Method for conducting reactions on preheated particles

Abstract

The present invention provides a method for conducting a reaction on preheated particles, comprising: (a) feeding particles (17) into a buffer vessel (3); (b) feeding the particles (17) from the buffer vessel (3) through a feed line (11) to a reactor (5); and (c) removing the particles (17) from the reactor (5); wherein the particles (17) are heated in the feed line (11).

Description

[Technical Field]

[0001] The present invention relates to a method for carrying out reactions on preheated particles. [Background technology]

[0002] The reaction with the preheated particles is a catalytic cracking reaction, such as vacuum gas oil (VGO) or fluid catalytic cracking (FCC) for producing fuels and liquefied petroleum gas (LPG) from long-chain hydrocarbons. In these reactions, the particles contain a catalyst for the fluid catalytic cracking reaction. Another type of reaction that can be carried out with preheated particles, which focuses on thermal activation of molecules, is pyrolysis.

[0003] These reactions are generally carried out at temperatures above 500°C, which can be achieved by heating the particles to a temperature at least corresponding to the reaction temperature. During such reactions, coke deposits on the solid particles and can be used to preheat the reactor-regenerator component particles by burning the coke deposits in the regenerator.

[0004] When a hydrocarbon feed is used that produces insufficient coke production, the temperature achieved by burning the coke in the regenerator will be too low, and the particles must be further preheated. For this purpose, for example, torch oil is added to the reaction feed where the required coke is formed. Furthermore, new processes for olefin production or pyrolysis applications are carried out at higher reaction temperatures, requiring higher particle temperatures that may be too high for the regenerator to handle. Therefore, it is necessary to buffer and regenerate the particles at a temperature below the reaction temperature and to provide additional heat between the regenerator and the reactor.

[0005] US2005 / 0003552A describes a test unit for studying particles in short contact time reactions between particles and reagents. The test unit comprises a buffer vessel for particles, a reactor, and a separator. The particles are stored and preheated in the buffer vessel. The preheated particles then flow into the reactor through a loading line that can be closed by a valve. The reactor is followed by a separator for separating the particles from the reaction products. However, the maximum temperature to which the catalyst can be preheated depends on the materials of the buffer vessel and the valve. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US2005 / 0003552A Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide a method for carrying out reactions on preheated particles that allows the particles to be fed to a reactor at a temperature above the temperature to which the particles can be preheated in a buffer vessel, and that optionally allows the catalyst contained in the particles to be regenerated at a lower temperature. [Means for solving the problem]

[0008] This object is achieved by a method for carrying out a reaction on preheated particles, the method comprising: (a) providing particles to a buffer vessel; and (b) feeding the particles from the buffer vessel to a reactor via a feed line; (c) removing the particles from the reactor; Including, Here, the particles are heated in the supply line.

[0009] Depending on the reaction to be carried out, the particles used in the present process may be, for example, catalysts containing particles. In this case, the particles may consist of catalytically active material or may contain catalytically active material on a support. In the case of fluid catalytic cracking, the particles may be, for example, composite materials containing a matrix and / or binder or zeolite, which may further contain rare earth metals as catalytically active materials. Suitable matrix and binder materials are, for example, silicon oxides or aluminum oxides, such as sand, silica, kaolin, or quartz.

[0010] For reactions that are carried out at high temperatures but do not require a catalyst, such as pyrolysis, the material of the particles is preferably selected so that the particles can be heated to the desired temperature and store heat, for example suitable materials are sand, silica, kaolin, quartz or silicon oxides or aluminum oxides such as zeolites.

[0011] By heating the particles in the feed line, it is possible to feed the particles to the reactor at a temperature higher than the temperature to which they can be preheated in the buffer vessel, and furthermore, it is possible to store the particles in the buffer vessel at a temperature that allows for catalyst regeneration.

[0012] The particles used in the reaction may be, for example, in powder form, or in granular or pellet form. To operate the process, it is necessary that the particles can be transported from the buffer vessel through a feed line to the reactor. For transport, the particles are usually fluidized, for example, by an inert gas. Thus, the form and type of particles depend on the reaction to be carried out in the reactor.

[0013] If the reaction is a cracking or pyrolysis reaction and coke is a by-product, coke typically deposits on the particles. Therefore, some of the heat required for the reaction can be provided by burning the coke. The additional heat required to heat the particles to the required temperature can be provided by any suitable heating means known to those skilled in the art. Such heating means can be, for example, an internal heater or an external heater. An internal heater can be, for example, a heating element such as a heating conductor. Furthermore, heat can also be provided by heating the walls of the feed line, for example, by an electric heating element surrounding the feed line or by conduction at high current and low voltage. Alternatively, the particles in the feed line can be heated by induction heating, as long as the particles or the material of the feed line are susceptible to induction.

[0014] The temperature to which the particles are heated in the supply line is preferably in the range of 400 to 1200° C., more preferably in the range of 500 to 1000° C., and particularly preferably in the range of 600 to 900° C. Heating the particles to such a temperature can enable, for example, an endothermic reaction such as a catalytic cracking reaction, particularly a fluid catalytic cracking reaction, or thermal cracking to be carried out in the reactor.

[0015] Preferably, a combustible and an oxidizer are added to heat the particles, and heat is supplied by combustion of the combustible and the oxidizer, which allows for uniform heating of the particles, particularly to a temperature that provides sufficient heat for the reaction without additional heating of the reactor.

[0016] To achieve such temperatures, the amount of combustible material added is preferably selected so that the specific heat output P / (m·ΔT) (where "P" is the heating power in watts, "m" is the amount of particles in kilograms, and "ΔT" is the intended temperature rise in Kelvin) is in the range of 5 to 50 W / (kg·K), more preferably in the range of 8 to 30 W / (kg·K), especially in the range of 10 to 25 W / (kg·K).

[0017] Furthermore, if such a temperature is required as the initiation temperature of an exothermic reaction, it may be necessary to provide sufficient heat to heat the reactants to such a temperature. However, in the case of an exothermic reaction, it is preferable to heat the particles using the heat released during the exothermic reaction, which has the advantage that no additional heat needs to be supplied to the method.

[0018] However, the process of the present invention is particularly useful for reactions carried out at temperatures in the range of 400-1000°C, for example catalytic cracking reactions such as fluid catalytic cracking (FCC) or high temperature thermal cracking applications.

[0019] The reactor used in the process of the present invention can be any reactor that allows for continuous reaction. Preferably, the reactor is a tubular reactor with entrained flow of particles, such as a riser or downflow reactor. Additionally, fluidized bed reactors operating in a reactor-regenerator configuration can benefit from additional preheating between the regenerator and the reactor.

[0020] Heating the particles to a temperature higher than the temperature at which the reaction is to be carried out allows the heated particles to provide all of the heat necessary to carry out the reaction, which has the added advantage of achieving a more uniform heat distribution within the reactor. Furthermore, for reactions that must be carried out in an inert atmosphere, especially an oxidant-free atmosphere, it is not possible to provide heat within the reactor by combustion, since the oxidant used in combustion also affects the reaction, and internal or external heaters are usually not sufficient to provide sufficient heat for such reactions.

[0021] To avoid feeding undesirable by-products from combustion to heat the particles into the reactor, it is preferable to use a combustible that can be completely converted to water, carbon monoxide, and carbon dioxide and does not form additional combustion products. Suitable combustibles are selected from the group consisting of, for example, hydrogen, methane, ethane, propane, and butane, and combinations thereof, such as dry gas (generally C1 and C2 hydrocarbons) or LPG (generally C3 and C4 hydrocarbons). The advantage of using combustibles that only form water, carbon monoxide, and carbon dioxide upon combustion is that these compounds are inert in the cracking reaction. Furthermore, hydrogen, methane, ethane, propane, and butane do not typically form coke if not completely combusted. In the case of catalytic reactions, this coke deposits on the catalyst, including the particles, which can reduce the catalyst's efficiency.

[0022] The oxidizing agent used in the combustion to heat the particles can be any suitable oxidizing agent that is utilized within the range of the explosion limit. In order to avoid the production of undesirable by-products, it is particularly preferred to use an oxygen-containing gas as the oxidizing agent, such as air, diluted air, oxygen-enriched air, oxygen, or a mixture of oxygen and an inert gas. It is particularly preferred to use oxygen as the oxidizing agent. By using oxygen as the oxidizing agent, any additional gas in the oxygen-containing gas does not need to be heated, and in particular, any additional gas that may affect the chemical reaction is not supplied to the reactor.

[0023] When a mixture of oxygen and an inert gas is used as the oxidizing agent, the inert gas is preferably nitrogen, argon, water vapor, or a mixture thereof.

[0024] Substoichiometric addition of the oxidizer is preferred, especially for reactions that must be carried out without additional oxygen to avoid the formation of by-products or that must not have additional oxygen for safety reasons. Substoichiometric addition of the oxidizer ensures that the oxidizer reacts completely with the combustibles during combustion. Therefore, no oxidizer is fed to the reactor. The amount of oxidizer added is preferably in the range of 10-100%, more preferably 30-90%, and especially 50-90%, where 100% means the stoichiometric amount of oxidizer for the combustion of the combustibles.

[0025] To avoid particle agglomeration and / or clogging in the feed lines, it is preferred to fluidize the particles by supplying a gas in the direction of particle flow to the feed lines. When the particles are heated by an external or internal heater, it is preferred that the gas be inert with respect to the reaction taking place in the reactor to avoid adverse effects on the reaction from gas that may be entrained by the particles.

[0026] When the particles are heated by combustion of added combustibles and oxidizers, it is particularly preferred that the combustibles and oxidizers are fed to the feed lines in gaseous form.

[0027] In the context of the present invention, the term "feed line" refers to a feed line for particles that are preheated in the feed line. The feed line is generally not directly connected to the reactor inlet, as the reactor inlet is connected to the reactant feed.

[0028] The temperature to which the particles are heated in the feed line depends on the chemical reaction in the reactor and therefore on the temperature at which this reaction takes place. If no additional heat can be supplied to the reactor or if the temperature distribution in the reactor is to be kept constant, the temperature of the particles must be high enough to provide the energy required to carry out the reaction. This is particularly important for endothermic reactions, which require the supply of heat to avoid the reaction stopping. On the other hand, for exothermic reactions, it is only important to provide the required starting temperature, since no additional heat is required after the reaction has started. Conversely, exothermic reactions usually require the dissipation of heat.

[0029] To continue the reaction, particles are removed from the reactor in the same amount as they are fed into the reactor by the feed line. The particle removal point and the feed line connection to the reactor are therefore preferably at opposite ends of the reactor. The particles removed from the reactor can either be discharged from the process or, preferably, recycled.

[0030] To reuse the particles, they are separated from the reaction product and preferably recycled to a buffer vessel after removal from the reactor, from which they then flow into the feed line where they can be heated and reused through the feed line to the reactor.

[0031] To reduce aging of the particles while they are buffered in the buffer vessel, it is preferable to buffer the particles at a temperature lower than the temperature of the particles in the reactor. In particular, when catalyst-containing particles are used, it is preferable to set the temperature in the buffer vessel so that the catalyst can be regenerated. If necessary, a regenerating medium can be added to the buffer vessel to improve catalyst regeneration. Such a regenerating medium depends on the type of catalyst used in the reaction and is well known to those skilled in the art. A typical regenerating medium is, for example, air.

[0032] If no regeneration medium is used, it is further advantageous to provide an inert atmosphere in the buffer vessel. Such an inert atmosphere ensures that the particles do not age in the buffer vessel. The inert atmosphere can be provided, for example, by flowing an inert gas, for example, nitrogen or a noble gas such as argon, into the buffer vessel. Particularly preferably, the inert gas is nitrogen.

[0033] In order to bring all catalyst-containing particles in the buffer vessel into contact with the regenerating medium, it is preferable to intimately mix the catalyst-containing particles with the regenerating medium. In the case of a gaseous regenerating medium, it is particularly preferable to feed the gaseous regenerating medium from below and to generate a fluidized bed in the buffer vessel by feeding the regenerating medium. In such a fluidized bed, all catalyst-containing particles come into contact with the regenerating medium.

[0034] If the particles do not need to be regenerated or only need to be buffered at a low temperature, the buffer vessel is set to a temperature that prevents particle aging within the buffer vessel without adding additional materials, or if the particles regenerate without adding additional materials, the temperature is set to a temperature that allows the particles to regenerate. The temperature at which aging is avoided and / or the particle regeneration temperature are also well known to those skilled in the art. Typically, the temperature of the particles within the buffer vessel is in the range of 400 to 850°C, more preferably in the range of 500 to 800°C, and particularly in the range of 650 to 750°C. Maintaining the temperature within the buffer vessel within this range has the additional advantage of minimizing the amount of heat that must be supplied to the particles in the feed line to achieve the required temperature at which the particles should be fed to the reactor. When heating is performed by combustion of combustibles and oxidizers, the amounts of combustibles and oxidizers can be minimized in this way, thereby minimizing the amount of impurities resulting from the combustion and fed to the reactor.

[0035] Another advantage of keeping the temperature within the above specified range is that the buffer vessel and the corresponding valve through which the particles are fed to the supply line can be made from standard materials such as steel, and there is no need to use special heat-resistant materials to achieve a satisfactory lifespan of the buffer vessel.

[0036] After removal from the reactor, the particles must be separated from the other media removed from the reactor, in particular from the reaction products and, if present, from unreacted reactants.

[0037] A separator can be used to separate the particles from other media. When the reaction is a catalytic cracking reaction, only the particles are solid, and all other media are gaseous. Therefore, a gas-solid separator can be used to separate the particles from other media. Such a gas-solid separator is, for example, a cyclone. Alternatively, it is possible to use a vessel into which the particles and the reaction medium are supplied. In the vessel, the particles can be collected at the bottom, and the gaseous medium can be removed from the top. However, to avoid the particles being removed together with the gaseous medium, it is preferable to use a gas-solid separator that removes solids from the gas, such as a cyclone.

[0038] The solids are removed from the gas-solids separator by suitable conveying means, such as a rotary feeder. The solids thus removed, including the solid particles, can then be recycled to a buffer vessel for particle reclamation and reuse. Alternatively, the solids can be removed from the process and disposed of.

[0039] It is further possible to recycle only a portion of the particles to the buffer vessel and remove the remaining solids from the process in order to remove impurities that may be deposited on the particles.

[0040] The gaseous reaction medium removed from the process can be used for further processes or, depending on the reaction carried out in the reactor and the reaction medium thus obtained, can be worked up.

[0041] In particular, in a further step, the reaction product obtained can be further processed, for example by separating the reaction product obtained from impurities, by-products and unreacted reagents.

[0042] The method is particularly suitable for use in a test unit. Such a test unit comprises a reactor connected by a supply line to a buffer vessel containing particles. The buffer vessel of such a test unit preferably has a particle intake capacity in the range of 0.15 to 15 L, more preferably in the range of 0.2 to 10 L. The particles used in the test unit preferably have a particle size in the range of 20 to 300 μm.

[0043] In such a test unit, the feed line for transporting particles from the buffer vessel to the reactor preferably has a length in the range of 0.3 to 5 m, particularly in the range of 0.5 to 2 m, and an internal diameter in the range of 0.2 to 2 cm, particularly in the range of 0.3 to 1.5 cm. The feed line is preferably arranged so that its longitudinal axis is at an angle in the range of 30° to 90° (preferably in the range of 40° to 70°) with respect to the horizontal. The inclination of the feed line allows for better control of the catalyst feed than a vertical arrangement. If the length of the feed line is 0.6 m or more, the feed line is preferably spiral in order to provide a space-saving configuration.

[0044] The reactor of the test unit is preferably a tubular reactor having a length in the range of 0.3 to 3 m, more preferably in the range of 0.5 to 2 m. The inner diameter of the tubular reactor is preferably in the range of 0.3 to 2 cm, more preferably in the range of 0.5 to 1.8 cm, particularly in the range of 0.6 to 1.5 cm, and the feed line preferably has a diameter smaller than that of the reactor.

[0045] To heat the particles within the feed line, it is preferred to use a heating device located directly adjacent to the exterior of the feed line.

[0046] Generally, the individual parts of the unit are separate from one another, and the buffer vessel and feed lines do not form an integral part of the reactor. The separate components can be connected by means known to those skilled in the art. The components can be connected, for example, by threaded connections or welding.

[0047] When the method is used in a test unit, it is further possible to analyze the reaction products by conventional analytical methods, such as chromatographic or spectroscopic methods, for example gas chromatography or infrared spectroscopy. Of course, any further analytical method for analyzing the reaction products can be used. Suitable methods for analyzing the reaction products are disclosed, for example, in US-A 2005 / 0003552.

[0048] Exemplary embodiments of the invention are illustrated in the accompanying drawings and described below. [Brief explanation of the drawings]

[0049] [Figure 1] FIG. 1 shows a laboratory test unit for operating the method of carrying out a reaction on preheated particles. [Figure 2] FIG. 1 shows an apparatus for operating the method of carrying out a reaction on preheated particles in a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0050] FIG. 1 is a test unit for operating the method of carrying out a reaction on preheated particles.

[0051] The test unit 1 for operating the method of carrying out a reaction with preheated particles in the gas phase comprises a buffer vessel 3 for the particles, a reactor 5 and a separator 7 for separating the reaction mixture from the solid particles.

[0052] To carry out a reaction in the reactor 5, liquid or gaseous reactants are fed to the reactor 5 via reactant feed 9. Furthermore, the buffer vessel 3 is connected to the reactor by a feed line 11. When the test unit is activated, at least one reactant is fed to the reactor 5 via reactant feed 9.

[0053] A suitable gas or liquid conveying device, such as a pump 13 or a compressor, can be used to ensure the supply of the at least one reactant to the reactor 5. The gas or liquid conveying device can be any pump or compressor capable of delivering the at least one reactant into the reactor. If the at least one reactant is preheated, a gas or liquid conveying device is typically used that can withstand the temperature of the at least one reactant flowing through the gas or liquid conveying device.

[0054] Valve 15 is also opened to feed particles into the reactor 5. By opening valve 15, particles 17 flow from buffer vessel 3 through feed line 11 into reactor 5.

[0055] 1 is a tubular reactor in which at least one reactant and particles flow cocurrently from top to bottom, and thus the flow of particles and at least one reactant within reactor 5 is supported by gravity.

[0056] According to the present invention, the particles are preheated in the feed line 11 to a temperature higher than the temperature of the reaction taking place in the reactor 5 before entering the reactor 5. Preheating the particles before entering the reactor 5 can provide, for example, the necessary energy to be used as the initiation energy for an exothermic reaction or to drive an endothermic reaction in the reactor 5. Any suitable heating means 19 can be used to heat the particles 17. A suitable heating means 19 is, for example, an internal heater such as a heating conductor. A suitable external heater is realized by heating the walls of the feed line 11, for example, by an electric heating element surrounding the feed line 11. Furthermore, the heating means 19 can also include induction heating of the particles in the feed line 11, which allows the particles or the feed line to be subjected to induction. To obtain particles that can be subjected to induction, it is possible, for example, to provide the particles with a magnetizable support. In addition to heating the particles by the heating means 19, it is also possible, and particularly preferred, to heat the particles by supplying a combustible and an oxidizer to the feed line 11. In the feed line 11, the combustible reacts with the oxidizer, thereby generating heat.

[0057] The temperature to which the particles are heated depends on the reaction carried out in reactor 5. Preferably, the particles are heated to a temperature 0 to 500°C higher than the temperature in the reactor, more preferably 100 to 400°C higher than the temperature in the reactor, and particularly 100 to 300°C higher than the temperature in the reactor. When the reaction is a fluid catalytic cracking reaction, the temperature to which the particles are heated is preferably in the range of 150 to 200°C higher than the temperature in the reactor.

[0058] After flowing through reactor 5, the gaseous reaction mixture and particles enter separator 7. In separator 7, the gaseous reaction mixture is separated from the solid particles. In the embodiment shown in FIG. 1, the solid particles are collected in separator 7, and the gaseous reaction products are removed via outlet line 21. The gaseous reaction products can then be transported to a unit for further processing, such as removing impurities from the reaction products and, if only a portion of at least one reactant has been converted, separating the products from unreacted reactants. Additionally, analyses can be performed to analyze the reaction products.

[0059] It is also possible to remove the particles collected in the separator. To do this, a valve 23 is provided which can be opened to remove the particles from the separator 7. Preferably, to remove the particles, an inert gas is flowed through the particles to form a fluidized bed, and the particles are removed from the top of the fluidized bed. A suitable inert gas is, for example, nitrogen.

[0060] After being removed from the separator, the particles are collected in a particle recovery device and can optionally be recycled externally. After being processed in the particle recovery device, the particles can be recycled to the buffer vessel 3 and reused.

[0061] As can be seen in Figure 1, the individual parts of the test unit 1 are separated from one another, and the buffer vessel 3 and the supply line 11 do not form an integral part of the reactor 5. The separated components can be connected by means known to those skilled in the art. The components may be connected by threaded connections or by welding. The term supply line 11 refers to the supply line 11 for preheated particles that are preheated in the particle supply line. The inlet of the reactor 5 is connected to the reactant supply 9, which supplies the reactants.

[0062] Preferably, the test unit 1 is used on a laboratory scale or on a small-scale test plant scale, and therefore the buffer vessel 3 preferably has a particle uptake capacity in the range of 0.15 to 15 liters, more preferably in the range of 0.2 to 10 liters.

[0063] The feed line 11 for transferring the particles from the buffer vessel 3 to the reactor 5 preferably has a length in the range of 0.3 to 5 m, more preferably in the range of 0.5 to 2 m. Preferably, the inner diameter of the feed line 11 is in the range of 0.2 to 2 cm, more preferably in the range of 0.3 to 1.5 cm. Heating of the particles in the feed line 11 is particularly preferably based on the use of a heating device arranged directly adjacent to the exterior of the feed line 11.

[0064] The reactor 5 preferably has a length in the range of 0.3 to 3 m, more preferably 0.5 to 2 m. The inner diameter of the reactor is preferably in the range of 0.3 to 2 cm, more preferably 0.5 to 1.8 cm, particularly 0.7 to 1.5 cm.

[0065] For carrying out the method according to the invention, it is preferred that the particles employed within the method have an average particle size in the range of 20 to 300 μm.

[0066] FIG. 2 shows an apparatus for operating the method of carrying out a reaction on preheated particles in a second embodiment.

[0067] The embodiment shown in Figure 2 differs from the embodiment of Figure 1, in particular in that the particles according to Figure 2 are circulated. Furthermore, the reactor 5 of the embodiment shown in Figure 2 is a riser reactor in which gas and particles flow from bottom to top against the direction of gravity. To operate the reactor of the embodiment of Figure 2, the velocities of the reactants and the resulting reaction mixture obtained by reaction in reactor 5 must be sufficiently high to transport the particles through the reactor 5.

[0068] The particles are fed into buffer vessel 3 and flow from there through feed line 11 to reactor 5. Buffer vessel 3 preferably also functions as a particle regenerator. In feed line 3, the particles are heated by suitable heating means, which may correspond to heating means 19 described above for the embodiment shown in FIG. 1 . However, particularly preferably, the particles are heated by feeding a combustible, such as methane, ethane, propane, butane, or hydrogen, and an oxidant, such as oxygen, via combustible feed line 27 to feed line 11. The particles are heated in the feed line by oxidation of the combustible. The amounts of combustible and oxidant are selected so as to avoid the total amount of oxidant reacting with the combustible in feed line 11 and feeding the oxidant to reactor 5, since, particularly in catalytic cracking reactions, the oxidant forms undesirable by-products, in particular carbon monoxide, which adversely affects the cracking reaction.

[0069] From reactor 5, the reaction mixture and particles flow into separator 7, which may also be called a "stripper." In separator 7, the reaction products are separated from the solid particles. To separate the particles from the reaction products, separator 7 may be, for example, a cyclone.

[0070] In the embodiment shown in FIG. 2, solid particles collect at the bottom of separator 7 and are transferred from separator 7 into buffer vessel 3 via connecting line 25. The temperature in buffer vessel 3 is lower than the reaction temperature to enable catalyst regeneration within buffer vessel 3. To ensure catalyst regeneration within buffer vessel 3, gas, such as air, can be added to buffer vessel 3 via gas supply line 29. The gas is preferably added via a suitable gas distributor 31 to create a fluidized bed within buffer vessel 3. This fluidized bed ensures that all catalyst particles come into contact with the gas. Furthermore, creating a fluidized bed helps to avoid particle agglomeration.

[0071] To maintain a constant pressure inside the buffer vessel 3, an exhaust line 33 is connected to the buffer vessel 3, through which the exhaust gases can be removed. If necessary, the exhaust gases can be treated and collected or released into the environment.

[0072] For particle circulation, the apparatus shown in Figure 1 is particularly useful as an experimental test unit, whereas the apparatus shown in Figure 2 is particularly suitable for use in industrial scale processes. [Explanation of symbols]

[0073] 1 test unit 3 Buffer container 5. Reactor 7 Separator 9. Reactant Supply 11 Supply Line 13 Pump 15 valves 17 particles 19 Heating means 21 Exit Line 23 Valve 25 connection lines 27 Combustible material supply line 29 Gas supply line 31 Gas distributor 33 Exhaust line

Claims

1. 1. A method for conducting a reaction on preheated particles, comprising: (a) providing particles (17) into a buffer vessel (3); (b) the particles (17) are fed from the buffer vessel (3) to the tubular reactor (5) through a feed line (11) that is not directly connected to the inlet of the tubular reactor (5), and the reactants are fed through a reactant feed (9) that is connected to the inlet of the reactor so that the particles (17) and the reactant flow are in co-current flow, and the buffer vessel (3) and the feed line (11) are not integral parts of the tubular reactor (5); and (c) removing the particles (17) from the tubular reactor (5); Including, The method wherein the particles (17) are heated in the supply line (11).

2. 2. The method of claim 1, wherein a combustible and an oxidizer are added to heat the particles (17), and the particles (17) are heated by combustion of the combustible and the oxidizer.

3. 3. The method of claim 2, wherein the combustible is selected from the group consisting of hydrogen, methane, ethane, propane, and butane.

4. 4. The method of claim 2 or 3, wherein the oxidizing agent is an oxygen-containing gas.

5. 5. The method of claim 4, wherein the oxygen-containing gas is air, diluted air, oxygen-enriched air, oxygen, or a mixture of oxygen and an inert gas.

6. The method according to any one of claims 2 to 5, wherein the oxidizing agent is added sub-stoichiometrically.

7. The method according to any one of claims 2 to 6, wherein the combustibles and the oxidizer are fed to the feed line (11) in counter-current flow relative to the flow direction of the particles.

8. The method according to any one of the preceding claims, wherein the particles (17) are heated in the supply line (11) to a temperature in the range of 400 to 1200°C.

9. The method according to any one of claims 1 to 8, wherein the particles (17) are recycled to the buffer vessel (3) after being removed from the tubular reactor (5).

10. The method according to any one of claims 1 to 9, wherein the particles (17) are regenerated in the buffer vessel (3).

11. The method according to any one of claims 1 to 10, wherein the temperature of the particles (17) in the buffer vessel (3) is in the range of 400 to 850°C.

12. The method according to any one of claims 1 to 11, wherein the reaction on the preheated particles is a catalytic cracking reaction.

13. The method according to any one of claims 1 to 11, wherein the reaction on the preheated particles is a pyrolysis reaction.

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