Process and system for preparing methanol

Abstract

Proposed is a process (100, 200, 300) for catalytic preparation of methanol, wherein a reactor system (10) having a first reaction zone (11) and a second reaction zone (12) is used, wherein the first reaction zone (11) and the second reaction zone (12) are operated adiabatically and each have a catalytic reaction zone (11), wherein at least a portion of a gas mixture flowing from the first reaction zone (11) is transferred into the second reaction zone (12), wherein a first feed stream is introduced at a first temperature level into the reactor system (10) upstream of the first reaction zone (11), wherein a second feed stream is introduced at a second temperature level into the reactor system (10) between the first reaction zone (11) and the second reaction zone (12), and wherein the first temperature range is above the second temperature range. The present invention also relates to a corresponding system.

Description

[0001] Description

[0002] Process and plant for the production of methanol

[0003] The invention relates to a process and a plant for producing methanol.

[0004] background

[0005] Methanol is traditionally produced from synthesis gas. Two molecules of hydrogen are reacted with one molecule of carbon monoxide to form methanol. If the synthesis gas contains carbon dioxide, three molecules of hydrogen are reacted with one molecule of carbon dioxide to form one molecule of methanol and one molecule of water. Such processes have a high reaction enthalpy, which requires the use of a cooled reactor. Furthermore, such processes are typically, but not exclusively, used in very large plants.

[0006] The so-called "green" methanol synthesis through direct hydrogenation of carbon dioxide is also known. The reaction equation is the same as for the reaction of carbon dioxide in synthesis gas. Limitations arise due to the fact that this is an equilibrium reaction and due to the partial pressure of water. However, these processes advantageously generate less waste heat due to the lower reaction enthalpy, and smaller amounts of byproducts are formed compared to conventional methanol synthesis.

[0007] Corresponding processes include the so-called Camere process (see Joo et al., CAMERE Process for methanol synthesis from CO2 hydrogenation, Studies in Surface Science and Catalysis 153:67-72, 2004), which involves a reverse water gas shift reaction, but in which methanol synthesis is carried out using synthesis gas. Tubular reactors can be used in these and other processes, as disclosed in US Pat. No. 9,040,594 B2.

[0008] The present invention aims to improve corresponding methods, particularly with regard to production costs and effort. Disclosure of the invention

[0009] This object is achieved by a method and a system having the respective features of the independent patent claims. Advantageous embodiments of the present invention are the subject of the dependent patent claims and the following description.

[0010] If reference is made below to a fresh feed containing hydrogen, this does not necessarily mean a pure hydrogen stream, but may also include a hydrogen-containing gas mixture that predominantly contains hydrogen, for example with a content of more than 75%, 80%, 85%, 90% or 95% by volume, mass or molar fraction. Accordingly, a fresh feed containing carbon dioxide does not necessarily mean a pure carbon dioxide stream, but may also include a carbon dioxide-containing gas mixture that predominantly contains carbon dioxide, for example with a content of more than 75%, 80%, 85%, 90% or 95% by volume, mass or molar fraction. A fresh feed differs from a recycle stream in that it does not contain any components that have already passed through a reactor system to which the fresh feed is fed.

[0011] A material stream can be "formed" in any way, for example, by branching off from a main or initial stream or by combining a first and a second material stream. The "formation" of a material stream can include pressurization, cooling, heating, evaporation, expulsion of components, or addition of components. If it is stated here that a second material stream is "formed using" a first material stream, this can also mean that the first material stream is used as the second material stream and, for example, is fed to a different function, meaning that the first and second material streams are otherwise identical.

[0012] Within the scope of the invention, a process for the catalytic production of methanol, in particular according to the reaction principles mentioned at the outset, is proposed, wherein a reactor system having a first reaction zone and a second reaction zone is used, wherein the first reaction zone and the second reaction zone are operated adiabatically and are each designed as catalytic reaction zones, wherein at least a portion of a gas mixture flowing out of the first reaction zone is transferred to the second reaction zone, wherein a first feed stream is fed into the reactor system at a first temperature level upstream of the first reaction zone, wherein a second feed stream is fed into the reactor system at a second temperature level between the first reaction zone and the second reaction zone, and wherein the first temperature range is above the second temperature range.

[0013] The present invention is based on the fact that the reactors currently used for "green" methanol production, as explained above, are comparatively small, i.e., they are typically designed for a daily production of well under 1,000 tons of methanol. This is especially true compared to conventional plants, where daily production typically amounts to up to approximately 6,000 tons per day. Especially for smaller plants, construction costs (CAPEX) have a greater impact on the overall costs and should therefore be advantageously reduced.

[0014] A reactor that is particularly advantageous for this purpose is operated adiabatically. However, the conversion to methanol is typically limited due to the high reactor outlet temperatures and the resulting shift in the reaction equilibrium toward the reactants. Furthermore, higher reactor outlet temperatures favor the formation of byproducts. Higher temperatures also cause high carbon monoxide levels in recycle streams due to a reverse water gas shift reaction. More carbon monoxide also favors the formation of byproducts.

[0015] Advantages of the present invention include, in particular, a low byproduct rate, since, on the one hand, carbon dioxide is used as the feedstock and, in particular, adiabatic operation is carried out, but with "cold feed" of the second material stream in the manner explained. This enables a long catalyst runtime. Adiabatic operation and the associated omission of an external cooling system result in lower investment costs and less equipment complexity, for example, because tube bundle reactors with corresponding cooling do not need to be provided. The process or a corresponding reactor can be operated relatively flexibly (with regard to the ratio of hydrogen to carbon dioxide and the gas space velocity), which enables adaptation to fluctuating hydrogen availability.Greater flexibility is also achieved by feeding two feed streams into the reactor.

[0016] Intermediate cooling and the corresponding condensation of water and methanol in a reactor concept that is, in principle, alternatively applicable could be used to increase methanol yield, but would also incur very high construction and operating costs (OPEX). The same applies to the use of tube-bundle reactors with a corresponding cooling system.

[0017] These disadvantages are overcome by the intermediate feed of the second feed stream proposed according to the invention, since the intermediate feed causes a cooling of the process gas or a dilution of the hot process gas emerging from the first reaction zone with cooler process gas. The first and second reaction zones can be arranged, in particular, in a common pressure vessel, with the flow pattern in the two reaction zones being, in particular, opposite to one another.In particular, a pressure vessel, in particular with a substantially cylindrical section, can be provided, wherein the reaction zones are arranged such that the gas flows through the first reaction zone in a first direction substantially parallel to the cylinder axis of the cylindrical section, and the gas flows through the second reaction zone in a second direction opposite to the first direction, parallel to the cylinder axis of the cylindrical section. "In one direction in total" is to be understood as meaning that the gas volume in the first and second reaction zones moves overall in a corresponding direction, but that individual gas molecules can also move in different directions (e.g., due to turbulence and the like, or deflection by particles of a catalyst bed).The first feed stream is fed in, in particular, in a first terminal region of the cylindrical section, and the second feed stream is fed in, in particular, in a second terminal region of the cylindrical section opposite the first terminal region. Within the scope of the present invention, the two reaction zones are operated adiabatically, which means that no external cooling system is assigned to the reaction zones. Although the second feed stream is fed in, it does not constitute external cooling, since the components of the second feed stream are added to the process gas stream passing through the reaction zones. Particularly effective cooling can be achieved without complex and costly measures when the second reaction feed stream is or comprises cold or liquefied gas (such as liquid carbon dioxide).In this way, within the scope of the present invention, an increase in the methanol yield can be achieved, which can be achieved in particular in the aforementioned smaller plants for “green” methanol production without significantly increased costs.

[0018] In the context of the present invention, the first feed stream contains, in particular, predominantly or exclusively hydrogen and carbon dioxide, wherein the term “predominantly” can in particular mean a content of more than 75, 80, 85, 90 or 95% on a volume or molar basis.

[0019] In one embodiment of the present invention, at least a portion of a gas mixture flowing out of the second reaction zone is subjected to phase separation to obtain a gas fraction and a liquid fraction, wherein a recycle stream is formed using at least a portion of the gas fraction, and wherein the first feed stream is formed using the recycle stream.

[0020] The phase separation can be carried out differently in different embodiments of the invention. It is always based on cooling the gas mixture flowing out of the second reaction zone and condensing the components that become liquid in the process, but can also comprise, in particular, stripping the liquid phase formed, as explained below. The condensing components include, in particular, water, methanol, and compounds that boil between water and methanol, for example, ethanol, which is formed as a by-product. The invention can, in particular, comprise the use of only a portion of the gas phase as a recycle stream, wherein a portion not used to form the recycle stream can be removed from the process in order to prevent the accumulation of unreacted components and / or inert components (e.g.

[0021] nitrogen) (so-called purge).

[0022] In one embodiment of the present invention, at least a portion of the gas mixture flowing out of the second reaction zone is cooled against at least a portion of the first feed stream. In this way, the present invention provides advantageous heat integration, by means of which the first feed stream can be brought to the temperature required to initiate the reaction. This is particularly advantageous when the first feed stream comprises very cold components, such as a liquid carbon dioxide stream.

[0023] In one embodiment of the present invention, the first feed stream is formed using a hydrogen-containing fresh feed stream. In this embodiment, the first feed stream can be formed, in particular, using the hydrogen-containing fresh feed stream and the recycle stream. Alternatively, the hydrogen-containing fresh feed stream can be fed into the phase separation, wherein at least a portion of the hydrogen in the hydrogen-containing fresh feed stream is converted into the gas fraction in the phase separation and from there into the recycle stream.

[0024] The first embodiment thus comprises a feed upstream of the first reaction zone or, in other words, a formation of the first feed stream using the hydrogen-containing fresh feed stream, a recycle stream, and a carbon dioxide-containing fresh feed stream, as explained below. In the second embodiment, however, the hydrogen-containing fresh feed stream is fed downstream of the second reaction zone. In this second embodiment, the hydrogen-containing fresh feed stream can be used as a stripping gas stream in the phase separation, resulting in a particularly advantageous dual use that also leads to a further depletion of light components in the liquid fraction. In particular, the reactants hydrogen and carbon dioxide can be expelled from the liquid phase for recycle and thus be better utilized. Here, too, an inert gas purge can be used in a recycle stream.This can also be subjected, for example, to pressure swing adsorption or another separation process, e.g., a membrane separation process. In one embodiment of the present invention, the first feed stream can be formed using a first portion of a carbon dioxide-containing fresh feed stream, and the second feed stream can be formed using a second portion of the carbon dioxide-containing fresh feed stream. The carbon dioxide-containing fresh feed stream can thus be divided and fed in fixed or adjustable proportions upstream of the first reaction zone and between the first and second reaction zones. Particularly good cooling can be achieved when the carbon dioxide-containing fresh feed stream is provided in the form of liquid carbon dioxide.

[0025] In one embodiment of the present invention, however, it is also possible for only or substantially only the recycle stream to be used to form the first feed stream, and for the second feed stream to be a fresh feed stream comprising hydrogen and carbon dioxide, or to be formed from a hydrogen-containing fresh feed stream and a carbon dioxide-containing fresh feed stream. The statement that "substantially only the recycle stream" is used to form the first feed stream is to be understood to mean that more than 90, 95, or 99% of the volume of the first feed stream is formed from the recycle stream. In such an embodiment, substantially all of the makeup or fresh feed is fed between the first and second reaction zones of the reactor system.

[0026] In embodiments of the present invention, the hydrogen-containing fresh feed stream can be provided using an electrolysis device configured with a proton or anion exchange membrane or a solid oxide electrolysis cell. Corresponding electrolysis processes allow for simplified provision of the hydrogen-containing fresh feed stream, as explained below.

[0027] In a corresponding embodiment, the hydrogen-containing fresh feed stream can be withdrawn from the electrolysis device, in particular an electrolysis device with a proton or anion exchange membrane, at an inlet pressure level of the first reaction zone or above. For this purpose, the electrolysis device is typically operated at a pressure that is, for example, approximately 5 bar above the inlet pressure level of the first reaction zone. In this way, compression and the provision of a corresponding compressor can be avoided. Increased hydrogen transfer through the membrane due to the increased pressure can be avoided by using a more stable or thicker (more gas-tight) membrane. A recombination catalyst, for example, can also be used in the membrane electrode assembly.Alternatively or additionally, the hydrogen-containing fresh feed stream can also be withdrawn from a corresponding electrolysis facility as a wet material stream and used in this state to form the reaction feed stream. This eliminates the need for a dryer.

[0028] In embodiments of the invention, the carbon dioxide-containing fresh feed stream can be provided, in particular, as a liquid stream, which is used in liquid form or evaporated using waste heat from the process. If a liquid stream is used, it can be brought, in particular in the liquid state, to a pressure above the inlet pressure of the first reaction zone, thereby eliminating the need for a gas compressor. In all cases, including evaporation using waste heat from the process, a pressure level below the critical pressure of carbon dioxide (approximately 74 bar) is advantageously maintained.

[0029] In embodiments of the invention, the reactor system can be operated at a pressure level of 40 to 90 bar, in particular 50 to 80 bar, absolute pressure and / or the first reaction zone and the second reaction zone can be operated with an inlet temperature level of 190 to 260 °C, in particular 190 to 230 °C and / or the first reaction zone can be operated with an outlet temperature level of 260 to 300 °C, in particular 260 to 280 °C, and / or the second reaction zone can be operated with an outlet temperature level below an outlet temperature level of the first reaction zone.

[0030] Corresponding pressure and temperature values ​​can be achieved in a particularly advantageous manner by the present invention.

[0031] In embodiments of the invention, the reactor system can furthermore be operated with an hourly gas space velocity of 2,000 to 12,000 h -1 , especially between 2,000 and 6,000 h -1 , operated.

[0032] In principle, one advantage of a high hourly gas space velocity is the higher space-time yield, but this typically results in a shorter catalyst lifetime. Conversely, with a low hourly gas space velocity, lower space-time yields are to be expected with a longer lifetime. A disadvantage of particularly low hourly gas space velocities is increasing trace components. The hourly gas space velocity to be selected is therefore a compromise between space-time yield and catalyst lifetime (as well as the formation of trace components that increase the purification effort). Depending on the application, different hourly gas space velocities can be selected. With a constant feed, optimization can be carried out within the specified range. This is particularly true in the range of 2,000 to 6,000 h -1. When using a flexible feed, however, hourly gas space velocities between 2,000 and 10,000 h -1 A "flexible feed" or feed is understood here to mean, in particular, a feed with a fluctuating hydrogen content, for example, with a fluctuation of more than 10 percentage points around an average value. Such fluctuation can occur, in particular, when hydrogen originates from an electrolysis plant with fluctuating power availability and possibly without a hydrogen buffer. In such a case, a flexible recirculation blower and a liquid storage unit can be used upstream of a crude methanol purification process in one or more columns.

[0033] In embodiments of the invention, the reactor system can be operated such that the ratio of hydrogen to carbon dioxide at the inlet to the first reaction zone is between 3 and 10, in particular between 7 and 9, and / or the ratio of hydrogen to carbon dioxide at the inlet to the second reaction zone is between 3 and 10, in particular between 7 and 9, and the hydrogen used to the carbon dioxide used is in a ratio of 2.8 to 3.3, in particular from 2.9 to 3.1. The composition of the recycle stream is predetermined by the ratios in the corresponding feed streams. Using more hydrogen reduces catalyst aging because the carbon dioxide and water partial pressures are reduced across the entire catalyst bed. Both components are largely responsible for aging. In addition, lower partial pressures of carbon dioxide are to be expected, and thus lower by-product formation.This also results in lower carbon losses due to purge streams. A disadvantage of using more hydrogen is the higher energy consumption for recycling compressors.

[0034] At low hydrogen to carbon dioxide ratios (in the range of 3 to 5), maximum space-time yield and lower compressor performance can be achieved. Within the scope of the present invention, values ​​of 5 to 10, particularly preferably 6 to 10, were found to be particularly advantageous, as this allows for a simpler column setup with lower trace components. The ratio is particularly influenced by carbon dioxide losses (e.g., during stripping) and by the hydrogen recycle rates (e.g., the use of pressure swing adsorption or other separation to recover hydrogen in a purge stream).

[0035] In one embodiment of the present invention, the liquid phase from the phase separation is fed at least in part into a separation unit, in particular a rectification column, wherein a liquid water stream is formed using a bottoms liquid from the separation unit, which may predominantly contain water, and a liquid methanol stream and a gaseous residual gas stream, which predominantly or exclusively comprises components boiling lower than methanol, are formed using one or more gases or gas mixtures withdrawn in an upper region of the separation unit. The methanol stream can be formed in particular using one or more separation stages above the top of the column, wherein gases or gas mixtures withdrawn in one or more separation stages are used. Furthermore, in this embodiment, a liquid side stream is withdrawn from the separation unit, which predominantly or exclusively contains components boiling between water and methanol, in particular ethanol.Regarding the term "predominantly," please refer to the above explanations. The terms "water stream" or "methanol stream" should therefore also refer to mixtures rich in corresponding components.A plant for the catalytic production of methanol, which has a reactor system with a first reaction zone and a second reaction zone, is also the subject of the present invention, wherein the first reaction zone and the second reaction zone are each set up for adiabatic operation and each have a catalytic reaction zone, and wherein the plant has means which are set up to transfer at least a portion of a gas mixture flowing out of the first reaction zone into the second reaction zone, to feed a first feed stream into the reactor system at a first temperature level upstream of the first reaction zone and to feed a second feed stream into the reactor system at a second temperature level between the first reaction zone and the second reaction zone, wherein the first temperature range is above the second temperature range.

[0036] For further features and advantages of a corresponding system, reference is expressly made to the above explanations of the method according to the invention and its embodiments, for the implementation of which a corresponding system can be set up.

[0037] To summarize, the advantages of the present invention include, in particular, low production costs. For example, if suitable electrolysis conditions are selected, a hydrogen compressor is not required and / or a dryer can be omitted. In embodiments of the invention, only one separation unit is required. The reactor system requires no cooling and no corresponding design, for example, in the form of a tube-bundle reactor. No installation of a reverse water-gas shift is required, and the use of complex heat exchangers, double shells, and intermediate separators can be dispensed with.

[0038] The intermediate feed provided within the scope of the invention leads to better reaction equilibria compared to a reactor system without such. However, due to the lower temperature in the second reaction zone, the conversion is comparable to that in a cooled reactor system. The temperature reduction also leads to reduced carbon monoxide formation. Since carbon monoxide contributes significantly to the formation of by-products, this is also reduced by the intermediate feed. Further embodiments of the invention can comprise the thermal or material use of the purge gas or a residual gas from the separation unit, for example in a fired heater, a catalytic unit or a high-temperature fuel cell. A (chemical) heat pump system can be used to recover heat generated in a low-temperature electrolysis at a low temperature level or from the reactor system (after, if necessary,other cooling steps), e.g. for a bottom evaporator of the separation unit.

[0039] Hydrogen can also, in principle, come from external sources. Carbon dioxide, for example, can be extracted through carbon capture. The resulting methanol can be further purified and / or used for fuel purposes or for conversion into fuel components such as methyl tert-butyl ether.

[0040] The invention will be further explained below with reference to the accompanying drawings, which illustrate embodiments of the present invention.

[0041] Short description of the drawings

[0042] Figure 1 illustrates a method according to an embodiment of the invention.

[0043] Figure 2 illustrates a method according to an embodiment of the invention.

[0044] Figure 3 illustrates a method according to an embodiment of the invention.

[0045] In the figures, structurally and / or functionally corresponding components are indicated with identical reference symbols and are not explained repeatedly for the sake of clarity.

[0046] In Figures 1 to 3, methods according to embodiments of the invention are illustrated using simplified process flow diagrams and are each designated overall by 100, 200, and 300, respectively. The following explanations relate to corresponding devices in the same way, with process steps and device components or apparatuses also being partially indicated with identical reference numerals.

[0047] Figures 1 to 3 each show a reactor system 10 having a first reaction zone 11 and a second reaction zone 12, wherein the first reaction zone 11 and the second reaction zone 12 are operated adiabatically. At least a portion of a gas mixture flowing out of the first reaction zone 11 is transferred to the second reaction zone 12. In each case, a first feed stream 1 is fed into the reactor system 10 at a first temperature level upstream of the first reaction zone 11, and a second feed stream is fed into the reactor system 10 at a second temperature level between the first reaction zone 11 and the second reaction zone 12. The first temperature range lies above the second temperature range.

[0048] In all embodiments 100, 200, and 300, a gas mixture 3 flowing out of the second reaction zone 12 is first passed through a heat exchanger 15 and cooled therein against at least a portion of the first feed stream 1. A bypass (not specifically designated) can be used to adjust the temperature of the first feed stream. The gas mixture 3 is fed into a further heat exchanger 16 for further cooling and, to obtain a gas fraction and a liquid fraction, is subjected to phase separation 13 in a suitable container. Using a portion of the gas fraction, a recycle stream R is formed, which is brought to a feed pressure in the reactor system 10 or the first reaction zone 11 by means of a compressor or blower. The first feed stream is therefore formed (at least) using the recycle stream in embodiments 100, 200, and 300.In the example shown, a purge stream P is also discharged from the gas phase.

[0049] In the embodiments 100 and 200 according to Figures 1 and 2, the first feed stream 1 is formed using a fresh feed stream containing hydrogen H2. In the embodiment 100 according to Figure 1, the first feed stream 1 is formed using the hydrogen-containing fresh feed stream H2 and the recycle stream R. In the embodiment 200 according to Figure 2, however, the hydrogen-containing fresh feed stream H2 is fed into the phase separation 13 as stripping gas, and therefore at least a portion of the hydrogen in the hydrogen-containing fresh feed stream is converted into the gas fraction in the phase separation 13 and from there into the recycle stream. In both cases, the first feed stream is formed using a first portion of a fresh feed stream CO2 containing carbon dioxide, and the second feed stream is formed using a second portion of the fresh feed stream CO2 containing carbon dioxide.represents this part.

[0050] Deviating from this, in the embodiment 300 according to Figure 3, only the recycle stream R is used to form the first feed stream 1, while the second feed stream 2 is a fresh feed stream containing hydrogen and carbon dioxide or is formed from a hydrogen-containing fresh feed stream H2 and a carbon dioxide-containing fresh feed stream CO2.

[0051] The figures illustrate that the liquid phase from the phase separation 13 is fed into a separation unit 14, in particular a rectification column, to which the heat exchangers (heaters or coolers) 17 and 18 and a separator 19 are assigned. Using a bottoms liquid from the separation unit 14, a water stream H2O is obtained, whereas using a gas from an upper region of the separation unit 14, a liquid methanol stream MeOH and a residual gas stream L consisting of components boiling lower than methanol are obtained. As illustrated in Figure 3, but fundamentally possible in all illustrated embodiments, a side stream S is withdrawn from the separation unit 14, which side stream S may contain components boiling between water and methanol, in particular ethanol.

Claims

Patent claims 1. A process (100, 200, 300) for the catalytic production of methanol, wherein a reactor system (10) with a first reaction zone (11) and a second reaction zone (12) is used, wherein the first reaction zone (11) and the second reaction zone (12) are operated adiabatically, wherein at least a part of a gas mixture flowing out of the first reaction zone (11) is transferred to the second reaction zone (12), wherein a first feed stream is fed upstream of the first reaction zone (11) at a first temperature level, and wherein a second feed stream is fed into the reactor system (10) at a second temperature level between the first reaction zone (11) and the second reaction zone (12), and wherein the first temperature range is above the second temperature range.

2. Method (100, 200, 300) according to claim 1, wherein at least a part of a gas mixture flowing out of the second reaction zone (12) is subjected to phase separation (13) to obtain a gas fraction and a liquid fraction, wherein a recirculation stream is formed using at least a part of the gas fraction, and wherein the first input stream is formed using the recirculation stream.

3. Method (100, 200, 300) according to claim 2, wherein at least a part of the gas mixture flowing out of the second reaction zone (12) is cooled against at least a part of the first input stream.

4. Method (100, 200) according to one of claims 2 or 3, wherein the first feed stream is formed using a fresh feed stream containing hydrogen.

5. Method (100) according to claim 4, wherein the first feed stream is formed using the fresh feed stream containing hydrogen and the recirculation stream.

6. Method (200) according to claim 4, wherein the fresh feed stream containing hydrogen is fed into the phase separation (13) and wherein at least part of the hydrogen in the hydrogen-containing fresh feed stream is transferred in the phase separation (13) into the gas fraction and from there into the return stream.

7. Method (100, 200) according to any one of claims 2 to 6, wherein the first feed stream is formed using a first part of a fresh feed stream containing carbon dioxide, and wherein the second feed stream is formed using a second part of the fresh feed stream containing carbon dioxide.

8. Method (300) according to one of claims 2 or 3, wherein only the recirculated current is used to form the first input stream and wherein the second input stream is a fresh input stream containing hydrogen and carbon dioxide or is formed from a fresh input stream containing hydrogen and a fresh input stream containing carbon dioxide.

9. Method (100, 200, 300) according to any one of claims 4 to 8, wherein the fresh input current containing hydrogen is provided using an electrolysis device configured as a proton or anion exchange electrolysis device or comprising a solid oxide electrolysis cell.

10. Method (100, 200, 300) according to claim 9, wherein the fresh input stream containing hydrogen is taken from the electrolysis device at an inlet pressure of the first reaction zone (11) and / or as a moist mass stream.

11. Method (100, 200, 300) according to one of claims 7 or 8, wherein the fresh feed stream containing carbon dioxide is provided as a liquid stream, which is used in liquid form or evaporated using waste heat from the method (100, 200, 300).

12. Method (100, 200, 300) according to one of the preceding claims, wherein the reactor system (10) is operated at a pressure level of 40 to 90 bar or 50 to 80 bar absolute pressure and / or wherein the first reaction zone (11) and the second reaction zone (12) are operated at an inlet temperature level of 190 to 260 °C or 190 to 230 °C and / or in which the first reaction zone (11) is operated with an outlet temperature level of 260 to 300 °C or 260 to 280 °C and / or in which the second reaction zone (12) is operated with an outlet temperature level below that of the first reaction zone (11). Method (100, 200, 300) according to one of the preceding claims, in which the reactor system (10) operates with an hourly gas space velocity of 2,000 to 12,000 h⁻¹, based on the total volume of the reactor system (10) and the total amount of gas fed into the reactor system (10). -1 or 2,000 to 10,000 hours -1is operated. Method (100, 200, 300) according to one of the preceding claims, wherein the reactor system (10) is operated such that the ratio of hydrogen to carbon dioxide at the inlet of the first reaction zone (11) is 3 to 10 or 4 to 9 and / or at the inlet of the second reaction zone (12) is 3 to 10 or 4 to 9 and / or in the second feed stream is 2.8 to 3.3 or 2.9 to 3.1.A plant for the catalytic production of methanol, comprising a reactor system (10) with a first reaction zone (11) and a second reaction zone (12), wherein the first reaction zone (11) and the second reaction zone (12) are each configured for adiabatic operation, and wherein the plant comprises means configured to transfer at least a portion of a gas mixture flowing out of the first reaction zone (11) into the second reaction zone (12), to feed a first feed stream into the reactor system (10) at a first temperature level upstream of the first reaction zone (11), and to feed a second feed stream into the reactor system (10) at a second temperature level between the first reaction zone (11) and the second reaction zone (12), wherein the first temperature range is above the second temperature range.

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