METHANOL SYNTHESIS PLATE REACTOR

Description

Technical field of the invention

[0001] The invention relates to a methanol synthesis reactor, in particular a methanol synthesis reactor comprising at least two integrated process units. State of the art

[0002] In non-integrated solutions for the production of condensable reaction products, such as crude methanol, the individual process steps take place in separate individual units or devices. In the example of methanol synthesis, these process steps consist at least of the reaction of synthesis gas to methanol, the cooling of the reaction mixture to condense crude methanol, and the separation (separation) of the condensed crude methanol from the unreacted synthesis gas (residual gas) and inert components of the gas mixture.

[0003] When using individual devices, the process media of the process unit are introduced through nozzles into a pressure device and from there into the respective internal device components, where they are distributed or collected, and then discharged. This occurs through dedicated device openings and internals for the respective device, as well as through connecting elements such as pipelines and valves, and, depending on the relative position of the process units, through additional conveying devices such as pumps.

[0004] Combining multiple process units requires multiple pressure vessels and external piping, which must be manufactured separately and installed on foundations or in a steel structure within a plant. This results in high economic expenditures in terms of the required capital expenditure (CAPEX) and operating costs (OPEX). This is particularly due to the large number of required pressure jackets and nozzles, as well as piping and conveying equipment. These factors lead to high pressure and heat losses across the associated large total volume and surface area, as well as to higher energy consumption for the required conveying equipment.

[0005] JP S60 168530 A discloses a methanol synthesis reactor comprising a plurality of catalyst-filled reaction tubes divided into several upper and lower stages. The gas to be reacted is passed through the reaction tubes in series, while the outer surface of each reaction tube is contacted with water for cooling. The temperature of the water in contact with the outer surface of a downstream reaction tube is maintained at a lower temperature than the water in contact with the outer surface of an upstream reaction tube.

[0006] US 4,743,432 A discloses a vertically arranged reactor for producing methanol. This reactor comprises a cylindrical housing with exchanger tubes penetrating the catalyst bed inside the housing, as well as a gas-permeable floor or mesh supporting the catalyst bed in the lower reactor section. Horizontal, gas-impermeable partition walls are arranged below the gas-permeable floor or mesh of the second-lowest and the next-highest catalyst bed at the level of the gas inlet or outlet openings.

[0007] US 2002 / 048541 A1 discloses a reactor for conducting a highly exothermic catalytic reaction in a process fluid, equipped with plates arranged parallel to one another at a distance from one another, forming flat channels in opposing lateral boundary surfaces. One part of the channels contains a solid catalyst and conducts the process fluid, and another part of the channels carries a heat transfer medium in indirect thermal contact with the process fluid. The plates are flat or provided with grooves or ribs, and the plates are at least partially coated with the catalyst on the surface facing the process fluid.

[0008] US 5,874,051 A discloses a method and apparatus for the selective catalytic oxidation of carbon monoxide. A gas mixture and an additionally added oxidizing gas are passed through a reactor containing the catalyst. The oxidizing gas is added at several points along the mixed gas stream at a controlled or regulated flow volume. The mixed gas stream is passively cooled by static mixing structures in the inlet region of the oxidation reactor. Description of the invention

[0009] An object of the present invention is to at least partially overcome the aforementioned disadvantages of the prior art.

[0010] A further object of the present invention is to provide a reactor for the synthesis of methanol, which makes it possible to reduce the number of connecting pipelines, individual pressure jackets and apparatus floors.

[0011] A further object of the present invention is to provide a reactor for the synthesis of methanol, which fulfills at least two process functions and has the smallest possible total volume and the smallest possible total surface area.

[0012] A further object of the present invention is to provide a reactor for the synthesis of methanol which requires the shortest possible total production time with respect to the fulfillment of at least two process functions.

[0013] A further object of the present invention is to provide a reactor for the synthesis of methanol which requires as few or no conveying devices as possible with respect to the process functions to be performed.

[0014] Another object of the present invention is to provide a reactor for the synthesis of methanol, which is designed to minimize material stresses in the metal-based components.

[0015] A contribution to at least partially fulfilling at least one of the above objects is made by the independent claims. The dependent claims provide preferred embodiments that contribute to at least partially fulfilling at least one of the objects. Preferred embodiments of components of one category of the invention are, where applicable, also preferred for components of the same name or corresponding components of another category of the invention.

[0016] The expressions "comprising," "comprising," or "containing," etc., do not exclude the possibility of additional elements, ingredients, etc. The indefinite article "a" does not exclude the possibility of a plural.

[0017] According to a first aspect of the invention, a methanol synthesis reactor for producing methanol from a synthesis gas mixture is proposed, comprising (a) a pressure shell with an interior space, wherein at least two fluidically connected process units are arranged one above the other in the interior space; (b) a first process unit, wherein the first process unit is configured as a reactor stage RS1 for synthesizing methanol from a synthesis gas stream on a catalyst bed CB1, whereby a methanol-containing product stream RP1 can be generated, and the first process unit is designed as a plate heat exchanger, wherein the first process unit has a plurality of plates arranged vertically and parallel to one another with plate interior spaces through which flow can occur, and plate spaces are formed between adjacent plates, wherein a solid methanol synthesis catalyst is arranged in the plate spaces, which forms the catalyst bed CB1, and the first process unit is configured such thatthat the synthesis gas stream and the methanol-containing product stream RP1 can flow through the plate interstices from top to bottom, and a first cooling medium stream CM1 can flow through the plate interstices from bottom to top, whereby the methanol-containing product stream RP1 can be cooled in countercurrent by the first cooling medium stream CM1, and wherein the first process unit has means for withdrawing the methanol-containing product stream RP1 from the first process unit; (c) a second process unit arranged below the first process unit, wherein the second process unit is designed as a plate heat exchanger, wherein the second process unit has a plurality of plates arranged vertically and parallel to one another with plate interstices through which flow can pass, and plate interstices are formed between adjacent plates, wherein the second process unit is configured such thatthat the plate interiors can be flowed through from bottom to top by a second cooling medium flow CM2, and wherein (c1) the second process unit is designed as a cooling stage and is configured such that the plate interstices can be flowed through from top to bottom by the methanol-containing product flow RP1, whereby the methanol-containing product flow RP1 can be cooled in countercurrent by the second cooling medium flow CM2, or (c2) the second process unit is designed as a reactor stage RS2 and is configured for the synthesis of methanol from the methanol-containing product flow RP1 withdrawn from the first process unit on a catalyst bed CB2, whereby a methanol-containing product flow RP2 can be generated, and wherein a solid methanol synthesis catalyst is arranged in the plate interstices, which forms the catalyst bed CB2, and the second process unit is configured such thatthat the spaces between the plates can be flowed through from top to bottom by the methanol-containing product stream RP1 and the methanol-containing product stream RP2, whereby the methanol-containing product stream RP2 can be cooled in countercurrent by the second cooling medium stream CM2.

[0018] According to the invention, a "multiplicity" of plates is understood to mean a plurality of plates, but preferably more than two plates, in particular at least 5 plates, or at least 10 plates, or at least 25 plates, or at least 50 plates.

[0019] The at least two process units in the interior of the pressure jacket include the first and the second process unit.

[0020] According to the invention, at least two process units are integrated into a common pressure shell. A pressure shell is understood to be an enveloping structure that can withstand higher internal pressures, in particular internal pressures significantly above atmospheric pressure, for example, pressures of more than 5 bar.

[0021] The first process unit functions as a reactor stage for synthesizing methanol from a synthesis gas stream that can be introduced into the reactor stage, referred to here as reactor stage RS1. To fulfill this function, the first process unit is designed as a plate heat exchanger. In other words, the first process unit has a plate heat exchanger structure.

[0022] Two adjacent plates of the plate heat exchanger are spaced apart from each other in such a way that a plate gap is formed between two adjacent plates.

[0023] A solid methanol synthesis catalyst is arranged in the interstices of the plate of the first process unit. The entire methanol synthesis catalyst arranged in the interstices of the plate of the first process unit forms the catalyst bed, referred to here as catalyst bed CB1.

[0024] The methanol synthesis catalyst is a methanol synthesis catalyst known to those skilled in the art, for example, a copper-based one. The methanol synthesis catalyst can be configured, for example, as a bed or structured packing.

[0025] The plate spaces containing the methanol synthesis catalyst are configured so that the synthesis gas stream and the product stream RP1 can flow through them from top to bottom.

[0026] Alternatively, the first process unit comprises means configured so that the spaces between the plates can be flowed through from top to bottom with the synthesis gas stream and the product stream RP1.

[0027] This causes an exothermic reaction of the synthesis gas stream on the methanol synthesis catalyst of the catalyst bed CB1. This produces the product stream RP1. Accordingly, the product stream RP1 can also flow through the interstices between the plates from top to bottom.

[0028] In particular, the methanol-containing product stream RP1 is cooled in countercurrent by the first cooling medium stream CM1 flowing through the plate interiors from bottom to top.

[0029] The synthesis gas of the synthesis gas stream comprises a carbon oxide, i.e., carbon monoxide or carbon dioxide, or a mixture thereof. Furthermore, the synthesis gas of the synthesis gas stream comprises hydrogen. Furthermore, the synthesis gas may generally contain inert components or components that are inert under the conditions of methanol synthesis. Examples are nitrogen or methane. The product stream RP1 comprises at least methanol and water as condensable components, as well as possibly undesired condensable and non-condensable by-products. Furthermore, the product stream RP1 may contain unconverted synthesis gas.

[0030] The plates of the first process unit have flow-through interiors. A first cooling medium flow CM1 flows through the interiors of the plates. The first process unit is configured so that the first cooling medium flow CM1 flows through the interiors of the plates from bottom to top.

[0031] Alternatively, the first process unit has means which are configured such that the cooling medium flow CM1 can flow through the plate interiors from bottom to top.

[0032] The plate interiors of the first process unit can preferably be flowed through in a vertical direction, in particular in a vertical direction from bottom to top by the first cooling medium flow.

[0033] The spaces between the plates of the first process unit can preferably be flowed through in the vertical direction, in particular in the vertical direction from top to bottom by the synthesis gas stream and the product stream RP1.

[0034] The second process unit fulfils either the function of a cooling stage or the function of a second reactor stage RS2.

[0035] The methanol-containing product stream RP1 can be withdrawn from the first process unit, which is configured as reactor stage RS1, and fed into the second process unit. In the second process unit, this product stream RP1 is either cooled (alternative c1) or further converted to a methanol-containing product stream RP2 (alternative c2). In the latter case, unconverted synthesis gas, i.e., remaining synthesis gas or residual gas, in the methanol-containing product stream RP1 is converted to methanol.

[0036] To fulfill these alternative functions, the second process unit is also designed as a plate heat exchanger. In other words, the second process unit has a plate heat exchanger structure.

[0037] Two adjacent plates of the plate heat exchanger are spaced apart from each other in such a way that a plate gap is formed between two adjacent plates.

[0038] The plates have flow-through interiors through which a second cooling medium flow CM2 flows. The second process unit is configured so that the second cooling medium flow CM2 flows through the plate interiors from bottom to top.

[0039] Alternatively, the first process unit has means which are configured such that the plate interiors can be flowed through by the second cooling medium flow CM2 from bottom to top.

[0040] The plate interiors of the second process unit can preferably be flowed through in the vertical direction by the second cooling medium flow CM2, in particular in the vertical direction from bottom to top by the second cooling medium flow.

[0041] According to alternative c1, the second process unit is designed as a cooling stage. According to this configuration, the methanol-containing product stream RP1 flows through the plate interstices of the second process unit from top to bottom. Alternatively, the second process unit according to alternative c1 has means configured such that the methanol-containing product stream RP1 flows through the plate interstices from top to bottom. The methanol-containing product stream RP1 preferably flows through the plate interstices in a vertical direction.

[0042] The methanol-containing product stream RP1 is cooled by the second cooling medium stream CM2 flowing through the plate interiors from bottom to top. In particular, the second process unit according to alternative c1 is configured such that the methanol-containing product stream RP1 is cooled to such an extent that condensation of methanol and water from the methanol-containing product stream RP1 occurs.

[0043] According to alternative c2, the second process unit is designed as reactor stage RS2.

[0044] According to this configuration c2, a solid methanol synthesis catalyst is arranged in the interstices of the plate of the second process unit. The entire methanol synthesis catalyst arranged in the interstices of the plate of the second process unit forms the catalyst bed, referred to here as catalyst bed CB2.

[0045] The methanol synthesis catalyst is a methanol synthesis catalyst known to those skilled in the art, for example, a copper-based one. The methanol synthesis catalyst can be configured, for example, as a bed or structured packing.

[0046] The plate interstices containing the methanol synthesis catalyst are configured so that the product streams RP1 and RP2 can flow through them from top to bottom. Alternatively, the second process unit has means configured so that the product streams RP1 and RP2 can flow through the plate interstices from top to bottom. This causes an exothermic reaction of the product stream RP1 at the methanol synthesis catalyst of the catalyst bed CB2. This forms the product stream RP2. Accordingly, the product stream RP2 can also flow through the plate interstices from top to bottom. In this case, the second process unit forms a second reactor stage RS2.In this second reactor stage RS2, the synthesis gas contained in product stream RP1 is converted to methanol. This synthesis gas could not be converted to methanol in the first reactor stage RS1 due to the formation of the thermodynamic equilibrium typical for methanol synthesis. This remaining synthesis gas, or residual gas, thus forms part of product stream RP1.

[0047] Product stream RP2 contains at least methanol and water as condensable components, as well as possibly undesired condensable and non-condensable by-products. Furthermore, product stream RP2 may still contain unconverted synthesis gas.

[0048] According to the configuration according to alternative c2, the methanol-containing product stream RP1 and the methanol-containing product stream RP2 flow through the plate interstices of the second process unit from top to bottom. Alternatively, the second process unit according to alternative c2 has means configured such that the methanol-containing product stream RP1 and the methanol-containing product stream RP2 flow through the plate interstices from top to bottom. The methanol-containing product stream RP1 and the methanol-containing product stream RP2 preferably flow through the plate interstices in a vertical direction.

[0049] The methanol-containing product stream RP2 is cooled in countercurrent by the second cooling medium stream CM2 flowing through the plate interiors from bottom to top.

[0050] The first and second process units are arranged one above the other within the pressure shell, with the second process unit located below the first process unit. Both process units are fluidically connected to one another. In particular, the first and second process units are fluidically connected to one another with respect to the synthesis gas stream and the methanol-containing product streams RP1 and RP2, in particular on the side of the plate interspaces.

[0051] Preferably, the first and second processing units are arranged in alignment one behind the other, i.e., along a straight line or axis common to the first and second processing units. Preferably, the second processing unit is therefore not offset from the first processing unit, and vice versa.

[0052] According to one embodiment, the methanol synthesis reactor is designed as a single-stage reactor with a reactor stage RS1 at the top and a cooling stage at the bottom. According to another embodiment, the methanol synthesis reactor is designed as a two-stage reactor with a first reactor stage RS1 at the top and a second reactor stage RS2 at the bottom.

[0053] The methanol synthesis reactor can further comprise further process units. For example, the methanol synthesis reactor according to alternative c1 can have a third process unit configured as a condenser below the second process unit. According to a further example, the methanol synthesis reactor according to alternative c1 can have a fourth process unit configured as a gas-liquid separator below the third process unit. According to a further example, the methanol synthesis reactor according to alternative c2 can have a third process unit configured as a cooling stage below the second process unit. According to a further example, the methanol synthesis reactor according to alternative c2 can have a fourth process unit configured as a condenser below the third process unit.According to a further example, the methanol synthesis reactor according to alternative c2 can have a fifth process unit configured as a gas-liquid separator below the fourth process unit. Embodiments are also conceivable in which the cooling stage is already configured as a condenser, so that complete condensation of condensable products and by-products already occurs in the cooling stage.

[0054] The cooling medium for the first cooling medium stream CM1 and / or second cooling medium stream CM2 can be any suitable gaseous or liquid cooling medium.

[0055] The cooling medium for the first process unit is preferably boiling water, in particular boiling boiler feed water. A preferred embodiment of the reactor is therefore characterized in that the first cooling medium stream CM1 comprises boiling boiler feed water. In particular, the first cooling medium stream CM1 is evaporable as it flows through the plate interiors of the first process unit.

[0056] In this case, the first process unit is designed as a water-cooled reactor stage RS1, thus fulfilling the function of a water-cooled reactor stage. The cooling medium evaporates primarily due to the thermal energy absorbed during the formation of the methanol-containing product stream RP1. The thermal energy required for evaporation corresponds to the evaporation enthalpy of the cooling medium.

[0057] The cooling medium for the second process unit is preferably a gaseous cooling medium. According to this embodiment, the second process unit is configured either as a gas-cooled cooling stage according to alternative c1 or as a gas-cooled reactor stage RS2 according to alternative c2. In the latter case, the second process unit fulfills the function of a gas-cooled reactor stage.

[0058] Figure 5 shows a typical temperature profile of a catalyst bed along the length of a methanol reactor, determined by measurement and simulation. This temperature profile can be spatially divided into four parts from the reactor inlet to the outlet, as explained below.

[0059] The first part of the catalyst bed serves to heat the synthesis gas, with heat being transferred from the coolant to the synthesis gas and the catalyst. This gradually initiates the reaction to form methanol. Due to the exothermic nature of the reaction, heat is generated and the temperature of both the catalyst and the gas mixture (synthesis gas and gaseous methanol / water, as well as unreacted synthesis gas) increases. As the reaction progresses, the temperature of the catalyst bed and the gas mixture approximately corresponds to the temperature of the coolant.

[0060] The reaction continues in a second part of the catalyst bed, generating more heat and further heating the catalyst bed and gas mixture. The rate of heat generation in this second part of the catalyst bed is faster than the heat transfer from the coolant, so that the temperatures of the gas mixture and the catalyst bed rise above the temperature of the coolant. The heat generated during the reaction first heats the solid catalyst. Heat is then transferred from the catalyst to the process gas mixture to cool the catalyst. The process gas mixture then transfers the heat to the coolant used in the reactor. Another type of heat transfer is heat convection from the solid catalyst to the reactor internals. The temperature in this part of the catalyst bed continues to rise above that of the coolant.As the reaction progresses, the reactants of the process gas mixture (carbon monoxide and hydrogen) continue to be consumed, and more and more crude methanol is produced as part of the process gas mixture. Since catalytic methanol synthesis is an equilibrium reaction, the reaction rate and thus the heat production rate approach a limit when the equilibrium concentration of reactants and products is reached.

[0061] In a third part of the catalyst bed, the rate of heat production slows as the reaction approaches equilibrium conditions. Heat transfer from the catalyst to the process gas mixture and ultimately to the cooling system continues, allowing the temperature of the catalyst bed to be lowered again.

[0062] In a final, fourth part of the catalyst bed, the reaction is in equilibrium without significant heat production. In this part of the catalyst bed, the temperature continues to drop toward the coolant temperature.

[0063] With regard to both the first and the second process unit, the plates are arranged vertically and the reacting or cooling process gases are guided from top to bottom within the plate spaces. According to the temperature profile explained in more detail above, the temperature on the plate space side will therefore fall from top to bottom in the broadest sense, i.e. a temperature gradient with falling temperature from top to bottom is formed over the longest section of the process unit. This applies even more clearly if the plate spaces of the second process unit are not filled with catalyst, as in the case of alternative c1. In this case, the temperature of the product stream RP1 in the second process unit drops continuously from top to bottom over the entire length of the process unit as cooling progresses.

[0064] Since the density of a medium at higher temperatures is relatively lower than the density of the same medium at lower temperatures, a density gradient develops during reactor operation, with a low density in an upper zone of the reactor or process unit leading to a higher density in a lower zone of the reactor or process unit. The intended flow direction of the respective process gas mixture on the plate space side, from top to bottom, is supported by the fact that heavier components (components with a higher density) collect in a lower region of the reactor or process unit due to the effect of gravity. Finally, the intended flow direction of the respective mixture is also favored by the vertical arrangement of the plates of the process units.

[0065] The advantages of the reactor according to the invention also extend to the guidance of the respective cooling media. According to the invention, the cooling media are guided from bottom to top on the inner side of the flow-through plates, while the process gas mixture to be cooled is guided from top to bottom on the inter-plate space side. The cooling medium therefore enters the respective process unit in a lower region and exits it in an upper region. In the process, it heats up continuously in the direction of flow from bottom to top due to the cooling of the process gas mixture and / or continuously changes from a liquid phase to a gaseous phase. The aforementioned temperature gradient and / or density gradient thus forms not only on the inner side of the plates, but also on the inter-plate space side.

[0066] In simplified terms, this means that the respective process unit is hottest in its head region and coldest in the bottom region. Furthermore, the media in the respective process unit essentially have the lowest density in the head region and the highest density in the bottom region. For alternative c1, this essentially applies to the entire reactor, since the second process unit serves only for cooling. Depending on the design of the cooling stage according to alternative c2, the mixture on the interplate space side also has a greater or lesser tendency to condense.

[0067] By combining the aforementioned effects, it is possible with regard to the reactor according to the invention to completely dispense with conveying devices with forced flow, such as pumps, both with regard to the process gas mixtures on the plate interspace side (synthesis gas stream and product streams RP1 and RP2) and with regard to the cooling media on the plate interior side.

[0068] If the cooling medium of the first process unit is boiling water, in particular boiling boiler feed water, the thermal energy required for evaporation corresponds to the evaporation enthalpy of the cooling medium. Since the device is hot in an upper zone during operation due to the aforementioned effects, evaporation in the upper zone is favored. As explained above, a density gradient forms on the plate interior side of the first process unit, with a low density in the upper zone and a high density in the lower zone. This leads to the so-called thermosyphon effect, which enables natural circulation of the cooling medium without the need for a forced-flow conveying device as described above.

[0069] Advantageously, by forming the aforementioned temperature and density gradients, the heating cooling medium is "sucked" upwards within the plate interiors of the first and / or second process unit, while the cooling and / or condensing process gas mixture "falls" downwards on the side of the plate interspaces of the first and / or second process unit.

[0070] The temperature gradient that develops during operation due to the inventive arrangement of the first and second process units and the inventive flow guidance is reflected not only in the flowing media, but also in the metallic structures of the device, since the heat of the media is transferred accordingly to the metallic structures. Since the temperature gradient continuously decreases from an upper region to a lower region, even in the metallic structures of the device, and essentially has no temperature peaks, potential thermal stresses due to locally occurring large temperature differences are reduced to a minimum. The first and second process units as well as the pressure jacket are made, in particular, of a metal or a metal alloy.Preferably, at least the media-carrying components of the first and second process units and the pressure jacket are made of a metal or a metal alloy.

[0071] An embodiment of the reactor according to the invention is characterized in that the plates of the first process unit and / or the plates of the second process unit are designed as cushion plates.

[0072] Pillow plates instead of conventional straight heat exchanger plates offer advantages, particularly with regard to the device according to the invention, in terms of mechanical stability and heat transfer efficiency. An improvement in heat transfer efficiency compared to conventional plates results particularly with regard to the generation of steam on the inside of the plates when the nucleation point is reached and the subsequent resulting vapor bubble formation. Pillow plate heat exchangers are described in more detail in DE 10 2016 005 999 A1, for example.

[0073] An embodiment of the reactor according to the invention is characterized in that the second process unit is configured such that the plate interiors can be flowed through by the synthesis gas stream, wherein the synthesis gas stream fulfills the function of the second cooling medium stream CM2, whereby a preheated synthesis gas stream can be generated.

[0074] To minimize the use of coolant, the synthesis gas stream intended for methanol synthesis is advantageously used as coolant CM2 in the second process unit. In this case, the second process unit either fulfills the function of a gas-cooled cooling stage (alternative c1) or the function of a gas-cooled reactor stage (alternative c2). The synthesis gas stream is advantageously preheated, thereby improving the heat integration of the reactor according to the invention. After introducing the preheated synthesis gas stream onto the plate space side of the first process unit to generate the methanol-containing product stream RP1, the temperature required for the conversion at the catalyst is reached more quickly. In addition, an external device for preheating the synthesis gas stream, for example a preheater, can be dispensed with.

[0075] An embodiment of the reactor according to the invention is therefore characterized in that the methanol synthesis reactor has means for discharging the preheated synthesis gas stream from the second process unit, as well as means for introducing the preheated synthesis gas stream into the first process unit to produce the methanol-containing product stream RP1.

[0076] An embodiment of the reactor according to the invention is characterized in that the plate interiors of the first process unit and the plate interiors of the second process unit are arranged at least partially in alignment one behind the other and / or the plate interspaces of the first process unit and the plate interspaces of the second process unit are arranged at least partially in alignment one behind the other.

[0077] An aligned arrangement one behind the other means that two plates of the first and second process unit arranged one behind the other in the flow direction of the process media (synthesis gas stream, methanol-containing product stream RP1, methanol-containing product stream RP2) are arranged along these longitudinal axes with respect to the longitudinal axes of their plate interiors or plate interspaces.

[0078] In particular, this arrangement takes place without the respective plate of the first process unit being arranged offset from the plate of the second process unit with respect to the respective longitudinal axis.

[0079] Further preferably, the two successively arranged plates of the first and second process unit are arranged in such a way that, with the same cross-sectional areas, they are arranged congruently with respect to these cross-sectional areas, i.e. that their two cross-sectional areas are congruent if they were displaced along the longitudinal axis and brought into alignment.

[0080] Preferably, the reactor is designed such that the aligned arrangement applies to all plates of the first process unit relative to all plates of the second process unit. This means that each plate of the first process unit has a counterpart plate in the second process unit arranged in alignment with it.

[0081] The aligned arrangement allows the volume of the reactor according to the invention to be minimized. In other words, the ratio of the required volume to the available usable area is minimized. The usable area is understood to be the area that can be used for cooling the process media with the cooling media or for synthesizing methanol from the process media.

[0082] An embodiment of the reactor according to the invention is characterized in that the methanol synthesis reactor has a support structure, wherein the support structure is designed as a support arranged at least partially below a process unit and / or as a suspension arranged at least partially above a process unit and thereby forms a mechanical connection between a process unit and the pressure shell.

[0083] A "support structure" within the meaning of the invention can alternatively also be referred to as a "support element".

[0084] The reactor according to the invention preferably has at least one support structure. The support structure forms a mechanical connection between a process unit and the pressure shell. The mechanical connection represents a fixed point between a process unit and the pressure shell.

[0085] Depending on the configuration, a single support structure may be sufficient for the entire reactor, forming a mechanical connection between a process unit and the pressure shroud. Multiple such support structures may also be required, for example, one support structure per process unit. The mechanical connection between the respective process unit and the pressure shroud can be a force-fit connection and / or a material connection.

[0086] An example of a force-locking connection is a screw connection. An example of a material-locking connection is a welded joint.

[0087] The support structure is designed as a suspension or as a support. In the case of a suspension, the support structure is arranged at least partially, i.e., partially or completely, above the respective process unit. In the case of a support, the support structure is arranged at least partially, i.e., partially or completely, below the respective process unit. According to one embodiment, the support is arranged completely below a process unit, and the suspension is arranged completely above a process unit.

[0088] It is advantageous to arrange the respective support structures not entirely next to a respective process unit, but at least partially above or below a process unit and to mechanically connect them to the respective process unit and the pressure jacket. This, and especially when arranged entirely above or below a process unit, allows the support structures or connecting elements to be positioned at a location where they do not significantly influence the internal diameter of the reactor. Parallel installation, i.e. installation at the same height of the process unit plates between the process unit and the shell wall, would noticeably increase the cross-section of the reactor, particularly with regard to the diameter of the pressure jacket. According to the vessel formula, the pressure jacket would have to be designed with correspondingly thicker walls, which would be disadvantageous.

[0089] Furthermore, the arrangement of the support structures at least partially above and / or at least partially below a process unit, in particular completely above and / or below a process unit, enables the design of an individual plate width for each of the heat exchanger plates. This allows a particularly round cross-sectional area (circular area) of the pressure shell to be utilized most effectively.

[0090] An embodiment of the reactor according to the invention is characterized in that the first process unit has a support structure arranged at least partially below the first process unit and designed as a support, and the second process unit has a support structure arranged at least partially above the second process unit and designed as a suspension.

[0091] According to this embodiment, the first, i.e., upper, process unit is connected to the pressure shroud via a support structure designed as a support. Additionally, the second, i.e., lower, process unit is connected to the pressure shroud via a support structure designed as a suspension. Each of the process units thus has a dedicated support structure. In certain reactor configurations, this leads to an advantageous two-part distribution of the loads of the process units within the pressure shroud.

[0092] Preferably, the support is arranged in the lower region of the first process unit, i.e., in the sump region of the first process unit, and establishes a mechanical connection between the first process unit and the pressure jacket in this region. The elements for forming the mechanical connection between the process unit and the pressure jacket are also arranged accordingly, preferably in the lower region or in the sump region of the first process unit.

[0093] Preferably, the suspension is arranged in the upper region of the second process unit, i.e., at the head region of the second process unit, and establishes a mechanical connection between the second process unit and the pressure jacket in this region. The elements for forming the mechanical connection between the process unit and the pressure jacket are also arranged accordingly, preferably in the upper region or at the head region of the second process unit.

[0094] Due to possible different materials used for the pressure jacket and the plates of the first and second process units and generally different temperatures between the process units and the pressure jacket, different relative expansions of these two elements can occur during reactor operation, which can lead to different upward and downward growth of these elements. In this case, it is advantageous if the plates of the first process unit and any other components mechanically connected to these plates can expand freely upwards. Furthermore, it is advantageous if the plates of the second process unit and any other components mechanically connected to these plates can expand freely downwards. The two process units therefore grow in opposite directions with increasing temperature, respectively upwards (first process unit) and downwards (second process unit).The mechanical fixed points of the suspension and support on the pressure shell are located close to each other. Stresses resulting from differential thermal expansion between these fixed points are kept to a minimum, as the distance between the fixed point of the upper support and the fixed point of the lower suspension is short.

[0095] An embodiment of the reactor according to the invention is characterized in that the first process unit has a support structure arranged at least partially above the first process unit and designed as a suspension, and wherein the first and the second process unit are mechanically connected to one another via a connecting element.

[0096] In particular, the connecting element does not establish a mechanical connection between the first process unit and the pressure jacket, and does not establish a mechanical connection between the second process unit and the pressure jacket.

[0097] According to this embodiment, the first, i.e., upper, process unit is connected to the pressure shroud via a support structure designed as a suspension. Thus, only the first process unit has a dedicated support structure. In certain reactor configurations, this leads to an advantageous, one-piece transfer of the loads of both process units downwards within the pressure shroud.

[0098] Preferably, the suspension is arranged in the upper region of the first process unit, i.e., at the head region of the first process unit, and establishes a mechanical connection between the first process unit and the pressure jacket in this region. The elements for forming the mechanical connection between the process unit and the pressure jacket are also arranged accordingly, preferably in the upper region or at the head region of the first process unit.

[0099] According to this embodiment with suspension as a support structure for the first process unit and connecting element between the first and second process unit, the entire construction comprising the heat exchanger plates of the first and second process unit and other components mechanically connected thereto can expand freely downwards when the temperature increases during reactor operation.

[0100] With this purely suspended construction of the first and second process units within the pressure jacket, the fixation to the pressure jacket is mechanically more complex, as additional weight acts on the mechanical connection.

[0101] However, this design can be advantageous, particularly when boiling boiler feed water is used as the cooling medium CM1 for the first process unit. In the first process unit, which is configured as reactor stage RS1, large quantities of steam are produced on the inside of the plate in certain reactor configurations, with the steam leaving the first process unit at the head region of the first process unit due to the routing of the coolant CM1 from bottom to top. The cooling medium supply line then tends to have a smaller cross-section than the steam-carrying cooling medium discharge line. A smaller cross-section is associated with a smaller wall thickness of the supply line, which means that the supply line can be made more flexible than the discharge line. Accordingly, it is advantageous to make the sump region of the first process unit flexible and the head region rigid.The former is realized by the flexible connecting element between the first and second process unit, which is not mechanically connected to the pressure jacket, the latter by the support structure realized as a suspension in the head area of ​​the first process unit.

[0102] To further reduce stresses, the cooling medium supply line can be routed parallel to the plates of the first process unit. The cooling medium inlet nozzle for the cooling medium CM1 is located in the head area of ​​the first process unit, and the line is then preferably routed vertically downwards.

[0103] An embodiment of the reactor according to the invention is characterized in that the second process unit has a support structure arranged at least partially below the second process unit and designed as a support, and wherein the first and the second process unit are mechanically connected to one another via a connecting element.

[0104] In particular, the connecting element does not establish a mechanical connection between the first process unit and the pressure jacket, and does not establish a mechanical connection between the second process unit and the pressure jacket.

[0105] According to this embodiment, the second, i.e., lower, process unit is connected to the pressure shroud via a support structure designed as a support. Thus, only the second process unit has a dedicated support structure. In certain reactor configurations, this leads to an advantageous, one-piece transfer of the loads of both process units upwards within the pressure shroud.

[0106] Preferably, the support is arranged in the lower region of the second process unit, i.e., in the sump region of the second process unit, and establishes a mechanical connection between the second process unit and the pressure jacket in this region. The elements for forming the mechanical connection between the process unit and the pressure jacket are also arranged accordingly, preferably in the lower region or in the sump region of the second process unit.

[0107] According to this embodiment with support as a support structure for the second process unit and connecting element between the first and second process unit, the entire construction comprising the heat exchanger plates of the first and second process unit and other components mechanically connected thereto can expand freely upwards when the temperature increases during reactor operation.

[0108] An embodiment of the reactor according to the invention is characterized in that the methanol synthesis reactor has a synthesis gas inlet nozzle extending through the pressure jacket, wherein the synthesis gas inlet nozzle is fluidically connected to the plate interiors of the second process unit and is configured to introduce the synthesis gas stream into the second process unit.

[0109] This embodiment is relevant for the case where the synthesis gas stream is used as a coolant on the inside of the plate of the second process unit. The synthesis gas inlet nozzle is then preferably arranged in the sump region of the second process unit and preferably extends horizontally through the pressure jacket.

[0110] If the second process unit is not operated with synthesis gas as coolant CM2, the synthesis gas inlet nozzle is preferably arranged at the head region of the first process unit and preferably extends horizontally through the pressure jacket.

[0111] An embodiment of the reactor according to the invention is characterized in that the second process unit has a distribution system in its sump region, which is fluidically connected to the synthesis gas inlet nozzle and the plate interiors of the second process unit and is configured to distribute the synthesis gas stream entering via the synthesis gas inlet nozzle to the plate interiors of the second process unit.

[0112] An embodiment of the reactor according to the invention is characterized in that the second process unit comprises a collector system in its head region, which is fluidically connected to the plate interiors of the second process unit and is configured to collect the preheated synthesis gas stream emerging from the plate interiors of the second process unit.

[0113] With respect to the cooling medium flow CM2, the second process unit preferably comprises in its head region a collector system which is fluidically connected to the plate interiors of the second process unit and is configured to collect the cooling medium flow CM2 emerging from the plate interiors of the second process unit.

[0114] An embodiment of the reactor according to the invention is characterized in that the first process unit comprises a distribution system in its head region, which is fluidically connected to the collector system of the second process unit and is configured to distribute the preheated synthesis gas to the plate interspaces of the first process unit.

[0115] If the synthesis gas stream is not used as a cooling medium stream CM2 in the second process unit, the first process unit preferably comprises a distribution system in its head region, which is configured to distribute the synthesis gas of the synthesis gas stream to the plate interspaces of the first process unit.

[0116] An embodiment of the reactor according to the invention is characterized in that the collector system of the second process unit and the distribution system of the first process unit are connected via a line bypassing the first process unit and running at least partially within the pressure jacket.

[0117] This embodiment is relevant when the synthesis gas stream is used as the cooling medium stream CM2 in the second process unit, and the collector system of the first process unit and the distribution system of the first process unit must be connected to each other by a corresponding line. It is then advantageous to lay this line such that it bypasses the first process unit between the pressure jacket and this first process unit, and in particular runs parallel to the plates of the first process unit.

[0118] An embodiment of the reactor according to the invention is characterized in that the methanol synthesis reactor has a cooling medium inlet nozzle extending through the pressure jacket, wherein the cooling medium inlet nozzle is fluidically connected to the plate interiors of the first process unit and is configured to introduce the cooling medium flow CM1 into the first process unit.

[0119] An embodiment of the reactor according to the invention is characterized in that the first process unit has a distribution system in its sump region, which is fluidically connected to the cooling medium inlet nozzle and the plate interiors of the first process unit and is configured to distribute the cooling medium flow CM1 entering via the cooling medium inlet nozzle to the plate interiors of the first process unit.

[0120] The cooling medium stream CM1 preferably comprises boiling boiler feed water with respect to the first process unit.

[0121] An embodiment of the reactor according to the invention is characterized in that the methanol synthesis reactor has a cooling medium outlet nozzle extending through the pressure jacket, wherein the cooling medium outlet nozzle is fluidically connected to the plate interiors of the first process unit and is configured to discharge the cooling medium stream CM1 from the first process unit.

[0122] When boiling boiler feed water is used for the cooling medium stream CM1, the discharged cooling medium stream CM1 comprises, in particular, steam.

[0123] An embodiment of the reactor according to the invention is characterized in that the first process unit has a collector system in its head region, which is fluidically connected to the cooling medium outlet nozzle and the plate interiors of the first process unit and is configured to collect the cooling medium flow CM1 emerging from the plate interiors of the first process unit.

[0124] An embodiment of the reactor according to the invention is characterized in that the methanol synthesis reactor comprises a product stream outlet nozzle extending through the pressure jacket, wherein the product stream outlet nozzle is fluidically connected to the plate interspaces of the second process unit and is configured to discharge the methanol-containing product stream RP1 and / or the methanol-containing product stream RP2 from the second process unit.

[0125] In the case of alternative c1, the product stream outlet nozzle is configured to discharge the methanol-containing product stream RP1 from the second process unit. In the case of alternative c2, the product stream outlet nozzle is configured to discharge the methanol-containing product stream RP2 from the second process unit.

[0126] An embodiment of the reactor according to the invention is characterized in that the second process unit has a collector system in its sump region, which is fluidically connected to the product stream outlet nozzle and the plate interstices of the second process unit and is configured to collect the methanol-containing product stream RP1 and / or methanol-containing product stream RP2 exiting from the plate interstices of the second process unit.

[0127] In the case of alternative c1, the collector system is configured to collect the methanol-containing product stream RP1 exiting the plate interstices of the second process unit. In the case of alternative c2, the collector system is configured to collect the methanol-containing product stream RP2 exiting the plate interstices of the second process unit.

[0128] An embodiment of the reactor according to the invention is characterized in that an intermediate space region is arranged between the first process unit and the second process unit within the pressure jacket, wherein the intermediate space region is fluidically connected to the plate interspaces of the first process unit and the plate interspaces of the second process unit and is configured to transfer the methanol-containing product stream RP1 from the first process unit to the second process unit.

[0129] The intermediate space region can comprise a collector system which is fluidically connected to the plate interspaces of the first process unit and is configured to collect the methanol-containing product stream RP1 emerging from the plate interspaces of the first process unit.

[0130] Furthermore, the intermediate space region may comprise a distribution system which is fluidically connected to the plate interspaces of the second process unit and is configured to distribute the methanol-containing product stream RP1 to the plate interspaces of the second process unit.

[0131] The collector system of the first process unit and the distribution system of the second process unit of the intermediate space area are fluidically connected to each other. Example

[0132] The invention is explained in more detail below by means of exemplary embodiments. In the following detailed description, reference is made to the accompanying drawings, which form a part of the exemplary embodiments and in which specific embodiments of the invention are shown by way of illustration. In this context, directional terminology such as "top," "bottom," "front," "back," etc., is used with reference to the orientation of the described figure. Since components of embodiments can be positioned in a variety of orientations, the directional terminology is for purposes of illustration and is in no way limiting.

[0133] The following detailed description is therefore not to be taken in a limiting sense, and the scope of the embodiments is defined by the appended claims. The drawings are not to scale unless otherwise indicated.

[0134] In the following description and in the drawings, identical elements are designated by identical reference numerals. Arrows indicate the flow direction of the process media, i.e., the synthesis gas stream and the methanol-containing product streams RP1 and RP2, as well as the cooling media CM1 and CM2.

[0135] It shows Figure 1 shows a highly simplified schematic representation of a methanol synthesis reactor according to alternative c1 in accordance with a first example of the invention, Figure 2 shows a highly simplified schematic representation of a methanol synthesis reactor according to alternative c1 in accordance with a second example of the invention, Figure 3 shows a highly simplified schematic representation of a methanol synthesis reactor according to alternative c2 in accordance with a third example of the invention, Figure 4 shows a highly simplified schematic representation of a methanol synthesis reactor according to alternative c2 in accordance with a fourth example of the invention, Figure 5 shows a typical temperature profile of a catalyst bed over the length of a methanol reactor, determined by measurement and simulation.

[0136] Figure 1shows a highly simplified schematic representation (principle sketch) of a methanol synthesis reactor 1 according to a first example of the invention. According to alternative c1, the methanol synthesis reactor 1 has a first process unit 13, which is designed as a reactor stage RS1. Furthermore, and according to alternative c1, the methanol synthesis reactor 1 has a second process unit 14a, which is designed as a cooling stage.

[0137] The methanol synthesis reactor 1 is on the left side of Figure 1 shown in a front view. Figure 1 further shows a side view of a part of the first process unit 13 top right and a side view of a part of the second process unit 14a bottom right.

[0138] The methanol synthesis reactor 1 according to Figure 1has a pressure jacket 11, in the interior 12 of which a first process unit 13 and a second process unit 14a are arranged. The first process unit 13 is arranged in an upper part of the interior 12, while the second process unit 14a is arranged in a lower part of the interior 12 and below the first process unit 13. Both process units 13 and 14a are fluidically connected to one another, for example via corresponding pipes of distribution and collector systems (not shown).

[0139] The methanol synthesis reactor 1 is configured as a single-stage reactor with a reactor stage RS1 and a cooling stage. The reactor stage RS1 is formed by the first process unit 13, and the cooling stage by the second process unit 14a. Boiling boiler feedwater is used as the cooling medium stream CM1 in the first reactor stage. The synthesis gas stream, which is also used in the reactor stage RS1 for conversion to methanol on a catalyst bed CB1, is used as the cooling medium stream CM2 in the cooling stage. The synthesis gas stream is preheated in the second process unit 14a and can then be introduced as a preheated synthesis gas stream into the first process unit 13 for conversion to methanol.

[0140] The first process unit 13 is designed as a plate heat exchanger, wherein the plate heat exchanger has a plurality of flow-through (heat exchanger) plates 15, which are designed as pillow plates (pillow plate structure not shown). The plates are arranged vertically and are accordingly flowed through in a vertical direction. The plates 15 each have a flow-through plate interior 16, through which the cooling medium flow CM1 33 flows from bottom to top. The flow of fresh cooling medium CM1 33 enters a plate 15 from below and exits the relevant plate 15 at the top as a flow of used cooling medium CM1 34. The fresh cooling medium flow CM1 33 is boiling boiler feed water. The used cooling medium flow CM1 34 is steam.

[0141] Two adjacent plates 15 of the first process unit 13 are spaced apart from each other to form a plate interspace 17. Pellets of a methanol synthesis catalyst are arranged in the plate interspaces 17, indicated by the black dots. The entirety of the catalyst pellets forms the catalyst bed CB1 18a. A preheated synthesis gas stream 29 enters the plate interspaces 17 from above and is at least partially converted in an exothermic reaction on the catalyst bed CB1 18a to a mixture of methanol and water (crude methanol). The plate interspaces are cooled in countercurrent by the cooling medium stream CM1 33, thereby controlling the temperature in the plate interspaces. During this exothermic reaction, a product stream RP1 30 is formed, which contains at least methanol, water, and unconverted synthesis gas (residual gas).This product stream RP1 30 exits the bottom of the plate gaps 17.

[0142] The second process unit 14a is also designed as a plate heat exchanger, wherein the plate heat exchanger has a plurality of flow-through (heat exchanger) plates 15, which are designed as pillow plates (pillow plate structure not shown). The plates are arranged vertically and are accordingly flowed through in a vertical direction. The plates 15 of the second process unit each have a flow-through plate interior 16, through which the cooling medium flow CM2 28 flows from bottom to top. The flow of fresh cooling medium CM2 28 enters the plate 15 from below and exits the plate 15 at the top as a flow of used cooling medium CM2 29. The fresh cooling medium flow CM2 28 is the synthesis gas flow. The used cooling medium flow CM2 29 is the preheated synthesis gas flow.

[0143] Two adjacent plates 15 of the second process unit 14a are spaced apart from each other to form a plate interspace 17. In contrast to the plate interspaces of the first process unit 13, no methanol synthesis catalyst is arranged in the plate interspaces 17 of the second process unit, since the second process unit serves solely to cool and, if necessary, condense the methanol-containing product stream RP1 30. The plate interspaces 17, through which the methanol-containing product stream RP1 30 flows from top to bottom, are cooled in countercurrent by the cooling medium stream CM2 28, whereby the initially hot methanol-containing product stream RP1 30 cools to the cold methanol-containing product stream RP1 31.Depending on the design of the second process unit 14a, the methanol-containing product stream RP1 31 can be obtained in merely cooled but still gaseous form, in partially condensed or fully condensed form with respect to the condensable components.

[0144] As on the right side of the Figure 1 As shown, the flow-through plates 15 with their plate interiors 16 and the plate interspaces 17 of the first and second process units 13 and 14a are arranged one behind the other in alignment with each other.

[0145] In other words, the plates and plate spaces of the first and second process units 13 and 14a are each located one behind the other on a common longitudinal axis.

[0146] The first process unit 13 of the methanol synthesis reactor 1 is mechanically connected to the pressure shell 11 via a support structure 19, whereby the support structure 19 forms a mechanical connection between the first process unit and the pressure shell 11 (the connection to the pressure shell lies in the plane of the drawing). The support structure 19 is designed as a support and is arranged at least partially below the first process unit 13. In contrast to an arrangement to the side of the first process unit 13, this arrangement has the advantage that the diameter of the methanol synthesis reactor 1 is not significantly influenced, in particular is not significantly increased. By designing the support structure 19 as a support, the first process unit can expand freely upwards. This particularly applies to the package of heat exchanger plates and the components mechanically connected thereto.Components mechanically connected to the heat exchanger plates are, in particular, the distributor and collector systems 24, 25 and 26.

[0147] The second process unit 14a of the methanol synthesis reactor 1 is mechanically connected to the pressure shell 11 via a support structure 20, whereby the support structure 20 forms a mechanical connection between the second process unit and the pressure shell 11 (the connection to the pressure shell lies in the plane of the drawing). The support structure 20 is designed as a suspension and is arranged at least partially above the second process unit 14a. In contrast to an arrangement to the side of the second process unit 14a, this arrangement has the advantage that the diameter of the methanol synthesis reactor 1 is not significantly influenced, in particular is not significantly increased. By designing the support structure 20 as a suspension, the second process unit 14a can expand freely downward. This particularly applies to the package of heat exchanger plates and the components mechanically connected thereto.Components mechanically connected to the heat exchanger plates are, in particular, the distributor and collector systems 22, 23 and 27.

[0148] The flow pattern in the reactor 1 according to the invention is explained below. The synthesis gas stream 28 enters the methanol synthesis reactor 1 via a synthesis gas inlet nozzle (not shown), which extends horizontally through the pressure jacket 11. The synthesis gas stream 28 is then distributed to the individual plate interiors 16 of the first process unit via a distribution system 22 (simplified and shown for clarity as part of a block with the components 22, 27). The synthesis gas then flows from bottom to top through the plate interiors 16, cooling the product stream RP1 30 in countercurrent on the side of the plate interspaces 17. The synthesis gas stream 28 fulfills the function of the cooling medium stream CM2.The resulting preheated synthesis gas stream 29 or used cooling medium stream CM2 is combined in a collector system 23 and fed via a bypass line (indicated by the dashed line) to the top of the first process unit. There, the preheated synthesis gas stream 29 enters a distribution system 24 (simplified and shown for clarity as part of a block with components 24, 26), which distributes the synthesis gas to the plate interspaces 17 of the first process unit. In the plate interspaces 17 of the first process unit, the preheated synthesis gas reacts at the methanol synthesis catalyst of the catalyst bed to form methanol and water, thus forming the product stream RP1 30, which also includes unconverted synthesis gas (residual gas).The product stream RP1 30 flows from top to bottom and is withdrawn from the first process unit 13 in the bottom region, flows through an interspace area (not shown), and then enters the plate interspaces 17 of the second process unit 14a for cooling. The cooled product stream RP1 31 is combined with the aid of a collector system 27 (simplified and shown for clarity as part of a block with the components 22, 27) and discharged from the reactor via a product stream outlet nozzle (not shown). The crude product thus obtained is then subjected to further treatment (e.g., further cooling and gas-liquid separation) and processing (e.g., distillation).

[0149] The intermediate space between the first and second process units may also comprise a corresponding collector system for the product stream RP1 in the bottom region of the first process unit 13 and a corresponding distributor system for the product stream RP1 at the top region of the second process unit 14a.

[0150] The fresh cooling medium stream CM1 33 enters the reactor via a horizontally arranged cooling medium inlet nozzle (not shown), which extends through the pressure jacket 11, and is distributed via a distribution system 25 to the plate interiors 16 of the first process unit 13. The boiling boiler feedwater used for the cooling medium stream CM1 33 evaporates, thereby cooling the product stream RP1 forming in the plate interstices. The steam or spent cooling medium stream CM1 34 is combined in a collector system 26 (simplified and shown for reasons of clarity as part of a block with the components 24, 26) and discharged from the reactor 1 via a horizontally arranged cooling medium outlet nozzle extending through the pressure jacket.

[0151] The examples according to Figures 2 to 4are not explained in detail below. Only differences, for example, according to Figure 1 received.

[0152] Figure 2 shows a highly simplified schematic representation (principle sketch) of a methanol synthesis reactor 2 according to a second example of the invention. According to alternative c1, the methanol synthesis reactor 2 also has a first process unit 13, which is designed as a reactor stage RS1. Furthermore, and according to alternative c1, the methanol synthesis reactor 2 has a second process unit 14a, which is designed as a cooling stage.

[0153] The methanol synthesis reactor 2 according to Figure 2 differs from the methanol synthesis reactor 1 according to Figure 1significantly by the type of mechanical fixation of the first and second process units 13 and 14a. Otherwise, the methanol synthesis reactor 2 is also configured as a single-stage reactor with a first process unit 13 designed as a water-cooled reactor stage RS1 and a second process unit 14a designed as a gas-cooled cooling stage 14a.

[0154] The methanol synthesis reactor 2 according to the example of Figure 2has only one mechanical support structure 20, which mechanically connects the first process unit 13 to the pressure jacket 11. The support structure 20 thus forms a mechanical connection between the first process unit 13 and the pressure jacket 11 (connection to the pressure jacket lies in the plane of the drawing). This support structure 20 is designed as a suspension and is arranged at least partially above the first process unit 13. In contrast to an arrangement to the side of the first process unit 13, this arrangement has, as already described in relation to the example according to Figure 1 mentions the advantage that the diameter of the methanol synthesis reactor 2 is not significantly affected, in particular it is not significantly increased.

[0155] In contrast to the example according to Figure 1the second process unit 14a is not mechanically connected to the pressure jacket 11 via a support structure. Rather, the first process unit 13 and the second process unit 14a are mechanically connected to one another via a connecting element 21. However, the connecting element 21 does not form a mechanical connection to the pressure jacket 11. As a result, the first process unit 13 and the second process unit 14a can expand freely downwards. This embodiment has the advantage, particularly with large steam quantities with respect to the cooling medium flow CM1 34, that the supply of the cooling medium flow CM1 33, in contrast to the embodiment according to Figure 1 can be made more mechanically flexible.

[0156] Figure 3shows a highly simplified schematic representation (principle sketch) of a methanol synthesis reactor 3 according to a third example of the invention. According to alternative c2, the methanol synthesis reactor 3 has a first process unit 13, which is designed as a reactor stage RS1. Furthermore, and according to alternative c2, the methanol synthesis reactor 3 has a second process unit 14b, which is designed as a further or second reactor stage RS2.

[0157] In contrast to the examples of the methanol synthesis reactor according to the Figures 1 and 2The methanol-containing product stream RP1 30 emerging from the first process unit 13 is not only cooled in the second process unit 14b, but is further converted into a methanol-containing product stream RP2 32. This is made possible by the fact that the methanol-containing product stream RP1 30 contains unreacted synthesis gas (carbon oxide(s) and hydrogen) due to the establishment of a thermodynamic equilibrium. This unreacted synthesis gas or residual gas is further converted into methanol and water on the plate interspace side, i.e., within the plate interspaces 17 of the second process unit 14b, on the catalyst bed CB2 18b arranged there. Cooling of this exothermic reaction is achieved via the synthesis gas stream 28 or fresh cooling medium stream CM2 28 fed into the bottom region of the second process unit.Accordingly, the methanol synthesis reactor 3 is designed as a two-stage reactor, wherein the first reactor stage (process unit 13) is configured as a water-cooled reactor stage RS1 with boiling boiler feed water as the cooling medium stream CM1 33 and the second reactor stage RS2 is configured as a gas-cooled reactor stage with synthesis gas as the cooling medium stream CM2 28.

[0158] The mechanical fixation of the first and second process units 13 and 14b via the support structures 19 and 20 on the pressure jacket 11 corresponds to the mechanical fixation as for the example of the methanol synthesis reactor 1 in Figure 1 shown and described.

[0159] Figure 4shows a highly simplified schematic representation (principle sketch) of a methanol synthesis reactor 4 according to a fourth example of the invention. According to alternative c2, the methanol synthesis reactor 4 has a first process unit 13, which is designed as a reactor stage RS1. Furthermore, and according to alternative c2, the methanol synthesis reactor 4 has a second process unit 14b, which is designed as a further or second reactor stage RS2. As in the example of the reactor according to Figure 3 The methanol synthesis reactor 4 is also designed as a two-stage reactor, with the first reactor stage RS1 being configured as a water-cooled reactor stage and the second reactor stage RS2 being configured as a gas-cooled reactor stage.

[0160] The mechanical fixing of the first and second process units 13 and 14b via the support structure 20 on the pressure jacket 11 and the connection of the first and second process units 13 and 14b via the connecting element 21 corresponds to the configuration as for the example of the methanol synthesis reactor 2 in Figure 2 shown and described. List of reference symbols

[0161] 1, 2, 3, 4 Methanol synthesis reactor 11 Pressure jacket 12 Interior 13 First process unit (reactor stage RS1) 14a Second process unit (cooling stage) 14b Second process unit (reactor stage RS2) 15 (Heat exchanger) plate 16 Plate interior 17 Plate interspace 18a Catalyst bed CB1 18b Catalyst bed CB2 19 Support (support structure) 20 Suspension (support structure) 21 Connecting element 22 Distribution system (for synthesis gas stream) 23 Collector system (for preheated synthesis gas stream) 24 Distribution system (for preheated synthesis gas stream) 25 Distribution system (for cooling medium) 26 Collector system (for cooling medium) 27 Collector system (for product stream RP1 or RP2) 28 Synthesis gas stream (cooling medium stream CM2, fresh) 29 Preheated synthesis gas stream (cooling medium stream CM2, used up) 30 Product stream RP1 31 Cooled product stream RP1 32 Product stream RP2 33 Cooling medium stream CM1, fresh 34 Cooling medium stream CM1, used up

Claims

1. Methanol synthesis reactor (1, 2, 3, 4) for producing methanol from a synthesis gas mixture comprising (a) a pressure jacket (11) having an interior (12), wherein at least two fluidically interconnected process units are arranged one atop the other in the interior (12); (b) a first process unit (13), wherein the first process unit is configured as reactor stage RS1 for synthesis of methanol from a synthesis gas stream (29) over a catalyst bed CB1 (18a), thus making it possible to produce a methanol-containing product stream RP1 (30), and the first process unit (13) is in the form of a plate heat exchanger, wherein the first process unit (13) comprises a multiplicity of plates (15) arranged vertically and parallel to one another with traversable plate interiors (16) and plate interspaces (17) are present between adjacent plates, wherein a solid methanol synthesis catalyst forming the catalyst bed CB1 (18a) is arranged in the plate interspaces (17) and the first process unit (13) is configured such that the plate interspaces (17) are traversable from top to bottom by the synthesis gas stream (29) and by the methanol-containing product stream RP1 (30) and the plate interiors (17) are traversable from bottom to top by a first cooling media stream CM1 (33), thus making the methanol-containing product stream RP1 (30) coolable in countercurrent by the first cooling media stream CM1 (33), and wherein the first process unit (13) comprises means for withdrawing the methanol-containing product stream RP1 (30) from the first process unit (13); (c) a second process unit (14a, 14b) arranged below the first process unit (13), wherein the second process unit (14a, 14b) is in the form of a plate heat exchanger, wherein the second process unit (14a, 14b) comprises a multiplicity of plates (15) arranged vertically and parallel to one another with traversable plate interiors (16), and plate interspaces (17) are present between adjacent plates (15), wherein the second process unit (14a, 14b) is configured such that the plate interiors (17) are traversable from bottom to top by a second cooling media stream CM2 (28) and wherein - (c1) the second process unit (14a) is in the form of a cooling stage and configured such that the plate interspaces (17) are traversable from top to bottom by the methanol-containing product stream RP1 (30), thus making the methanol-containing product stream RP1 (30) coolable in countercurrent by the second cooling media stream CM2 (28) or - (c2) the second process unit (14b) is in the form of reactor stage RS2 and configured for synthesis of methanol from the methanol-containing product stream RP1 (30) withdrawable from the first process unit (13) over a catalyst bed CB2 (18b), thus making it possible to produce a methanol-containing product stream RP2 (32), and wherein a solid methanol synthesis catalyst forming the catalyst bed CB2 (18b) is arranged in the plate interspaces (17) and the second process unit (14b) is configured such that the plate interspaces (17) are traversable from top to bottom by the methanol-containing product stream RP1 (30) and the methanol-containing product stream RP2 (32), thus making the methanol-containing product stream RP2 (32) coolable in countercurrent by the second cooling media stream CM2 (28).

2. Methanol synthesis reactor according to Claim 1, characterized in that the plates of the first process unit (13) and / or the plates of the second process unit (14a, 14b) are in the form of pillow plates.

3. Methanol synthesis reactor according to Claim 1 or 2, characterized in that the second process unit (14a, 14b) is configured such that the plate interiors (17) are traversable by the synthesis gas stream (28), wherein the synthesis gas stream (28) fulfils the function of the second cooling media stream CM2 (28), thus making it possible to produce a preheated synthesis gas stream (29).

4. Methanol synthesis reactor according to Claim 3, characterized in that the methanol synthesis reactor comprises means for discharging the preheated synthesis gas stream (29) from the second process unit (14a, 14b) and comprises means for introducing the preheated synthesis gas stream (29) into the first process unit (13) to produce the methanol-containing product stream RP1 (30).

5. Methanol synthesis reactor according to any of the preceding claims, characterized in that the plate interiors (16) of the first process unit (13) and the plate interiors (16) of the second process unit (14a, 14b) are arranged at least partially in serial alignment and / or the plate interspaces (17) of the first process unit (13) and the plate interspaces (17) of the second process unit (14a, 14b) are arranged at least partially in serial alignment.

6. Methanol synthesis reactor according to any of the preceding claims, characterized in that the methanol synthesis reactor comprises a support structure (19, 20), wherein the support structure is in the form of a propping means (19) which is at least partially arranged below a process unit and / or in the form of a suspending means (20) arranged at least partially above a process unit and thus forms a mechanical connection between a process unit (13, 14a, 14b) and the pressure jacket (11).

7. Methanol synthesis reactor according to Claim 6, characterized in that the first process unit (13) has a support structure which is arranged at least partially below the first process unit (13) and is in the form of a propping means (19) and the second process unit (14a, 14b) has a support structure which is arranged at least partially above the second process unit (14a, 14b) and is in the form of a suspending means (20).

8. Methanol synthesis reactor according to Claim 6, characterized in that the first process unit (13) has a support structure which is arranged at least partially above the first process unit (13) and is in the form of a suspending means and wherein the first and the second process unit are mechanically connected to one another via a connecting element (21).

9. Methanol synthesis reactor according to any of Claims 3 to 8, characterized in that the methanol synthesis reactor comprises a synthesis gas inlet port extending through the pressure jacket (11), wherein the synthesis gas inlet port is fluidically connected to the plate interiors (16) of the second process unit (14a, 14b) and is configured for introducing the synthesis gas stream (28) into the second process unit (14a, 14b).

10. Methanol synthesis reactor according to Claim 9, characterized in that the second process unit (14a, 14b) comprises in its bottom region a distributor system (22) which is fluidically connected to the synthesis gas inlet port and the plate interiors (16) of the second process unit (14a, 14b) and is configured for distributing the synthesis gas stream (28) entering via the synthesis gas inlet port to the plate interiors (16) of the second process unit (14a, 14b).

11. Methanol synthesis reactor according to any of Claims 3 to 10, characterized in that the second process unit (14a, 14b) comprises in its top region a collector system (23) which is fluidically connected to the plate interiors (16) of the second process unit (14a, 14b) and is configured for collecting the preheated synthesis gas stream (29) exiting from the plate interiors (16) of the second process unit (14a, 14b).

12. Methanol synthesis reactor according to Claim 11, characterized in that the first process unit (13) comprises in its top region a distributor system (24) which is fluidically connected to the collector system (23) of the second process unit (14a, 14b) and configured for distributing the preheated synthesis gas (29) to the plate interspaces (17) of the first process unit (13).

13. Methanol synthesis reactor according to Claim 12, characterized in that the collector system (23) of the second process unit (14a, 14b) and the distributor system (24) of the first process unit (13) are connected via a conduit bypassing the first process unit and at least partially running inside the pressure jacket.

14. Methanol synthesis reactor according to any of the preceding claims, characterized in that the first cooling media stream CM1 (33) comprises boiling boiler feed water and the first cooling media stream CM1 (33) is especially evaporable upon traversal of the plate interiors (17) of the first process unit (13).

15. Methanol synthesis reactor according to any of the preceding claims, characterized in that an interspace region is arranged within the pressure jacket (11) between the first process unit (13) and the second process unit (14a, 14b), wherein the interspace region is fluidically connected to the plate interspaces (17) of the first process unit (13) and the plate interspaces (17) of the second process unit (14a, 14b) and is configured for transferring the methanol-containing product stream RP1 (30) from the first process unit (13) into the second process unit (14a, 14b).