357 by a lower reactor hood or a gas outlet hood 20 with a gas outlet nozzle 51.
• reaction gas 11 enters the gas outlet hood 20 and is discharged through the gas outlet nozzle 51 - now referred to as product gas 43 - from the cooler.
• the exemplary embodiment of a reactor system 1 according to the invention shown in FIG. 4 has a preheater 2, a tube bundle reactor according to the invention (eg the exemplary embodiments illustrated in FIG. 1 or 3) as a first reactor stage 3 with a first catalyst bed 4, a condenser 5, a compressor 6, a heating zone 7 and a second reactor stage 8 with a second catalyst bed 9, all in the flow direction of the Reactor system 1 flowing through the feed gas 10 and reaction gas 11 are arranged one behind the other.
• the feed gas 10 is heated prior to its entry into the tube bundle reactor 12 to at least the so-called light-off temperature of the catalyst of the catalyst bed 4. This is the temperature necessary for a catalytic reaction to take place.
• the feed gas 10 is adjusted to a temperature which is 5 K to 30 K higher than the light-off temperature. It is also possible to heat in the tube bundle reactor 12 directly in front of the catalyst bed 4. As a result, a part of the system is saved.
• the reaction gas 11 exiting from the first reactor stage is cooled to a temperature below the dew point of at least a portion of the constituents of the reaction gas 11 and a portion of the condensed constituents 41 are discharged.
• the water formed during the reactions in the tube bundle reactor 12 is partially condensed out and discharged into lines.
• the compressed reaction gas 1 1 is heated to at least the light-off temperature of the second catalyst bed 9 of the second reactor stage 8.
• the second reactor stage 8 is an adiabatic reactor 42.
• the reaction of the reaction gas 11 is completed by achieving a high conversion at a relatively low temperature.
• the degree of conversion is in the range from 98.0% to 99.6%.
• the water produced in the process is generally almost completely condensed out.
• the product gas 43 now consists largely of methane CH 4 with a methane concentration corresponding to a given feed specification.
• the first and second reactor stages 3, 8 are designed as a structural unit in the form of a so-called combined reactor 100.
• Combined reactor 100 has in this embodiment both for the first reactor stage 3
• Reaction tubes 114A as well as for the second reactor stage 8 reaction tubes 114B, which are combined in a single tube bundle 113 and distributed mixed there.
• the tube bundle 113 is enclosed by a reactor jacket 117, so that the reaction tubes 114A,
• reaction tubes 114A, 14B of both the first and second reactor stages 3, 8 are filled with catalyst material and are flowed through by reaction gas 11 during operation, with the reaction tubes 114A of the first reactor stage 3 in fluid communication with another gas distribution space and gas collection space Reaction tubes 114 B of the second reactor stage eighth
• the reaction tubes 114A of the first reactor stage 3 are filled with the first catalyst bed 4, which, as described above, is subdivided into at least one catalyst layer 4a and one catalyst layer 4b, and flows through from top to bottom. They are attached at their ends with a first upper and a first lower tube sheet 115A, 1 16A gas-tight.
• a metering tube 21 is arranged coaxially, which is at least partially embedded in the first catalyst bed 4.
• the metering tubes 21 and this first catalyst bed 4 may be formed, for example, as shown in FIG.
• the reaction tubes 114B of the second reactor stage 8 are filled with the second catalyst bed 9 and are flowed through from bottom to top. They are gas-tightly secured at their ends to a second upper tube sheet 1 15B spaced above the first upper tube sheet 115A and into a second lower tube sheet 116B spaced below the first lower tube sheet 116A.
• the reaction tubes 14B of the second reactor stage 8 are filled exclusively with the second catalyst bed 9 and contain no metering tubes.
• the second upper tube sheet 1 15B is spanned by an upper reactor hood 1 19 and the second lower tube sheet 116B by a lower reactor hood 120.
• the (first) gas inlet space 119A and the space between the first lower and the second lower tubesheet 16A, 116B form the (first) gas collecting space 120A for the reaction tubes 114A of the first reactor stage 3.
• the lower reactor hood 120 forms the (second) gas inlet space 1 19B and the upper reactor hood 119 forms the (second) gas collecting space 120B for the reaction tubes 14B of the second reactor stage 8.
• the exemplary embodiment of a reactor system 101 according to the invention shown in FIG. 5 is operated as follows:
• a gas stream with a first feed gas component 10a and a gas stream with a second feed gas component 10b are combined into a feed gas 10 in a mixer, not shown here.
• This is heated to the light-off temperature of the first catalyst bed 4 before it enters the first reactor stage 3 during ongoing stationary operation in countercurrent in a preheater 102 by the product gas 43 coming from the second reactor stage 8.
• the feed gas 10 is therefore heated during the starting process by a preferably electrically operated starting preheater 102.1.
• the operation of this Anfahrvor lockerrs 102.1 is possible in any way - for example, with steam, if a steam network is available.
• the diversion of the feed gas stream 10 takes place by corresponding opening or closing of shut-off valves 150 in the pipeline.
• the preheated feed gas 10 flows into the (first) gas distribution chamber 119A of the first reactor stage 3 of the combined reactor 100 and from there into the reaction tubes 114A with the metering tubes 21. After emerging from these reaction tubes 14A, the reaction gas 11 is passed into the first gas collection chamber 120A.
• the water 41 contained in the reaction gas 11 - in the case of methanation - is partially condensed and discharged in a condenser 105, so that the reaction gas 11 only contains a water content of about 20% by volume.
• the cooled reaction gas 11 is then heated again in the heat exchanger 151 before it is conducted into the (second) gas distribution chamber 1 19B of the second reactor stage 8 of the combined reactor 100. From there, the reaction gas 11 flows into the reaction tubes 14B of the second reactor stage 8, where the residual conversion takes place towards the desired product gas composition.
• the reaction gas 11 then enters from these reaction tubes 14B into the second gas collection chamber 120B in the upper reactor hood 119, from where it is led out of the combined reactor 100 as product gas 43.
• the product gas 43 heats the feed gas 10 entering the first reactor stage 3 and is subsequently conducted into a second condenser 152 where the water 153 still formed in the second reactor stage 8 is condensed out and discharged.
• the dry product gas 43 is then transferred to the gas feed unit.
• the combination reactor 100 shown is a boiling water reactor.
• the operating pressure is 55 bara, resulting in an operating temperature of 270 ° C.
• at least some of the feed water is used as the cooling medium for the condensers.
• the feed water 155 supplied by means of a pump 154 is used as a coolant in the condenser 105 between the first and second reactor stages 3, 8 before being supplied to the steam drum 156 of the coolant circuit 157 of the boiling water reactor 100.
• the reactor system 101 is further equipped with a measuring, control and control system, not shown here, as is customary for systems of this type.
• the composition of the reaction gas 1 1 is analyzed between the first and second reactor stage 3.8. In this case, it is checked whether the conversion of the first reactor stage 3 is sufficiently high, so that the residual conversion in the second reactor stage 8 does not lead to unacceptably high temperatures.
• Temperature measuring points are furthermore expedient in all process streams and in the second reactor stage 8.
• the process streams in this case include the feed gas components 10a, 10b before and after the mixture, the reaction gas 11, the heat carrier 118, condensed water 41, 43, feed water 155 for the boiling water cycle 157 and any other auxiliary currents.
• FIG. 6 shows a variant 200 of the combined reactor 100 shown in FIG. 5.
• the reaction tubes 214A, 214B of the first and second reaction stages 3, 8 are not distributed uniformly over the reactor cross section, but are arranged in separate regions ,
• the reaction tubes 214A of the first reactor stage 3 are arranged in an annular tube bundle 213A, which encloses a central tube bundle 213B with the reaction tubes 214B of the second reactor stage 8.
• the reaction tubes 214A of the first reactor stage 3 each contain a coaxially arranged metering tube 21 which is at least partially embedded in the first catalyst bed 4.
• the first catalyst bed 4 is divided into a catalyst layer 4a and a catalyst layer 4b.
• the reaction tubes 214B of the second reactor stage 8 are filled exclusively with the second catalyst bed 9; Metering tubes do not contain them.
• the upper reactor hood 219 forms the (first) gas distributor space 219 A of the first reactor stage 3 and has a gas inlet nozzle 250 A for the feed gas 10.
• the lower reactor hood 220 forms the (first) gas collecting space 220A of the first reactor stage 3 and has a gas outlet nozzle 251 A for the reaction gas 11.
• the (second) gas distribution chamber 219B of the second reactor stage 8 is passed through a distributor hood
• the second gas collection chamber 220B is formed by a collecting hood 253 which is located within the upper reactor hood 219, d. H. within the first gas distribution space 219A, and is connected to a second gas exit port 251B which extends through and out of the upper reactor cap 219.
• the distributor hood 252 is fastened to the side of the lower tube bottom 216 facing the lower reactor hood 220.
• the collecting hood 253 is fastened on the side of the upper tube bottom 215 facing the upper reactor hood 219.
• the second gas inlet nozzle 250B and the second gas outlet nozzle 251 B each have a strain compensator 254.
• the feed gas 10 is introduced into the first gas distribution chamber 219A and from there enters the reaction tubes 214A of the first reactor stage 3.
• reaction gas 11 enters the first gas collection chamber 220A and is discharged from the combination reactor 200 by means of the first gas flow strut 251A.
• reaction gas 1 1 is cooled so far in a condenser, not shown here, that in the reaction gas 1 1 - in the case of methanation - contained water is condensed and a portion of the water is discharged. Thereafter, the reaction gas 1 1 is heated in a heating zone, also not shown here again to the light-off temperature of the second catalyst bed 9 of the second reaction stage 8. The heated reaction gas 11 enters the second gas inlet port 250B again
• reaction gas 1 1 enters the reaction tubes 214B of the second reactor stage 8.
• reaction gas 11 enters the second gas collecting space 220B (the collecting hood 253), and is discharged from the combination reactor 200 by means of the second gas discharge port 251B as the product gas 43.
• the second reactor stage 8 presented in FIGS. 5 and 6, as a tube bundle reactor integrated in the combined reactor 100, 200, it is possible to control the overall reaction more effectively and to optimize the size of the entire reactor system 101.
• the particular advantage of these reactor systems 101 is that overheating in the second reactor stage 8 can be ruled out by the cooling and the conversion is kept at a stable and high level, at the same time achieving a compact construction.
• a combined reactor 400 is shown as an exemplary embodiment, in which all components of the reactor system are housed in a housing.
• the reaction gas 11 flows through this combined reactor 400 from bottom to top.
• the combi-reactor 400 contains the following components:
• a lower reactor hood 420 forms a gas distributor space 419A, into which the feed gas preheated in a preheater 450 enters.
• the gas distribution chamber 419A is followed by a shell-and-tube reactor 412 as the first reactor stage 3.
• the reaction tubes 414 of the tube bundle reactor 412 contain the first catalyst bed 4 into which metering tubes 21 are at least partially embedded, similar to that shown in FIG. However, the metering tubes 21 are rotated by 180 ° relative to FIG. 2 so that their gas inlet opening is in each case in flow connection with the gas distributor chamber 419A.
• the sequence of the catalyst layers 4a, 4b in the flow direction of the reaction gas corresponds to that in FIG. 2. That is, in the tube bundle reactor 412, the catalyst layer 4 a is below the catalyst layer 4 b, so that the reaction gas partial stream 11. 1 entering from below directly into the annular space between the metering tube and the reaction tube again first enters the catalyst layer 4 a lower activity.
• a heat transfer medium 18 is hereby conducted in cocurrent with the reaction gas 11 through the heat transfer space 418A via a heat carrier inlet connection 451 and a heat transfer outlet connection 452 in a heat transfer circuit.
• the heat carrier 18 may, for. As liquid salt or boiling water or pressurized water.
• a working space 453 is arranged for a mechanic.
• the working space 453 is accessible through a manhole 454 and serves to fill the reaction tubes 414 with catalyst material during the initial filling or to change the catalyst material and for other work, such. B. the installation of thermometers.
• this working space 453 there is a device 455 for collecting condensed constituents 456 of the reaction gas 11 - in the case of methanation, ie water - and for diverting the condensed constituents 456.
• the said device 455 is penetrated by at least one covered passage 457 for reaction gas 11 so that the reaction gas 11 can flow from the first reactor stage 3 in the combined reactor 400 further up to the still following components.
• the roof 458 prevents condensed components from entering the working space 453 or the first reactor stage 3.
• a condenser 405 connects to a bundle 459 catalyst-free cooling raw re 460, which are traversed by the reaction gas 11, which is cooled so far that a portion of the components - such as water - condenses.
• the condensed components 456 flow down into the cooling tubes 460 into the collecting and diverting regions 455, 456.
• the condenser 405 has an inlet connection 461 and an outlet connection 462 for the coolant 463, which here is passed countercurrently to the reaction gas flow through the condenser 405 ,
• the coolant 463 for example, water can be used.
• a heating zone 407 Connected to the condenser 405 is a heating zone 407, in which the reaction gas 11 leaving the condenser 405 is heated to the reaction temperature of the second catalyst bed 9 in the second reactor stage 8.
• the tubes 460 extend continuously through the condenser 405 and the heating zone 407 and are free of catalyst material.
• heat transfer medium 466 is here in countercurrent to the reaction gas flow through the heating zone 407 guided.
• the heat transfer medium 466 may, as in the first reactor stage 3 z. As liquid salt or boiling water or pressurized water.
• the reaction gas 1 1 enters the second reactor stage 8, which is an adiabatic reactor 442 in the illustrated embodiment. It contains the second catalyst bed 9 in which the residual reaction of the reaction gas 11 takes place.
• reaction gas 11 enters the upper reactor hood 419, which forms a gas collection chamber 420A, from which the finished reaction gas emerges as product gas 43. If the product gas 43 is still too moist, for example during methanation, it can be fed to a further condenser 467, in which this residual moisture 468 is condensed out.

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• 2018
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  • 2019-04-24 WO PCT/EP2019/060446 patent/WO2019233673A1/de unknown
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