Fluidized bed reaction system, method for dry reforming of methane and carbon dioxide

Abstract

The present application relates to the technical fields of chemical synthesis, and discloses a fluidized bed reaction system and a dry reforming reaction method of methane and carbon dioxide, wherein the reaction system comprises a fluidized bed reactor, a regenerator and a heater; the bottom of the fluidized bed reactor is provided with a reaction raw material inlet, and the side of the fluidized bed reactor is provided with a reaction raw material nozzle for introducing the reaction raw material; the inlet of the regenerator is connected with the fluidized bed reactor, and is used for regenerating part of the spent catalyst in the fluidized bed reactor to obtain regenerated catalyst which is returned to the fluidized bed reactor; and the heater and the fluidized bed reactor form a circulation loop, and are used for heating part of the spent catalyst in the fluidized bed reactor and then returning the spent catalyst to the fluidized bed reactor.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, specifically to a fluidized bed reaction system and a method for dry reforming of methane and carbon dioxide. Background Technology

[0002] Carbon dioxide and methane are not only major greenhouse gases but also important carbon-containing resources. How to effectively utilize carbon dioxide has attracted widespread attention worldwide. The reforming of methane and carbon dioxide to produce syngas combines the comprehensive utilization of methane with the resource utilization of carbon dioxide, providing a technological route for the large-scale utilization of carbon and hydrogen sources. This aligns with the requirements of green chemical engineering, and the development of efficient carbon dioxide-methane reforming technology is of great significance for achieving carbon emission reduction in fossil energy utilization processes.

[0003] CN104587912A discloses a fluidized bed reactor and a fluidized bed reaction apparatus, as well as a method for methane steam reforming. A catalytically active foamed metal plate is installed in the reaction zone of the reactor, preventing the catalyst from undergoing frequent regeneration along with the adsorbent, thus reducing energy consumption during the regeneration process and avoiding unnecessary degradation of catalyst activity. However, the methane steam reforming process for producing syngas has drawbacks such as limited operational flexibility, high energy consumption, large and complex equipment, and high operating costs.

[0004] CN117049474A discloses a method for catalyzing the dry reforming reaction of methane and carbon dioxide using a nickel-based catalyst. The method uses electrostatic adsorption deposition to disperse active nickel species on a CaAl2O4 support. The catalyst can operate stably for more than 1100 hours at 750℃ without significant deactivation, agglomeration, or coking. However, it has many limitations on the types of catalyst support and active components, and lacks universality in production.

[0005] CN116510741A discloses an anti-coking methane dry reforming catalyst and its preparation and application method. The catalyst uses ZrO2-MgO as a mesoporous support to support a bimetallic Ni-Mo catalyst in a fixed-bed reactor, which can reduce catalyst coking, improve catalytic efficiency, and extend catalyst life. However, the aforementioned methane dry reforming reaction is carried out in a fixed-bed reactor, which cannot achieve simultaneous catalyst regeneration, resulting in poor reaction continuity.

[0006] Currently, conventional reaction systems suffer from problems such as poor long-term catalyst stability, easy carbon buildup in the reactor, and easy sintering of active metals, which limit the large-scale application and industrial promotion of methane and carbon dioxide dry reforming reaction technology. Therefore, it is necessary to have both reaction and regeneration functions to achieve long-term stable operation of the reaction and promote the large-scale application of methane and carbon dioxide utilization technologies. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of low conversion rate under pressure, easy catalyst deactivation due to carbon buildup, and uneven heat distribution in the bed of methane and carbon dioxide dry reforming reaction in the prior art. The invention provides a fluidized bed reaction system and a method for methane and carbon dioxide dry reforming reaction. The fluidized bed reaction system has a uniform internal temperature distribution, catalyst regeneration through circulation, and high syngas yield.

[0008] To achieve the above objectives, a first aspect of the present invention provides a fluidized bed reaction system, wherein the reaction system includes a fluidized bed reactor, a regenerator, and a heater;

[0009] The fluidized bed reactor has a reaction material inlet at the bottom and a reaction material nozzle on the side for introducing the reaction material.

[0010] The inlet of the regenerator is connected to the fluidized bed reactor and is used to regenerate part of the catalyst to be generated in the fluidized bed reactor, and the regenerated catalyst is returned to the fluidized bed reactor.

[0011] The heater forms a circulation loop with the fluidized bed reactor, and is used to heat a portion of the catalyst to be generated in the fluidized bed reactor before returning it to the fluidized bed reactor.

[0012] Preferably, the vertical distance between the position of the reaction material nozzle and the bottom of the fluidized bed reactor is no more than 0.5 times the height of the fluidized bed reactor, and more preferably it is located at 0.2-0.4 times the height of the fluidized bed reactor.

[0013] Preferably, the reaction system further includes a heating circulation inclined tube, which is connected to the outlet of the heater and the fluidized bed reactor.

[0014] Preferably, the connection port between the heating circulation inclined tube and the fluidized bed reactor is located above the nozzle, and the distance between it and the nearest nozzle is not less than 0.2 times the vertical height of the fluidized bed reactor.

[0015] A second aspect of the present invention provides a method for a dry reforming reaction of methane and carbon dioxide, wherein the method is carried out in the reaction system described in the first aspect, and the method includes:

[0016] (1) Raw materials containing methane and carbon dioxide are introduced into a fluidized bed reactor through a raw material inlet and a raw material nozzle, respectively, and are contacted with the catalyst to carry out a dry reforming reaction to obtain a product stream containing syngas.

[0017] (2) Part of the catalyst in step (1) is used as catalyst A to regenerate the regenerated catalyst, which is then returned to the fluidized bed reactor.

[0018] (3) The catalyst to be generated in step (1) and the catalyst obtained in the settling tank are heated as catalyst B and then returned to the fluidized bed reactor.

[0019] The beneficial effects achieved through the above technical solution are as follows:

[0020] (1) In this invention, the reaction system is provided with a reaction material nozzle and a reaction material inlet in the fluidized bed reactor. Some of the reaction materials enter from the lower part of the reactor, which reduces the temperature drop in the lower section of the reactor and makes the temperature in the reactor uniformly distributed, which helps to improve the efficiency of dry reforming reaction.

[0021] (2) In this invention, preferably, the reaction system is used for dry reforming reaction of methane and carbon dioxide, timely regenerating and removing the carbon deposits generated on the catalyst during the reaction, maintaining the catalyst activity, heating the circulating catalyst, and supplementing the heat required for the dry reforming reaction.

[0022] (3) In this invention, the reaction product stream is mixed with the quenching medium to rapidly reduce the temperature of the reaction product stream, effectively suppress carbon monoxide dismutation and carbon deposit formation, and the catalyst flow rate into the riser of the fluidized bed reactor is changed by adjusting the circulation amount of catalyst B. Through the collision and friction between the catalyst and the inner wall, the carbon deposits adsorbed on the inner wall can be carried out of the riser to the settling device along with the reaction product stream, avoiding excessive carbon accumulation on the inner wall of the riser and blockage. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the fluidized bed reaction system of the method of the present invention.

[0024] Explanation of reference numerals in the attached figures

[0025] 1- Fluidized bed reactor; 2- Reactant feed inlet; 3- Production line

[0026] 4-Conveying medium inlet; 5-Regenerating medium inlet; 6-Regenerator

[0027] 7-Regenerator Cyclone Separator 8-Regenerator Outlet 9-Degassing Tank

[0028] 10-Degassing medium inlet; 11-Regeneration pipeline; 12-Reactor cyclone separator

[0029] 13-Reactor outlet; 14-Riser pipe; 15-Quick cooling medium inlet

[0030] 16-Settling inclined tube 17-Settling device 18-Heater

[0031] 19-Heating Circulation Inclined Tube; 20-Reaction Material Nozzle; 21-Heating Inclined Tube

[0032] 22-Heating medium inlet; 23-Cooler; 24-Product gas outlet Detailed Implementation

[0033] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0034] The first aspect of the present invention provides a fluidized bed reaction system, wherein the reaction system includes a fluidized bed reactor, a regenerator, and a heater;

[0035] The fluidized bed reactor has a reaction material inlet at the bottom and a reaction material nozzle on the side for introducing the reaction material.

[0036] The inlet of the regenerator is connected to the fluidized bed reactor and is used to regenerate part of the catalyst to be generated in the fluidized bed reactor, and the regenerated catalyst is returned to the fluidized bed reactor.

[0037] The heater forms a circulation loop with the fluidized bed reactor, and is used to heat a portion of the catalyst to be generated in the fluidized bed reactor before returning it to the fluidized bed reactor.

[0038] In this invention, the fluidized bed reaction system has a raw material inlet at the bottom of the fluidized bed reactor and a raw material nozzle on the side of the fluidized bed reactor. The raw materials are introduced from different positions in the reactor, which can reduce the temperature drop in the lower section of the reactor and make the temperature in the reactor more uniform, thus helping to improve the efficiency of the dry reforming reaction.

[0039] According to the present invention, preferably, the vertical distance between the position of the reactant nozzle and the bottom of the fluidized bed reactor is no more than 0.5 times the height of the fluidized bed reactor, and more preferably 0.2-0.4 times the height of the fluidized bed reactor. When the horizontal positions of the reactant nozzles are not at the same height, the position of the reactant nozzle is calculated based on the highest reactant nozzle.

[0040] According to the present invention, preferably, the number of reaction material nozzles is at least two, and more preferably two to four. In this invention, providing at least two reaction material nozzles enables the reaction material to be dispersed into the fluidized bed reactor, reducing the temperature drop in the middle of the reactor and making the internal temperature distribution of the reactor more uniform.

[0041] According to the present invention, preferably, when the number of reactant nozzles is 2-3, the reactant nozzles are symmetrically distributed at the same height relative to the central axis of the fluidized bed reactor. For example, when there are 2 reactant nozzles, the two reactant nozzles are symmetrically distributed about the central axis of the fluidized bed reactor; when there are 3 reactant nozzles, the angle formed by the line connecting any two adjacent reactant nozzles to the central axis of the fluidized bed reactor is 120°.

[0042] According to the present invention, preferably, when the number of reaction material nozzles is four, the reaction material nozzles are symmetrically distributed at the same height relative to the central axis of the fluidized bed reactor, or are divided into two groups and symmetrically distributed at different heights relative to the central axis of the fluidized bed reactor.

[0043] In this invention, preferably, when the reaction material nozzles are divided into two groups, the distance between the reaction material nozzles in different groups is not less than 0.1 times the height of the fluidized bed reactor, preferably 0.1-0.2 times.

[0044] In this invention, setting the reaction raw material nozzle in the above manner can effectively eliminate the dead zone of catalyst particle flow, enhance the two-phase mixing and movement of raw gas and catalyst particles in the nozzle spray zone, and enhance the mass transfer between gas and solid, thereby helping to improve the yield of syngas from the reforming reaction.

[0045] According to the present invention, preferably, the reaction system further includes a settling device, the inlet of which is connected to the top outlet of the fluidized bed reactor.

[0046] According to the present invention, preferably, a reactor cyclone separator is provided at the top of the settler for removing catalyst from the product gas obtained from the fluidized bed reactor. The product gas and the removed catalyst are separated by the reactor cyclone separator.

[0047] In this invention, preferably, a dry reforming reaction of methane and carbon dioxide is carried out in the fluidized bed reactor to obtain a product stream containing syngas. Preferably, the reaction system further includes a riser for drawing the product stream containing syngas from the fluidized bed reactor and sending it to a settling tank.

[0048] In this invention, preferably, a quenching medium inlet is provided on the riser pipe, through which a quenching medium is introduced and mixed with the product stream containing syngas for quenching. In this invention, the rapid quenching of the product stream containing syngas starting from the riser pipe at the fluidized bed reactor outlet can suppress the disproportionation reaction of carbon monoxide, preventing carbon monoxide from undergoing disproportionation and producing carbon deposits in the settling tank. Even if carbon deposits are generated during the quenching process due to carbon monoxide disproportionation, these deposits are adsorbed onto the inner wall of the riser pipe or onto the catalyst. Simultaneously, through the collision and friction between the catalyst and the inner wall, the adsorbed carbon deposits on the inner wall can be carried out of the riser pipe and to the settling tank with the product gas, avoiding excessive carbon buildup on the inner wall of the riser pipe that could lead to blockage.

[0049] In this invention, the flow rate of the catalyst entering the riser is not particularly limited, and those skilled in the art can adjust it adaptively. Preferably, the circulation rate of the heated catalyst is adjusted by adjusting the flow rate of the catalyst from the settling tank to the heater, thereby achieving the adjustment of the catalyst level in the fluidized bed reactor. When the catalyst level in the reactor reaches the saturation height, the catalyst flow rate in the riser is adjusted by adjusting the flow rate of the catalyst from the settling tank to the heater.

[0050] In this invention, preferably, a reactor outlet is provided at the top of the settler for drawing out product gas.

[0051] In this invention, preferably, the reaction system further includes a cooler and a product gas outlet. The inlet of the cooler is connected to the outlet of the reactor and is used to cool the product gas. The product gas outlet is used to send the cooled product gas into subsequent processes.

[0052] In this invention, preferably, the reaction system further includes a pre-generation pipeline and a transport medium inlet. The pre-generation pipeline is connected to the bottom of the fluidized bed reactor. A portion of the pre-generation catalyst in the fluidized bed reactor flows out through the pre-generation pipeline, and the transport medium introduced through the transport medium inlet is lifted to the regenerator.

[0053] According to the present invention, preferably, a regeneration medium inlet is provided at the bottom of the regenerator for introducing a regeneration medium to regenerate the catalyst to be regenerated.

[0054] According to a preferred embodiment of the present invention, a regenerator separator, preferably a regenerator cyclone separator, is provided at the top of the regenerator for separating the regeneration catalyst and the reaction products of the regeneration medium. Preferably, a regenerator outlet is also provided at the top of the regenerator for discharging the separated reaction products of the regeneration medium from the regenerator.

[0055] According to the present invention, preferably, the reaction system further includes a degassing tank, the inlet of which is connected to a regenerator, and the outlet of which is connected to a fluidized bed reactor.

[0056] According to the present invention, preferably, a degassing medium inlet is provided at the bottom of the degassing tank for introducing a degassing medium to degas the regenerated catalyst.

[0057] In this invention, preferably, the reaction system further includes a regeneration pipeline, which connects the outlet of the degassing tank to the fluidized bed reactor, for returning the degassed regenerated catalyst to the fluidized bed reactor.

[0058] According to the present invention, preferably, the reaction system further includes a settling inclined tube, which connects the settling outlet and the heater inlet, for feeding the catalyst removed by the reactor cyclone separator into the heater.

[0059] In this invention, preferably, the reaction system further includes a heating inclined tube, which is connected to the fluidized bed heater and the heater inlet, and is used to feed a portion of the catalyst to be generated into the heater.

[0060] According to the present invention, preferably, the reaction system further includes a heating circulation inclined tube, which is connected to the outlet of the heater and the fluidized bed reactor.

[0061] According to the present invention, preferably, the connection port of the heating circulation inclined tube to the fluidized bed reactor is located above the nozzle, and the distance between it and the nearest reactant nozzle is not less than 0.2 times the vertical height of the fluidized bed reactor.

[0062] In this invention, a reaction material nozzle and a reaction material inlet are set in the fluidized bed reactor. Part of the raw material is introduced from the middle of the fluidized bed reactor to reduce the temperature drop in the lower section of the reactor and balance the temperature drop in the middle section, so that the temperature distribution in the reactor is more uniform. The circulating catalyst is heated by a heater to supplement the reactor and maintain the catalyst bed temperature. At the same time, the spent catalyst after the reaction is regenerated to remove the generated carbon deposits and maintain the catalyst activity.

[0063] A second aspect of the present invention provides a method for a dry reforming reaction of methane and carbon dioxide, wherein the method is carried out in the reaction system described in the first aspect, and the method includes:

[0064] (1) Raw materials containing methane and carbon dioxide are introduced into a fluidized bed reactor through a raw material inlet and a raw material nozzle, respectively, and are contacted with the catalyst to carry out a dry reforming reaction to obtain a product stream containing syngas.

[0065] (2) Part of the catalyst in step (1) is used as catalyst A to regenerate the regenerated catalyst, which is then returned to the fluidized bed reactor.

[0066] (3) The catalyst to be generated in step (1) and the catalyst obtained in the settling tank are heated as catalyst B and then returned to the fluidized bed reactor.

[0067] In this invention, preferably, the methane-carbon dioxide dry reforming reaction is carried out in the aforementioned reaction system. Since this reaction is a strongly endothermic reaction, when the reactants enter the reactor and react with the catalyst, the catalyst temperature in the lower section of the fluidized bed reactor drops rapidly, resulting in an uneven temperature distribution between the upper, middle, and lower bed layers within the reactor. By introducing reactants containing methane and carbon dioxide into the fluidized bed reactor through the reactant inlet and reactant nozzle, the temperature drop in the lower section is reduced, the temperature drop in the middle section is balanced, and the dry reforming reaction is ensured to proceed at a suitable temperature.

[0068] According to the present invention, preferably, the catalyst comprises an active component and a support. The source of the catalyst is not particularly limited; it can be commercially available or prepared using existing methods. The size and shape of the catalyst are not particularly limited; those skilled in the art can adjust the size and shape of the catalyst according to the structural adaptability to the fluidized bed reactor.

[0069] According to the present invention, the type and source of the support are not particularly limited, and it is a conventional catalyst support in the art, which can be commercially available or prepared by existing methods. Preferably, the support is selected from at least one of Al2O3, SiO2, MgO and TiO2, and more preferably Al2O3 and / or MgO.

[0070] According to the present invention, preferably, the active component is selected from at least one of Cu, Fe, Co, Ni, Rh, and Tr. When a catalyst containing the above-mentioned active component is used in a dry reforming reaction, the catalyst exhibits good catalytic activity and can improve the reaction efficiency of converting methane and carbon dioxide into syngas containing carbon monoxide and hydrogen.

[0071] According to the present invention, preferably, the content of active metal elements in the catalyst, based on the total mass of the catalyst, is 0.5-15 wt%, for example, 1 wt%, 2 wt%, 4 wt%, 5 wt%, 6 wt%, 8 wt%, 10 wt%, 11 wt%, 12 wt%, 14 wt%, 15 wt%, or any range between the two, preferably 3-11 wt%. In the present invention, the content of active metals in the catalyst is determined by X-ray fluorescence spectrometry (XRF).

[0072] In this invention, the composition and source of the raw materials containing methane and carbon dioxide are not particularly limited. Those skilled in the art can adaptively adjust the molar ratio of methane to carbon dioxide in the raw materials containing methane and carbon dioxide according to the dry reforming reaction. According to the present invention, preferably, the molar ratio of methane to carbon dioxide in the raw materials containing methane and carbon dioxide is 0.7-1.3:1, more preferably 0.9-1.1:1.

[0073] In this invention, the reaction conditions for the dry reforming reaction are not particularly limited, and are the conventional methane-carbon dioxide dry reforming reaction conditions in the art. Preferably, the reaction conditions for the dry reforming reaction include: a reaction temperature of 650-900℃, more preferably 750-850℃; a reaction pressure of 0-2MPa, more preferably 0.1-0.5MPa; and a total mass hourly space velocity (WHSV) of 0.1-6h⁻¹ for methane and carbon dioxide. -1 Preferably 0.4-4h -1 .

[0074] According to the present invention, preferably, step (1) further includes mixing the product stream containing syngas with a quenching medium to obtain a quenched product.

[0075] According to the present invention, preferably, the method further includes: separating the quenched product in a settling tank to obtain the catalyst and the quenched syngas. The catalyst is then heated in a heater and returned to the fluidized bed reactor.

[0076] According to the present invention, preferably, the temperature of the quenched synthesis gas is not higher than 600°C, and more preferably 300-520°C. In the present invention, the product stream containing synthesis gas is rapidly cooled to suppress the occurrence of carbon monoxide dismutation reaction and avoid the carbon deposits generated by the dismutation reaction from clogging the riser pipe.

[0077] According to the present invention, preferably, the method further includes: cooling the quenched synthesis gas in a cooler to obtain cooled synthesis gas.

[0078] According to the present invention, preferably, the quenching medium is water and / or cooled synthesis gas, more preferably cooled synthesis gas.

[0079] According to the present invention, preferably, in step (2), the circulation rate of catalyst A and the methane feed rate follow the formula F. A =a×G,F A Let be the catalyst A circulation rate, 'a' be a coefficient ranging from 0.05 to 0.8, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or any range between the two, preferably 0.2 to 0.6, and G be the methane feed rate. The methane feed rate is the mass flow rate of methane fed per unit time in the raw material. Those skilled in the art can adjust the methane feed rate adaptively according to the size of the reaction system.

[0080] In this invention, preferably, the circulation rate of catalyst A is adjusted according to the methane feed flow rate, the coking rate of the reaction, and the amount of catalyst stored in the reactor. This allows for timely replenishment of the highly active catalyst to catalyze the dry reforming reaction of methane and carbon dioxide, ensuring a high syngas yield and reactant conversion rate in the dry reforming reaction. It also avoids excessive catalyst coking leading to a decrease in activity, thus extending the catalyst activity time and consequently extending the operating time of the reaction system.

[0081] In this invention, preferably, in step (2), the catalyst A is lifted to the regenerator via a conveying medium, wherein the conveying medium is carbon dioxide and / or nitrogen.

[0082] According to the present invention, preferably, the regeneration conditions include: a regeneration temperature of 600-900℃, more preferably 750-850℃; and a regeneration pressure of 0-2MPa, more preferably 0.1-0.5MPa.

[0083] According to the present invention, preferably, the absolute value of the temperature difference between the regeneration temperature in step (2) and the dry reforming reaction temperature in step (1) is not greater than 100°C, and more preferably not greater than 70°C.

[0084] In this invention, preferably, the regeneration is carried out in the presence of a regeneration medium to obtain a regenerated catalyst, wherein the regeneration medium is an oxygen-containing gas, preferably air.

[0085] In this invention, controlling the temperature difference between the regeneration temperature and the dry reforming reaction temperature to meet the above-mentioned range can improve the yield of syngas from the dry reforming reaction while saving system energy consumption. If the regeneration temperature is too high, the energy consumption of the regeneration system will be high. If the temperature difference between the regeneration temperature and the reaction temperature is too large, it will cause a serious imbalance in the heat of the catalyst in the reactor when catalyst A is recycled back to the reactor, thus affecting the reaction conversion rate and the total yield of syngas.

[0086] In this invention, preferably, the regenerated catalyst is degassed in a degassed tank in the presence of a degassed medium to obtain a degassed product. In this invention, the degassed medium is nitrogen and / or carbon dioxide. Degasting via a degassed tank avoids the safety risks caused by oxygen entrainment into the reactor.

[0087] According to the present invention, the circulation rate of catalyst B can be adaptively adjusted by those skilled in the art based on the feed rate and the dry reforming reaction conditions. Preferably, the circulation rate of catalyst B and the methane feed rate follow the formula F. B ×(t 加热 -t 反应 )=b×G,F B The amount of catalyst B circulating is t. 加热 The temperature (t) after catalyst B is heated is the numerical value. 反应is the dry reforming reaction temperature, b is a coefficient with a value ranging from 300 to 1200, such as 300, 400, 500, 600, 700, 800, 900, 1000, 1200, or any range between the two, preferably 400-800, and G is the methane feed flow rate.

[0088] According to the present invention, preferably, the temperature difference between the catalyst temperature after heating in step (3) and the catalyst temperature after dry reforming reaction is not less than 30°C, for example 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, or any range between the two, preferably 50-100°C.

[0089] In this invention, the temperature of the catalyst after heating is higher than the temperature of the catalyst after the dry reforming reaction. Heat is added to maintain the temperature of the catalyst bed and provide heat for the dry reforming reaction.

[0090] According to a preferred embodiment of the present invention, in Figure 1 The reaction system shown undergoes a dry reforming reaction of methane and carbon dioxide. The raw materials containing methane and carbon dioxide are fed into the fluidized bed reactor 1 through the raw material inlet 2 and the raw material nozzle 20 to contact the catalyst and carry out the dry reforming reaction. The resulting product stream containing syngas flows through the riser 14 at the top of the fluidized bed reactor 1 and is mixed with the quench medium introduced by the quench medium inlet 15. After quenching, the product stream enters the settling tank 17. After the catalyst is removed by the reactor cyclone separator 12, the product stream flows out of the settling tank 17 through the reactor outlet 13 and enters the cooler 23 for cooling. Finally, the product gas flows through the product gas outlet 24 to the subsequent process.

[0091] In the fluidized bed reactor 1, part of the catalyst, as catalyst A, flows out from the bottom of the fluidized bed reactor 1 through the regeneration pipeline 3. It is then lifted to the regenerator 6 by the conveying medium introduced through the conveying medium inlet 4. The regeneration medium is introduced through the regeneration medium inlet 5 to contact and regenerate catalyst A. The reaction products of the regenerated catalyst and the regeneration medium are separated by the cyclone separator 7 in the regenerator. The reaction products of the regeneration medium are discharged through the regenerator outlet 8. The regenerated catalyst is sent to the degassing tank 9 and degassed by the degassing medium introduced through the degassing medium inlet 10. After degassing, it is returned to the fluidized bed reactor 1 through the regeneration pipeline 11.

[0092] The catalyst removed by the reactor cyclone separator 12 enters the heater 18 through the settling inclined tube 16. Part of the catalyst in the fluidized bed reactor 1, as catalyst B, enters the heater 18 through the heating inclined tube 21. The heating medium is introduced into the heater 18 through the heating medium inlet 22 to heat the catalyst. The heated catalyst is returned to the fluidized bed reactor 1 through the heating circulation inclined tube 19.

[0093] The present invention will be described in detail below through examples and comparative examples. Unless otherwise specified, all reagents used in the following examples and comparative examples are commercially available.

[0094] Example 1

[0095] exist Figure 1 The reaction system shown undergoes a dry reforming reaction of methane and carbon dioxide. The raw materials containing methane and carbon dioxide are fed into the fluidized bed reactor 1 through the raw material inlet 2 and the raw material nozzle 20 to contact the catalyst and carry out the dry reforming reaction. The resulting product stream containing syngas flows through the riser 14 at the top of the fluidized bed reactor 1 and is mixed with the quench medium introduced by the quench medium inlet 15 and quenched to a temperature of 350°C. Then it enters the settling tank 17, and after the catalyst is removed by the reactor cyclone separator 12, it flows out of the settling tank 17 through the reactor outlet 13 and enters the cooler 23 for cooling. Finally, it flows to the subsequent process through the product gas outlet 24.

[0096] In the fluidized bed reactor 1, a portion of the catalyst, known as catalyst A, flows out from the bottom of the fluidized bed reactor 1 via the regeneration pipeline 3. It is then lifted to the regenerator 6 by the conveying medium introduced through the conveying medium inlet 4. The regeneration medium is introduced through the regeneration medium inlet 5 to contact and regenerate catalyst A. The reaction products of the regenerated catalyst and the regeneration medium are separated by the cyclone separator 7 in the regenerator. The reaction products of the regeneration medium are discharged through the regenerator outlet 8. The regenerated catalyst is sent to the degassing tank 9 and degassed by the degassing medium introduced through the degassing medium inlet 10. After degassing, it is returned to the fluidized bed reactor 1 via the regeneration pipeline 11. The circulation rate of catalyst A is controlled at 8 kg / h (where a = 0.4, G = 20 kg / h).

[0097] The catalyst removed by the reactor cyclone separator 12 enters the heater 18 via the settling inclined tube 16. Part of the catalyst in the fluidized bed reactor 1 enters the heater 18 via the heating inclined tube 21. Heating medium is introduced through the heating medium inlet 22 to heat the catalyst. The heated catalyst, as catalyst B, is returned to the fluidized bed reactor 1 via the heating circulation inclined tube 19. The circulation rate of catalyst B is controlled at 186 kg / h (b = 650, G = 20 kg / h, (t...). 加热 -t 反应 The value of ) is 70), and the temperature of catalyst B after heating is 70°C higher than the reaction temperature of dry reforming.

[0098] The reactor has two reaction material nozzles 20, namely reaction material nozzle I and reaction material nozzle II. The reaction material nozzle I and reaction material nozzle II are axially symmetrically distributed at the same height. The positions of the reaction material nozzle I and reaction material nozzle II are located at 0.3 of the vertical height of the fluidized bed reactor.

[0099] The connection port between the heating circulation inclined tube and the fluidized bed reactor is located above the nozzle, and the distance between it and the nearest nozzle is 0.25 times the vertical height of the fluidized bed reactor.

[0100] Examples 2-6

[0101] exist Figure 1 The reaction system shown is used to produce synthesis gas from methane by dry reforming with carbon dioxide under the conditions shown in Table 1.

[0102] Example 7

[0103] Syngas was produced by dry reforming according to the method of Example 1, except that the circulation rate of catalyst A in step (2) was adjusted to 2 kg / h (where a = 0.1, G = 20 kg / h), and other conditions were the same as in Example 1.

[0104] Example 8

[0105] The dry reforming process for producing syngas was carried out according to the method in Example 1, except that the circulation rate of catalyst B in step (3) was adjusted to 86 kg / h (b = 300, G = 20 kg / h, (t) 加热 -t 反应 The value of ) is 70), and other conditions are the same as in Example 1.

[0106] Example 9

[0107] Syngas was produced by dry reforming according to the method of Example 1, except that the temperature difference between the catalyst B after heating in step (3) and the catalyst temperature in the reactor was adjusted to 30°C, and other conditions were the same as in Example 1.

[0108] Example 10

[0109] exist Figure 1 The reaction system shown carries out a dry reforming reaction of methane and carbon dioxide, except that the position of the reactant nozzle 20 is 0.5 times the vertical height of the fluidized bed reactor.

[0110] Example 11

[0111] exist Figure 1 The reaction system shown carries out a dry reforming reaction of methane and carbon dioxide. The difference is that the connection port between the heating circulation inclined tube and the fluidized bed reactor is located above the nozzle. The position of the heating circulation inclined tube and the distance between it and the nearest nozzle are adjusted to 0.1 times the vertical height of the fluidized bed reactor.

[0112] Comparative Example 1

[0113] The dry reforming process was carried out to produce syngas according to the method of Example 1, except that the apparatus did not have a reactant nozzle, and other conditions were the same as in Example 1.

[0114] Comparative Example 2

[0115] Syngas was produced by dry reforming according to the method of Example 1, except that the active metal of the catalyst was Zr, and other conditions were the same as in Example 1.

[0116] Comparative Example 3

[0117] Syngas was produced by dry reforming according to the method of Example 1, except that the circulation rate of catalyst A was 0, that is, the catalyst was not regenerated, and other conditions were the same as in Example 1.

[0118] Table 1 shows the process conditions for the dry reforming of methane and carbon dioxide to produce syngas in the embodiments and comparative examples of the present invention, including the reaction, catalyst, regeneration, and reduction.

[0119] Table 1

[0120]

[0121]

[0122] In this invention, the results of the reactions in the examples and comparative examples after 720 hours are shown in Table 2.

[0123] Methane conversion rate = (G1*C) 1甲烷 -G2*C 2甲烷 ) / (G1*C 1甲烷 )*100%;

[0124] Carbon dioxide conversion rate = (G1*C) 1二氧化碳 -G2*C 2二氧化碳 ) / (G1*C 1二氧化碳 )*100%;

[0125] Syngas yield = (G2*C) 2氢气 +G2*C 2一氧化碳 ) / (G1*C 1甲烷 +G1*C 1二氧化碳 )*100%;

[0126] G1 is the feed gas flow rate, in kg / h; G2 is the product gas flow rate, in kg / h. 1甲烷 The mass percentage of methane in the feed gas, in %; C 1二氧化碳 The mass percentage of carbon dioxide in the feed gas, in %; C 2甲烷 The percentage of methane by mass in the product gas, in %; C 2二氧化碳 The percentage of carbon dioxide by mass in the product gas, in %; C 2氢气 The mass percentage of hydrogen in the product gas, in %; C 2一氧化碳 The percentage of carbon monoxide in the product gas, expressed in %.

[0127] Table 2 shows the reaction results of the dry reforming of methane and carbon dioxide to produce syngas in the embodiments and comparative examples of the present invention.

[0128] Table 2

[0129]

[0130]

[0131] As can be seen from the results in Table 2, the embodiments using the continuous reaction regeneration technology of the present invention have significantly better effects, such as high methane conversion rate, high carbon dioxide conversion rate, and high syngas yield.

[0132] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A fluidized bed reaction system, characterized in that, The reaction system includes a fluidized bed reactor, a regenerator, and a heater; The fluidized bed reactor has a reaction material inlet at the bottom and a reaction material nozzle on the side for introducing the reaction material. The inlet of the regenerator is connected to the fluidized bed reactor and is used to regenerate part of the catalyst to be generated in the fluidized bed reactor, and the regenerated catalyst is returned to the fluidized bed reactor. The heater forms a circulation loop with the fluidized bed reactor, and is used to heat a portion of the catalyst to be generated in the fluidized bed reactor before returning it to the fluidized bed reactor.

2. The reaction system according to claim 1, wherein, The vertical distance between the position of the reaction material nozzle and the bottom of the fluidized bed reactor is no higher than 0.5 times the height of the fluidized bed reactor, and preferably 0.2-0.4 times the height of the fluidized bed reactor; Preferably, the number of reaction material nozzles is at least two, and more preferably two to four; Preferably, when the number of reactant nozzles is 2-3, the reactant nozzles are symmetrically distributed at the same height relative to the central axis of the fluidized bed reactor; Preferably, when there are four reaction material nozzles, the reaction material nozzles are symmetrically distributed at the same height relative to the central axis of the fluidized bed reactor, or divided into two groups and symmetrically distributed at different heights relative to the central axis of the fluidized bed reactor.

3. The reaction system according to claim 1 or 2, wherein, The reaction system also includes a settling device, the inlet of which is connected to the top outlet of the fluidized bed reactor; Preferably, a reactor cyclone separator is provided at the top of the settling tank to remove the catalyst from the product gas obtained from the fluidized bed reactor; Preferably, the reaction system further includes a settling inclined tube, which connects the settling outlet and the heater inlet, for feeding the catalyst removed by the reactor cyclone separator into the heater; Preferably, the reaction system further includes a heating circulation inclined tube, which is connected to the outlet of the heater and the fluidized bed reactor; Preferably, the connection port between the heating circulation inclined tube and the fluidized bed reactor is located above the nozzle, and the distance between it and the nearest reactant nozzle is not less than 0.2 times the vertical height of the fluidized bed reactor.

4. The reaction system according to any one of claims 1-3, wherein, The bottom of the regenerator is provided with a regeneration medium inlet for introducing regeneration medium to regenerate the catalyst to be regenerated; Preferably, the reaction system further includes a degassing tank, the inlet of which is connected to a regenerator, and the outlet of which is connected to a fluidized bed reactor; Preferably, the bottom of the degassing tank is provided with a degassing medium inlet for introducing a degassing medium to degas the regenerated catalyst.

5. A method for a dry reforming reaction of methane and carbon dioxide, characterized in that, The method is carried out in the reaction system according to any one of claims 1-4, and the method comprises: (1) Raw materials containing methane and carbon dioxide are introduced into a fluidized bed reactor through a raw material inlet and a raw material nozzle, respectively, and are contacted with the catalyst to carry out a dry reforming reaction to obtain a product stream containing syngas. (2) Part of the catalyst in step (1) is used as catalyst A to regenerate the regenerated catalyst, which is then returned to the fluidized bed reactor. (3) The catalyst to be generated in step (1) and the catalyst obtained in the settling tank are heated as catalyst B and then returned to the fluidized bed reactor.

6. The method according to claim 5, wherein, The catalyst includes an active component and a support; Preferably, the support is selected from at least one of Al2O3, SiO2, MgO and TiO2, and more preferably Al2O3 and / or MgO; Preferably, the active component is selected from at least one of Cu, Fe, Co, Ni, Rh, and Tr; Preferably, the content of active metal elements in the catalyst is 0.5-15 wt%, more preferably 3-11 wt%, based on the total mass of the catalyst.

7. The method according to claim 5 or 6, wherein, The molar ratio of methane to carbon dioxide in the raw material containing methane and carbon dioxide is 0.7-1.3:1, preferably 0.9-1.1:1; Preferably, the reaction conditions for the dry reforming reaction include: a reaction temperature of 650-900℃, more preferably 750-850℃; a reaction pressure of 0-2 MPa, more preferably 0.1-0.5 MPa; and a total mass hourly space velocity (MHV) of 0.1-6 h⁻¹ for methane and carbon dioxide. -1 Preferably 0.4-4h -1 .

8. The method according to any one of claims 5-7, wherein, The mass ratio of the feed rate of the reactant nozzle to the feed rate of the reactant inlet is 0.1-1:1, preferably 0.2-0.6:1; Preferably, step (1) further includes mixing the product stream containing syngas with a quenching medium to obtain a quenched product; Preferably, the method further includes: separating the quenched product in a settling tank to obtain the catalyst and the quenched syngas; Preferably, the temperature of the quenched synthesis gas is not higher than 600°C, and more preferably 300-520°C; Preferably, the method further includes: cooling the quenched syngas in a cooler to obtain cooled syngas; Preferably, the quenching medium is water and / or cooled synthesis gas, and more preferably cooled synthesis gas.

9. The method according to any one of claims 5-8, wherein, In step (2), the circulation rate of catalyst A and the methane feed rate follow the formula F. A =a×G,F A Where A is the catalyst A circulation rate, a is a coefficient with a value ranging from 0.05 to 0.8, preferably from 0.2 to 0.6, and G is the methane feed flow rate. Preferably, the regeneration conditions include: a regeneration temperature of 600-900℃, more preferably 750-850℃; and a regeneration pressure of 0-2MPa, more preferably 0.1-0.5MPa. Preferably, the absolute value of the temperature difference between the regeneration temperature in step (2) and the dry reforming reaction temperature in step (1) is not greater than 100°C, and more preferably not greater than 70°C.

10. The method according to any one of claims 5-9, wherein, The circulation rate of catalyst B is related to the methane feed rate according to formula F. B ×(t 加热 -t 反应 )=b×G,F B The amount of catalyst B circulating is t. 加热 The temperature (t) after catalyst B is heated is the numerical value. 反应 Here, b is the dry reforming reaction temperature, b is a coefficient with a value ranging from 300 to 1200, preferably from 400 to 800, and G is the methane feed flow rate. Preferably, the temperature difference between the catalyst temperature after heating in step (3) and the catalyst temperature after the dry reforming reaction is not less than 30°C, and preferably 50-100°C.

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