Carbon dioxide hydrogenation to olefins reactor, its working method and applications

Abstract

The application discloses a carbon dioxide hydrogenation olefin reactor and a working method and application thereof. The carbon dioxide hydrogenation olefin reactor comprises an outer shell and an inner shell. The outer shell is used for synthesizing methanol through the reaction of carbon dioxide and hydrogen. The outer shell is provided with a catalyst inlet for entering a catalyst and an outer reaction heat remover for leading out reaction heat in the outer shell. The inner shell is used for synthesizing olefin through a methanol dehydration reaction. The inner shell is arranged in the outer shell, and the inner shell is provided with a heater for heating reaction materials, an inner reaction heat remover for leading out reaction heat in the inner shell, a first inlet and a first outlet for the circulation flow of the reaction materials between the inner shell and the outer shell. The carbon dioxide hydrogenation olefin reactor has high carbon dioxide conversion rate and olefin selectivity, simple overall structure, less equipment investment and high comprehensive benefit.

Description

Technical Field

[0001] This application belongs to the field of energy conservation and emission reduction technology, and in particular relates to a carbon dioxide hydrogenation reactor for olefin production, its working method and application. Background Technology

[0002] Climate change is a major global challenge, profoundly impacting the economic and social development and ecological environment of all countries. Research by the International Energy Agency (IEA) indicates that to achieve the goal set forth in the Paris Agreement of limiting global average temperature rise to well below 2°C above pre-industrial levels, CCUS (Carbon Dioxide-Based Energy) will contribute 10% to 20% of emissions reductions, assuming optimal configuration of various emission reduction technologies. This means that without CCUS technology, the goal of limiting temperature rise to 2°C cannot be achieved. Carbon dioxide utilization technology is a crucial means of achieving carbon neutrality. CO2-to-olefins (CO2-to-olefins) is one such CO2 utilization technology that converts CO2 into high-value olefin products, representing a significant step towards reducing CO2 emissions from high-cost to low-cost or even negative-cost levels.

[0003] CO2 can be chemically utilized to produce a variety of products, including syngas, natural gas, formic acid, methanol, olefins, gasoline, carbonates, and urea. Olefins are important basic organic chemical raw materials, especially low-carbon olefins such as ethylene and propylene, which have the widest applications and are the foundational raw materials for the three major synthetic materials (plastics, rubber, and fibers). Ethylene and propylene are the world's highest-value chemical products, and olefin production technology and capacity are important indicators of a country's petrochemical industry development level.

[0004] Significant progress has been made in catalyst research for CO2 hydrogenation to olefins technology. A relatively mature synthesis method is a two-step reaction via methanol. However, the reaction conditions for the two steps typically differ considerably, making it impossible to simultaneously achieve optimal conditions for each step using a traditional single reactor, resulting in low overall conversion and selectivity. Using two separate reactors for each reaction complicates the process and increases initial investment.

[0005] Therefore, there is an urgent need for a single reactor design that can perform two-step reactions while allowing for individual control of the reaction conditions in each step, with high conversion rate and selectivity, a simple overall process, low equipment investment, and high comprehensive benefits. Summary of the Invention

[0006] In view of this, one objective of this application is to provide a carbon dioxide hydrogenation reactor for olefins, which has an inner shell for synthesizing olefins and an outer shell for synthesizing methanol. The olefin synthesis temperature is controlled by a heater and an internal reaction heat exchanger, and the methanol synthesis temperature is controlled by an external reaction heat exchanger. The reactants circulate between the inner and outer shells to achieve stepwise reaction. It has a high carbon dioxide conversion rate and olefin selectivity, a simple overall structure, low equipment investment, and high comprehensive benefits.

[0007] Another objective of this application is to provide a method for operating a carbon dioxide hydrogenation reactor for producing olefins.

[0008] Another objective of this application is to provide a system for producing olefins by hydrogenating carbon dioxide.

[0009] Another objective of this application is to provide a method for operating a carbon dioxide hydrogenation to olefins system.

[0010] To achieve the above objectives, a first aspect of this application provides a carbon dioxide hydrogenation reactor for olefin production, comprising:

[0011] An outer shell for the reaction of carbon dioxide and hydrogen to synthesize methanol, the outer shell having a catalyst inlet for entering the catalyst and an external reaction heat exchanger for removing the heat of reaction inside the outer shell;

[0012] The inner shell is used for methanol dehydration reaction to synthesize olefins; the inner shell is disposed within the outer shell, and the inner shell has a heater for heating the reactants, an internal reaction heat exchanger for discharging the reaction heat within the inner shell, and a first inlet and a first outlet for circulating the reactants between the inner shell and the outer shell; the first inlet and the first outlet are arranged opposite to each other, and the first inlet is adjacent to and opposite to the catalyst inlet.

[0013] In some embodiments, the inner shell includes a first part and a second part that are interconnected. The first part has the first outlet, and the second part has the first inlet. The cross-sections of the first part and the second part along the direction from the first inlet to the first outlet are both isosceles trapezoids. The dimensions of the first part at the end with the first outlet and the second part at the end with the first inlet are both smaller than the dimensions of the connection between the first part and the second part.

[0014] In some embodiments, the inner housing and the outer housing are arranged along a common centerline in the direction from the first inlet to the first outlet.

[0015] In some embodiments, the middle portion of the cross-section of the outer casing along the direction from the first inlet to the first outlet is rectangular.

[0016] In some embodiments, the outer shell is cylindrical, and the sidewall of the outer shell is provided with a plurality of second inlets for the raw material gases carbon dioxide and hydrogen to enter the interior of the outer shell, and the plurality of second inlets open along the tangential direction of the inner wall of the outer shell.

[0017] In some embodiments, a plurality of second inlets are distributed at intervals along the direction of the first inlet and the first outlet on the housing, and adjacent second inlets are positioned opposite to or staggered.

[0018] In some embodiments, the internal reaction heat exchanger is disposed on the inner surface and / or outer surface of the inner shell.

[0019] In some embodiments, the outer casing is provided with the external reaction heat exchanger and the product outlet on the side adjacent to the first outlet.

[0020] In some embodiments, the heater is installed inside the inner housing adjacent to the first inlet, and an air multiplier is installed at the first inlet for drawing catalyst from the catalyst inlet into the inner housing.

[0021] In some embodiments, the outer casing has a funnel-shaped structure at one end adjacent to the first inlet, and the side of the funnel-shaped structure away from the first inlet is the catalyst inlet; the funnel-shaped structure is mounted on a base, and a vibrator for loosening the catalyst deposited on the sidewall of the funnel-shaped structure is installed on the funnel-shaped structure.

[0022] To achieve the above objectives, a second aspect of this application provides a method for operating a carbon dioxide hydrogenation to olefins reactor, comprising:

[0023] Methanol is synthesized from the raw materials carbon dioxide and hydrogen in the outer shell under the action of a catalyst.

[0024] Driven by the raw material gas, methanol and catalyst are heated and enter the inner shell through the first inlet to synthesize olefins, forming a mixed gas carrying the catalyst;

[0025] The mixed gas enters the outer shell from the first outlet, then part of it is discharged from the outer shell, and the other part is cooled to form a reactive material circulation between the outer shell and the inner shell;

[0026] The temperature of the synthesized methanol and the temperature of the synthesized olefin are controlled by the external reaction heat exchanger and the internal reactor heat exchanger, respectively.

[0027] In some embodiments, the working method further includes the step of introducing the raw material gases carbon dioxide and hydrogen into the outer shell through a plurality of second inlets along the inner tangential direction of the outer shell, forming a spiral gas flow with the catalyst inside the outer shell, and synthesizing methanol.

[0028] In some embodiments, the method of operation further includes the step of loosening the catalyst deposited on the sidewalls of the funnel-shaped structure by vibrating with a vibrator.

[0029] In some embodiments, the working method further includes the step of feeding the raw gas and catalyst into the inner shell via the gas multiplier.

[0030] In some embodiments, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide, and unreacted hydrogen.

[0031] In some embodiments, the volume ratio of hydrogen to carbon dioxide in the feed gas is (2-4):1.

[0032] In some embodiments, the temperature for methanol synthesis within the outer casing is 200-300°C, and the pressure is 0.5-8 MPa.

[0033] In some embodiments, the temperature for synthesizing olefins within the inner shell is 300-400°C, and the pressure is 0.5-8 MPa.

[0034] In some embodiments, the catalyst is a carbon dioxide hydrogenation catalyst for olefins.

[0035] In some embodiments, the catalyst is carried into the outer casing through the catalyst inlet by a carrier gas, wherein the carrier gas is at least one of carbon dioxide, hydrogen, and an inert gas.

[0036] To achieve the above objectives, a third aspect of this application provides a carbon dioxide hydrogenation to olefins system, comprising:

[0037] The reactor is a carbon dioxide hydrogenation to olefins reactor according to an embodiment of this application, and the feed gas inlet of the reactor is connected to a first preheater.

[0038] A cyclone separator, wherein the inlet of the cyclone separator is connected to the product outlet of the reactor, the gas outlet of the cyclone separator is connected to a gas-liquid separation device, and the solid outlet of the cyclone separator is sequentially connected to a catalyst regenerator and a catalyst feed line;

[0039] An olefin separation unit is provided, wherein the inlet of the olefin separation unit is connected to the gas outlet of the gas-liquid separation unit, the impurity outlet of the olefin separation unit is sequentially connected to the cold side of the heat exchanger, the second preheater 3 and the catalyst feed line, the hot side of the heat exchanger is connected to the internal reaction heat exchanger, and the catalyst feed line is connected to the catalyst inlet.

[0040] To achieve the above objectives, a fourth aspect of this application provides a method for operating a carbon dioxide hydrogenation to olefins system, comprising:

[0041] After the raw materials carbon dioxide and hydrogen enter the reactor, olefins are synthesized under the action of a catalyst.

[0042] The mixed gas carrying the catalyst discharged from the inner shell is partially discharged from the outer shell and then separated by a cyclone separator. The catalyst obtained from the separation process is regenerated and reused in the reactor. The gas phase obtained from the separation process is sequentially processed by a gas-liquid separation device and an olefin separation device to obtain olefin products and the unreacted raw material gas.

[0043] The unreacted feed gas is heated by a heat transfer medium from the internal reactor heat exchanger, and then preheated before being used as a catalyst carrier gas.

[0044] In some embodiments, a method for synthesizing olefins from the feed gas carbon dioxide and hydrogen in the presence of a catalyst includes:

[0045] Preheated raw material gases, carbon dioxide and hydrogen, are introduced into the outer shell;

[0046] The airflow multiplier is activated to establish a circulation of the raw material gas flow between the inner shell and the outer shell.

[0047] Turn on the heater and heat the inner shell to the temperature of methanol-to-olefins synthesis, thereby causing methanol to be converted into olefins within the inner shell.

[0048] Turn on the internal and external reaction heat exchangers to maintain a stable temperature in each area of ​​the reactor.

[0049] Open the product outlet and catalyst inlet to establish a stable cycle between the reactor and the rest of the carbon dioxide hydrogenation to olefins system;

[0050] The carbon dioxide and hydrogen are synthesized into methanol in the outer shell under the action of the catalyst, and the methanol is synthesized into olefins in the inner shell under the action of the catalyst.

[0051] The carbon dioxide hydrogenation reactor for olefins in this application has at least the following beneficial effects:

[0052] Unlike traditional reactors that can only maintain one reaction condition, the carbon dioxide hydrogenation to olefins reactor of this application is a double-shell reactor with two reaction zones: an inner shell and an outer shell. This allows for separate control of the methanol synthesis reaction temperature and the olefin synthesis reaction temperature, enabling the simultaneous occurrence of a two-step CO2 hydrogenation to olefins reaction. Compared to traditional single-stage reactors, this solves the problem of high conversion rates and selectivity due to the significant difference in optimal reaction temperatures between the two steps. Compared to multi-stage reactors in series, it overcomes the problems of complex processes and high initial investment costs associated with multi-stage reactors. The carbon dioxide hydrogenation to olefins reactor of this application achieves high carbon dioxide conversion and olefin selectivity while maintaining a relatively simple process flow and lower initial equipment investment.

[0053] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0054] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0055] Figure 1 This is a schematic diagram of the structure of a carbon dioxide hydrogenation reactor for producing olefins, as illustrated in an exemplary embodiment of this application.

[0056] Figure 2 This is a schematic diagram of the structure of a carbon dioxide hydrogenation to olefins system illustrated in an exemplary embodiment of this application.

[0057] Figure label:

[0058] 1-Outer shell; 2-Inner shell; 201-First section; 202-Second section; 3-First inlet; 4-First outlet; 5-Inner reaction heat exchanger; 501-First sub-heat exchanger; 502-Second sub-heat exchanger; 6-Second inlet; 7-Outer reaction heat exchanger; 8-Product outlet; 9-Functional structure; 10-Vibrator; 11-Base; 12-Heater; 13-Airflow multiplier; 14-Catalyst inlet; 15-First preheater; 16-Cyclone separator; 17-Gas-liquid separation device; 18-Olefin separation device; 19-Heat exchanger; 20-Second preheater; 21-Catalyst regenerator; 22-Catalyst feed line; 23-Reactor. Detailed Implementation

[0059] The embodiments of this application are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0060] In the application, the disclosure of the numerical range includes all values ​​throughout the range and the disclosure of further subdivisions of the range, including the endpoints and subranges given for these ranges.

[0061] Unless otherwise specified, all raw materials and equipment involved in the application are those that can be manufactured commercially or by known methods; and all methods involved are conventional methods unless otherwise specified.

[0062] The following description, in conjunction with the accompanying drawings, describes the working method of the carbon dioxide hydrogenation olefins reactor, the carbon dioxide hydrogenation olefins reactor, the carbon dioxide hydrogenation olefins system, and the working method of the carbon dioxide hydrogenation olefins system according to embodiments of this application.

[0063] Figure 1 This is a schematic diagram of the structure of a carbon dioxide hydrogenation reactor for producing olefins, as illustrated in an exemplary embodiment of this application.

[0064] like Figure 1 As shown, the carbon dioxide hydrogenation reactor for producing olefins according to an embodiment of this application includes an outer shell 1 and an inner shell 2.

[0065] The outer shell 1 is used for the reaction of carbon dioxide and hydrogen to synthesize methanol. The outer shell 1 has a catalyst inlet 14 for entering the catalyst and an external reaction heat exchanger 7 for removing the heat of reaction inside the outer shell 1.

[0066] The inner shell 2 is used for the methanol dehydration reaction to synthesize olefins. The inner shell 2 is located inside the outer shell 1, and the inner shell 2 has a heater 12 for heating the reactants, an internal reaction heat extractor 5 for removing the heat of reaction inside the inner shell 2, and a first inlet 3 and a first outlet 4 for circulating the reactants between the inner shell 2 and the outer shell 1; the first inlet 3 and the first outlet 4 are arranged opposite to each other, and the first inlet 3 is adjacent to and opposite to the catalyst inlet 14.

[0067] The carbon dioxide hydrogenation reactor for olefins in this embodiment has an inner shell for olefin synthesis and an outer shell for methanol synthesis. The olefin synthesis temperature is controlled by a heater and an internal reaction heat exchanger, while the methanol synthesis temperature is controlled by an external reaction heat exchanger. The reactants circulate between the inner and outer shells, enabling the reaction to proceed in steps. This solves the problems of low conversion and selectivity in the original single reactor and the complex and costly dual reactor process. As a result, the carbon dioxide hydrogenation reactor for olefins in this embodiment has a high carbon dioxide conversion rate and olefin selectivity, a simple overall structure, low equipment investment, and high comprehensive benefits.

[0068] It should be noted that in the embodiments of this application, the arrangement of the outer shell and inner shell is not limited; they can be vertically arranged, horizontally arranged, or inclined. Preferably, both the outer shell and inner shell are vertically arranged, in which case the first inlet is located at the bottom of the inner shell, and the first outlet is located at the top of the inner shell (e.g., Figure 1 (As shown).

[0069] In some embodiments, the inner shell 2 includes a first part 201 and a second part 202 that are interconnected. The first part 201 is provided with a first outlet 4, and the second part 202 is provided with a first inlet 3. The cross sections of the first part 201 and the second part 202 along the direction from the first inlet 3 to the first outlet 4 are both isosceles trapezoids. The dimensions of the first part 201 at the end where the first outlet 4 is provided and the dimensions of the second part 202 at the end where the first inlet 3 is provided are both smaller than the dimensions of the connection between the first part 201 and the second part 201.

[0070] In some embodiments, the cross-section of the inner shell 2 along the direction perpendicular to the first inlet 3 to the first outlet 4 is one of a circular, rectangular, or square shape. That is, the cross-section of the first part 201 and the second part 202 along the direction perpendicular to the first inlet 3 to the first outlet 4 is one of a circular, rectangular, or square shape.

[0071] It is understood that the shapes of the first and second parts include, but are not limited to, hollow frustums, hollow truncated pyramids, and similar shapes. When it is a frustum, the dimension refers to the diameter or radius; when it is a truncated pyramid, the dimension refers to the length and width, or the side length.

[0072] As an optional example, both the first part 201 and the second part 202 are hollow frustum shapes. The first part 201 has a first outlet 4 at the end adjacent to the catalyst, and the second part 202 has a first inlet 3 at the end away from the first part. The diameter of the end of the first part 201 adjacent to the second part 202 is larger than the diameter of the end of the first part 201 with the first outlet 4. The diameter of the end of the second part 202 adjacent to the first part 201 is approximately the same as the diameter of the end of the first part 201 adjacent to the second part 202. The diameter of the end of the second part 202 adjacent to the first part 201 is larger than the diameter of the end of the second part 202 with the first inlet 3.

[0073] In some embodiments, the connection method between the first part and the second part includes, but is not limited to, integral molding, welding, etc.

[0074] In some embodiments, the middle portion of the cross-section of the outer casing 1 along the direction from the first inlet 3 to the first outlet 4 is rectangular.

[0075] In some embodiments, the outer casing 1 has a circular cross-section along the direction perpendicular to the first inlet 3 to the first outlet 4.

[0076] Understandably, the outer shell can be cylindrical or cylindrical in shape.

[0077] In some embodiments, the inner housing 2 and the outer housing 1 are arranged along a common centerline in the direction from the first inlet 3 to the first outlet 4. For example, when the first portion 201 and the second portion 202 of the inner housing 2 are both frustum-shaped and the outer housing is cylindrical, the two are arranged coaxially.

[0078] In some embodiments, the sidewall of the outer casing 1 is provided with a plurality of second inlets 6 for the raw materials carbon dioxide and hydrogen to enter the interior of the outer casing 1. Preferably, the plurality of second inlets 6 are distributed at intervals on the outer casing 1 along the direction of the first inlet 3 and the first outlet 4, and adjacent two second inlets 6 are arranged opposite or staggered. Here, opposite arrangement is, for example, left and right sides; staggered arrangement is, for example, adjacent two second inlets are arranged at a certain angle and are not in the same vertical plane and the same horizontal plane.

[0079] As an alternative example, when the outer shell 1 is cylindrical, multiple second inlets 6 for the raw material gases carbon dioxide and hydrogen to enter the interior of the outer shell 1 are opened along the tangential direction of the inner wall of the outer shell 1. The multiple second inlets 6 are distributed at intervals on the outer shell 1 along the direction of the first inlet 3 and the first outlet 4, and the positions of two adjacent second inlets 6 are opposite or staggered.

[0080] In the embodiments of this application, the number of second entry points 6 is at least 2, including but not limited to 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0081] In some embodiments, the outer casing 1 is provided with an external reaction heat exchanger 7 and a product outlet 8 on the side adjacent to the first outlet 4.

[0082] As an alternative example, the outer shell 1 is an ellipsoidal head adjacent to the first outlet, and an external reaction heat exchanger 7 is installed on the side adjacent to the first outlet to remove the heat released by the reaction; the product outlet 8 mentioned above is provided at the center of the ellipsoidal head.

[0083] In some embodiments, the internal reaction heat exchanger 5 can be disposed on the inner surface of the inner shell 2; in other embodiments, the internal reaction heat exchanger 5 can be disposed on the outer surface of the inner shell 2; in still other embodiments, the internal reaction heat exchanger 5 can be disposed on both the inner and outer surfaces of the inner shell. It should be noted that the larger the heat exchange area between the internal reaction heat exchanger and the inner shell, the more beneficial it is to removing the heat released by the olefin synthesis process inside the inner shell.

[0084] In some embodiments, both the internal reaction heat exchanger 5 and the external reaction heat exchanger 7 can be heat exchange coils, heat exchange plates, etc. During use, a circulating cooling medium, such as cooling water or oil, can be introduced into them. The cooling medium absorbs the heat released by the reaction and then discharges from the reactor, thereby achieving the purpose of removing the heat of reaction from the reactor.

[0085] In some embodiments, the outer casing 1 has a funnel-shaped structure 9 at one end adjacent to the first inlet 3, and the side of the funnel-shaped structure 9 away from the first inlet 3 is the catalyst inlet 14; the funnel-shaped structure 9 is mounted on the base 11, and a vibrator 10 for loosening the catalyst deposited on the sidewall of the funnel-shaped structure 9 is mounted on the funnel-shaped structure 9. Preferably, the vibrator 10 is mounted on the outer surface of the funnel-shaped structure (the surface adjacent to the base).

[0086] In some embodiments, the funnel-shaped structure is a cone-shaped structure that is open on both sides and hollow, a hollow frustum-shaped structure, a hollow truncated pyramid-shaped structure, etc., and the dimension (e.g., diameter, etc.) on the side adjacent to the first inlet 3 is greater than the dimension (e.g., diameter, etc.) on the side away from the first inlet 3.

[0087] The vibrator structure in the embodiments of this application is not limited, and includes, but is not limited to, one of the following: air hammer vibration device, pneumatic vibrator, ultrasonic transducer, electromagnetic vibrator, etc. The intermittent vibration of the vibrator can prevent the catalyst from accumulating on the sidewalls of the funnel-shaped structure and causing blockage.

[0088] In some embodiments, the heater 12 is installed inside the inner housing 2 immediately adjacent to the first inlet 3, and an airflow multiplier 13 for drawing catalyst from the catalyst inlet 14 into the inner housing is installed at the first inlet 3. Preferably, the airflow multiplier 13 is installed between the first inlet 3 and the catalyst inlet 14, with a gap between them. As a non-limiting example, the gap between the airflow multiplier 13 and the catalyst inlet 14 is no greater than 20% of the inner diameter of the outer housing and no less than 10% of the inner diameter of the outer reactor. This ensures that the catalyst is efficiently drawn into the inner housing; if the gap is too large, the solid catalyst cannot be carried into the inner reactor by the airflow to form a cycle; if the gap is too small, the gap between the bottom slope of the outer housing (i.e., the sidewall of the funnel-shaped structure) and the inner housing is too small, causing the catalyst settling in the outer housing to be unable to slide to the lowest point, resulting in blockage and preventing the formation of a cycle.

[0089] It should be noted that although the heater in this embodiment can be used to heat the reactants entering the inner shell and increase the reaction temperature for olefin synthesis in the inner shell, the reactants circulate between the inner and outer shells during the reaction process, which is equivalent to indirectly heating the material entering the outer shell and increasing the reaction temperature for methanol synthesis in the outer shell.

[0090] Optionally, the airflow multiplier structure is not limited, and by way of example, it includes, but is not limited to, bladeless fans, axial fans, etc., which can draw the catalyst that enters from the catalyst inlet and is deposited on the side wall of the funnel-shaped structure (when the outer shell is set vertically, that is, the bottom of the outer shell) into the inner shell to participate in the reaction.

[0091] In some embodiments, the heater 12 includes, but is not limited to, an electric heater, a steam heater, a gas heater, etc.

[0092] In some embodiments, the multiple second inlets 6, product outlets 8, catalyst inlets 14, inlets and outlets of the internal reaction heat exchanger 5 and the external reaction heat exchanger 7 are all provided with flow controllers for regulating flow rates.

[0093] In some embodiments, in order to monitor the reaction temperature and reaction pressure in real time, temperature measuring devices such as temperature sensors and pressure testing devices such as pressure sensors are installed on both the inner shell 2 and the outer shell 1.

[0094] In some embodiments, in order to preheat the raw material gas, a heating unit may be provided on the outer side wall of the outer shell. The heating unit includes, but is not limited to, a heat exchange jacket, an electric heater, etc. When a heat exchange jacket is used, hot water, hot flue gas, etc. can be introduced into the jacket.

[0095] The operating method of the carbon dioxide hydrogenation to olefins reactor in this application includes the following steps:

[0096] S1, raw material gases carbon dioxide and hydrogen are synthesized into methanol in outer shell 1 under the action of a catalyst.

[0097] In some embodiments, when the outer shell is cylindrical and the inner shell size gradually decreases from the side adjacent to the first inlet to the side away from the first inlet (i.e., the cross-section of the inner shell has a structure that is larger at one end and smaller at the other), the working method of this embodiment further includes the step of introducing the raw material gas carbon dioxide and hydrogen into the outer shell 1 through multiple second inlets 6 along the tangential direction of the inner side of the outer shell 1, forming a spiral gas flow with the catalyst in the outer shell 1, and synthesizing methanol.

[0098] Specifically, the feed gas enters the outer shell through multiple second inlets along the inner tangential direction, providing power for the gas inside the reactor. Driven by the feed gas flow, the feed gas and catalyst form a spiral airflow within the outer shell. This spiral airflow reduces the falling velocity of the catalyst, prolongs the catalyst residence time, and improves the single-pass reaction efficiency. Because the inner shell has a cross-section that is larger at one end and smaller at the other, the flow area gradually decreases and the gas velocity gradually increases as the gas flows through the outer shell. Therefore, the gas flow and catalyst maintain a spiral flow and react to synthesize methanol. The gas and catalyst eventually converge at the bottom of the outer shell and are sent into the inner shell together with the catalyst entering through the catalyst inlet to participate in the subsequent olefin synthesis.

[0099] In some embodiments, the volume ratio of hydrogen to carbon dioxide in the feed gas is (2-4):1, including but not limited to 2:1, 3:1, 4:1 or 2.5:1.

[0100] In some embodiments, the temperature at which methanol is synthesized inside the outer casing 1 is 200-300°C, including but not limited to 200°C, 225°C, 250°C, 275°C, or 300°C.

[0101] In some embodiments, the pressure for synthesizing methanol inside the outer casing 1 is 0.5-8 MPa, including but not limited to 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa or 8 MPa.

[0102] In some embodiments, the catalyst is a carbon dioxide hydrogenation to olefins catalyst, including but not limited to metal oxides such as Cu-Zn-Al, Zn-Zr, and In2O3 in the methanol pathway, as well as bifunctional catalysts coupled with molecular sieves such as SAPO-34 and SAPO-18.

[0103] It should be noted that in the embodiments of this application, since the reactants circulate between the inner shell and the outer shell, the catalyst for synthesizing methanol in the outer shell and the catalyst for synthesizing olefins in the inner shell are the same catalyst, that is, the catalyst mentioned above that enters the reactor through the catalyst inlet.

[0104] In some embodiments, the catalyst is carried into the outer casing 1 from the catalyst inlet 14 by a carrier gas, which includes, but is not limited to, at least one of carbon dioxide, hydrogen, and an inert gas. The inert gas includes, but is not limited to, at least one of nitrogen, helium, and argon.

[0105] S2. Driven by the raw material gas, methanol and catalyst are heated and enter the inner shell 2 through the first inlet 3 to synthesize olefins, forming a mixed gas carrying the catalyst.

[0106] In some embodiments, the olefin is a low-carbon olefin, including but not limited to at least one of ethylene, propylene, butene, etc.

[0107] In some embodiments, the temperature for synthesizing olefins within the inner shell 2 is 300-400°C, including but not limited to 300°C, 325°C, 350°C, 375°C, or 400°C.

[0108] In some embodiments, the pressure for synthesizing olefins within the inner shell 2 is 0.5-8 MPa, including but not limited to 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, or 8 MPa.

[0109] In some embodiments, the working method of this embodiment further includes the step of loosening the catalyst deposited on the sidewall of the funnel-shaped structure by vibrating the vibrator 10.

[0110] In some embodiments, the working method of this embodiment further includes the step of feeding the raw gas and catalyst into the inner shell 2 via the gas multiplier 13.

[0111] In some embodiments, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide, and unreacted hydrogen.

[0112] It should be noted that in the embodiments of this application, since CO2 and H2 will generate CO byproduct under the action of the methanol production catalyst, the mixed gas carrying the catalyst produced by the reaction should contain CO; and since CO and H2 can also further react to generate methanol under the action of the catalyst in the embodiments of this application, it is not necessary to separate CO separately in the subsequent separation steps.

[0113] It should be noted that the selection of catalyst in step S2 and the method of entering the catalyst inlet (carried by carrier gas) are similar to those in step S1, and will not be repeated here.

[0114] S3. The catalyst-carrying mixed gas obtained in step S2 enters the outer shell 1 from the first outlet 4, and then part of it is discharged from the outer shell 1, while the other part is cooled and forms a reaction material circulation between the outer shell 1 and the inner shell 2.

[0115] In some embodiments, the volume ratio of the mixed gas discharged from the outer shell to the mixed gas circulating between the outer and inner shells after cooling is 2-20:1, including but not limited to 2:1, 5:1, 10:1, 15:1, or 20:1. Maintaining a volume ratio within this range ensures a high yield and low production cost per unit volume of reactor; a ratio greater than 20:1 leads to a lower yield; and a ratio less than 2:1 results in excessive subsequent separation load and increased costs.

[0116] S4. During operation, the temperature of methanol synthesis and the temperature of olefin synthesis are controlled by the external reaction heat exchanger 7 and the internal reactor heat exchanger, respectively.

[0117] In the embodiments of this application, the temperature of methanol synthesis and the temperature of olefin synthesis are controlled by the external reaction heat exchanger 7 and the internal reactor heat exchanger, respectively. This is mainly to remove the heat released by the synthesis of methanol and olefin in a timely manner through heat exchange, so as to ensure the stability of the methanol synthesis temperature and the olefin synthesis temperature.

[0118] It should be noted that the step of controlling the temperature of methanol synthesis via the external reaction heat exchanger 7 in step S4 can be carried out simultaneously with step S1, the step of controlling the temperature of olefin synthesis via the internal reactor heat exchanger can be carried out simultaneously with step S2, and the entire step S4 can be carried out simultaneously with step S3.

[0119] Furthermore, it should be noted that in the embodiments of this application, the time for methanol synthesis and the time for olefin synthesis are usually measured by the time the reactants are in contact with the catalyst (i.e., space velocity). However, since the reactants circulate between the inner shell and the outer shell in the embodiments of this application, the time for methanol synthesis and the time for olefin synthesis can be measured by a single reaction time. Since the final product is olefin, this reaction time can be uniformly named the olefin synthesis reaction time.

[0120] In some embodiments, the olefin synthesis reaction time in this application is measured by space velocity, which is 1800-36000 L / kg catalyst / h, including but not limited to 1800 L / kg catalyst / h, 5000 L / kg catalyst / h, 10000 L / kg catalyst / h, 15000 L / kg catalyst / h, 20000 L / kg catalyst / h, 25000 L / kg catalyst / h, 30000 L / kg catalyst / h, or 36000 L / kg catalyst / h.

[0121] Figure 2 This is a schematic diagram of the structure of a carbon dioxide hydrogenation to olefins system illustrated in an exemplary embodiment of this application.

[0122] like Figure 2 As shown, the carbon dioxide hydrogenation to olefins system of this application embodiment includes a reactor 23, a cyclone separator 16 and an olefin separation device 18.

[0123] Reactor 23 is a carbon dioxide hydrogenation reactor for producing olefins according to an embodiment of this application. The feed gas inlet of reactor 23 (i.e., the aforementioned plurality of second inlets 6) is connected to a first preheater 15. It should be noted that the plurality of second inlets 6 may each be connected to a first preheater 15 separately, or they may be connected together to a first preheater 15.

[0124] The inlet of cyclone separator 16 is connected to the product outlet 8 of reactor 23, the gas outlet of cyclone separator 16 is connected to gas-liquid separation device 17, and the solid outlet of cyclone separator 16 is connected in sequence to catalyst regenerator 21 and catalyst feed line 22. The catalyst feed line is used to feed the catalyst carried by the carrier gas into the reactor through the catalyst inlet.

[0125] The inlet of the olefin separation unit 18 is connected to the gas outlet of the gas-liquid separation unit 17. The impurity outlet of the olefin separation unit 18 is connected in sequence to the cold side of the heat exchanger 19, the second preheater 20 and the catalyst feed line 22. The hot side of the heat exchanger 19 is connected to the internal reaction heat exchanger 5. The catalyst feed line 22 is connected to the catalyst inlet 14.

[0126] In some embodiments, the gas-liquid separation device 17 includes, but is not limited to, a gas-liquid separator, a condenser, a condensation tower, etc.

[0127] As an alternative example, gas-liquid separation device 17 employs a gas-liquid separator. High-boiling-point water and methanol are condensed and separated from other gases by cooling.

[0128] In some embodiments, the olefin separation device 18 includes, but is not limited to, a distillation column, a pressure swing adsorption separation device, etc.

[0129] As an alternative example, the olefin separation unit 18 employs a distillation column. Reactants can be separated from olefins at different locations within the distillation column, and further purification of the olefins requires coordinated distillation in multiple columns.

[0130] In some embodiments, the catalyst regenerator 21 includes, but is not limited to, a regeneration tower, a regenerator, etc.

[0131] As an alternative example, catalyst regenerator 21 is a regeneration tower. The catalyst reacts at high temperature from top to bottom with air from bottom to top to remove carbon deposits formed on the catalyst surface.

[0132] In some embodiments, during the catalyst regeneration process, a portion of the catalyst to be regenerated is released ( Figure 2 (Catalyst discharge). Sufficient catalyst activity is maintained by continuously discharging a portion of the old catalyst and adding new catalyst, because even if the catalyst can be regenerated, its performance will still decline after multiple cycles.

[0133] In some embodiments, the first preheater 15 and the second preheater 20 may be one of, but not limited to, air preheaters, tubular heat exchangers, plate heat exchangers, etc.

[0134] The operating method of the carbon dioxide hydrogenation to olefins system according to the embodiments of this application includes the following steps:

[0135] S101: After the raw materials carbon dioxide and hydrogen enter the reactor, olefins are synthesized under the action of a catalyst.

[0136] In some embodiments, a method for synthesizing olefins from feed gases carbon dioxide and hydrogen in the presence of a catalyst includes the following steps:

[0137] (1) Introduce the preheated raw material gases, carbon dioxide and hydrogen, into the outer shell;

[0138] (2) Turn on the airflow multiplier to establish a circulation of the raw material gas flow between the inner shell and the outer shell;

[0139] (3) Turn on the heater and heat the inner shell to the temperature of methanol to olefins on the side adjacent to the first inlet, so as to promote the conversion of methanol into olefins in the inner shell;

[0140] (4) Turn on the internal reaction heat exchanger and the external reaction heat exchanger to maintain the temperature stability of each area in the reactor;

[0141] (5) Open the product outlet and catalyst inlet to establish a stable cycle between the reactor and the rest of the carbon dioxide hydrogenation to olefins system;

[0142] (6) Carbon dioxide and hydrogen are used to synthesize methanol in the outer shell under the action of a catalyst, and methanol is used to synthesize olefins in the inner shell under the action of a catalyst.

[0143] In some embodiments, in step (1), the raw material gases carbon dioxide and hydrogen are preheated by a first preheater.

[0144] It should be noted that steps (1)-(5) above are the steps for preparing olefins in the start-up stage of the carbon dioxide hydrogenation to olefins system according to the embodiments of this application. There is no catalyst at the beginning of the start-up stage. The catalyst needs to be added after the reactor and the external system (the rest of the carbon dioxide hydrogenation to olefins system) establish a cycle. At the beginning, no reaction occurs inside the reactor, only the cycle is established. The reaction gradually begins as the catalyst is added.

[0145] After the carbon dioxide hydrogenation to olefins system has been running smoothly (after the reactor and the rest of the carbon dioxide hydrogenation to olefins system have established a stable cycle), the other operations in step S101 (specifically the process of synthesizing olefins in step (6)) are basically the same as the working method of the carbon dioxide hydrogenation to olefins reactor described above, and will not be repeated here.

[0146] S102. The mixed gas carrying the catalyst discharged from the inner shell 2 is partially discharged from the outer shell 1 and then separated by the cyclone separator 16. The catalyst obtained from the separation process is regenerated and reused in the reactor. The gas phase obtained from the separation process is successively processed by the gas-liquid separator 17 and the olefin separator 18 to obtain olefin products and unreacted raw material gas.

[0147] In some embodiments, the mixed gas composition includes: olefins, water vapor, carbon monoxide, a small amount of methanol, unreacted carbon dioxide, and unreacted hydrogen.

[0148] In the embodiments of this application, the purpose of the cyclone separator is to separate the catalyst particles in the mixed gas; the catalyst obtained by the cyclone separator is fed into the catalyst regenerator to regenerate and remove carbon deposits, while the catalyst with smaller particle size is discharged, and the remaining regenerated catalyst that meets the particle size requirements is fed into the reactor together with the fresh catalyst through the catalyst inlet.

[0149] In the embodiments of this application, the gas phase obtained by the cyclone separator is separated into water and a small amount of methanol (liquid) by the gas-liquid separator, and the gas phase containing olefins enters the olefin separation device to separate and refine olefin products.

[0150] S103. The unreacted feed gas is heated by a heat transfer medium from the heat exchanger of the internal reactor, and then used as a catalyst carrier gas after preheating.

[0151] The preheating in step S103 is carried out using a second preheater.

[0152] The following non-limiting embodiments further illustrate certain features of the present technology.

[0153] Example 1

[0154] like Figure 1 As shown, the carbon dioxide hydrogenation to olefins reactor in this embodiment is a cyclone-type double-shell CO2 hydrogenation to olefins reactor, suitable for a two-step CO2 hydrogenation to olefins reaction. This carbon dioxide hydrogenation to olefins reactor includes an outer shell 1 and an inner shell 2.

[0155] The outer shell 1 is used for the reaction of carbon dioxide and hydrogen to synthesize methanol. The outer shell 1 is cylindrical and vertically positioned. The top of the outer shell 1 is an ellipsoidal head with a material outlet 8 at its center. An external reaction heat exchanger 7, located inside the outer shell 1, is installed on the ellipsoidal head to discharge and cool the reaction heat inside the outer shell 1. The external reaction heat exchanger 7 is a heat exchange coil with circulating cooling water inside. The bottom of the outer shell 1 is a conical head (i.e., a funnel-shaped structure) with a catalyst inlet 14 at its bottom. The conical head is mounted on a base 11 to secure the entire carbon dioxide hydrogenation to olefins reactor. The side of the base 11 that contacts the conical head has a shape similar to the conical head, and a vibrator 10, a commercially available pneumatic hammer, is installed on the outer surface of the conical head on one side of the base 11 to loosen the catalyst deposited at the bottom.

[0156] The outer shell 1 has two second inlets 6 on its side wall for the entry of raw material gases carbon dioxide and hydrogen. The two second inlets 6 are respectively located on the left and right sides of the outer shell 1. The two second inlets 6 are set at a certain distance from each other, but both are located between the material outlet 8 and the catalyst inlet 14. Both second inlets 6 open along the tangential direction of the inner wall of the outer shell 1.

[0157] The inner shell 2 is used for the methanol dehydration reaction to synthesize olefins. The inner shell 2 is disposed within the outer shell 1 and is coaxially arranged with the outer shell 1. The inner shell 2 includes a first part 201 and a second part 202 that are integrally connected (the connection method may be integral molding, etc.). The first part 201 is located above the second part 202, and the two are connected. Both the first part 201 and the second part 202 are frustum-shaped with a trapezoidal longitudinal section. The top diameter of the first part 201 is larger than its bottom diameter, and the top diameter of the second part 202 is approximately equal to the bottom diameter of the first part 201, while the top diameter of the second part 202 is larger than its bottom diameter.

[0158] The first part has a first outlet 4 at the top for discharging reactants from the inner shell 2; the second part has a first inlet 3 at the bottom for entering the inner shell 1. The first inlet 3 is adjacent to the catalyst inlet 14 and the two are positioned opposite each other. The arrangement of the first inlet 3 and the first outlet 4 allows the reactants to circulate between the inner shell 2 and the outer shell 1. A bladeless air multiplier 13 is installed at the first inlet 3. The air multiplier 13 is located directly above the catalyst inlet 14, and there is a gap between them that is no more than 20% and no less than 10% (preferably 15%) of the inner diameter of the outer shell. The air multiplier 13 is a bladeless fan that can draw the catalyst that enters from the catalyst inlet and is deposited at the bottom of the outer shell (the sidewall of the conical head) into the inner shell to participate in the olefin synthesis reaction. Both the inner and outer surfaces of the first part are equipped with internal reaction heat exchangers 5 for dissipating the reaction heat within the inner shell 2. For ease of description, the internal reaction heat exchanger 5 located on the outer surface of the first part can be labeled as the first sub-heat exchanger 501, and the internal reaction heat exchanger 5 located on the inner surface of the first part can be labeled as the second sub-heat exchanger 502. The first sub-heat exchanger 501 and the second sub-heat exchanger 502 are interconnected heat exchange coils, with circulating cooling water flowing inside, removing the reaction heat released during the olefin synthesis process within the inner shell 2 through heat exchange.

[0159] The inner wall of the second part is equipped with a heater 12 for heating the reactants to increase the reaction temperature. The heater 12 is an electric heater.

[0160] The two second inlets 6, the product outlet 8, the catalyst inlet 14, the inlet and outlet of the internal reaction heat exchanger 5, and the inlet and outlet of the external reaction heat exchanger 7 are all equipped with flow controllers for adjusting the flow rate.

[0161] In order to monitor the reaction temperature and reaction pressure in real time, temperature sensors, pressure sensors and the like are installed on both the inner shell 2 and the outer shell 1.

[0162] The operation method of the carbon dioxide hydrogenation to olefins reactor in this embodiment is as follows: Carbon dioxide and hydrogen are introduced into the outer shell 1 through two second inlets 6 (each second inlet 6 is for both carbon dioxide and hydrogen) along the tangential direction inside the outer shell 1, providing power for the gas within the entire reactor. Driven by the gas flow, the gas and catalyst form a spiral airflow within the outer shell 1. This spiral airflow reduces the catalyst's falling velocity, prolongs the catalyst's residence time, and improves the single-pass reaction efficiency. Because the first part of the inner shell 2 has a cross-section that is smaller at the top and larger at the bottom, the flow area gradually decreases and the gas velocity gradually increases as the gas flows from top to bottom within the outer shell 1. Therefore, the gas flow and catalyst... The catalyst will maintain a spiral flow and react to synthesize methanol. The gas and catalyst will eventually converge at the bottom of the outer shell 1 and be sent into the inner shell 2 through the first inlet 3 together with the catalyst entering through the catalyst inlet 14. The gas and catalyst in the inner shell 2 will flow from bottom to top and react to synthesize olefins. Finally, it will be discharged from the first outlet 4 at the top of the inner shell 2. Part of the discharged mixed gas (including olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide and unreacted hydrogen) and catalyst will be discharged from the product outlet 9 to the outside of the outer shell 1. The remaining mixed gas and catalyst will be cooled by the external reaction heat exchanger 7 and flow downward along the outer shell 1 to form a cycle.

[0163] During operation, the volume ratio of hydrogen to carbon dioxide in the feed gas is (2-3):1; the catalyst is a CO2 hydrogenation catalyst for olefins, such as a bifunctional catalyst coupled with molecular sieves like SAPO-34 and SAPO-18, using metal oxides like Cu-Zn-Al, Zn-Zr, and In2O3 in the methanol pathway; the temperature for methanol synthesis in the outer shell 1 is 200~300℃, and the temperature for olefin synthesis in the inner shell 2 is 300~400℃, with a reaction pressure of 0.5~5MPa. The vibrator 10 intermittently taps the bottom of the outer shell to prevent catalyst buildup and blockage on the inclined surface of the conical head.

[0164] Example 2

[0165] like Figure 2 As shown, the carbon dioxide hydrogenation to olefins system of this embodiment includes a reactor 23, a cyclone separator 16, and an olefin separation device 18.

[0166] Reactor 23 is the carbon dioxide hydrogenation to olefins reactor of Example 1. Both feed gas inlets of reactor 23 (i.e. the two second inlets 6 of Example 1) are connected to a first preheater 15.

[0167] The inlet of cyclone separator 16 is connected to the product outlet 8 of reactor 23, the gas outlet of cyclone separator 16 is connected to gas-liquid separation device 17, and the solid outlet of cyclone separator 16 is connected in sequence to catalyst regenerator 21 and catalyst feed line 22. The catalyst feed line is used to feed the catalyst carried by the carrier gas into the reactor through the catalyst inlet.

[0168] The inlet of the olefin separation unit 18 is connected to the gas outlet of the gas-liquid separation unit 17. The impurity outlet of the olefin separation unit 18 is sequentially connected to the cold side of the heat exchanger 19, the second preheater 20, and the catalyst feed line 22. The hot side of the heat exchanger 19 is connected to the internal reaction heat extractor 5 to achieve preheating utilization. The catalyst feed line 22 is connected to the catalyst inlet 14.

[0169] Among them, the gas-liquid separation device 17 is a gas-liquid separator, the olefin separation device 18 is a distillation column, and the catalyst regenerator 21 is a regeneration column; the first preheater 15 and the second preheater 20 are both air preheaters.

[0170] The operating method of the carbon dioxide hydrogenation to olefins system in this embodiment is as follows: The raw material gases, carbon dioxide and hydrogen, preheated by the first preheater 15, enter the outer shell 1. A CO2 hydrogenation to methanol reaction occurs within the outer shell 1 at a temperature of 200-300°C. Since this reaction is exothermic, an external reaction heat exchanger 7 is required to maintain temperature equilibrium. The gas and catalyst react as the gas flows downwards in a spiral to produce methanol. A gas multiplier 13 is located at the bottom between the outer shell 1 and the inner shell 2, which can send the gas, catalyst, and gas and catalyst introduced through the catalyst inlet 14 from the bottom into the inner shell 2. Since the inner shell 2 is for the methanol-to-olefins reaction, which occurs at a temperature of 300-400°C, higher than that of the outer shell 1, a heater 12 is added to the bottom of the inner shell 2 to rapidly heat the reactants. In the inner shell 2, the gas and catalyst flow from bottom to top and react to produce olefins. It should also be an exothermic reaction, so an internal reaction heat exchanger 5 is needed to maintain a stable reaction temperature. The mixed gas carrying the catalyst (the mixed gas contains olefins, water vapor, carbon monoxide, a small amount of methanol, unreacted carbon dioxide, and unreacted hydrogen) discharged from the inner shell 2 is partially discharged from the outer shell 1 through the product outlet 8. This part of the mixed gas is first separated from the catalyst particles by the cyclone separator 16. The separated catalyst particles are first regenerated by the catalyst regenerator 21 to remove carbon deposits and discharge catalyst with smaller particle size. Finally, it is fed into the reactor together with the fresh catalyst through the catalyst inlet 14. The gas after cyclone separation then enters the gas-liquid separator 17 to separate water and a small amount of methanol. It is then separated and refined into olefin products by the olefin separator 18. The remaining unreacted raw material gas is heated by the heat exchanger 19 and the second preheater 20 and then enters the reactor together with the catalyst through the catalyst inlet 14.

[0171] Example 3

[0172] The synthesis of olefins using the carbon dioxide hydrogenation to olefins system of Example 2 specifically includes the following steps: First, the feed gas with a volume ratio of H2:CO2 of 3:1 is preheated to 250°C and pressurized to 3MPa, and then introduced into the outer shell 1 through the upper and lower feed gas inlets (i.e., the two second inlets 6); then the gas multiplier 13 is turned on to establish circulation between the fluid (feed gas) in the inner shell 2 and the outer shell 1; next, the heater 12 is turned on to heat the bottom temperature of the inner shell 2 to 380°C to promote the methanol-to-olefins reaction; then the internal reaction heat exchanger 5 and the external reaction heat exchanger 7 are turned on to maintain the temperature stability of each area of ​​the reactor; then the top product outlet 8 and the bottom catalyst inlet 14 are turned on to establish a stable circulation between the reactor and the external system (cyclone separator, gas-liquid separator, olefin separator, heat exchanger, second preheater, catalyst regenerator, etc. in the carbon dioxide hydrogenation to olefins system). Finally, in the outer shell 1 of the reactor, the feed gas undergoes a CO2 hydrogenation reaction to produce methanol via the catalyst CuZnAl-SAPO-34, generating methanol and water. The temperature of methanol synthesis is controlled by the external reaction heat exchanger 7. In the inner shell 1 of the reactor, methanol is dehydrated under the action of the catalyst CuZnAl-SAPO-34 to synthesize low-carbon olefins (C2~C4 olefins). The temperature of olefin synthesis is controlled by the internal reaction heat exchanger 5. The space velocity of the entire olefin synthesis reaction is 12000 L / kg catalyst / h. The reaction results are shown in Table 1.

[0173] In the process of synthesizing olefins in this embodiment, cyclone separation, gas-liquid separation, olefin separation, catalyst regeneration and other routine operations are carried out, and specific details will not be repeated here.

[0174] Example 4

[0175] This embodiment is basically the same as embodiment 3, except that:

[0176] The feed gas with a volume ratio of H2:CO2 of 3:1 is preheated to 300℃; the catalyst is ZnZrO-SAPO-34 catalyst.

[0177] Comparative Example 1

[0178] This comparative example is basically the same as Example 3, except that:

[0179] The reactor in the carbon oxidizing hydrogenation to olefins system uses a conventional fluidized bed reactor. In the method of synthesizing olefins, the feed gas has a volume ratio of H2:CO2 of 3:1, the reaction temperature is 380℃, the pressure is 3MPa, and the catalyst is CuZnAl-SAPO-34. The feed undergoes two-stage reactions in one reactor, the space velocity is 12000L / kg catalyst / h, and the reaction results are shown in Table 1.

[0180] Comparative Example 2

[0181] This comparative example is basically the same as Example 3, except that:

[0182] The reactor in the carbon oxidizing hydrogenation to olefins system uses an existing two-stage fluidized bed reactor. In the method for synthesizing olefins: the first stage feedstock H2:CO2 volume ratio is 3:1, the reaction temperature is 250℃, the pressure is 3MPa, and CuZnAl catalyst is used. The reaction product is fed into the second stage reactor, where the reaction temperature is 380℃, the pressure is 3MPa, SAPO-34 catalyst is used, and the space velocity is 12000L / kg catalyst / h. The reaction results of the second stage reactor are shown in Table 1.

[0183] Comparative Example 3

[0184] This comparative example is basically the same as Example 3, except that:

[0185] The reactor in the carbon oxidizing hydrogenation to olefins system uses a conventional fluidized bed reactor. In the method of synthesizing olefins, the feed gas has a volume ratio of H2:CO2 of 3:1, the reaction temperature is 380℃, the pressure is 3MPa, and a ZnZrO-SAPO-34 catalyst is used. The feed undergoes two-stage reactions in one reactor, with a space velocity of 12000 L / kg catalyst / h. The reaction results are shown in Table 1.

[0186] Comparative Example 4

[0187] This comparative example is basically the same as Example 3, except that:

[0188] The reactor in the carbon oxidizing hydrogenation to olefins system uses an existing two-stage fluidized bed reactor. In the method for synthesizing olefins: the first stage feedstock H2:CO2 volume ratio is 3:1, the reaction temperature is 250℃, the pressure is 3MPa, and a ZnO-ZrO2 catalyst is used. The reaction product is fed into the second stage reactor, where the reaction temperature is 380℃, the pressure is 3MPa, a SAPO-34 catalyst is used, and the space velocity is 12000L / kg catalyst / h. The reaction results of the second stage reactor are shown in Table 1.

[0189] Table 1. Reaction results of Examples 3-4 and Comparative Examples 1-4

[0190]

[0191] Note: In Table 1, "low carbon olefins" refers to olefins of C2 to C4.

[0192] According to Table 1:

[0193] Comparing Examples 3 and 4, it can be seen that, under the same reaction conditions and with different catalysts, the carbon dioxide conversion rate and olefin selectivity are basically the same when synthesizing olefins using the carbon dioxide hydrogenation to olefins system of this application.

[0194] As can be seen from Comparative Examples 3 and 1, under completely identical reaction conditions, the synthesis of olefins using a single reactor in the carbon dioxide hydrogenation to olefins system of this application can achieve higher carbon dioxide conversion and olefin selectivity.

[0195] Comparing Example 3 and Comparative Example 2, it can be seen that under the same reaction conditions, the single reactor of the carbon dioxide hydrogenation to olefins system of this application can achieve a carbon dioxide conversion rate and olefin selectivity that are basically equivalent to those of the two-stage fluidized bed reactor. However, since the reactor of Example 3 is a single reactor, its structure is simpler than that of the two-stage fluidized bed reactor of Comparative Example 2, and it only needs to control the temperature of methanol to olefins, so the cost is lower and the operation is more convenient.

[0196] As can be seen from Comparative Examples 4 and 3, under essentially the same reaction conditions, the single-reactor synthesis of olefins using the carbon dioxide hydrogenation to olefins system of the present application embodiments can achieve higher carbon dioxide conversion and olefin selectivity.

[0197] Comparing Example 4 and Comparative Example 4, it can be seen that, under essentially the same reaction conditions, the single-reactor synthesis of olefins using the carbon dioxide hydrogenation to olefins system of this application, employing a ZnZrO-SAPO-34 catalyst, can achieve a higher carbon dioxide conversion rate. Furthermore, since the reactor in Example 4 is a single reactor, its structure is simpler than the two-stage fluidized bed reactor in Comparative Example 4, and only the temperature of methanol to olefins needs to be controlled, resulting in lower cost and more convenient operation.

[0198] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0199] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0200] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0201] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0202] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0203] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A reactor for the hydrogenation of carbon dioxide to olefins, characterized in that, include: An outer shell for the reaction of carbon dioxide and hydrogen to synthesize methanol, the outer shell having a catalyst inlet for entering the catalyst and an external reaction heat exchanger for removing the heat of reaction inside the outer shell; An inner shell is used for the methanol dehydration reaction to synthesize olefins. The inner shell is disposed within the outer shell and has a heater for heating the reactants, an internal reaction heat exchanger for removing the heat of reaction within the inner shell, and a first inlet and a first outlet for circulating the reactants between the inner shell and the outer shell. The first inlet and the first outlet are arranged opposite to each other, with the first inlet being adjacent to and opposite to the catalyst inlet. An air multiplier is installed at the first inlet for drawing catalyst from the catalyst inlet into the inner shell.

2. The carbon dioxide hydrogenation to olefins reactor according to claim 1, characterized in that, The inner shell includes a first part and a second part that are interconnected. The first part has the first outlet, and the second part has the first inlet. The cross-sections of the first part and the second part along the direction from the first inlet to the first outlet are both isosceles trapezoids. The dimensions of the first part at the end with the first outlet and the second part at the end with the first inlet are both smaller than the dimensions of the connection between the first part and the second part.

3. The carbon dioxide hydrogenation to olefins reactor according to claim 1, characterized in that, The inner shell and the outer shell are arranged along a common centerline in the direction from the first inlet to the first outlet; And / or, the middle portion of the cross-section of the outer casing along the direction from the first inlet to the first outlet is rectangular.

4. The carbon dioxide hydrogenation to olefins reactor according to claim 1, characterized in that, The outer shell is cylindrical, and the side wall of the outer shell is provided with a plurality of second inlets for the raw material gases carbon dioxide and hydrogen to enter the interior of the outer shell, and the plurality of second inlets open along the tangential direction of the inner wall of the outer shell. And / or, the outer shell has a funnel-shaped structure at one end adjacent to the first inlet, and the side of the funnel-shaped structure away from the first inlet is the catalyst inlet; The funnel-shaped structure is mounted on a base, and a vibrator is installed on the funnel-shaped structure to loosen the catalyst deposited on the sidewall of the funnel-shaped structure.

5. The carbon dioxide hydrogenation to olefins reactor according to claim 4, characterized in that, Multiple second inlets are distributed at intervals along the direction of the first inlet and the first outlet on the outer casing, and adjacent second inlets are positioned opposite or staggered.

6. The carbon dioxide hydrogenation to olefins reactor according to claim 1, characterized in that, The internal reaction heat exchanger is located on the inner surface and / or outer surface of the inner shell; And / or, the outer casing is provided with the external reaction heat exchanger and product outlet on the side adjacent to the first outlet.

7. The carbon dioxide hydrogenation to olefins reactor according to claim 1, characterized in that, The heater is installed inside the inner housing on the side adjacent to the first inlet.

8. A method for operating a carbon dioxide hydrogenation to olefins reactor as described in any one of claims 1, 2, 3, 6, and 7, characterized in that, include: Methanol is synthesized from the raw materials carbon dioxide and hydrogen in the outer shell under the action of a catalyst. Driven by the raw material gas, methanol and catalyst are heated and enter the inner shell through the first inlet to synthesize olefins, forming a mixed gas carrying the catalyst; The mixed gas enters the outer shell from the first outlet, then part of it is discharged from the outer shell, and the other part is cooled to form a reactive material circulation between the outer shell and the inner shell; The temperature of the synthesized methanol and the temperature of the synthesized olefin are controlled by the external reaction heat exchanger and the internal reactor heat exchanger, respectively.

9. The working method according to claim 8, characterized in that, The working method also includes the step of feeding the raw gas and catalyst into the inner shell via the gas multiplier; And / or, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide, and unreacted hydrogen. And / or, in the raw material gas, the mixing volume ratio of hydrogen and carbon dioxide is (2-4):1; And / or, the temperature for methanol synthesis within the outer casing is 200-300℃, and the pressure is 0.5-8MPa; And / or, the temperature for synthesizing olefins within the inner shell is 300-400℃, and the pressure is 0.5-8MPa; And / or, the catalyst is a catalyst for the hydrogenation of carbon dioxide to olefins; And / or, the catalyst is carried by a carrier gas from the catalyst inlet into the outer casing, the carrier gas being at least one of carbon dioxide, hydrogen, and an inert gas.

10. A method for operating a carbon dioxide hydrogenation to olefins reactor as described in claim 4 or 5, characterized in that, include: Methanol is synthesized from the raw materials carbon dioxide and hydrogen in the outer shell under the action of a catalyst. Driven by the raw material gas, methanol and catalyst are heated and enter the inner shell through the first inlet to synthesize olefins, forming a mixed gas carrying the catalyst; The mixed gas enters the outer shell from the first outlet, then part of it is discharged from the outer shell, and the other part is cooled to form a reactive material circulation between the outer shell and the inner shell; The temperature of the synthesized methanol and the temperature of the synthesized olefin are controlled by the external reaction heat exchanger and the internal reactor heat exchanger, respectively.

11. The working method according to claim 10, characterized in that, The working method also includes the step of introducing the raw material gases carbon dioxide and hydrogen into the outer shell through multiple second inlets along the inner tangential direction of the outer shell, forming a spiral gas flow with the catalyst inside the outer shell, and synthesizing methanol. And / or, the method of operation further includes the step of loosening the catalyst deposited on the sidewall of the funnel-shaped structure by vibrating with a vibrator; And / or, the working method further includes the step of feeding the raw gas and catalyst into the inner shell via the gas multiplier; And / or, the mixed gas includes olefins, water vapor, carbon monoxide, unreacted methanol, unreacted carbon dioxide, and unreacted hydrogen. And / or, in the raw material gas, the mixing volume ratio of hydrogen and carbon dioxide is (2-4):1; And / or, the temperature for methanol synthesis within the outer casing is 200-300℃, and the pressure is 0.5-8MPa; And / or, the temperature for synthesizing olefins within the inner shell is 300-400℃, and the pressure is 0.5-8MPa; And / or, the catalyst is a catalyst for the hydrogenation of carbon dioxide to olefins; And / or, the catalyst is carried by a carrier gas from the catalyst inlet into the outer casing, the carrier gas being at least one of carbon dioxide, hydrogen, and an inert gas.

12. A system for producing olefins by hydrogenation of carbon dioxide, characterized in that, include: The reactor is a carbon dioxide hydrogenation to olefins reactor as described in any one of claims 1 to 7, wherein the feed gas inlet of the reactor is connected to a first preheater. A cyclone separator, wherein the inlet of the cyclone separator is connected to the product outlet of the reactor, the gas outlet of the cyclone separator is connected to a gas-liquid separation device, and the solid outlet of the cyclone separator is sequentially connected to a catalyst regenerator and a catalyst feed line; An olefin separation unit is provided, wherein the inlet of the olefin separation unit is connected to the gas outlet of the gas-liquid separation unit, the impurity outlet of the olefin separation unit is sequentially connected to the cold side of a heat exchanger, a second preheater and the catalyst feed line, the hot side of the heat exchanger is connected to the internal reaction heat exchanger, and the catalyst feed line is connected to the catalyst inlet.

13. A method of operating the carbon dioxide hydrogenation to olefins system as described in claim 12, characterized in that, include: After the raw materials carbon dioxide and hydrogen enter the reactor, olefins are synthesized under the action of a catalyst. The mixed gas carrying the catalyst discharged from the inner shell is partially discharged from the outer shell and then separated by a cyclone separator. The catalyst obtained from the separation process is regenerated and reused in the reactor. The gas phase obtained from the separation process is sequentially processed by a gas-liquid separation device and an olefin separation device to obtain olefin products and the unreacted raw material gas. The unreacted feed gas is heated by a heat transfer medium from the internal reactor heat exchanger, and then preheated before being used as a catalyst carrier gas.

14. The working method according to claim 13, characterized in that, The method for synthesizing olefins from the feed gas carbon dioxide and hydrogen in the reactor under the action of a catalyst includes: Preheated raw material gases, carbon dioxide and hydrogen, are introduced into the outer shell; The airflow multiplier is activated to establish a circulation of the raw material gas flow between the inner shell and the outer shell. Turn on the heater and heat the inner shell to the temperature of methanol-to-olefins synthesis, thereby causing methanol to be converted into olefins within the inner shell. Turn on the internal and external reaction heat exchangers to maintain a stable temperature in each area of ​​the reactor. Open the product outlet and catalyst inlet to establish a stable cycle between the reactor and the rest of the carbon dioxide hydrogenation to olefins system; The carbon dioxide and hydrogen are synthesized into methanol in the outer shell under the action of the catalyst, and the methanol is synthesized into olefins in the inner shell under the action of the catalyst.

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