Improved catalyst recovery process in hydrocarbon synthesis

Abstract

A method for hydrocarbon synthesis is disclosed. The method comprises performing a first reaction in the form of a reaction of methanol over a zeolite catalyst; and performing a second reaction in the form of a regeneration of particles of the zeolite catalyst comprising coke and / or coke precursors, by oxidation substantially in the absence of nitrogen. Furthermore, a system for carrying out the method is disclosed.

Description

[0001] 2024 PF00777

[0002] 1

[0003] Description

[0004] Improved catalyst recovery process in hydrocarbon synthesis

[0005] The present invention relates to hydrocarbon synthesis processes, in particular methanol-based hydrocarbon synthesis processes. The invention also relates to catalyst recovery processes in such synthesis processes.

[0006] The production of renewable fuels includes, among other things, the use of methanol-to-gasoline (MTG) or methanol-to-oleic (MTO) reactors. MTG and MTO are processes that can be carried out in fluidized bed and fixed-bed reactors. According to current technology, the methanol used in the production of renewable fuels is generated from synthesis gas in an upstream step.

[0007] In MTG, MTO, or MTP synthesis, methanol is reacted over zeolite catalysts. Hydrocarbons and water vapor are produced as the main products of the reaction, along with typically polycyclic aromatic hydrocarbons. These polycyclic aromatic hydrocarbons are also known as coke precursors.

[0008] Under the operating conditions of MTG and MTO / MTP reactors, these polycyclic aromatic hydrocarbons produce coke. The resulting coke comprises mixtures of highly carbon-containing components, which reduce the selectivity and activity of the zeolite catalyst. In particular, the coke accumulates in the pores of the zeolite catalysts and can significantly impair their free passage and activity. This leads to the gradual deactivation of the catalyst.

[0009] Therefore, the state of the art suggests continuously regenerating the zeolite catalyst. (State of the art 2024 PF00777)

[0010] 2

[0011] In this process, coke is converted into exhaust gases by combustion with air at a controlled temperature and thus removed from the pores of the catalyst. In state-of-the-art processes, coke formation corresponds to a yield of 2% to 5% based on the added methanol. In state-of-the-art processes, this carbon is lost as exhaust gas after combustion and is not available for further use.

[0012] This leads to losses of carbon components in hydrocarbon synthesis processes, particularly in the MTG and MTO / MTP processes. Such losses are especially undesirable when the methanol is produced from renewable CO2, as this is comparatively complex and expensive to obtain, meaning that such losses can significantly and negatively impact the economic viability of the process.

[0013] It is therefore an object of the invention to provide a methanol-based hydrocarbon synthesis process with reduced carbon losses and a corresponding system.

[0014] An optional object of the invention is to provide a methanol-based hydrocarbon synthesis process with improved catalyst recovery.

[0015] A solution to this problem is provided in the independent claims. Further advantageous embodiments of the invention are described in the dependent claims, the following description, and the figures.

[0016] A process for hydrocarbon synthesis is disclosed, comprising: carrying out a first reaction in the form of a reaction of methanol over a zeolite catalyst; and carrying out a second reaction in the form of a regeneration of particles of the zeolite catalyst, which contain coke and / or coke precursor, by oxidation essentially in the absence of nitrogen. 2024 PF00777

[0017] 3

[0018] The methanol can be supplied in gaseous form. The methanol can be produced in a methanol synthesis process. The methanol synthesis process can, in particular, involve the use of renewable CO2 as a reactant.

[0019] The zeolite catalyst in the reactor for

[0020] Hydrocarbon synthesis can be present, in particular, in the form of zeolite particles or grains.

[0021] For example, the zeolite catalysts ZSM-5 or SAPO-34 can be used.

[0022] Hydrocarbon synthesis can be part of an MTO process and / or an MTG process. Specifically, the products of hydrocarbon synthesis can be water and hydrocarbons.

[0023] The coke precursors can be polycyclic aromatic hydrocarbons. They can be byproducts of hydrocarbon synthesis. Coke can be produced from the coke precursors.

[0024] Oxidation, essentially in the absence of nitrogen, can include oxidation with oxygen. In particular, oxidation can occur in the absence of nitrogen. For example, oxidation can take place at a controlled temperature.

[0025] The disclosed process optionally and advantageously enables the regeneration of the zeolite catalyst essentially without the formation of nitrogen oxides (NOx), so that the carbon that has reacted to form coke and / or coke precursors remains available. In particular, the carbon that has reacted to form coke and / or coke precursors can be used as carbon dioxide and / or carbon monoxide in methanol synthesis, which can optionally and advantageously reduce the carbon requirement of the process. Furthermore, the oxidation of the second reaction can be carried out with a regeneration gas mixture, wherein the regeneration gas mixture contains oxygen and at least one

[0026] 4

[0027] It contains an inert material and is essentially free of nitrogen.

[0028] In the context of the disclosed process and system, “essentially in the absence of nitrogen” or “essentially free of nitrogen” can be understood to mean that the nitrogen volume fraction on the reactant side of the second reaction, in particular the nitrogen volume fraction in the regeneration gas mixture, is, for example, less than 1%, less than 0.5%, less than 0.1% or less than a value in the range of 0.01% to 1%.

[0029] In particular, at least one inert material can be used for temperature control.

[0030] At least one inert substance can be inert with respect to the reaction in the regenerator. Optionally, and advantageously, the inert substance cannot form any further compounds with the coke and / or the coke precursors in the second reaction that do not already occur during oxidation. For example, nitrogen cannot be considered an inert substance in this case, since nitrogen would be oxidized to nitrogen oxides under the given conditions.

[0031] This optionally and advantageously avoids the formation of nitrogen compounds, which preferably do not enter the feed stream of methanol synthesis, and allows the exhaust gas from regeneration to be used for further methanol synthesis without complex separation of nitrogen and / or nitrogen compounds.

[0032] The inert material can be or comprise carbon dioxide. Optionally, and advantageously, the carbon dioxide can be a product of regeneration and thus alternatively be used for further regeneration.

[0033] Furthermore, the process can include: venting exhaust gas from the second reaction, wherein the exhaust gas contains carbon dioxide; and using carbon dioxide from the exhaust gas in 2024 PF00777

[0034] 5

[0035] a methanol synthesis process, which supplies the first reaction with methanol. The exhaust gas can, for example, be treated in at least one further step before being fed into the methanol synthesis process.

[0036] In particular, the process can include the use of the exhaust gas without further afterburning, for example, if the methanol synthesis process is designed to use a mixture of carbon dioxide and carbon monoxide as a feedstock. This can optionally simplify the process, as fewer pieces of equipment and / or fewer process steps are required.

[0037] Furthermore, the process can include: separating catalyst particles from the exhaust gas using an electrostatic precipitator. This optionally allows remaining catalyst particles to be advantageously separated from the exhaust gas stream, thus preventing particle emissions into the environment or transport of the particles into downstream process steps, such as the methanol synthesis process or other catalytic processes.

[0038] Furthermore, the process can include: cooling the exhaust gas and / or separating water from the exhaust gas. In particular, cooling the exhaust gas and separating water from the cooled exhaust gas can be achieved in a single device, e.g., by cooling and aerosol separation. This can optionally and advantageously improve the equilibrium of the methanol synthesis process, so that more methanol is produced with each pass through the reactor.

[0039] Furthermore, the process can include: operating a steam generator with the exhaust gas. In particular, the process can include operating a heat exchanger with an attached steam generator using exhaust gases from the second reaction process. This allows, optionally and advantageously, the waste heat from regeneration to be used and the energy balance of the process to be improved. 2024 PF00777

[0040] 6

[0041] Furthermore, the process can include: afterburning the exhaust gas in an afterburner. This can optionally and advantageously reduce the carbon monoxide content of the exhaust gas and increase the carbon dioxide content, so that the process can also be implemented, for example, in plants designed for methanol synthesis using carbon dioxide as a feedstock and which tolerate little or no carbon monoxide in the reactant stream. In particular, the afterburner can be located upstream of the electrostatic precipitator. This can optionally and advantageously reduce the risk of explosion due to the presence of flammable carbon monoxide and rod particles in the electrostatic precipitator. The process can also include cooling the afterburned exhaust gas, separating water from the cooled afterburned exhaust gas, and removing excess oxygen from the afterburned exhaust gas.In this way, the exhaust gas of the regenerator can optionally and advantageously be converted essentially into carbon dioxide for feeding into the methanol synthesis process, and in particular the supply of oxygen to the methanol synthesis process can be avoided.

[0042] Oxygen removal can, in particular, involve cryogenic cooling of the afterburned exhaust gas. This cryogenic cooling can take place after cooling the exhaust gas and removing the water. This allows, advantageously, the oxygen to be separated and reused, especially when the exhaust gas has a comparatively high oxygen content.

[0043] Alternatively, oxygen separation can involve removing the oxygen through a catalytic reaction with hydrogen in a deoxygen catalyst. In the deoxygen catalyst, the oxygen can be separated from the carbon dioxide using hydrogen, for example, hydrogen from a water electrolysis process. This allows for optional separation even with a comparatively low oxygen content.

[0044] 7

[0045] The exhaust gas stream of the afterburner efficiently removes oxygen from the carbon dioxide. The DeOxo catalyst can, for example, contain platinum and / or palladium.

[0046] The oxygen can be obtained through water electrolysis. Therefore, when using renewable carbon dioxide, the process can be carried out entirely with renewable raw materials.

[0047] Furthermore, the method may include: providing at least two fixed-bed reactors, comprising a first and a second fixed-bed reactor, wherein the first and second fixed-bed reactors are set up in a reactor mode to carry out the first reaction and are set up in a regeneration mode to carry out the second reaction.

[0048] The first and second fixed-bed reactors can each be operated in reactor mode to carry out the first reaction. The first and second fixed-bed reactors can each be operated in regeneration mode to carry out the second reaction.

[0049] In addition, further fixed-bed reactors, in particular further first and second fixed-bed reactors, may be provided, each of which can be operated in reactor mode and in regeneration mode.

[0050] Furthermore, the procedure can include: operating the first fixed-bed reactor in reactor mode and operating the second fixed-bed reactor in regeneration mode.

[0051] For example, the first fixed-bed reactor can be operated in reactor mode while the second fixed-bed reactor is operated in regeneration mode.

[0052] Furthermore, the procedure can include: switching the mode of the first and / or second fixed-bed reactor between reactor mode and regeneration mode, so that the first 2024 PF00777

[0053] 8

[0054] fixed-bed reactor is operated in regeneration mode and / or so that the second fixed-bed reactor is operated in reactor mode.

[0055] For example, at a first time tl, the first reactor can be operated in reactor mode, while simultaneously the second reactor is operated in regeneration mode. Subsequently, a mode change can occur for the first and second reactors, so that at a second time t2, the first reactor is operated in regeneration mode, while simultaneously the second reactor is operated in reactor mode.

[0056] By means of the aforementioned further development, the first and second fixed-bed reactors can optionally and advantageously be operated regularly, in particular alternately, in regeneration mode. In this way, the process according to the disclosure or a corresponding plant can be operated continuously without performance losses due to catalyst degradation.

[0057] The mode-switching can also be applied to other fixed-bed reactors, especially other first and second fixed-bed reactors.

[0058] Furthermore, the following step can precede the mode-changing step: Determining whether a performance parameter of the first reaction falls below a threshold value, where the performance parameter is indicative of the state of the zeolite catalyst. In particular, the mode-changing step can be initiated as soon as it has been determined that the performance parameter falls below the threshold value.

[0059] This allows the system to detect when the catalyst needs regeneration to prevent process performance losses. This enables the reactor currently operating in regeneration mode to be switched to regeneration mode in a timely manner. Simultaneously, the reactor currently operating in regeneration mode can be switched back to normal reactor operation. 2024 PF00777

[0060] 9

[0061] so that regeneration occurs continuously while the process continues to be carried out productively.

[0062] Furthermore, the following steps can precede the mode-change step: purging with the inert material, in particular carbon dioxide, so that the methanol from the first reaction is displaced from the first fixed-bed reactor; and / or purging with the inert material, in particular carbon dioxide, so that the oxygen from the second reaction is displaced from the second fixed-bed reactor. This ensures that no explosive gas mixtures are present in the fixed-bed reactors or the corresponding inlet and outlet lines as a result of the mode-change step.

[0063] In principle, changing the function of fixed-bed reactors carries the risk of forming explosive gas mixtures. For example, if oxygen were introduced into the first fixed-bed reactor, in which methanol was previously catalytically converted into hydrocarbons during reactor operation, due to the mode change with the regeneration mixture, explosive methanol / hydrocarbon-oxygen mixtures could form. To prevent this, piping equipped with shut-off valves can be provided, enabling the purging of the first and second fixed-bed reactors as described above. The purging steps can include both the purging of the fixed-bed reactors themselves and the purging of the inlet and outlet piping of the fixed-bed reactors, specifically up to the respective shut-off valves.

[0064] Purging displaces the flammable substances to such an extent that no explosive mixtures remain in the fixed-bed reactors and the adjacent piping. Once displaced, the oxygen required for regeneration can be added along with the regeneration mixture. Purging can also be performed when switching back from regeneration mode to reactor mode, ensuring that the oxygen is present.

[0065] 10

[0066] is displaced before methanol is reintroduced into the fixed-bed reactor.

[0067] In addition to or as an alternative to providing at least two fixed-bed reactors, the procedure may include:

[0068] Providing a fluidized bed reactor and a regenerator, in particular wherein the fluidized bed reactor is set up to carry out the first reaction, and the regenerator is set up to carry out the second reaction.

[0069] The fluidized bed reactor can include a catalyst inlet for the zeolite catalyst. The fluidized bed reactor can also include a reactor discharge in which used catalyst is collected and through which it can be discharged from the fluidized bed reactor. To separate the zeolite catalyst and other solid reaction products from gaseous reaction products, the fluidized bed reactor can include one or more cyclones and / or other mechanical separation elements.

[0070] The regeneration of the particles of the zeolite catalyst can be carried out in the regenerator by oxidation with the regeneration gas mixture.

[0071] The regenerator can be designed as a fluidized bed reactor. The regenerator can include a catalyst inlet for receiving used catalyst from the reactor, in particular from the catalyst discharge of the reactor.

[0072] Furthermore, a system for

[0073] Hydrocarbon synthesis. Advantages, explanations, definitions and characteristics of the process may be applicable to the system accordingly.

[0074] The system comprises a container arrangement with a first and a second container. The first container is 2024 PF00777.

[0075] 11

[0076] The first vessel is set up to carry out a first reaction in the form of a reaction of methanol on a zeolite catalyst. The second vessel is set up to carry out a second reaction in the form of a regeneration of particles of the zeolite catalyst, which contain coke and / or coke precursor, by oxidation essentially in the absence of nitrogen.

[0077] In other words, the first container is set up to carry out the above procedure for the first reaction, and the second container is set up to carry out the above procedure for the second reaction.

[0078] Furthermore, the first vessel can be a reactor, in particular a fluidized bed reactor, with a reactor inlet, and the second vessel can be a regenerator with a regenerator feed. The system can be designed to supply methanol to the reactor via the reactor inlet and to supply catalyst particles from the reactor to the regenerator via the regenerator feed.

[0079] Alternatively, the first vessel can be a first fixed-bed reactor and the second vessel can be a second fixed-bed reactor, with the first and second fixed-bed reactors set up in a reactor mode to carry out the first reaction and in a regeneration mode to carry out the second reaction.

[0080] Thus, the first vessel can be the first fixed-bed reactor or the fluidized-bed reactor disclosed in connection with the process. Furthermore, the second vessel can be the second fixed-bed reactor or the regenerator disclosed in connection with the process.

[0081] Accordingly, the first and second fixed-bed reactors can be operated in the reactor mode described above and in the regeneration mode, whereby the first and second fixed-bed reactors can be switched between these modes by means of the mode switching described above.2024 PF00777

[0082] 12

[0083] Modes can be switched. The fluidized bed reactor can be operated permanently in the reactor mode described above. The regenerator can be operated permanently in the regeneration mode described above.

[0084] As shown above, oxidation can take place in the first / second fixed-bed reactor or in the regenerator in the absence of nitrogen.

[0085] The system can be designed to supply the regeneration gas mixture to the container in regeneration mode. The regeneration gas mixture can include oxygen and at least one inert substance and be essentially free of nitrogen. This allows the resulting exhaust gas to be optionally and advantageously reused as described above, thus reducing carbon loss.

[0086] The system can be configured, in particular, to regulate the temperature in the regeneration chamber by means of the supplied inert material. Specifically, the temperature and mass flow rate of the supplied inert material can be controlled and / or regulated. This optionally and advantageously prevents thermally induced changes in the catalyst.

[0087] Furthermore, the system can include an analysis unit and a control unit. The analysis unit can be configured to determine whether a performance parameter of the first reaction falls below a threshold value, where the performance parameter is indicative of the state of the zeolite catalyst.

[0088] The control unit can be configured to switch the mode of the first and / or second fixed-bed reactor between reactor mode and regeneration mode, so that the fixed-bed reactor currently in reactor mode is switched to regeneration mode, and / or so that the fixed-bed reactor currently in regeneration mode is switched to reactor mode. 2024 PF00777

[0089] 13

[0090] Furthermore, the container arrangement can have an inlet-side piping system designed to flush the container arrangement with an inert substance, in particular carbon dioxide, so that the methanol from the first reaction and / or the oxygen from the second reaction is displaced from the container arrangement.

[0091] The system can be configured to introduce exhaust gas from the tank in regeneration mode into the methanol synthesis process. In particular, the system can be configured to perform further (auxiliary) processes for treating the exhaust gas before introducing it into the methanol synthesis process, as described in the procedure.

[0092] In the context of the system, the term "methanol synthesis process" can in particular refer to a sub-system that is set up to carry out the methanol synthesis process.

[0093] The system may include an electrostatic precipitator. The electrostatic precipitator may be designed to separate catalyst particles from the exhaust gas of the vessel assembly, in particular the first / second fixed-bed reactor or the regenerator.

[0094] The system can include an afterburner for the afterburning of the exhaust gas from the regenerator. As described in the process, the system can alternatively be configured to introduce the exhaust gas into the methanol synthesis process without afterburning.

[0095] The system may include a steam generator for generating steam using heat from the exhaust gases from the vessel arrangement, in particular from the first / second fixed-bed reactor or from the regenerator.

[0096] The steam generator can have a heat exchanger to utilize the waste heat from the exhaust gases from the tank arrangement, in particular 2024 PF00777

[0097] 14

[0098] from the first / second fixed-bed reactor or from the regenerator. The steam generator may also be configured to use heat from the afterburner, provided the system includes the afterburner.

[0099] The system may include a cooling device for cooling the exhaust gas from the vessel arrangement, in particular from the first / second fixed-bed reactor or from the regenerator.

[0100] The system may, in particular, include a cooling device for cooling the exhaust gas from the vessel assembly, especially from the first / second fixed-bed reactor or from the regenerator, and for separating water from the exhaust gas. Such a cooling device may include an aerosol separator.

[0101] The system may include a device for separating oxygen from the exhaust gas. The oxygen separation device may be located between the afterburner and the methanol synthesis process.

[0102] The device for separating oxygen can be configured for cryogenic cooling. This can be particularly advantageous, as described above, when the afterburned exhaust gas contains a high proportion of oxygen.

[0103] The device for separating oxygen may also include a DeOxo catalyst for the catalytic reaction of oxygen with hydrogen.

[0104] Exemplary embodiments of the invention are explained in more detail by the following description of the figures. These schematically show:

[0105] Fig. 1 shows a methanol-based hydrocarbon synthesis process (MTG / MTO process) according to the state of the art, 2024 PF00777

[0106] 15

[0107] Fig. 2 shows an MTG / MTO process and a system according to a first embodiment of the invention,

[0108] Fig. 3 shows an MTG-MTO process and a system according to a second embodiment of the invention.

[0109] Fig. 4 shows an MTG / MTO process and a system according to a third embodiment of the invention, and

[0110] Figures 5-7 each show an alternative embodiment to the embodiments according to Figures 2-4.

[0111] Fig. 1 shows the methanol-based hydrocarbon synthesis process (MTG / MTO process) according to the state of the art, as well as a system for carrying it out. In the example of Fig.

[0112] 1. Methanol is produced via a methanol synthesis process 100. For the sake of clarity, the equipment used for this process is not shown. In the prior art, the methanol is produced, for example, from (non-renewable) methanol synthesis gas, i.e., CO + 2 H2.

[0113] The methanol is evaporated and heated via a methanol evaporator 110 and a feed heater 120 and fed into a reactor 10, which is designed for hydrocarbon synthesis.

[0114] The system includes a reactor 10. In reactor 10, methanol is converted to hydrocarbons, particularly products for the production of renewable kerosene or gasoline, using a zeolite catalyst, specifically zeolite catalyst particles. The zeolite catalyst is typically present in particle form in reactor 10. Reactor 10 is typically designed as a fluidized bed reactor.

[0115] In hydrocarbon synthesis, in addition to the desired hydrocarbons, polycyclic aromatic hydrocarbons, also known as coke precursors, are formed. These coke precursors then form coke, which, as described earlier, is deposited in the pores of the zeolite catalyst 2024 PF00777.

[0116] 16

[0117] deposits, thus reducing the selectivity and activity of the catalyst.

[0118] According to the prior art solution, the catalyst material is separated from the gaseous reaction products by means of cyclones in the upper part of the reactor. Typically, the reactor 10 is designed such that the gaseous water and the gaseous hydrocarbons leave the reactor 10, while the solids, in particular the catalyst and the coke, remain in the reactor 10 and are collected in a catalyst discharge device (not shown).

[0119] In particular, the catalyst particles are collected with the coke at cyclical intervals in the catalyst discharge and, after a complete reaction cycle, are replaced by regenerated catalyst from a catalyst input (not shown).

[0120] In the state of the art, the catalyst and the coke in the catalyst discharge are processed in a regenerator 20.

[0121] Typically, the catalyst and the coke are transported to the catalyst input of a regenerator 20 using a barrier gas.

[0122] In regenerator 20, the coke deposited on the catalyst is incompletely combusted using air and recirculated gas, according to the prior art. The recirculated gas typically consists primarily of carbon dioxide and nitrogen. Due to the incomplete combustion, the coke is mainly converted to carbon monoxide and carbon dioxide (CCR). Water and nitrogen oxides (NOx) are also formed. X by the combustion of coke and air. The regenerated catalyst is typically collected in a catalyst discharge of the regenerator 20 (not shown) and is available for a subsequent reaction cycle.

[0123] The circulating gas is used, among other things, to regulate the temperature in regenerator 20. In particular, 2024 PF00777

[0124] 17

[0125] The temperature in regenerator 10 is limited to temperatures up to 650 °C in order to preserve the properties of the catalyst. In particular, temperatures above 650 °C risk a breakdown of the catalyst structure, a loss of adsorption capacity and / or sintering of the catalyst.

[0126] The gaseous products of the incomplete combustion in the regenerator 20 are then completely oxidized in an afterburner with steam generator 210 using excess air to prevent the emission of carbon monoxide into the environment. The afterburning in the afterburner 210 is exothermic, so the heat generated can be used, for example, to produce steam.

[0127] In addition, remaining catalyst particles are separated from the exhaust gas of the regenerator 20 by an electrostatic precipitator 212 from the exhaust gas stream of the afterburner with the steam generator 210. Part of the exhaust gas stream is then released into the environment, and part is fed to a cooling unit for water separation 214. In the prior art, air (represented by the arrow "air") is then added to the cooled and dehydrated exhaust gas stream, subsequently compressed by a compressor 220, and fed back to the regenerator 20. This portion of the exhaust gas stream can thus serve as a recirculating gas and is used, as described above, for temperature control and as a fluidizing medium in the regenerator 20, which can also be configured as a fluidized bed reactor.

[0128] In the current state of the art, the exhaust gas stream released into the environment comprises carbon dioxide, which is formed from carbon atoms from the supplied methanol. Between 2% and 5% of the carbon atoms supplied by the methanol are lost as exhaust gas and are no longer available for further processing. This increases the carbon consumption and the greenhouse effect of the overall process. 2024 PF00777

[0129] 18

[0130] Fig. 2 shows a first embodiment of the method according to the invention and a corresponding system according to the invention.

[0131] The system comprises a vessel arrangement with a first and a second vessel, wherein the first vessel is configured to carry out a first reaction in the form of a reaction of methanol on a zeolite catalyst, and wherein the second vessel is configured to carry out a second reaction in the form of a regeneration of particles of the zeolite catalyst, which contain coke and / or coke precursor, by oxidation substantially in the absence of nitrogen.

[0132] The first container is provided in the form of a reactor 10 and the second container is provided in the form of a regenerator 20.

[0133] The process in Fig. 2 comprises a methanol synthesis process 100 which preferably uses regenerative CO2 and H2 from a water electrolysis process as starting materials.

[0134] The methanol produced in this way is fed into reactor 10 for hydrocarbon synthesis, analogous to the process shown in Fig. 1. The methanol is also vaporized and heated before being fed into reactor 10; these process steps are not shown for the sake of clarity.

[0135] In reactor 10, which can be designed as a fluidized bed reactor as in the prior art, methanol is converted to hydrocarbons and other products using a zeolite catalyst. As described above, this process involves the formation of polycyclic aromatic hydrocarbons and / or coke, referred to as coke precursors, which are deposited in the pores of the zeolite catalyst. Therefore, in the example shown in Figures 2-4, the catalyst used is replaced with regenerated catalyst either continuously or discontinuously, as in the prior art. 2024 PF00777

[0136] 19

[0137] For this purpose, the catalyst used, which comprises coke, is introduced into a regenerator 20 in the example shown in Figures 2-4. In the regenerator 20, the catalyst is regenerated using regeneration gas. According to the invention, the regeneration takes place essentially in the absence of nitrogen. The regeneration gas supplied to the regenerator 20 consists essentially of oxygen and carbon dioxide in the example shown in Figures 2-4. The regeneration gas is preferably mixed and / or supplied such that the air-fuel ratio in the regenerator is < 1, so that, in other words, incomplete combustion of the coke and / or the coke precursors occurs in the regenerator. The products of the incomplete combustion mainly comprise carbon monoxide and water; carbon dioxide can also be formed in small quantities. The supplied carbon dioxide acts primarily inertly and, in the example shown in Figures 2-4,2-4 hardly participate in the reaction.

[0138] The supplied CCf is used, among other things, for temperature regulation and / or temperature control of the regeneration in regenerator 20. As described above, the temperature in regenerator 20 is preferably limited to 650 °C to avoid changes in the catalyst. The regenerated catalyst remains essentially in regenerator 20 and is removed from regenerator 20 via the regenerator discharge, for example, to be returned to reactor 10. In the embodiment of the process according to the invention, the exhaust gas from the regeneration is now essentially free of nitrogen and nitrogen oxides (NOx). X ) . It can now, in principle, be used in the methanol synthesis process or in other processes that use carbon dioxide and / or carbon monoxide as feedstocks without the need for complex separation of nitrogen and / or nitrogen oxides.

[0139] In the example shown in Fig. 2, the exhaust gas is fed to a heat exchanger with a steam generator 210a, so that the [unclear] at 2024 PF00777

[0140] 20

[0141] The heat generated by incomplete combustion can be utilized. Furthermore, in the example shown in Fig. 2, the exhaust gas is fed to an electric dust separator 212 to remove any remaining catalyst particles from the exhaust gas and prevent them from entering downstream process steps.

[0142] In the example shown in Fig. 2, after the catalyst particles have been separated, the exhaust gas is fed to a cooling device 214, in which water is separated from the exhaust gas stream. The cooling device 214 can, for example, be coupled with an aerosol separator.

[0143] The remaining exhaust gas stream, as shown in Fig. 2, consists primarily of carbon dioxide and carbon monoxide. It can, for example, be fed into the methanol synthesis process 100. Optionally, a purge line 222 is connected downstream of the cooling device 214 for the removal of unwanted substances.

[0144] As schematically illustrated in Fig. 2, the regeneration gas can be provided from oxygen and carbon dioxide, which can be obtained in a plant for the production of renewable fuels from water electrolysis and a renewable carbon dioxide source. In contrast to the prior art process, this allows all essential reactants to be obtained from renewable sources, and the loss of carbon from renewable carbon dioxide during regeneration is avoided or at least reduced. This significantly increases the economic viability of renewable fuel production.Particularly when opening the electrostatic dust separator 212, it may be optionally advantageous to intermittently flood the electrostatic dust separator 212 with carbon dioxide to prevent the ingress of oxygen or to displace any oxygen that has entered, thus preventing combustion of oxygen and the supplied carbon monoxide. 2024 PF00777.

[0145] 21

[0146] Figures 3-4 each show a different embodiment of the process and the corresponding system according to the invention. These embodiments can optionally be advantageous for supplying a methanol synthesis process 100, which is designed to use carbon dioxide as feedstock, i.e., as reactant.

[0147] Therefore, in Figures 3-4j, an afterburner, in particular an afterburner with steam generator 210, is provided. In the example shown in the figures, this is arranged between the regenerator 20 and the electrostatic precipitator 212. In the afterburner, the exhaust gas from the regenerator 20 is oxidized with oxygen, in particular the carbon monoxide is oxidized to carbon dioxide. Preferably, at least a low concentration of oxygen is present during this process.

[0148] Excess oxygen. Afterburning typically takes place at temperatures between 900 °C and 1100 °C. Since the regenerated zeolite catalyst essentially remains in the regenerator 20, damage to the catalyst during afterburning is advantageously avoided.

[0149] In the examples shown in Figs. 3-4, the exhaust gas from the afterburner essentially comprises carbon dioxide, oxygen, water, and other catalyst particles, which are separated in the electrostatic precipitator 212. Feeding the electrostatic precipitator 212 with additional carbon dioxide is unnecessary, particularly in the example of Figs. 3-4, since the exhaust gas reaching the electrostatic precipitator 212 no longer contains flammable carbon monoxide.

[0150] Analogous to Fig. 2, the exhaust gas is also cooled in a cooling device 214 and the water is separated from the exhaust gas stream.

[0151] In the embodiment shown in Fig. 3, the oxygen remaining after afterburning is separated from the exhaust gas stream by cryogenic cooling 216 and can thus be reused. The cryogenic cooling can be 2024 PF00777

[0152] 22

[0153] This can be particularly advantageous if the excess oxygen during afterburning is comparatively large and, accordingly, the oxygen content in the exhaust gas stream after afterburning is correspondingly higher.

[0154] In the embodiment shown in Fig. 4, after cooling and removal of the water from the exhaust gas stream by a DeOxo catalyst 218, the remaining oxygen is converted to water by catalytic reaction with hydrogen, which is separated from the carbon dioxide.

[0155] In the embodiments shown in Figs. 3-4, an exhaust gas stream from the regeneration process is thus supplied with a high

[0156] Carbon dioxide concentration, in particular essentially carbon dioxide, was returned to the methanol synthesis process 100.

[0157] Prior to the recirculation, in the embodiments of Fig. 2-4 in the methanol synthesis process 100, a buffer tank (not shown) can be arranged to store the carbon dioxide and to provide a continuous carbon dioxide stream.

[0158] Figures 5-7 show further embodiments of the method and a corresponding system according to the invention. The embodiment shown in Figures 5-7 corresponds to the embodiment according to Figures 2-4 with the following differences.

[0159] A fixed-bed reactor vessel arrangement 8 (shown in Fig. 5-7 as a dashed outline 8) comprises a first vessel in the form of a first fixed-bed reactor 11 and a second vessel in the form of a second fixed-bed reactor 21 together with inlet and outlet piping 12, 14 as well as a control unit and an analysis unit (not shown).

[0160] The first 11 and second 21 fixed-bed reactors can each be operated in a reactor mode and a regeneration mode. In reactor mode, the fixed-bed reactors 11 and 212024 PF00777 are...

[0161] 23

[0162] The reactors are set up to carry out the first reaction. In regeneration mode, fixed-bed reactors 11 and 21 are set up to carry out the second reaction.

[0163] The fixed-bed reactor vessel assembly 8 has piping with inlet-side piping 12 and outlet-side piping 14. The piping is configured for purging the vessel assembly with the inert material, so that the methanol from the first reaction and / or the oxygen from the second reaction is displaced from the vessel assembly. For this purpose, the piping can, for example, include an arrangement of shut-off valves, as shown in the figure.

[0164] The system also includes the analysis unit and the control unit (not shown). The analysis unit is configured to determine whether a performance parameter of the first reaction falls below a threshold, where the performance parameter is indicative of the state of the zeolite catalyst. The control unit is configured to switch the mode of the first and / or second fixed-bed reactor between reactor mode and regeneration mode.

[0165] For example, the first fixed-bed reactor 11 can be in reactor mode while the second fixed-bed reactor 21 is simultaneously in regeneration mode. As soon as the analysis unit determines that a performance parameter of the second reaction, in this case of the second fixed-bed reactor 21, falls below the threshold, the control unit first initiates a purging of the piping and the fixed-bed reactors 11 and 21 with the inert substance and then the mode change.

[0166] The performance parameter and the corresponding threshold can, for example, relate to the selectivity and / or activity of the zeolite catalyst. Furthermore, the performance parameter and the corresponding threshold can relate to a pressure drop or a temperature profile of the fixed-bed reactor in reactor mode. Thus, the performance parameter and the corresponding threshold 2024 PF00777

[0167] 24

[0168] be indicative of the performance of the fixed-bed reactor in reactor mode or of the condition of its zeolite catalyst.

[0169] Once the control unit has initiated the mode change, the first fixed-bed reactor 11 is switched to regeneration mode and the second fixed-bed reactor 21 is switched to reactor mode. Since the fixed-bed reactors and the piping were previously purged with the inert substance, no explosive gas mixtures form in the system during the mode change.

[0170] Optionally, the fixed-bed reactor vessel arrangement can include 8 additional first fixed-bed reactors 11 and / or additional second fixed-bed reactors 21. Thus, a large number of fixed-bed reactors can be arranged and operated in parallel. A first subset can be operated in reactor mode, while a second subset can be operated simultaneously in regeneration mode. The first and second subsets can be selected during the design of the

[0171] The system / process can be defined depending on the duration of the regeneration periods. The first and second subsets can also be adjusted variably during system operation.

[0172] For example, catalyst deactivation in fixed-bed reactors operating in reactor mode may proceed more slowly than catalyst regeneration in fixed-bed reactors operating in regeneration mode. In this case, more fixed-bed reactors can be operated in reactor mode than in regeneration mode.

[0173] Apart from the different fixed-bed reactor vessel arrangement 8 described above, the embodiment of Fig. 5 corresponds to that of Fig. 2, the embodiment of Fig. 6 to that of Fig. 3, and the embodiment of Fig. 7 to that of Fig. 4. For clarity, the fixed-bed reactor vessel arrangement 8 of Fig. 5 is shown in Figures 6 and 7 only by means of the dashed outline 8.

Claims

2024 PF00777 25 Patent claims 1. Process for hydrocarbon synthesis, comprising - Carrying out a first reaction in the form of a reaction of methanol on a zeolite catalyst; and - Carrying out a second reaction in the form of regeneration of particles of the zeolite catalyst, which contain coke and / or coke precursor, by oxidation essentially in the absence of nitrogen.

2. Method according to claim 1, wherein the oxidation of the second reaction is carried out with a regeneration gas mixture, wherein the regeneration gas mixture contains oxygen and an inert substance and is substantially free of nitrogen, wherein in particular the inert substance is used for temperature control, and wherein in particular the oxygen of the regeneration gas mixture is obtained by water electrolysis.

3. The method of claim 2, wherein the inert material comprises carbon dioxide or is carbon dioxide.

4. Method according to any one of the preceding claims, comprising: - Discharge of exhaust gas from the second reaction, the exhaust gas containing carbon dioxide; - Using carbon dioxide from the exhaust gas in a methanol synthesis process, which supplies the first reaction with methanol.

5. The method of claim 4, comprising: - Separation of catalyst particles from the exhaust gas using an electrostatic dust separator (212 ) ; - Cooling the exhaust gas and / or separating water from the exhaust gas; - Operating a steam generator with the exhaust gas; and / or 2024 PF00777 26 - Afterburning of the exhaust gas in an afterburning system ( 210 ) , in particular wherein the afterburning system is arranged upstream of the electric dust separator ( 212 ).

6. Method according to one of the preceding claims, comprising: - Providing at least two fixed-bed reactors ( 11 , 21 ) comprising a first ( 11 ) and a second ( 21 ) fixed-bed reactor, wherein the first ( 11 ) and second ( 21 ) fixed-bed reactor are set up in a reactor mode to carry out the first reaction and are set up in a regeneration mode to carry out the second reaction .

7. Method according to claim 6, comprising: - Operating the first fixed-bed reactor ( 11 ) in reactor mode and operating the second fixed-bed reactor ( 21 ) in regeneration mode; and - Switching the mode of the first (11) and / or second (21) fixed-bed reactor between reactor mode and regeneration mode, so that the first fixed-bed reactor (11) is operated in regeneration mode and / or soda ss the second fixed-bed reactor ( 21 ) is operated in reactor mode .

8. Method according to claim 7, wherein the mode-changing step is preceded by the following steps: - Determine whether a performance parameter of the first reaction falls below a threshold value, where the performance parameter is indicative of the state of the zeolite catalyst; and - Rinsing with an inert substance, especially Carbon dioxide, so that the methanol from the first reaction is displaced from the first fixed-bed reactor (11); and / or - rinsing with an inert substance, in particular Carbon dioxide, so that the oxygen from the second reaction is displaced from the second solid-bed reactor (21). 2024 PF00777 27 9. System for hydrocarbon synthesis, comprising a vessel arrangement ( 8 ) with a first and a second vessel, - wherein the first vessel is set up to carry out a first reaction in the form of a reaction of methanol on a zeolite catalyst, and - wherein the second vessel is set up to carry out a second reaction in the form of a regeneration of particles of the zeolite catalyst which contain coke and / or coke precursor, by oxidation essentially in the absence of nitrogen .

10. System according to claim 9, wherein the first container is a reactor (10), in particular a fluidized bed reactor, with a reactor inlet and wherein the second container is a regenerator (20) with a regenerator inlet, wherein the system is designed to supply methanol to the reactor ( 10 ) via the reactor inlet and to supply catalyst particles from the reactor to the regenerator (20 ) via the regenerator inlet.

11. System according to claim 9, wherein the first container is a first fixed-bed reactor ( 11 ) and the second container is a second fixed-bed reactor (21 ), wherein the first and second fixed-bed reactors are set up in a reactor mode to carry out the first reaction and are set up in a regeneration mode to carry out the second reaction.

12. System according to claim 11, comprising an analysis unit and a control unit, - wherein the analysis unit is configured to determine whether a performance parameter of the first reaction falls below a threshold, the performance parameter being indicative of the state of the zeolite catalyst; and - wherein the control unit is configured to switch the mode of the first (11) and / or second (21) fixed-bed reactor between reactor mode and regeneration mode, such that the im2024 PF00777 28 The fixed-bed reactor (11, 21) in reactor mode is switched to regeneration mode and / or the fixed-bed reactor (11, 21) in regeneration mode is switched to reactor mode.

13. System according to claim 11 or 12, wherein the container arrangement ( 8 ) has a piping ( 12 , 14 ) which is configured to flush the container arrangement ( 8 ) with an inert substance, in particular carbon dioxide, so that the methanol of the first reaction and / or the oxygen of the second reaction is displaced from the container arrangement.

14. System according to one of claims 9-13, wherein the system is configured to introduce exhaust gas from the container arrangement into a methanol synthesis process ( 100 ), and / or wherein the system comprises an electro-dust separator ( 212 ).

15. System according to one of claims 9-14, wherein the system comprises an afterburner for afterburning the exhaust gas from the container arrangement, or wherein the system is configured to introduce the exhaust gas into the methanol synthesis process (100) without afterburning.

16. System according to one of claims 9-15, wherein the system comprises a cooling device for cooling the exhaust gas from the container arrangement, in particular a cooling device for cooling the exhaust gas from the container arrangement and for separating water from the exhaust gas (214).

17. System according to one of claims 9-16, wherein the system comprises a device for separating oxygen from the exhaust gas (216, 218), wherein the device for separating oxygen is arranged between the afterburner and the methanol synthesis process (100), wherein the device for separating oxygen is configured in particular for cryogenic cooling (216), and / or comprises a DeOxo catalyst (218) for catalytic reaction with hydrogen.

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